vendor/go.opentelemetry.io/otel/sdk/resource/os.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import (
+	"context"
+	"strings"
+
+	"go.opentelemetry.io/otel/attribute"
+	semconv "go.opentelemetry.io/otel/semconv/v1.12.0"
+)
+
+type osDescriptionProvider func() (string, error)
+
+var defaultOSDescriptionProvider osDescriptionProvider = platformOSDescription
+
+var osDescription = defaultOSDescriptionProvider
+
+func setDefaultOSDescriptionProvider() {
+	setOSDescriptionProvider(defaultOSDescriptionProvider)
+}
+
+func setOSDescriptionProvider(osDescriptionProvider osDescriptionProvider) {
+	osDescription = osDescriptionProvider
+}
+
+type osTypeDetector struct{}
+type osDescriptionDetector struct{}
+
+// Detect returns a *Resource that describes the operating system type the
+// service is running on.
+func (osTypeDetector) Detect(ctx context.Context) (*Resource, error) {
+	osType := runtimeOS()
+
+	osTypeAttribute := mapRuntimeOSToSemconvOSType(osType)
+
+	return NewWithAttributes(
+		semconv.SchemaURL,
+		osTypeAttribute,
+	), nil
+}
+
+// Detect returns a *Resource that describes the operating system the
+// service is running on.
+func (osDescriptionDetector) Detect(ctx context.Context) (*Resource, error) {
+	description, err := osDescription()
+
+	if err != nil {
+		return nil, err
+	}
+
+	return NewWithAttributes(
+		semconv.SchemaURL,
+		semconv.OSDescriptionKey.String(description),
+	), nil
+}
+
+// mapRuntimeOSToSemconvOSType translates the OS name as provided by the Go runtime
+// into an OS type attribute with the corresponding value defined by the semantic
+// conventions. In case the provided OS name isn't mapped, it's transformed to lowercase
+// and used as the value for the returned OS type attribute.
+func mapRuntimeOSToSemconvOSType(osType string) attribute.KeyValue {
+	// the elements in this map are the intersection between
+	// available GOOS values and defined semconv OS types
+	osTypeAttributeMap := map[string]attribute.KeyValue{
+		"darwin":    semconv.OSTypeDarwin,
+		"dragonfly": semconv.OSTypeDragonflyBSD,
+		"freebsd":   semconv.OSTypeFreeBSD,
+		"linux":     semconv.OSTypeLinux,
+		"netbsd":    semconv.OSTypeNetBSD,
+		"openbsd":   semconv.OSTypeOpenBSD,
+		"solaris":   semconv.OSTypeSolaris,
+		"windows":   semconv.OSTypeWindows,
+	}
+
+	var osTypeAttribute attribute.KeyValue
+
+	if attr, ok := osTypeAttributeMap[osType]; ok {
+		osTypeAttribute = attr
+	} else {
+		osTypeAttribute = semconv.OSTypeKey.String(strings.ToLower(osType))
+	}
+
+	return osTypeAttribute
+}

vendor/go.opentelemetry.io/otel/sdk/resource/os_release_darwin.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import (
+	"encoding/xml"
+	"fmt"
+	"io"
+	"os"
+)
+
+type plist struct {
+	XMLName xml.Name `xml:"plist"`
+	Dict    dict     `xml:"dict"`
+}
+
+type dict struct {
+	Key    []string `xml:"key"`
+	String []string `xml:"string"`
+}
+
+// osRelease builds a string describing the operating system release based on the
+// contents of the property list (.plist) system files. If no .plist files are found,
+// or if the required properties to build the release description string are missing,
+// an empty string is returned instead. The generated string resembles the output of
+// the `sw_vers` commandline program, but in a single-line string. For more information
+// about the `sw_vers` program, see: https://www.unix.com/man-page/osx/1/SW_VERS.
+func osRelease() string {
+	file, err := getPlistFile()
+	if err != nil {
+		return ""
+	}
+
+	defer file.Close()
+
+	values, err := parsePlistFile(file)
+	if err != nil {
+		return ""
+	}
+
+	return buildOSRelease(values)
+}
+
+// getPlistFile returns a *os.File pointing to one of the well-known .plist files
+// available on macOS. If no file can be opened, it returns an error.
+func getPlistFile() (*os.File, error) {
+	return getFirstAvailableFile([]string{
+		"/System/Library/CoreServices/SystemVersion.plist",
+		"/System/Library/CoreServices/ServerVersion.plist",
+	})
+}
+
+// parsePlistFile process the file pointed by `file` as a .plist file and returns
+// a map with the key-values for each pair of correlated <key> and <string> elements
+// contained in it.
+func parsePlistFile(file io.Reader) (map[string]string, error) {
+	var v plist
+
+	err := xml.NewDecoder(file).Decode(&v)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(v.Dict.Key) != len(v.Dict.String) {
+		return nil, fmt.Errorf("the number of <key> and <string> elements doesn't match")
+	}
+
+	properties := make(map[string]string, len(v.Dict.Key))
+	for i, key := range v.Dict.Key {
+		properties[key] = v.Dict.String[i]
+	}
+
+	return properties, nil
+}
+
+// buildOSRelease builds a string describing the OS release based on the properties
+// available on the provided map. It tries to find the `ProductName`, `ProductVersion`
+// and `ProductBuildVersion` properties. If some of these properties are not found,
+// it returns an empty string.
+func buildOSRelease(properties map[string]string) string {
+	productName := properties["ProductName"]
+	productVersion := properties["ProductVersion"]
+	productBuildVersion := properties["ProductBuildVersion"]
+
+	if productName == "" || productVersion == "" || productBuildVersion == "" {
+		return ""
+	}
+
+	return fmt.Sprintf("%s %s (%s)", productName, productVersion, productBuildVersion)
+}

vendor/go.opentelemetry.io/otel/sdk/resource/os_release_unix.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build aix || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
+// +build aix dragonfly freebsd linux netbsd openbsd solaris zos
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+)
+
+// osRelease builds a string describing the operating system release based on the
+// properties of the os-release file. If no os-release file is found, or if the
+// required properties to build the release description string are missing, an empty
+// string is returned instead. For more information about os-release files, see:
+// https://www.freedesktop.org/software/systemd/man/os-release.html
+func osRelease() string {
+	file, err := getOSReleaseFile()
+	if err != nil {
+		return ""
+	}
+
+	defer file.Close()
+
+	values := parseOSReleaseFile(file)
+
+	return buildOSRelease(values)
+}
+
+// getOSReleaseFile returns a *os.File pointing to one of the well-known os-release
+// files, according to their order of preference. If no file can be opened, it
+// returns an error.
+func getOSReleaseFile() (*os.File, error) {
+	return getFirstAvailableFile([]string{"/etc/os-release", "/usr/lib/os-release"})
+}
+
+// parseOSReleaseFile process the file pointed by `file` as an os-release file and
+// returns a map with the key-values contained in it. Empty lines or lines starting
+// with a '#' character are ignored, as well as lines with the missing key=value
+// separator. Values are unquoted and unescaped.
+func parseOSReleaseFile(file io.Reader) map[string]string {
+	values := make(map[string]string)
+	scanner := bufio.NewScanner(file)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		if skip(line) {
+			continue
+		}
+
+		key, value, ok := parse(line)
+		if ok {
+			values[key] = value
+		}
+	}
+
+	return values
+}
+
+// skip returns true if the line is blank or starts with a '#' character, and
+// therefore should be skipped from processing.
+func skip(line string) bool {
+	line = strings.TrimSpace(line)
+
+	return len(line) == 0 || strings.HasPrefix(line, "#")
+}
+
+// parse attempts to split the provided line on the first '=' character, and then
+// sanitize each side of the split before returning them as a key-value pair.
+func parse(line string) (string, string, bool) {
+	parts := strings.SplitN(line, "=", 2)
+
+	if len(parts) != 2 || len(parts[0]) == 0 {
+		return "", "", false
+	}
+
+	key := strings.TrimSpace(parts[0])
+	value := unescape(unquote(strings.TrimSpace(parts[1])))
+
+	return key, value, true
+}
+
+// unquote checks whether the string `s` is quoted with double or single quotes
+// and, if so, returns a version of the string without them. Otherwise it returns
+// the provided string unchanged.
+func unquote(s string) string {
+	if len(s) < 2 {
+		return s
+	}
+
+	if (s[0] == '"' || s[0] == '\'') && s[0] == s[len(s)-1] {
+		return s[1 : len(s)-1]
+	}
+
+	return s
+}
+
+// unescape removes the `\` prefix from some characters that are expected
+// to have it added in front of them for escaping purposes.
+func unescape(s string) string {
+	return strings.NewReplacer(
+		`\$`, `$`,
+		`\"`, `"`,
+		`\'`, `'`,
+		`\\`, `\`,
+		"\\`", "`",
+	).Replace(s)
+}
+
+// buildOSRelease builds a string describing the OS release based on the properties
+// available on the provided map. It favors a combination of the `NAME` and `VERSION`
+// properties as first option (falling back to `VERSION_ID` if `VERSION` isn't
+// found), and using `PRETTY_NAME` alone if some of the previous are not present. If
+// none of these properties are found, it returns an empty string.
+//
+// The rationale behind not using `PRETTY_NAME` as first choice was that, for some
+// Linux distributions, it doesn't include the same detail that can be found on the
+// individual `NAME` and `VERSION` properties, and combining `PRETTY_NAME` with
+// other properties can produce "pretty" redundant strings in some cases.
+func buildOSRelease(values map[string]string) string {
+	var osRelease string
+
+	name := values["NAME"]
+	version := values["VERSION"]
+
+	if version == "" {
+		version = values["VERSION_ID"]
+	}
+
+	if name != "" && version != "" {
+		osRelease = fmt.Sprintf("%s %s", name, version)
+	} else {
+		osRelease = values["PRETTY_NAME"]
+	}
+
+	return osRelease
+}

vendor/go.opentelemetry.io/otel/sdk/resource/os_unix.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+type unameProvider func(buf *unix.Utsname) (err error)
+
+var defaultUnameProvider unameProvider = unix.Uname
+
+var currentUnameProvider = defaultUnameProvider
+
+func setDefaultUnameProvider() {
+	setUnameProvider(defaultUnameProvider)
+}
+
+func setUnameProvider(unameProvider unameProvider) {
+	currentUnameProvider = unameProvider
+}
+
+// platformOSDescription returns a human readable OS version information string.
+// The final string combines OS release information (where available) and the
+// result of the `uname` system call.
+func platformOSDescription() (string, error) {
+	uname, err := uname()
+	if err != nil {
+		return "", err
+	}
+
+	osRelease := osRelease()
+	if osRelease != "" {
+		return fmt.Sprintf("%s (%s)", osRelease, uname), nil
+	}
+
+	return uname, nil
+}
+
+// uname issues a uname(2) system call (or equivalent on systems which doesn't
+// have one) and formats the output in a single string, similar to the output
+// of the `uname` commandline program. The final string resembles the one
+// obtained with a call to `uname -snrvm`.
+func uname() (string, error) {
+	var utsName unix.Utsname
+
+	err := currentUnameProvider(&utsName)
+	if err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%s %s %s %s %s",
+		unix.ByteSliceToString(utsName.Sysname[:]),
+		unix.ByteSliceToString(utsName.Nodename[:]),
+		unix.ByteSliceToString(utsName.Release[:]),
+		unix.ByteSliceToString(utsName.Version[:]),
+		unix.ByteSliceToString(utsName.Machine[:]),
+	), nil
+}
+
+// getFirstAvailableFile returns an *os.File of the first available
+// file from a list of candidate file paths.
+func getFirstAvailableFile(candidates []string) (*os.File, error) {
+	for _, c := range candidates {
+		file, err := os.Open(c)
+		if err == nil {
+			return file, nil
+		}
+	}
+
+	return nil, fmt.Errorf("no candidate file available: %v", candidates)
+}

vendor/go.opentelemetry.io/otel/sdk/resource/os_unsupported.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !aix
+// +build !darwin
+// +build !dragonfly
+// +build !freebsd
+// +build !linux
+// +build !netbsd
+// +build !openbsd
+// +build !solaris
+// +build !windows
+// +build !zos
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+// platformOSDescription is a placeholder implementation for OSes
+// for which this project currently doesn't support os.description
+// attribute detection. See build tags declaration early on this file
+// for a list of unsupported OSes.
+func platformOSDescription() (string, error) {
+	return "<unknown>", nil
+}

vendor/go.opentelemetry.io/otel/sdk/resource/os_windows.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import (
+	"fmt"
+	"strconv"
+
+	"golang.org/x/sys/windows/registry"
+)
+
+// platformOSDescription returns a human readable OS version information string.
+// It does so by querying registry values under the
+// `SOFTWARE\Microsoft\Windows NT\CurrentVersion` key. The final string
+// resembles the one displayed by the Version Reporter Applet (winver.exe).
+func platformOSDescription() (string, error) {
+	k, err := registry.OpenKey(
+		registry.LOCAL_MACHINE, `SOFTWARE\Microsoft\Windows NT\CurrentVersion`, registry.QUERY_VALUE)
+
+	if err != nil {
+		return "", err
+	}
+
+	defer k.Close()
+
+	var (
+		productName               = readProductName(k)
+		displayVersion            = readDisplayVersion(k)
+		releaseID                 = readReleaseID(k)
+		currentMajorVersionNumber = readCurrentMajorVersionNumber(k)
+		currentMinorVersionNumber = readCurrentMinorVersionNumber(k)
+		currentBuildNumber        = readCurrentBuildNumber(k)
+		ubr                       = readUBR(k)
+	)
+
+	if displayVersion != "" {
+		displayVersion += " "
+	}
+
+	return fmt.Sprintf("%s %s(%s) [Version %s.%s.%s.%s]",
+		productName,
+		displayVersion,
+		releaseID,
+		currentMajorVersionNumber,
+		currentMinorVersionNumber,
+		currentBuildNumber,
+		ubr,
+	), nil
+}
+
+func getStringValue(name string, k registry.Key) string {
+	value, _, _ := k.GetStringValue(name)
+
+	return value
+}
+
+func getIntegerValue(name string, k registry.Key) uint64 {
+	value, _, _ := k.GetIntegerValue(name)
+
+	return value
+}
+
+func readProductName(k registry.Key) string {
+	return getStringValue("ProductName", k)
+}
+
+func readDisplayVersion(k registry.Key) string {
+	return getStringValue("DisplayVersion", k)
+}
+
+func readReleaseID(k registry.Key) string {
+	return getStringValue("ReleaseID", k)
+}
+
+func readCurrentMajorVersionNumber(k registry.Key) string {
+	return strconv.FormatUint(getIntegerValue("CurrentMajorVersionNumber", k), 10)
+}
+
+func readCurrentMinorVersionNumber(k registry.Key) string {
+	return strconv.FormatUint(getIntegerValue("CurrentMinorVersionNumber", k), 10)
+}
+
+func readCurrentBuildNumber(k registry.Key) string {
+	return getStringValue("CurrentBuildNumber", k)
+}
+
+func readUBR(k registry.Key) string {
+	return strconv.FormatUint(getIntegerValue("UBR", k), 10)
+}

vendor/go.opentelemetry.io/otel/sdk/resource/process.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/user"
+	"path/filepath"
+	"runtime"
+
+	semconv "go.opentelemetry.io/otel/semconv/v1.12.0"
+)
+
+type pidProvider func() int
+type executablePathProvider func() (string, error)
+type commandArgsProvider func() []string
+type ownerProvider func() (*user.User, error)
+type runtimeNameProvider func() string
+type runtimeVersionProvider func() string
+type runtimeOSProvider func() string
+type runtimeArchProvider func() string
+
+var (
+	defaultPidProvider            pidProvider            = os.Getpid
+	defaultExecutablePathProvider executablePathProvider = os.Executable
+	defaultCommandArgsProvider    commandArgsProvider    = func() []string { return os.Args }
+	defaultOwnerProvider          ownerProvider          = user.Current
+	defaultRuntimeNameProvider    runtimeNameProvider    = func() string {
+		if runtime.Compiler == "gc" {
+			return "go"
+		}
+		return runtime.Compiler
+	}
+	defaultRuntimeVersionProvider runtimeVersionProvider = runtime.Version
+	defaultRuntimeOSProvider      runtimeOSProvider      = func() string { return runtime.GOOS }
+	defaultRuntimeArchProvider    runtimeArchProvider    = func() string { return runtime.GOARCH }
+)
+
+var (
+	pid            = defaultPidProvider
+	executablePath = defaultExecutablePathProvider
+	commandArgs    = defaultCommandArgsProvider
+	owner          = defaultOwnerProvider
+	runtimeName    = defaultRuntimeNameProvider
+	runtimeVersion = defaultRuntimeVersionProvider
+	runtimeOS      = defaultRuntimeOSProvider
+	runtimeArch    = defaultRuntimeArchProvider
+)
+
+func setDefaultOSProviders() {
+	setOSProviders(
+		defaultPidProvider,
+		defaultExecutablePathProvider,
+		defaultCommandArgsProvider,
+	)
+}
+
+func setOSProviders(
+	pidProvider pidProvider,
+	executablePathProvider executablePathProvider,
+	commandArgsProvider commandArgsProvider,
+) {
+	pid = pidProvider
+	executablePath = executablePathProvider
+	commandArgs = commandArgsProvider
+}
+
+func setDefaultRuntimeProviders() {
+	setRuntimeProviders(
+		defaultRuntimeNameProvider,
+		defaultRuntimeVersionProvider,
+		defaultRuntimeOSProvider,
+		defaultRuntimeArchProvider,
+	)
+}
+
+func setRuntimeProviders(
+	runtimeNameProvider runtimeNameProvider,
+	runtimeVersionProvider runtimeVersionProvider,
+	runtimeOSProvider runtimeOSProvider,
+	runtimeArchProvider runtimeArchProvider,
+) {
+	runtimeName = runtimeNameProvider
+	runtimeVersion = runtimeVersionProvider
+	runtimeOS = runtimeOSProvider
+	runtimeArch = runtimeArchProvider
+}
+
+func setDefaultUserProviders() {
+	setUserProviders(defaultOwnerProvider)
+}
+
+func setUserProviders(ownerProvider ownerProvider) {
+	owner = ownerProvider
+}
+
+type processPIDDetector struct{}
+type processExecutableNameDetector struct{}
+type processExecutablePathDetector struct{}
+type processCommandArgsDetector struct{}
+type processOwnerDetector struct{}
+type processRuntimeNameDetector struct{}
+type processRuntimeVersionDetector struct{}
+type processRuntimeDescriptionDetector struct{}
+
+// Detect returns a *Resource that describes the process identifier (PID) of the
+// executing process.
+func (processPIDDetector) Detect(ctx context.Context) (*Resource, error) {
+	return NewWithAttributes(semconv.SchemaURL, semconv.ProcessPIDKey.Int(pid())), nil
+}
+
+// Detect returns a *Resource that describes the name of the process executable.
+func (processExecutableNameDetector) Detect(ctx context.Context) (*Resource, error) {
+	executableName := filepath.Base(commandArgs()[0])
+
+	return NewWithAttributes(semconv.SchemaURL, semconv.ProcessExecutableNameKey.String(executableName)), nil
+}
+
+// Detect returns a *Resource that describes the full path of the process executable.
+func (processExecutablePathDetector) Detect(ctx context.Context) (*Resource, error) {
+	executablePath, err := executablePath()
+	if err != nil {
+		return nil, err
+	}
+
+	return NewWithAttributes(semconv.SchemaURL, semconv.ProcessExecutablePathKey.String(executablePath)), nil
+}
+
+// Detect returns a *Resource that describes all the command arguments as received
+// by the process.
+func (processCommandArgsDetector) Detect(ctx context.Context) (*Resource, error) {
+	return NewWithAttributes(semconv.SchemaURL, semconv.ProcessCommandArgsKey.StringSlice(commandArgs())), nil
+}
+
+// Detect returns a *Resource that describes the username of the user that owns the
+// process.
+func (processOwnerDetector) Detect(ctx context.Context) (*Resource, error) {
+	owner, err := owner()
+	if err != nil {
+		return nil, err
+	}
+
+	return NewWithAttributes(semconv.SchemaURL, semconv.ProcessOwnerKey.String(owner.Username)), nil
+}
+
+// Detect returns a *Resource that describes the name of the compiler used to compile
+// this process image.
+func (processRuntimeNameDetector) Detect(ctx context.Context) (*Resource, error) {
+	return NewWithAttributes(semconv.SchemaURL, semconv.ProcessRuntimeNameKey.String(runtimeName())), nil
+}
+
+// Detect returns a *Resource that describes the version of the runtime of this process.
+func (processRuntimeVersionDetector) Detect(ctx context.Context) (*Resource, error) {
+	return NewWithAttributes(semconv.SchemaURL, semconv.ProcessRuntimeVersionKey.String(runtimeVersion())), nil
+}
+
+// Detect returns a *Resource that describes the runtime of this process.
+func (processRuntimeDescriptionDetector) Detect(ctx context.Context) (*Resource, error) {
+	runtimeDescription := fmt.Sprintf(
+		"go version %s %s/%s", runtimeVersion(), runtimeOS(), runtimeArch())
+
+	return NewWithAttributes(
+		semconv.SchemaURL,
+		semconv.ProcessRuntimeDescriptionKey.String(runtimeDescription),
+	), nil
+}

vendor/go.opentelemetry.io/otel/sdk/resource/resource.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package resource // import "go.opentelemetry.io/otel/sdk/resource"
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sync"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+)
+
+// Resource describes an entity about which identifying information
+// and metadata is exposed.  Resource is an immutable object,
+// equivalent to a map from key to unique value.
+//
+// Resources should be passed and stored as pointers
+// (`*resource.Resource`).  The `nil` value is equivalent to an empty
+// Resource.
+type Resource struct {
+	attrs     attribute.Set
+	schemaURL string
+}
+
+var (
+	emptyResource       Resource
+	defaultResource     *Resource
+	defaultResourceOnce sync.Once
+)
+
+var errMergeConflictSchemaURL = errors.New("cannot merge resource due to conflicting Schema URL")
+
+// New returns a Resource combined from the user-provided detectors.
+func New(ctx context.Context, opts ...Option) (*Resource, error) {
+	cfg := config{}
+	for _, opt := range opts {
+		cfg = opt.apply(cfg)
+	}
+
+	resource, err := Detect(ctx, cfg.detectors...)
+
+	var err2 error
+	resource, err2 = Merge(resource, &Resource{schemaURL: cfg.schemaURL})
+	if err == nil {
+		err = err2
+	} else if err2 != nil {
+		err = fmt.Errorf("detecting resources: %s", []string{err.Error(), err2.Error()})
+	}
+
+	return resource, err
+}
+
+// NewWithAttributes creates a resource from attrs and associates the resource with a
+// schema URL. If attrs contains duplicate keys, the last value will be used. If attrs
+// contains any invalid items those items will be dropped. The attrs are assumed to be
+// in a schema identified by schemaURL.
+func NewWithAttributes(schemaURL string, attrs ...attribute.KeyValue) *Resource {
+	resource := NewSchemaless(attrs...)
+	resource.schemaURL = schemaURL
+	return resource
+}
+
+// NewSchemaless creates a resource from attrs. If attrs contains duplicate keys,
+// the last value will be used. If attrs contains any invalid items those items will
+// be dropped. The resource will not be associated with a schema URL. If the schema
+// of the attrs is known use NewWithAttributes instead.
+func NewSchemaless(attrs ...attribute.KeyValue) *Resource {
+	if len(attrs) == 0 {
+		return &emptyResource
+	}
+
+	// Ensure attributes comply with the specification:
+	// https://github.com/open-telemetry/opentelemetry-specification/blob/v1.0.1/specification/common/common.md#attributes
+	s, _ := attribute.NewSetWithFiltered(attrs, func(kv attribute.KeyValue) bool {
+		return kv.Valid()
+	})
+
+	// If attrs only contains invalid entries do not allocate a new resource.
+	if s.Len() == 0 {
+		return &emptyResource
+	}
+
+	return &Resource{attrs: s} //nolint
+}
+
+// String implements the Stringer interface and provides a
+// human-readable form of the resource.
+//
+// Avoid using this representation as the key in a map of resources,
+// use Equivalent() as the key instead.
+func (r *Resource) String() string {
+	if r == nil {
+		return ""
+	}
+	return r.attrs.Encoded(attribute.DefaultEncoder())
+}
+
+// MarshalLog is the marshaling function used by the logging system to represent this exporter.
+func (r *Resource) MarshalLog() interface{} {
+	return struct {
+		Attributes attribute.Set
+		SchemaURL  string
+	}{
+		Attributes: r.attrs,
+		SchemaURL:  r.schemaURL,
+	}
+}
+
+// Attributes returns a copy of attributes from the resource in a sorted order.
+// To avoid allocating a new slice, use an iterator.
+func (r *Resource) Attributes() []attribute.KeyValue {
+	if r == nil {
+		r = Empty()
+	}
+	return r.attrs.ToSlice()
+}
+
+// SchemaURL returns the schema URL associated with Resource r.
+func (r *Resource) SchemaURL() string {
+	if r == nil {
+		return ""
+	}
+	return r.schemaURL
+}
+
+// Iter returns an iterator of the Resource attributes.
+// This is ideal to use if you do not want a copy of the attributes.
+func (r *Resource) Iter() attribute.Iterator {
+	if r == nil {
+		r = Empty()
+	}
+	return r.attrs.Iter()
+}
+
+// Equal returns true when a Resource is equivalent to this Resource.
+func (r *Resource) Equal(eq *Resource) bool {
+	if r == nil {
+		r = Empty()
+	}
+	if eq == nil {
+		eq = Empty()
+	}
+	return r.Equivalent() == eq.Equivalent()
+}
+
+// Merge creates a new resource by combining resource a and b.
+//
+// If there are common keys between resource a and b, then the value
+// from resource b will overwrite the value from resource a, even
+// if resource b's value is empty.
+//
+// The SchemaURL of the resources will be merged according to the spec rules:
+// https://github.com/open-telemetry/opentelemetry-specification/blob/bad49c714a62da5493f2d1d9bafd7ebe8c8ce7eb/specification/resource/sdk.md#merge
+// If the resources have different non-empty schemaURL an empty resource and an error
+// will be returned.
+func Merge(a, b *Resource) (*Resource, error) {
+	if a == nil && b == nil {
+		return Empty(), nil
+	}
+	if a == nil {
+		return b, nil
+	}
+	if b == nil {
+		return a, nil
+	}
+
+	// Merge the schema URL.
+	var schemaURL string
+	switch true {
+	case a.schemaURL == "":
+		schemaURL = b.schemaURL
+	case b.schemaURL == "":
+		schemaURL = a.schemaURL
+	case a.schemaURL == b.schemaURL:
+		schemaURL = a.schemaURL
+	default:
+		return Empty(), errMergeConflictSchemaURL
+	}
+
+	// Note: 'b' attributes will overwrite 'a' with last-value-wins in attribute.Key()
+	// Meaning this is equivalent to: append(a.Attributes(), b.Attributes()...)
+	mi := attribute.NewMergeIterator(b.Set(), a.Set())
+	combine := make([]attribute.KeyValue, 0, a.Len()+b.Len())
+	for mi.Next() {
+		combine = append(combine, mi.Attribute())
+	}
+	merged := NewWithAttributes(schemaURL, combine...)
+	return merged, nil
+}
+
+// Empty returns an instance of Resource with no attributes. It is
+// equivalent to a `nil` Resource.
+func Empty() *Resource {
+	return &emptyResource
+}
+
+// Default returns an instance of Resource with a default
+// "service.name" and OpenTelemetrySDK attributes.
+func Default() *Resource {
+	defaultResourceOnce.Do(func() {
+		var err error
+		defaultResource, err = Detect(
+			context.Background(),
+			defaultServiceNameDetector{},
+			fromEnv{},
+			telemetrySDK{},
+		)
+		if err != nil {
+			otel.Handle(err)
+		}
+		// If Detect did not return a valid resource, fall back to emptyResource.
+		if defaultResource == nil {
+			defaultResource = &emptyResource
+		}
+	})
+	return defaultResource
+}
+
+// Environment returns an instance of Resource with attributes
+// extracted from the OTEL_RESOURCE_ATTRIBUTES environment variable.
+func Environment() *Resource {
+	detector := &fromEnv{}
+	resource, err := detector.Detect(context.Background())
+	if err != nil {
+		otel.Handle(err)
+	}
+	return resource
+}
+
+// Equivalent returns an object that can be compared for equality
+// between two resources. This value is suitable for use as a key in
+// a map.
+func (r *Resource) Equivalent() attribute.Distinct {
+	return r.Set().Equivalent()
+}
+
+// Set returns the equivalent *attribute.Set of this resource's attributes.
+func (r *Resource) Set() *attribute.Set {
+	if r == nil {
+		r = Empty()
+	}
+	return &r.attrs
+}
+
+// MarshalJSON encodes the resource attributes as a JSON list of { "Key":
+// "...", "Value": ... } pairs in order sorted by key.
+func (r *Resource) MarshalJSON() ([]byte, error) {
+	if r == nil {
+		r = Empty()
+	}
+	return r.attrs.MarshalJSON()
+}
+
+// Len returns the number of unique key-values in this Resource.
+func (r *Resource) Len() int {
+	if r == nil {
+		return 0
+	}
+	return r.attrs.Len()
+}
+
+// Encoded returns an encoded representation of the resource.
+func (r *Resource) Encoded(enc attribute.Encoder) string {
+	if r == nil {
+		return ""
+	}
+	return r.attrs.Encoded(enc)
+}

vendor/go.opentelemetry.io/otel/sdk/trace/batch_span_processor.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"context"
+	"runtime"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/internal/global"
+	"go.opentelemetry.io/otel/sdk/internal/env"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Defaults for BatchSpanProcessorOptions.
+const (
+	DefaultMaxQueueSize       = 2048
+	DefaultScheduleDelay      = 5000
+	DefaultExportTimeout      = 30000
+	DefaultMaxExportBatchSize = 512
+)
+
+// BatchSpanProcessorOption configures a BatchSpanProcessor.
+type BatchSpanProcessorOption func(o *BatchSpanProcessorOptions)
+
+// BatchSpanProcessorOptions is configuration settings for a
+// BatchSpanProcessor.
+type BatchSpanProcessorOptions struct {
+	// MaxQueueSize is the maximum queue size to buffer spans for delayed processing. If the
+	// queue gets full it drops the spans. Use BlockOnQueueFull to change this behavior.
+	// The default value of MaxQueueSize is 2048.
+	MaxQueueSize int
+
+	// BatchTimeout is the maximum duration for constructing a batch. Processor
+	// forcefully sends available spans when timeout is reached.
+	// The default value of BatchTimeout is 5000 msec.
+	BatchTimeout time.Duration
+
+	// ExportTimeout specifies the maximum duration for exporting spans. If the timeout
+	// is reached, the export will be cancelled.
+	// The default value of ExportTimeout is 30000 msec.
+	ExportTimeout time.Duration
+
+	// MaxExportBatchSize is the maximum number of spans to process in a single batch.
+	// If there are more than one batch worth of spans then it processes multiple batches
+	// of spans one batch after the other without any delay.
+	// The default value of MaxExportBatchSize is 512.
+	MaxExportBatchSize int
+
+	// BlockOnQueueFull blocks onEnd() and onStart() method if the queue is full
+	// AND if BlockOnQueueFull is set to true.
+	// Blocking option should be used carefully as it can severely affect the performance of an
+	// application.
+	BlockOnQueueFull bool
+}
+
+// batchSpanProcessor is a SpanProcessor that batches asynchronously-received
+// spans and sends them to a trace.Exporter when complete.
+type batchSpanProcessor struct {
+	e SpanExporter
+	o BatchSpanProcessorOptions
+
+	queue   chan ReadOnlySpan
+	dropped uint32
+
+	batch      []ReadOnlySpan
+	batchMutex sync.Mutex
+	timer      *time.Timer
+	stopWait   sync.WaitGroup
+	stopOnce   sync.Once
+	stopCh     chan struct{}
+}
+
+var _ SpanProcessor = (*batchSpanProcessor)(nil)
+
+// NewBatchSpanProcessor creates a new SpanProcessor that will send completed
+// span batches to the exporter with the supplied options.
+//
+// If the exporter is nil, the span processor will preform no action.
+func NewBatchSpanProcessor(exporter SpanExporter, options ...BatchSpanProcessorOption) SpanProcessor {
+	maxQueueSize := env.BatchSpanProcessorMaxQueueSize(DefaultMaxQueueSize)
+	maxExportBatchSize := env.BatchSpanProcessorMaxExportBatchSize(DefaultMaxExportBatchSize)
+
+	if maxExportBatchSize > maxQueueSize {
+		if DefaultMaxExportBatchSize > maxQueueSize {
+			maxExportBatchSize = maxQueueSize
+		} else {
+			maxExportBatchSize = DefaultMaxExportBatchSize
+		}
+	}
+
+	o := BatchSpanProcessorOptions{
+		BatchTimeout:       time.Duration(env.BatchSpanProcessorScheduleDelay(DefaultScheduleDelay)) * time.Millisecond,
+		ExportTimeout:      time.Duration(env.BatchSpanProcessorExportTimeout(DefaultExportTimeout)) * time.Millisecond,
+		MaxQueueSize:       maxQueueSize,
+		MaxExportBatchSize: maxExportBatchSize,
+	}
+	for _, opt := range options {
+		opt(&o)
+	}
+	bsp := &batchSpanProcessor{
+		e:      exporter,
+		o:      o,
+		batch:  make([]ReadOnlySpan, 0, o.MaxExportBatchSize),
+		timer:  time.NewTimer(o.BatchTimeout),
+		queue:  make(chan ReadOnlySpan, o.MaxQueueSize),
+		stopCh: make(chan struct{}),
+	}
+
+	bsp.stopWait.Add(1)
+	go func() {
+		defer bsp.stopWait.Done()
+		bsp.processQueue()
+		bsp.drainQueue()
+	}()
+
+	return bsp
+}
+
+// OnStart method does nothing.
+func (bsp *batchSpanProcessor) OnStart(parent context.Context, s ReadWriteSpan) {}
+
+// OnEnd method enqueues a ReadOnlySpan for later processing.
+func (bsp *batchSpanProcessor) OnEnd(s ReadOnlySpan) {
+	// Do not enqueue spans if we are just going to drop them.
+	if bsp.e == nil {
+		return
+	}
+	bsp.enqueue(s)
+}
+
+// Shutdown flushes the queue and waits until all spans are processed.
+// It only executes once. Subsequent call does nothing.
+func (bsp *batchSpanProcessor) Shutdown(ctx context.Context) error {
+	var err error
+	bsp.stopOnce.Do(func() {
+		wait := make(chan struct{})
+		go func() {
+			close(bsp.stopCh)
+			bsp.stopWait.Wait()
+			if bsp.e != nil {
+				if err := bsp.e.Shutdown(ctx); err != nil {
+					otel.Handle(err)
+				}
+			}
+			close(wait)
+		}()
+		// Wait until the wait group is done or the context is cancelled
+		select {
+		case <-wait:
+		case <-ctx.Done():
+			err = ctx.Err()
+		}
+	})
+	return err
+}
+
+type forceFlushSpan struct {
+	ReadOnlySpan
+	flushed chan struct{}
+}
+
+func (f forceFlushSpan) SpanContext() trace.SpanContext {
+	return trace.NewSpanContext(trace.SpanContextConfig{TraceFlags: trace.FlagsSampled})
+}
+
+// ForceFlush exports all ended spans that have not yet been exported.
+func (bsp *batchSpanProcessor) ForceFlush(ctx context.Context) error {
+	var err error
+	if bsp.e != nil {
+		flushCh := make(chan struct{})
+		if bsp.enqueueBlockOnQueueFull(ctx, forceFlushSpan{flushed: flushCh}) {
+			select {
+			case <-flushCh:
+				// Processed any items in queue prior to ForceFlush being called
+			case <-ctx.Done():
+				return ctx.Err()
+			}
+		}
+
+		wait := make(chan error)
+		go func() {
+			wait <- bsp.exportSpans(ctx)
+			close(wait)
+		}()
+		// Wait until the export is finished or the context is cancelled/timed out
+		select {
+		case err = <-wait:
+		case <-ctx.Done():
+			err = ctx.Err()
+		}
+	}
+	return err
+}
+
+// WithMaxQueueSize returns a BatchSpanProcessorOption that configures the
+// maximum queue size allowed for a BatchSpanProcessor.
+func WithMaxQueueSize(size int) BatchSpanProcessorOption {
+	return func(o *BatchSpanProcessorOptions) {
+		o.MaxQueueSize = size
+	}
+}
+
+// WithMaxExportBatchSize returns a BatchSpanProcessorOption that configures
+// the maximum export batch size allowed for a BatchSpanProcessor.
+func WithMaxExportBatchSize(size int) BatchSpanProcessorOption {
+	return func(o *BatchSpanProcessorOptions) {
+		o.MaxExportBatchSize = size
+	}
+}
+
+// WithBatchTimeout returns a BatchSpanProcessorOption that configures the
+// maximum delay allowed for a BatchSpanProcessor before it will export any
+// held span (whether the queue is full or not).
+func WithBatchTimeout(delay time.Duration) BatchSpanProcessorOption {
+	return func(o *BatchSpanProcessorOptions) {
+		o.BatchTimeout = delay
+	}
+}
+
+// WithExportTimeout returns a BatchSpanProcessorOption that configures the
+// amount of time a BatchSpanProcessor waits for an exporter to export before
+// abandoning the export.
+func WithExportTimeout(timeout time.Duration) BatchSpanProcessorOption {
+	return func(o *BatchSpanProcessorOptions) {
+		o.ExportTimeout = timeout
+	}
+}
+
+// WithBlocking returns a BatchSpanProcessorOption that configures a
+// BatchSpanProcessor to wait for enqueue operations to succeed instead of
+// dropping data when the queue is full.
+func WithBlocking() BatchSpanProcessorOption {
+	return func(o *BatchSpanProcessorOptions) {
+		o.BlockOnQueueFull = true
+	}
+}
+
+// exportSpans is a subroutine of processing and draining the queue.
+func (bsp *batchSpanProcessor) exportSpans(ctx context.Context) error {
+	bsp.timer.Reset(bsp.o.BatchTimeout)
+
+	bsp.batchMutex.Lock()
+	defer bsp.batchMutex.Unlock()
+
+	if bsp.o.ExportTimeout > 0 {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, bsp.o.ExportTimeout)
+		defer cancel()
+	}
+
+	if l := len(bsp.batch); l > 0 {
+		global.Debug("exporting spans", "count", len(bsp.batch), "total_dropped", atomic.LoadUint32(&bsp.dropped))
+		err := bsp.e.ExportSpans(ctx, bsp.batch)
+
+		// A new batch is always created after exporting, even if the batch failed to be exported.
+		//
+		// It is up to the exporter to implement any type of retry logic if a batch is failing
+		// to be exported, since it is specific to the protocol and backend being sent to.
+		bsp.batch = bsp.batch[:0]
+
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// processQueue removes spans from the `queue` channel until processor
+// is shut down. It calls the exporter in batches of up to MaxExportBatchSize
+// waiting up to BatchTimeout to form a batch.
+func (bsp *batchSpanProcessor) processQueue() {
+	defer bsp.timer.Stop()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	for {
+		select {
+		case <-bsp.stopCh:
+			return
+		case <-bsp.timer.C:
+			if err := bsp.exportSpans(ctx); err != nil {
+				otel.Handle(err)
+			}
+		case sd := <-bsp.queue:
+			if ffs, ok := sd.(forceFlushSpan); ok {
+				close(ffs.flushed)
+				continue
+			}
+			bsp.batchMutex.Lock()
+			bsp.batch = append(bsp.batch, sd)
+			shouldExport := len(bsp.batch) >= bsp.o.MaxExportBatchSize
+			bsp.batchMutex.Unlock()
+			if shouldExport {
+				if !bsp.timer.Stop() {
+					<-bsp.timer.C
+				}
+				if err := bsp.exportSpans(ctx); err != nil {
+					otel.Handle(err)
+				}
+			}
+		}
+	}
+}
+
+// drainQueue awaits the any caller that had added to bsp.stopWait
+// to finish the enqueue, then exports the final batch.
+func (bsp *batchSpanProcessor) drainQueue() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	for {
+		select {
+		case sd := <-bsp.queue:
+			if sd == nil {
+				if err := bsp.exportSpans(ctx); err != nil {
+					otel.Handle(err)
+				}
+				return
+			}
+
+			bsp.batchMutex.Lock()
+			bsp.batch = append(bsp.batch, sd)
+			shouldExport := len(bsp.batch) == bsp.o.MaxExportBatchSize
+			bsp.batchMutex.Unlock()
+
+			if shouldExport {
+				if err := bsp.exportSpans(ctx); err != nil {
+					otel.Handle(err)
+				}
+			}
+		default:
+			close(bsp.queue)
+		}
+	}
+}
+
+func (bsp *batchSpanProcessor) enqueue(sd ReadOnlySpan) {
+	ctx := context.TODO()
+	if bsp.o.BlockOnQueueFull {
+		bsp.enqueueBlockOnQueueFull(ctx, sd)
+	} else {
+		bsp.enqueueDrop(ctx, sd)
+	}
+}
+
+func recoverSendOnClosedChan() {
+	x := recover()
+	switch err := x.(type) {
+	case nil:
+		return
+	case runtime.Error:
+		if err.Error() == "send on closed channel" {
+			return
+		}
+	}
+	panic(x)
+}
+
+func (bsp *batchSpanProcessor) enqueueBlockOnQueueFull(ctx context.Context, sd ReadOnlySpan) bool {
+	if !sd.SpanContext().IsSampled() {
+		return false
+	}
+
+	// This ensures the bsp.queue<- below does not panic as the
+	// processor shuts down.
+	defer recoverSendOnClosedChan()
+
+	select {
+	case <-bsp.stopCh:
+		return false
+	default:
+	}
+
+	select {
+	case bsp.queue <- sd:
+		return true
+	case <-ctx.Done():
+		return false
+	}
+}
+
+func (bsp *batchSpanProcessor) enqueueDrop(ctx context.Context, sd ReadOnlySpan) bool {
+	if !sd.SpanContext().IsSampled() {
+		return false
+	}
+
+	// This ensures the bsp.queue<- below does not panic as the
+	// processor shuts down.
+	defer recoverSendOnClosedChan()
+
+	select {
+	case <-bsp.stopCh:
+		return false
+	default:
+	}
+
+	select {
+	case bsp.queue <- sd:
+		return true
+	default:
+		atomic.AddUint32(&bsp.dropped, 1)
+	}
+	return false
+}
+
+// MarshalLog is the marshaling function used by the logging system to represent this exporter.
+func (bsp *batchSpanProcessor) MarshalLog() interface{} {
+	return struct {
+		Type         string
+		SpanExporter SpanExporter
+		Config       BatchSpanProcessorOptions
+	}{
+		Type:         "BatchSpanProcessor",
+		SpanExporter: bsp.e,
+		Config:       bsp.o,
+	}
+}

vendor/go.opencensus.io/opencensus.go → vendor/go.opentelemetry.io/otel/sdk/trace/doc.go

-// Copyright 2017, OpenCensus Authors
+// Copyright The OpenTelemetry Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,10 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package opencensus contains Go support for OpenCensus.
-package opencensus // import "go.opencensus.io"
+/*
+Package trace contains support for OpenTelemetry distributed tracing.
 
-// Version is the current release version of OpenCensus in use.
-func Version() string {
-	return "0.23.0"
-}
+The following assumes a basic familiarity with OpenTelemetry concepts.
+See https://opentelemetry.io.
+*/
+package trace // import "go.opentelemetry.io/otel/sdk/trace"

vendor/github.com/openzipkin/zipkin-go/noop.go → vendor/go.opentelemetry.io/otel/sdk/trace/event.go

-// Copyright 2019 The OpenZipkin Authors
+// Copyright The OpenTelemetry Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,30 +12,26 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package zipkin
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
 
 import (
 	"time"
 
-	"github.com/openzipkin/zipkin-go/model"
+	"go.opentelemetry.io/otel/attribute"
 )
 
-type noopSpan struct {
-	model.SpanContext
-}
-
-func (n *noopSpan) Context() model.SpanContext { return n.SpanContext }
-
-func (n *noopSpan) SetName(string) {}
-
-func (*noopSpan) SetRemoteEndpoint(*model.Endpoint) {}
+// Event is a thing that happened during a Span's lifetime.
+type Event struct {
+	// Name is the name of this event
+	Name string
 
-func (*noopSpan) Annotate(time.Time, string) {}
+	// Attributes describe the aspects of the event.
+	Attributes []attribute.KeyValue
 
-func (*noopSpan) Tag(string, string) {}
+	// DroppedAttributeCount is the number of attributes that were not
+	// recorded due to configured limits being reached.
+	DroppedAttributeCount int
 
-func (*noopSpan) Finish() {}
-
-func (*noopSpan) FinishedWithDuration(duration time.Duration) {}
-
-func (*noopSpan) Flush() {}
+	// Time at which this event was recorded.
+	Time time.Time
+}

vendor/go.opencensus.io/trace/evictedqueue.go → vendor/go.opentelemetry.io/otel/sdk/trace/evictedqueue.go

-// Copyright 2019, OpenCensus Authors
+// Copyright The OpenTelemetry Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,26 +12,32 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package trace
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
 
+// evictedQueue is a FIFO queue with a configurable capacity.
 type evictedQueue struct {
 	queue        []interface{}
 	capacity     int
 	droppedCount int
 }
 
-func newEvictedQueue(capacity int) *evictedQueue {
-	eq := &evictedQueue{
-		capacity: capacity,
-		queue:    make([]interface{}, 0),
+func newEvictedQueue(capacity int) evictedQueue {
+	// Do not pre-allocate queue, do this lazily.
+	return evictedQueue{capacity: capacity}
 }
 
-	return eq
+// add adds value to the evictedQueue eq. If eq is at capacity, the oldest
+// queued value will be discarded and the drop count incremented.
+func (eq *evictedQueue) add(value interface{}) {
+	if eq.capacity == 0 {
+		eq.droppedCount++
+		return
 	}
 
-func (eq *evictedQueue) add(value interface{}) {
-	if len(eq.queue) == eq.capacity {
-		eq.queue = eq.queue[1:]
+	if eq.capacity > 0 && len(eq.queue) == eq.capacity {
+		// Drop first-in while avoiding allocating more capacity to eq.queue.
+		copy(eq.queue[:eq.capacity-1], eq.queue[1:])
+		eq.queue = eq.queue[:eq.capacity-1]
 		eq.droppedCount++
 	}
 	eq.queue = append(eq.queue, value)

vendor/go.opentelemetry.io/otel/sdk/trace/id_generator.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"context"
+	crand "crypto/rand"
+	"encoding/binary"
+	"math/rand"
+	"sync"
+
+	"go.opentelemetry.io/otel/trace"
+)
+
+// IDGenerator allows custom generators for TraceID and SpanID.
+type IDGenerator interface {
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// NewIDs returns a new trace and span ID.
+	NewIDs(ctx context.Context) (trace.TraceID, trace.SpanID)
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// NewSpanID returns a ID for a new span in the trace with traceID.
+	NewSpanID(ctx context.Context, traceID trace.TraceID) trace.SpanID
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+}
+
+type randomIDGenerator struct {
+	sync.Mutex
+	randSource *rand.Rand
+}
+
+var _ IDGenerator = &randomIDGenerator{}
+
+// NewSpanID returns a non-zero span ID from a randomly-chosen sequence.
+func (gen *randomIDGenerator) NewSpanID(ctx context.Context, traceID trace.TraceID) trace.SpanID {
+	gen.Lock()
+	defer gen.Unlock()
+	sid := trace.SpanID{}
+	_, _ = gen.randSource.Read(sid[:])
+	return sid
+}
+
+// NewIDs returns a non-zero trace ID and a non-zero span ID from a
+// randomly-chosen sequence.
+func (gen *randomIDGenerator) NewIDs(ctx context.Context) (trace.TraceID, trace.SpanID) {
+	gen.Lock()
+	defer gen.Unlock()
+	tid := trace.TraceID{}
+	_, _ = gen.randSource.Read(tid[:])
+	sid := trace.SpanID{}
+	_, _ = gen.randSource.Read(sid[:])
+	return tid, sid
+}
+
+func defaultIDGenerator() IDGenerator {
+	gen := &randomIDGenerator{}
+	var rngSeed int64
+	_ = binary.Read(crand.Reader, binary.LittleEndian, &rngSeed)
+	gen.randSource = rand.New(rand.NewSource(rngSeed))
+	return gen
+}

vendor/go.opentelemetry.io/otel/sdk/trace/link.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Link is the relationship between two Spans. The relationship can be within
+// the same Trace or across different Traces.
+type Link struct {
+	// SpanContext of the linked Span.
+	SpanContext trace.SpanContext
+
+	// Attributes describe the aspects of the link.
+	Attributes []attribute.KeyValue
+
+	// DroppedAttributeCount is the number of attributes that were not
+	// recorded due to configured limits being reached.
+	DroppedAttributeCount int
+}

vendor/go.opentelemetry.io/otel/sdk/trace/provider.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/internal/global"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	"go.opentelemetry.io/otel/trace"
+)
+
+const (
+	defaultTracerName = "go.opentelemetry.io/otel/sdk/tracer"
+)
+
+// tracerProviderConfig.
+type tracerProviderConfig struct {
+	// processors contains collection of SpanProcessors that are processing pipeline
+	// for spans in the trace signal.
+	// SpanProcessors registered with a TracerProvider and are called at the start
+	// and end of a Span's lifecycle, and are called in the order they are
+	// registered.
+	processors []SpanProcessor
+
+	// sampler is the default sampler used when creating new spans.
+	sampler Sampler
+
+	// idGenerator is used to generate all Span and Trace IDs when needed.
+	idGenerator IDGenerator
+
+	// spanLimits defines the attribute, event, and link limits for spans.
+	spanLimits SpanLimits
+
+	// resource contains attributes representing an entity that produces telemetry.
+	resource *resource.Resource
+}
+
+// MarshalLog is the marshaling function used by the logging system to represent this exporter.
+func (cfg tracerProviderConfig) MarshalLog() interface{} {
+	return struct {
+		SpanProcessors  []SpanProcessor
+		SamplerType     string
+		IDGeneratorType string
+		SpanLimits      SpanLimits
+		Resource        *resource.Resource
+	}{
+		SpanProcessors:  cfg.processors,
+		SamplerType:     fmt.Sprintf("%T", cfg.sampler),
+		IDGeneratorType: fmt.Sprintf("%T", cfg.idGenerator),
+		SpanLimits:      cfg.spanLimits,
+		Resource:        cfg.resource,
+	}
+}
+
+// TracerProvider is an OpenTelemetry TracerProvider. It provides Tracers to
+// instrumentation so it can trace operational flow through a system.
+type TracerProvider struct {
+	mu             sync.Mutex
+	namedTracer    map[instrumentation.Scope]*tracer
+	spanProcessors atomic.Value
+
+	// These fields are not protected by the lock mu. They are assumed to be
+	// immutable after creation of the TracerProvider.
+	sampler     Sampler
+	idGenerator IDGenerator
+	spanLimits  SpanLimits
+	resource    *resource.Resource
+}
+
+var _ trace.TracerProvider = &TracerProvider{}
+
+// NewTracerProvider returns a new and configured TracerProvider.
+//
+// By default the returned TracerProvider is configured with:
+//  - a ParentBased(AlwaysSample) Sampler
+//  - a random number IDGenerator
+//  - the resource.Default() Resource
+//  - the default SpanLimits.
+//
+// The passed opts are used to override these default values and configure the
+// returned TracerProvider appropriately.
+func NewTracerProvider(opts ...TracerProviderOption) *TracerProvider {
+	o := tracerProviderConfig{
+		spanLimits: NewSpanLimits(),
+	}
+	o = applyTracerProviderEnvConfigs(o)
+
+	for _, opt := range opts {
+		o = opt.apply(o)
+	}
+
+	o = ensureValidTracerProviderConfig(o)
+
+	tp := &TracerProvider{
+		namedTracer: make(map[instrumentation.Scope]*tracer),
+		sampler:     o.sampler,
+		idGenerator: o.idGenerator,
+		spanLimits:  o.spanLimits,
+		resource:    o.resource,
+	}
+
+	global.Info("TracerProvider created", "config", o)
+
+	for _, sp := range o.processors {
+		tp.RegisterSpanProcessor(sp)
+	}
+
+	return tp
+}
+
+// Tracer returns a Tracer with the given name and options. If a Tracer for
+// the given name and options does not exist it is created, otherwise the
+// existing Tracer is returned.
+//
+// If name is empty, DefaultTracerName is used instead.
+//
+// This method is safe to be called concurrently.
+func (p *TracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.Tracer {
+	c := trace.NewTracerConfig(opts...)
+
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if name == "" {
+		name = defaultTracerName
+	}
+	is := instrumentation.Scope{
+		Name:      name,
+		Version:   c.InstrumentationVersion(),
+		SchemaURL: c.SchemaURL(),
+	}
+	t, ok := p.namedTracer[is]
+	if !ok {
+		t = &tracer{
+			provider:             p,
+			instrumentationScope: is,
+		}
+		p.namedTracer[is] = t
+		global.Info("Tracer created", "name", name, "version", c.InstrumentationVersion(), "schemaURL", c.SchemaURL())
+	}
+	return t
+}
+
+// RegisterSpanProcessor adds the given SpanProcessor to the list of SpanProcessors.
+func (p *TracerProvider) RegisterSpanProcessor(s SpanProcessor) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	new := spanProcessorStates{}
+	if old, ok := p.spanProcessors.Load().(spanProcessorStates); ok {
+		new = append(new, old...)
+	}
+	newSpanSync := &spanProcessorState{
+		sp:    s,
+		state: &sync.Once{},
+	}
+	new = append(new, newSpanSync)
+	p.spanProcessors.Store(new)
+}
+
+// UnregisterSpanProcessor removes the given SpanProcessor from the list of SpanProcessors.
+func (p *TracerProvider) UnregisterSpanProcessor(s SpanProcessor) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	spss := spanProcessorStates{}
+	old, ok := p.spanProcessors.Load().(spanProcessorStates)
+	if !ok || len(old) == 0 {
+		return
+	}
+	spss = append(spss, old...)
+
+	// stop the span processor if it is started and remove it from the list
+	var stopOnce *spanProcessorState
+	var idx int
+	for i, sps := range spss {
+		if sps.sp == s {
+			stopOnce = sps
+			idx = i
+		}
+	}
+	if stopOnce != nil {
+		stopOnce.state.Do(func() {
+			if err := s.Shutdown(context.Background()); err != nil {
+				otel.Handle(err)
+			}
+		})
+	}
+	if len(spss) > 1 {
+		copy(spss[idx:], spss[idx+1:])
+	}
+	spss[len(spss)-1] = nil
+	spss = spss[:len(spss)-1]
+
+	p.spanProcessors.Store(spss)
+}
+
+// ForceFlush immediately exports all spans that have not yet been exported for
+// all the registered span processors.
+func (p *TracerProvider) ForceFlush(ctx context.Context) error {
+	spss, ok := p.spanProcessors.Load().(spanProcessorStates)
+	if !ok {
+		return fmt.Errorf("failed to load span processors")
+	}
+	if len(spss) == 0 {
+		return nil
+	}
+
+	for _, sps := range spss {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		default:
+		}
+
+		if err := sps.sp.ForceFlush(ctx); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Shutdown shuts down the span processors in the order they were registered.
+func (p *TracerProvider) Shutdown(ctx context.Context) error {
+	spss, ok := p.spanProcessors.Load().(spanProcessorStates)
+	if !ok {
+		return fmt.Errorf("failed to load span processors")
+	}
+	if len(spss) == 0 {
+		return nil
+	}
+
+	for _, sps := range spss {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		default:
+		}
+
+		var err error
+		sps.state.Do(func() {
+			err = sps.sp.Shutdown(ctx)
+		})
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// TracerProviderOption configures a TracerProvider.
+type TracerProviderOption interface {
+	apply(tracerProviderConfig) tracerProviderConfig
+}
+
+type traceProviderOptionFunc func(tracerProviderConfig) tracerProviderConfig
+
+func (fn traceProviderOptionFunc) apply(cfg tracerProviderConfig) tracerProviderConfig {
+	return fn(cfg)
+}
+
+// WithSyncer registers the exporter with the TracerProvider using a
+// SimpleSpanProcessor.
+//
+// This is not recommended for production use. The synchronous nature of the
+// SimpleSpanProcessor that will wrap the exporter make it good for testing,
+// debugging, or showing examples of other feature, but it will be slow and
+// have a high computation resource usage overhead. The WithBatcher option is
+// recommended for production use instead.
+func WithSyncer(e SpanExporter) TracerProviderOption {
+	return WithSpanProcessor(NewSimpleSpanProcessor(e))
+}
+
+// WithBatcher registers the exporter with the TracerProvider using a
+// BatchSpanProcessor configured with the passed opts.
+func WithBatcher(e SpanExporter, opts ...BatchSpanProcessorOption) TracerProviderOption {
+	return WithSpanProcessor(NewBatchSpanProcessor(e, opts...))
+}
+
+// WithSpanProcessor registers the SpanProcessor with a TracerProvider.
+func WithSpanProcessor(sp SpanProcessor) TracerProviderOption {
+	return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
+		cfg.processors = append(cfg.processors, sp)
+		return cfg
+	})
+}
+
+// WithResource returns a TracerProviderOption that will configure the
+// Resource r as a TracerProvider's Resource. The configured Resource is
+// referenced by all the Tracers the TracerProvider creates. It represents the
+// entity producing telemetry.
+//
+// If this option is not used, the TracerProvider will use the
+// resource.Default() Resource by default.
+func WithResource(r *resource.Resource) TracerProviderOption {
+	return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
+		var err error
+		cfg.resource, err = resource.Merge(resource.Environment(), r)
+		if err != nil {
+			otel.Handle(err)
+		}
+		return cfg
+	})
+}
+
+// WithIDGenerator returns a TracerProviderOption that will configure the
+// IDGenerator g as a TracerProvider's IDGenerator. The configured IDGenerator
+// is used by the Tracers the TracerProvider creates to generate new Span and
+// Trace IDs.
+//
+// If this option is not used, the TracerProvider will use a random number
+// IDGenerator by default.
+func WithIDGenerator(g IDGenerator) TracerProviderOption {
+	return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
+		if g != nil {
+			cfg.idGenerator = g
+		}
+		return cfg
+	})
+}
+
+// WithSampler returns a TracerProviderOption that will configure the Sampler
+// s as a TracerProvider's Sampler. The configured Sampler is used by the
+// Tracers the TracerProvider creates to make their sampling decisions for the
+// Spans they create.
+//
+// This option overrides the Sampler configured through the OTEL_TRACES_SAMPLER
+// and OTEL_TRACES_SAMPLER_ARG environment variables. If this option is not used
+// and the sampler is not configured through environment variables or the environment
+// contains invalid/unsupported configuration, the TracerProvider will use a
+// ParentBased(AlwaysSample) Sampler by default.
+func WithSampler(s Sampler) TracerProviderOption {
+	return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
+		if s != nil {
+			cfg.sampler = s
+		}
+		return cfg
+	})
+}
+
+// WithSpanLimits returns a TracerProviderOption that configures a
+// TracerProvider to use the SpanLimits sl. These SpanLimits bound any Span
+// created by a Tracer from the TracerProvider.
+//
+// If any field of sl is zero or negative it will be replaced with the default
+// value for that field.
+//
+// If this or WithRawSpanLimits are not provided, the TracerProvider will use
+// the limits defined by environment variables, or the defaults if unset.
+// Refer to the NewSpanLimits documentation for information about this
+// relationship.
+//
+// Deprecated: Use WithRawSpanLimits instead which allows setting unlimited
+// and zero limits. This option will be kept until the next major version
+// incremented release.
+func WithSpanLimits(sl SpanLimits) TracerProviderOption {
+	if sl.AttributeValueLengthLimit <= 0 {
+		sl.AttributeValueLengthLimit = DefaultAttributeValueLengthLimit
+	}
+	if sl.AttributeCountLimit <= 0 {
+		sl.AttributeCountLimit = DefaultAttributeCountLimit
+	}
+	if sl.EventCountLimit <= 0 {
+		sl.EventCountLimit = DefaultEventCountLimit
+	}
+	if sl.AttributePerEventCountLimit <= 0 {
+		sl.AttributePerEventCountLimit = DefaultAttributePerEventCountLimit
+	}
+	if sl.LinkCountLimit <= 0 {
+		sl.LinkCountLimit = DefaultLinkCountLimit
+	}
+	if sl.AttributePerLinkCountLimit <= 0 {
+		sl.AttributePerLinkCountLimit = DefaultAttributePerLinkCountLimit
+	}
+	return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
+		cfg.spanLimits = sl
+		return cfg
+	})
+}
+
+// WithRawSpanLimits returns a TracerProviderOption that configures a
+// TracerProvider to use these limits. These limits bound any Span created by
+// a Tracer from the TracerProvider.
+//
+// The limits will be used as-is. Zero or negative values will not be changed
+// to the default value like WithSpanLimits does. Setting a limit to zero will
+// effectively disable the related resource it limits and setting to a
+// negative value will mean that resource is unlimited. Consequentially, this
+// means that the zero-value SpanLimits will disable all span resources.
+// Because of this, limits should be constructed using NewSpanLimits and
+// updated accordingly.
+//
+// If this or WithSpanLimits are not provided, the TracerProvider will use the
+// limits defined by environment variables, or the defaults if unset. Refer to
+// the NewSpanLimits documentation for information about this relationship.
+func WithRawSpanLimits(limits SpanLimits) TracerProviderOption {
+	return traceProviderOptionFunc(func(cfg tracerProviderConfig) tracerProviderConfig {
+		cfg.spanLimits = limits
+		return cfg
+	})
+}
+
+func applyTracerProviderEnvConfigs(cfg tracerProviderConfig) tracerProviderConfig {
+	for _, opt := range tracerProviderOptionsFromEnv() {
+		cfg = opt.apply(cfg)
+	}
+
+	return cfg
+}
+
+func tracerProviderOptionsFromEnv() []TracerProviderOption {
+	var opts []TracerProviderOption
+
+	sampler, err := samplerFromEnv()
+	if err != nil {
+		otel.Handle(err)
+	}
+
+	if sampler != nil {
+		opts = append(opts, WithSampler(sampler))
+	}
+
+	return opts
+}
+
+// ensureValidTracerProviderConfig ensures that given TracerProviderConfig is valid.
+func ensureValidTracerProviderConfig(cfg tracerProviderConfig) tracerProviderConfig {
+	if cfg.sampler == nil {
+		cfg.sampler = ParentBased(AlwaysSample())
+	}
+	if cfg.idGenerator == nil {
+		cfg.idGenerator = defaultIDGenerator()
+	}
+	if cfg.resource == nil {
+		cfg.resource = resource.Default()
+	}
+	return cfg
+}

vendor/go.opentelemetry.io/otel/sdk/trace/sampler_env.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	tracesSamplerKey    = "OTEL_TRACES_SAMPLER"
+	tracesSamplerArgKey = "OTEL_TRACES_SAMPLER_ARG"
+
+	samplerAlwaysOn                = "always_on"
+	samplerAlwaysOff               = "always_off"
+	samplerTraceIDRatio            = "traceidratio"
+	samplerParentBasedAlwaysOn     = "parentbased_always_on"
+	samplerParsedBasedAlwaysOff    = "parentbased_always_off"
+	samplerParentBasedTraceIDRatio = "parentbased_traceidratio"
+)
+
+type errUnsupportedSampler string
+
+func (e errUnsupportedSampler) Error() string {
+	return fmt.Sprintf("unsupported sampler: %s", string(e))
+}
+
+var (
+	errNegativeTraceIDRatio       = errors.New("invalid trace ID ratio: less than 0.0")
+	errGreaterThanOneTraceIDRatio = errors.New("invalid trace ID ratio: greater than 1.0")
+)
+
+type samplerArgParseError struct {
+	parseErr error
+}
+
+func (e samplerArgParseError) Error() string {
+	return fmt.Sprintf("parsing sampler argument: %s", e.parseErr.Error())
+}
+
+func (e samplerArgParseError) Unwrap() error {
+	return e.parseErr
+}
+
+func samplerFromEnv() (Sampler, error) {
+	sampler, ok := os.LookupEnv(tracesSamplerKey)
+	if !ok {
+		return nil, nil
+	}
+
+	sampler = strings.ToLower(strings.TrimSpace(sampler))
+	samplerArg, hasSamplerArg := os.LookupEnv(tracesSamplerArgKey)
+	samplerArg = strings.TrimSpace(samplerArg)
+
+	switch sampler {
+	case samplerAlwaysOn:
+		return AlwaysSample(), nil
+	case samplerAlwaysOff:
+		return NeverSample(), nil
+	case samplerTraceIDRatio:
+		if !hasSamplerArg {
+			return TraceIDRatioBased(1.0), nil
+		}
+		return parseTraceIDRatio(samplerArg)
+	case samplerParentBasedAlwaysOn:
+		return ParentBased(AlwaysSample()), nil
+	case samplerParsedBasedAlwaysOff:
+		return ParentBased(NeverSample()), nil
+	case samplerParentBasedTraceIDRatio:
+		if !hasSamplerArg {
+			return ParentBased(TraceIDRatioBased(1.0)), nil
+		}
+		ratio, err := parseTraceIDRatio(samplerArg)
+		return ParentBased(ratio), err
+	default:
+		return nil, errUnsupportedSampler(sampler)
+	}
+}
+
+func parseTraceIDRatio(arg string) (Sampler, error) {
+	v, err := strconv.ParseFloat(arg, 64)
+	if err != nil {
+		return TraceIDRatioBased(1.0), samplerArgParseError{err}
+	}
+	if v < 0.0 {
+		return TraceIDRatioBased(1.0), errNegativeTraceIDRatio
+	}
+	if v > 1.0 {
+		return TraceIDRatioBased(1.0), errGreaterThanOneTraceIDRatio
+	}
+
+	return TraceIDRatioBased(v), nil
+}

vendor/go.opentelemetry.io/otel/sdk/trace/sampling.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"context"
+	"encoding/binary"
+	"fmt"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Sampler decides whether a trace should be sampled and exported.
+type Sampler interface {
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// ShouldSample returns a SamplingResult based on a decision made from the
+	// passed parameters.
+	ShouldSample(parameters SamplingParameters) SamplingResult
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// Description returns information describing the Sampler.
+	Description() string
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+}
+
+// SamplingParameters contains the values passed to a Sampler.
+type SamplingParameters struct {
+	ParentContext context.Context
+	TraceID       trace.TraceID
+	Name          string
+	Kind          trace.SpanKind
+	Attributes    []attribute.KeyValue
+	Links         []trace.Link
+}
+
+// SamplingDecision indicates whether a span is dropped, recorded and/or sampled.
+type SamplingDecision uint8
+
+// Valid sampling decisions.
+const (
+	// Drop will not record the span and all attributes/events will be dropped.
+	Drop SamplingDecision = iota
+
+	// Record indicates the span's `IsRecording() == true`, but `Sampled` flag
+	// *must not* be set.
+	RecordOnly
+
+	// RecordAndSample has span's `IsRecording() == true` and `Sampled` flag
+	// *must* be set.
+	RecordAndSample
+)
+
+// SamplingResult conveys a SamplingDecision, set of Attributes and a Tracestate.
+type SamplingResult struct {
+	Decision   SamplingDecision
+	Attributes []attribute.KeyValue
+	Tracestate trace.TraceState
+}
+
+type traceIDRatioSampler struct {
+	traceIDUpperBound uint64
+	description       string
+}
+
+func (ts traceIDRatioSampler) ShouldSample(p SamplingParameters) SamplingResult {
+	psc := trace.SpanContextFromContext(p.ParentContext)
+	x := binary.BigEndian.Uint64(p.TraceID[0:8]) >> 1
+	if x < ts.traceIDUpperBound {
+		return SamplingResult{
+			Decision:   RecordAndSample,
+			Tracestate: psc.TraceState(),
+		}
+	}
+	return SamplingResult{
+		Decision:   Drop,
+		Tracestate: psc.TraceState(),
+	}
+}
+
+func (ts traceIDRatioSampler) Description() string {
+	return ts.description
+}
+
+// TraceIDRatioBased samples a given fraction of traces. Fractions >= 1 will
+// always sample. Fractions < 0 are treated as zero. To respect the
+// parent trace's `SampledFlag`, the `TraceIDRatioBased` sampler should be used
+// as a delegate of a `Parent` sampler.
+//nolint:revive // revive complains about stutter of `trace.TraceIDRatioBased`
+func TraceIDRatioBased(fraction float64) Sampler {
+	if fraction >= 1 {
+		return AlwaysSample()
+	}
+
+	if fraction <= 0 {
+		fraction = 0
+	}
+
+	return &traceIDRatioSampler{
+		traceIDUpperBound: uint64(fraction * (1 << 63)),
+		description:       fmt.Sprintf("TraceIDRatioBased{%g}", fraction),
+	}
+}
+
+type alwaysOnSampler struct{}
+
+func (as alwaysOnSampler) ShouldSample(p SamplingParameters) SamplingResult {
+	return SamplingResult{
+		Decision:   RecordAndSample,
+		Tracestate: trace.SpanContextFromContext(p.ParentContext).TraceState(),
+	}
+}
+
+func (as alwaysOnSampler) Description() string {
+	return "AlwaysOnSampler"
+}
+
+// AlwaysSample returns a Sampler that samples every trace.
+// Be careful about using this sampler in a production application with
+// significant traffic: a new trace will be started and exported for every
+// request.
+func AlwaysSample() Sampler {
+	return alwaysOnSampler{}
+}
+
+type alwaysOffSampler struct{}
+
+func (as alwaysOffSampler) ShouldSample(p SamplingParameters) SamplingResult {
+	return SamplingResult{
+		Decision:   Drop,
+		Tracestate: trace.SpanContextFromContext(p.ParentContext).TraceState(),
+	}
+}
+
+func (as alwaysOffSampler) Description() string {
+	return "AlwaysOffSampler"
+}
+
+// NeverSample returns a Sampler that samples no traces.
+func NeverSample() Sampler {
+	return alwaysOffSampler{}
+}
+
+// ParentBased returns a composite sampler which behaves differently,
+// based on the parent of the span. If the span has no parent,
+// the root(Sampler) is used to make sampling decision. If the span has
+// a parent, depending on whether the parent is remote and whether it
+// is sampled, one of the following samplers will apply:
+// - remoteParentSampled(Sampler) (default: AlwaysOn)
+// - remoteParentNotSampled(Sampler) (default: AlwaysOff)
+// - localParentSampled(Sampler) (default: AlwaysOn)
+// - localParentNotSampled(Sampler) (default: AlwaysOff)
+func ParentBased(root Sampler, samplers ...ParentBasedSamplerOption) Sampler {
+	return parentBased{
+		root:   root,
+		config: configureSamplersForParentBased(samplers),
+	}
+}
+
+type parentBased struct {
+	root   Sampler
+	config samplerConfig
+}
+
+func configureSamplersForParentBased(samplers []ParentBasedSamplerOption) samplerConfig {
+	c := samplerConfig{
+		remoteParentSampled:    AlwaysSample(),
+		remoteParentNotSampled: NeverSample(),
+		localParentSampled:     AlwaysSample(),
+		localParentNotSampled:  NeverSample(),
+	}
+
+	for _, so := range samplers {
+		c = so.apply(c)
+	}
+
+	return c
+}
+
+// samplerConfig is a group of options for parentBased sampler.
+type samplerConfig struct {
+	remoteParentSampled, remoteParentNotSampled Sampler
+	localParentSampled, localParentNotSampled   Sampler
+}
+
+// ParentBasedSamplerOption configures the sampler for a particular sampling case.
+type ParentBasedSamplerOption interface {
+	apply(samplerConfig) samplerConfig
+}
+
+// WithRemoteParentSampled sets the sampler for the case of sampled remote parent.
+func WithRemoteParentSampled(s Sampler) ParentBasedSamplerOption {
+	return remoteParentSampledOption{s}
+}
+
+type remoteParentSampledOption struct {
+	s Sampler
+}
+
+func (o remoteParentSampledOption) apply(config samplerConfig) samplerConfig {
+	config.remoteParentSampled = o.s
+	return config
+}
+
+// WithRemoteParentNotSampled sets the sampler for the case of remote parent
+// which is not sampled.
+func WithRemoteParentNotSampled(s Sampler) ParentBasedSamplerOption {
+	return remoteParentNotSampledOption{s}
+}
+
+type remoteParentNotSampledOption struct {
+	s Sampler
+}
+
+func (o remoteParentNotSampledOption) apply(config samplerConfig) samplerConfig {
+	config.remoteParentNotSampled = o.s
+	return config
+}
+
+// WithLocalParentSampled sets the sampler for the case of sampled local parent.
+func WithLocalParentSampled(s Sampler) ParentBasedSamplerOption {
+	return localParentSampledOption{s}
+}
+
+type localParentSampledOption struct {
+	s Sampler
+}
+
+func (o localParentSampledOption) apply(config samplerConfig) samplerConfig {
+	config.localParentSampled = o.s
+	return config
+}
+
+// WithLocalParentNotSampled sets the sampler for the case of local parent
+// which is not sampled.
+func WithLocalParentNotSampled(s Sampler) ParentBasedSamplerOption {
+	return localParentNotSampledOption{s}
+}
+
+type localParentNotSampledOption struct {
+	s Sampler
+}
+
+func (o localParentNotSampledOption) apply(config samplerConfig) samplerConfig {
+	config.localParentNotSampled = o.s
+	return config
+}
+
+func (pb parentBased) ShouldSample(p SamplingParameters) SamplingResult {
+	psc := trace.SpanContextFromContext(p.ParentContext)
+	if psc.IsValid() {
+		if psc.IsRemote() {
+			if psc.IsSampled() {
+				return pb.config.remoteParentSampled.ShouldSample(p)
+			}
+			return pb.config.remoteParentNotSampled.ShouldSample(p)
+		}
+
+		if psc.IsSampled() {
+			return pb.config.localParentSampled.ShouldSample(p)
+		}
+		return pb.config.localParentNotSampled.ShouldSample(p)
+	}
+	return pb.root.ShouldSample(p)
+}
+
+func (pb parentBased) Description() string {
+	return fmt.Sprintf("ParentBased{root:%s,remoteParentSampled:%s,"+
+		"remoteParentNotSampled:%s,localParentSampled:%s,localParentNotSampled:%s}",
+		pb.root.Description(),
+		pb.config.remoteParentSampled.Description(),
+		pb.config.remoteParentNotSampled.Description(),
+		pb.config.localParentSampled.Description(),
+		pb.config.localParentNotSampled.Description(),
+	)
+}

vendor/go.opentelemetry.io/otel/sdk/trace/simple_span_processor.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel"
+)
+
+// simpleSpanProcessor is a SpanProcessor that synchronously sends all
+// completed Spans to a trace.Exporter immediately.
+type simpleSpanProcessor struct {
+	exporterMu sync.RWMutex
+	exporter   SpanExporter
+	stopOnce   sync.Once
+}
+
+var _ SpanProcessor = (*simpleSpanProcessor)(nil)
+
+// NewSimpleSpanProcessor returns a new SpanProcessor that will synchronously
+// send completed spans to the exporter immediately.
+//
+// This SpanProcessor is not recommended for production use. The synchronous
+// nature of this SpanProcessor make it good for testing, debugging, or
+// showing examples of other feature, but it will be slow and have a high
+// computation resource usage overhead. The BatchSpanProcessor is recommended
+// for production use instead.
+func NewSimpleSpanProcessor(exporter SpanExporter) SpanProcessor {
+	ssp := &simpleSpanProcessor{
+		exporter: exporter,
+	}
+	return ssp
+}
+
+// OnStart does nothing.
+func (ssp *simpleSpanProcessor) OnStart(context.Context, ReadWriteSpan) {}
+
+// OnEnd immediately exports a ReadOnlySpan.
+func (ssp *simpleSpanProcessor) OnEnd(s ReadOnlySpan) {
+	ssp.exporterMu.RLock()
+	defer ssp.exporterMu.RUnlock()
+
+	if ssp.exporter != nil && s.SpanContext().TraceFlags().IsSampled() {
+		if err := ssp.exporter.ExportSpans(context.Background(), []ReadOnlySpan{s}); err != nil {
+			otel.Handle(err)
+		}
+	}
+}
+
+// Shutdown shuts down the exporter this SimpleSpanProcessor exports to.
+func (ssp *simpleSpanProcessor) Shutdown(ctx context.Context) error {
+	var err error
+	ssp.stopOnce.Do(func() {
+		stopFunc := func(exp SpanExporter) (<-chan error, func()) {
+			done := make(chan error)
+			return done, func() { done <- exp.Shutdown(ctx) }
+		}
+
+		// The exporter field of the simpleSpanProcessor needs to be zeroed to
+		// signal it is shut down, meaning all subsequent calls to OnEnd will
+		// be gracefully ignored. This needs to be done synchronously to avoid
+		// any race condition.
+		//
+		// A closure is used to keep reference to the exporter and then the
+		// field is zeroed. This ensures the simpleSpanProcessor is shut down
+		// before the exporter. This order is important as it avoids a
+		// potential deadlock. If the exporter shut down operation generates a
+		// span, that span would need to be exported. Meaning, OnEnd would be
+		// called and try acquiring the lock that is held here.
+		ssp.exporterMu.Lock()
+		done, shutdown := stopFunc(ssp.exporter)
+		ssp.exporter = nil
+		ssp.exporterMu.Unlock()
+
+		go shutdown()
+
+		// Wait for the exporter to shut down or the deadline to expire.
+		select {
+		case err = <-done:
+		case <-ctx.Done():
+			// It is possible for the exporter to have immediately shut down
+			// and the context to be done simultaneously. In that case this
+			// outer select statement will randomly choose a case. This will
+			// result in a different returned error for similar scenarios.
+			// Instead, double check if the exporter shut down at the same
+			// time and return that error if so. This will ensure consistency
+			// as well as ensure the caller knows the exporter shut down
+			// successfully (they can already determine if the deadline is
+			// expired given they passed the context).
+			select {
+			case err = <-done:
+			default:
+				err = ctx.Err()
+			}
+		}
+	})
+	return err
+}
+
+// ForceFlush does nothing as there is no data to flush.
+func (ssp *simpleSpanProcessor) ForceFlush(context.Context) error {
+	return nil
+}
+
+// MarshalLog is the marshaling function used by the logging system to represent this Span Processor.
+func (ssp *simpleSpanProcessor) MarshalLog() interface{} {
+	return struct {
+		Type     string
+		Exporter SpanExporter
+	}{
+		Type:     "SimpleSpanProcessor",
+		Exporter: ssp.exporter,
+	}
+}

vendor/go.opentelemetry.io/otel/sdk/trace/snapshot.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"time"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// snapshot is an record of a spans state at a particular checkpointed time.
+// It is used as a read-only representation of that state.
+type snapshot struct {
+	name                  string
+	spanContext           trace.SpanContext
+	parent                trace.SpanContext
+	spanKind              trace.SpanKind
+	startTime             time.Time
+	endTime               time.Time
+	attributes            []attribute.KeyValue
+	events                []Event
+	links                 []Link
+	status                Status
+	childSpanCount        int
+	droppedAttributeCount int
+	droppedEventCount     int
+	droppedLinkCount      int
+	resource              *resource.Resource
+	instrumentationScope  instrumentation.Scope
+}
+
+var _ ReadOnlySpan = snapshot{}
+
+func (s snapshot) private() {}
+
+// Name returns the name of the span.
+func (s snapshot) Name() string {
+	return s.name
+}
+
+// SpanContext returns the unique SpanContext that identifies the span.
+func (s snapshot) SpanContext() trace.SpanContext {
+	return s.spanContext
+}
+
+// Parent returns the unique SpanContext that identifies the parent of the
+// span if one exists. If the span has no parent the returned SpanContext
+// will be invalid.
+func (s snapshot) Parent() trace.SpanContext {
+	return s.parent
+}
+
+// SpanKind returns the role the span plays in a Trace.
+func (s snapshot) SpanKind() trace.SpanKind {
+	return s.spanKind
+}
+
+// StartTime returns the time the span started recording.
+func (s snapshot) StartTime() time.Time {
+	return s.startTime
+}
+
+// EndTime returns the time the span stopped recording. It will be zero if
+// the span has not ended.
+func (s snapshot) EndTime() time.Time {
+	return s.endTime
+}
+
+// Attributes returns the defining attributes of the span.
+func (s snapshot) Attributes() []attribute.KeyValue {
+	return s.attributes
+}
+
+// Links returns all the links the span has to other spans.
+func (s snapshot) Links() []Link {
+	return s.links
+}
+
+// Events returns all the events that occurred within in the spans
+// lifetime.
+func (s snapshot) Events() []Event {
+	return s.events
+}
+
+// Status returns the spans status.
+func (s snapshot) Status() Status {
+	return s.status
+}
+
+// InstrumentationScope returns information about the instrumentation
+// scope that created the span.
+func (s snapshot) InstrumentationScope() instrumentation.Scope {
+	return s.instrumentationScope
+}
+
+// InstrumentationLibrary returns information about the instrumentation
+// library that created the span.
+func (s snapshot) InstrumentationLibrary() instrumentation.Library {
+	return s.instrumentationScope
+}
+
+// Resource returns information about the entity that produced the span.
+func (s snapshot) Resource() *resource.Resource {
+	return s.resource
+}
+
+// DroppedAttributes returns the number of attributes dropped by the span
+// due to limits being reached.
+func (s snapshot) DroppedAttributes() int {
+	return s.droppedAttributeCount
+}
+
+// DroppedLinks returns the number of links dropped by the span due to limits
+// being reached.
+func (s snapshot) DroppedLinks() int {
+	return s.droppedLinkCount
+}
+
+// DroppedEvents returns the number of events dropped by the span due to
+// limits being reached.
+func (s snapshot) DroppedEvents() int {
+	return s.droppedEventCount
+}
+
+// ChildSpanCount returns the count of spans that consider the span a
+// direct parent.
+func (s snapshot) ChildSpanCount() int {
+	return s.childSpanCount
+}

vendor/go.opentelemetry.io/otel/sdk/trace/span.go

+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"runtime"
+	rt "runtime/trace"
+	"sync"
+	"time"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
+	"go.opentelemetry.io/otel/sdk/internal"
+	"go.opentelemetry.io/otel/sdk/resource"
+	semconv "go.opentelemetry.io/otel/semconv/v1.12.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// ReadOnlySpan allows reading information from the data structure underlying a
+// trace.Span. It is used in places where reading information from a span is
+// necessary but changing the span isn't necessary or allowed.
+//
+// Warning: methods may be added to this interface in minor releases.
+type ReadOnlySpan interface {
+	// Name returns the name of the span.
+	Name() string
+	// SpanContext returns the unique SpanContext that identifies the span.
+	SpanContext() trace.SpanContext
+	// Parent returns the unique SpanContext that identifies the parent of the
+	// span if one exists. If the span has no parent the returned SpanContext
+	// will be invalid.
+	Parent() trace.SpanContext
+	// SpanKind returns the role the span plays in a Trace.
+	SpanKind() trace.SpanKind
+	// StartTime returns the time the span started recording.
+	StartTime() time.Time
+	// EndTime returns the time the span stopped recording. It will be zero if
+	// the span has not ended.
+	EndTime() time.Time
+	// Attributes returns the defining attributes of the span.
+	// The order of the returned attributes is not guaranteed to be stable across invocations.
+	Attributes() []attribute.KeyValue
+	// Links returns all the links the span has to other spans.
+	Links() []Link
+	// Events returns all the events that occurred within in the spans
+	// lifetime.
+	Events() []Event
+	// Status returns the spans status.
+	Status() Status
+	// InstrumentationScope returns information about the instrumentation
+	// scope that created the span.
+	InstrumentationScope() instrumentation.Scope
+	// InstrumentationLibrary returns information about the instrumentation
+	// library that created the span.
+	// Deprecated: please use InstrumentationScope instead.
+	InstrumentationLibrary() instrumentation.Library
+	// Resource returns information about the entity that produced the span.
+	Resource() *resource.Resource
+	// DroppedAttributes returns the number of attributes dropped by the span
+	// due to limits being reached.
+	DroppedAttributes() int
+	// DroppedLinks returns the number of links dropped by the span due to
+	// limits being reached.
+	DroppedLinks() int
+	// DroppedEvents returns the number of events dropped by the span due to
+	// limits being reached.
+	DroppedEvents() int
+	// ChildSpanCount returns the count of spans that consider the span a
+	// direct parent.
+	ChildSpanCount() int
+
+	// A private method to prevent users implementing the
+	// interface and so future additions to it will not
+	// violate compatibility.
+	private()
+}
+
+// ReadWriteSpan exposes the same methods as trace.Span and in addition allows
+// reading information from the underlying data structure.
+// This interface exposes the union of the methods of trace.Span (which is a
+// "write-only" span) and ReadOnlySpan. New methods for writing or reading span
+// information should be added under trace.Span or ReadOnlySpan, respectively.
+//
+// Warning: methods may be added to this interface in minor releases.
+type ReadWriteSpan interface {
+	trace.Span
+	ReadOnlySpan
+}
+
+// recordingSpan is an implementation of the OpenTelemetry Span API
+// representing the individual component of a trace that is sampled.
+type recordingSpan struct {
+	// mu protects the contents of this span.
+	mu sync.Mutex
+
+	// parent holds the parent span of this span as a trace.SpanContext.
+	parent trace.SpanContext
+
+	// spanKind represents the kind of this span as a trace.SpanKind.
+	spanKind trace.SpanKind
+
+	// name is the name of this span.
+	name string
+
+	// startTime is the time at which this span was started.
+	startTime time.Time
+
+	// endTime is the time at which this span was ended. It contains the zero
+	// value of time.Time until the span is ended.
+	endTime time.Time
+
+	// status is the status of this span.
+	status Status
+
+	// childSpanCount holds the number of child spans created for this span.
+	childSpanCount int
+
+	// spanContext holds the SpanContext of this span.
+	spanContext trace.SpanContext
+
+	// attributes is a collection of user provided key/values. The collection
+	// is constrained by a configurable maximum held by the parent
+	// TracerProvider. When additional attributes are added after this maximum
+	// is reached these attributes the user is attempting to add are dropped.
+	// This dropped number of attributes is tracked and reported in the
+	// ReadOnlySpan exported when the span ends.
+	attributes        []attribute.KeyValue
+	droppedAttributes int
+
+	// events are stored in FIFO queue capped by configured limit.
+	events evictedQueue
+
+	// links are stored in FIFO queue capped by configured limit.
+	links evictedQueue
+
+	// executionTracerTaskEnd ends the execution tracer span.
+	executionTracerTaskEnd func()
+
+	// tracer is the SDK tracer that created this span.
+	tracer *tracer
+}
+
+var _ ReadWriteSpan = (*recordingSpan)(nil)
+var _ runtimeTracer = (*recordingSpan)(nil)
+
+// SpanContext returns the SpanContext of this span.
+func (s *recordingSpan) SpanContext() trace.SpanContext {
+	if s == nil {
+		return trace.SpanContext{}
+	}
+	return s.spanContext
+}
+
+// IsRecording returns if this span is being recorded. If this span has ended
+// this will return false.
+func (s *recordingSpan) IsRecording() bool {
+	if s == nil {
+		return false
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	return s.endTime.IsZero()
+}
+
+// SetStatus sets the status of the Span in the form of a code and a
+// description, overriding previous values set. The description is only
+// included in the set status when the code is for an error. If this span is
+// not being recorded than this method does nothing.
+func (s *recordingSpan) SetStatus(code codes.Code, description string) {
+	if !s.IsRecording() {
+		return
+	}
+
+	status := Status{Code: code}
+	if code == codes.Error {
+		status.Description = description
+	}
+
+	s.mu.Lock()
+	s.status = status
+	s.mu.Unlock()
+}
+
+// SetAttributes sets attributes of this span.
+//
+// If a key from attributes already exists the value associated with that key
+// will be overwritten with the value contained in attributes.
+//
+// If this span is not being recorded than this method does nothing.
+//
+// If adding attributes to the span would exceed the maximum amount of
+// attributes the span is configured to have, the last added attributes will
+// be dropped.
+func (s *recordingSpan) SetAttributes(attributes ...attribute.KeyValue) {
+	if !s.IsRecording() {
+		return
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	limit := s.tracer.provider.spanLimits.AttributeCountLimit
+	if limit == 0 {
+		// No attributes allowed.
+		s.droppedAttributes += len(attributes)
+		return
+	}
+
+	// If adding these attributes could exceed the capacity of s perform a
+	// de-duplication and truncation while adding to avoid over allocation.
+	if limit > 0 && len(s.attributes)+len(attributes) > limit {
+		s.addOverCapAttrs(limit, attributes)
+		return
+	}
+
+	// Otherwise, add without deduplication. When attributes are read they
+	// will be deduplicated, optimizing the operation.
+	for _, a := range attributes {
+		if !a.Valid() {
+			// Drop all invalid attributes.
+			s.droppedAttributes++
+			continue
+		}
+		a = truncateAttr(s.tracer.provider.spanLimits.AttributeValueLengthLimit, a)
+		s.attributes = append(s.attributes, a)
+	}
+}
+
+// addOverCapAttrs adds the attributes attrs to the span s while
+// de-duplicating the attributes of s and attrs and dropping attributes that
+// exceed the limit.
+//
+// This method assumes s.mu.Lock is held by the caller.
+//
+// This method should only be called when there is a possibility that adding
+// attrs to s will exceed the limit. Otherwise, attrs should be added to s
+// without checking for duplicates and all retrieval methods of the attributes
+// for s will de-duplicate as needed.
+//
+// This method assumes limit is a value > 0. The argument should be validated
+// by the caller.
+func (s *recordingSpan) addOverCapAttrs(limit int, attrs []attribute.KeyValue) {
+	// In order to not allocate more capacity to s.attributes than needed,
+	// prune and truncate this addition of attributes while adding.
+
+	// Do not set a capacity when creating this map. Benchmark testing has
+	// showed this to only add unused memory allocations in general use.
+	exists := make(map[attribute.Key]int)
+	s.dedupeAttrsFromRecord(&exists)
+
+	// Now that s.attributes is deduplicated, adding unique attributes up to
+	// the capacity of s will not over allocate s.attributes.
+	for _, a := range attrs {
+		if !a.Valid() {
+			// Drop all invalid attributes.
+			s.droppedAttributes++
+			continue
+		}
+
+		if idx, ok := exists[a.Key]; ok {
+			// Perform all updates before dropping, even when at capacity.
+			s.attributes[idx] = a
+			continue
+		}
+
+		if len(s.attributes) >= limit {
+			// Do not just drop all of the remaining attributes, make sure
+			// updates are checked and performed.
+			s.droppedAttributes++
+		} else {
+			a = truncateAttr(s.tracer.provider.spanLimits.AttributeValueLengthLimit, a)
+			s.attributes = append(s.attributes, a)
+			exists[a.Key] = len(s.attributes) - 1
+		}
+	}
+}
+
+// truncateAttr returns a truncated version of attr. Only string and string
+// slice attribute values are truncated. String values are truncated to at
+// most a length of limit. Each string slice value is truncated in this fasion
+// (the slice length itself is unaffected).
+//
+// No truncation is perfromed for a negative limit.
+func truncateAttr(limit int, attr attribute.KeyValue) attribute.KeyValue {
+	if limit < 0 {
+		return attr
+	}
+	switch attr.Value.Type() {
+	case attribute.STRING:
+		if v := attr.Value.AsString(); len(v) > limit {
+			return attr.Key.String(v[:limit])
+		}
+	case attribute.STRINGSLICE:
+		// Do no mutate the original, make a copy.
+		trucated := attr.Key.StringSlice(attr.Value.AsStringSlice())
+		// Do not do this.
+		//
+		//   v := trucated.Value.AsStringSlice()
+		//   cp := make([]string, len(v))
+		//   /* Copy and truncate values to cp ... */
+		//   trucated.Value = attribute.StringSliceValue(cp)
+		//
+		// Copying the []string and then assigning it back as a new value with
+		// attribute.StringSliceValue will copy the data twice. Instead, we
+		// already made a copy above that only this function owns, update the
+		// underlying slice data of our copy.
+		v := trucated.Value.AsStringSlice()
+		for i := range v {
+			if len(v[i]) > limit {
+				v[i] = v[i][:limit]
+			}
+		}
+		return trucated
+	}
+	return attr
+}
+
+// End ends the span. This method does nothing if the span is already ended or
+// is not being recorded.
+//
+// The only SpanOption currently supported is WithTimestamp which will set the
+// end time for a Span's life-cycle.
+//
+// If this method is called while panicking an error event is added to the
+// Span before ending it and the panic is continued.
+func (s *recordingSpan) End(options ...trace.SpanEndOption) {
+	// Do not start by checking if the span is being recorded which requires
+	// acquiring a lock. Make a minimal check that the span is not nil.
+	if s == nil {
+		return
+	}
+
+	// Store the end time as soon as possible to avoid artificially increasing
+	// the span's duration in case some operation below takes a while.
+	et := internal.MonotonicEndTime(s.startTime)
+
+	// Do relative expensive check now that we have an end time and see if we
+	// need to do any more processing.
+	if !s.IsRecording() {
+		return
+	}
+
+	config := trace.NewSpanEndConfig(options...)
+	if recovered := recover(); recovered != nil {
+		// Record but don't stop the panic.
+		defer panic(recovered)
+		opts := []trace.EventOption{
+			trace.WithAttributes(
+				semconv.ExceptionTypeKey.String(typeStr(recovered)),
+				semconv.ExceptionMessageKey.String(fmt.Sprint(recovered)),
+			),
+		}
+
+		if config.StackTrace() {
+			opts = append(opts, trace.WithAttributes(
+				semconv.ExceptionStacktraceKey.String(recordStackTrace()),
+			))
+		}
+
+		s.addEvent(semconv.ExceptionEventName, opts...)
+	}
+
+	if s.executionTracerTaskEnd != nil {
+		s.executionTracerTaskEnd()
+	}
+
+	s.mu.Lock()
+	// Setting endTime to non-zero marks the span as ended and not recording.
+	if config.Timestamp().IsZero() {
+		s.endTime = et
+	} else {
+		s.endTime = config.Timestamp()
+	}
+	s.mu.Unlock()
+
+	if sps, ok := s.tracer.provider.spanProcessors.Load().(spanProcessorStates); ok {
+		if len(sps) == 0 {
+			return
+		}
+		snap := s.snapshot()
+		for _, sp := range sps {
+			sp.sp.OnEnd(snap)
+		}
+	}
+}
+
+// RecordError will record err as a span event for this span. An additional call to
+// SetStatus is required if the Status of the Span should be set to Error, this method
+// does not change the Span status. If this span is not being recorded or err is nil
+// than this method does nothing.
+func (s *recordingSpan) RecordError(err error, opts ...trace.EventOption) {
+	if s == nil || err == nil || !s.IsRecording() {
+		return
+	}
+
+	opts = append(opts, trace.WithAttributes(
+		semconv.ExceptionTypeKey.String(typeStr(err)),
+		semconv.ExceptionMessageKey.String(err.Error()),
+	))
+
+	c := trace.NewEventConfig(opts...)
+	if c.StackTrace() {
+		opts = append(opts, trace.WithAttributes(
+			semconv.ExceptionStacktraceKey.String(recordStackTrace()),
+		))
+	}
+
+	s.addEvent(semconv.ExceptionEventName, opts...)
+}
+
+func typeStr(i interface{}) string {
+	t := reflect.TypeOf(i)
+	if t.PkgPath() == "" && t.Name() == "" {
+		// Likely a builtin type.
+		return t.String()
+	}
+	return fmt.Sprintf("%s.%s", t.PkgPath(), t.Name())
+}
+
+func recordStackTrace() string {
+	stackTrace := make([]byte, 2048)
+	n := runtime.Stack(stackTrace, false)
+
+	return string(stackTrace[0:n])
+}
+
+// AddEvent adds an event with the provided name and options. If this span is
+// not being recorded than this method does nothing.
+func (s *recordingSpan) AddEvent(name string, o ...trace.EventOption) {
+	if !s.IsRecording() {
+		return
+	}
+	s.addEvent(name, o...)
+}
+
+func (s *recordingSpan) addEvent(name string, o ...trace.EventOption) {
+	c := trace.NewEventConfig(o...)
+	e := Event{Name: name, Attributes: c.Attributes(), Time: c.Timestamp()}
+
+	// Discard attributes over limit.
+	limit := s.tracer.provider.spanLimits.AttributePerEventCountLimit
+	if limit == 0 {
+		// Drop all attributes.
+		e.DroppedAttributeCount = len(e.Attributes)
+		e.Attributes = nil
+	} else if limit > 0 && len(e.Attributes) > limit {
+		// Drop over capacity.
+		e.DroppedAttributeCount = len(e.Attributes) - limit
+		e.Attributes = e.Attributes[:limit]
+	}
+
+	s.mu.Lock()
+	s.events.add(e)
+	s.mu.Unlock()
+}
+
+// SetName sets the name of this span. If this span is not being recorded than
+// this method does nothing.
+func (s *recordingSpan) SetName(name string) {
+	if !s.IsRecording() {
+		return
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.name = name
+}
+
+// Name returns the name of this span.
+func (s *recordingSpan) Name() string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.name
+}
+
+// Name returns the SpanContext of this span's parent span.
+func (s *recordingSpan) Parent() trace.SpanContext {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.parent
+}
+
+// SpanKind returns the SpanKind of this span.
+func (s *recordingSpan) SpanKind() trace.SpanKind {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.spanKind
+}
+
+// StartTime returns the time this span started.
+func (s *recordingSpan) StartTime() time.Time {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.startTime
+}
+
+// EndTime returns the time this span ended. For spans that have not yet
+// ended, the returned value will be the zero value of time.Time.
+func (s *recordingSpan) EndTime() time.Time {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.endTime
+}
+
+// Attributes returns the attributes of this span.
+//
+// The order of the returned attributes is not guaranteed to be stable.
+func (s *recordingSpan) Attributes() []attribute.KeyValue {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.dedupeAttrs()
+	return s.attributes
+}
+
+// dedupeAttrs deduplicates the attributes of s to fit capacity.
+//
+// This method assumes s.mu.Lock is held by the caller.
+func (s *recordingSpan) dedupeAttrs() {
+	// Do not set a capacity when creating this map. Benchmark testing has
+	// showed this to only add unused memory allocations in general use.
+	exists := make(map[attribute.Key]int)
+	s.dedupeAttrsFromRecord(&exists)
+}
+
+// dedupeAttrsFromRecord deduplicates the attributes of s to fit capacity
+// using record as the record of unique attribute keys to their index.
+//
+// This method assumes s.mu.Lock is held by the caller.
+func (s *recordingSpan) dedupeAttrsFromRecord(record *map[attribute.Key]int) {
+	// Use the fact that slices share the same backing array.
+	unique := s.attributes[:0]
+	for _, a := range s.attributes {
+		if idx, ok := (*record)[a.Key]; ok {
+			unique[idx] = a
+		} else {
+			unique = append(unique, a)
+			(*record)[a.Key] = len(unique) - 1
+		}
+	}
+	// s.attributes have element types of attribute.KeyValue. These types are
+	// not pointers and they themselves do not contain pointer fields,
+	// therefore the duplicate values do not need to be zeroed for them to be
+	// garbage collected.
+	s.attributes = unique
+}
+
+// Links returns the links of this span.
+func (s *recordingSpan) Links() []Link {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if len(s.links.queue) == 0 {
+		return []Link{}
+	}
+	return s.interfaceArrayToLinksArray()
+}
+
+// Events returns the events of this span.
+func (s *recordingSpan) Events() []Event {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if len(s.events.queue) == 0 {
+		return []Event{}
+	}
+	return s.interfaceArrayToEventArray()
+}
+
+// Status returns the status of this span.
+func (s *recordingSpan) Status() Status {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.status
+}
+
+// InstrumentationScope returns the instrumentation.Scope associated with
+// the Tracer that created this span.
+func (s *recordingSpan) InstrumentationScope() instrumentation.Scope {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.tracer.instrumentationScope
+}
+
+// InstrumentationLibrary returns the instrumentation.Library associated with
+// the Tracer that created this span.
+func (s *recordingSpan) InstrumentationLibrary() instrumentation.Library {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.tracer.instrumentationScope
+}
+
+// Resource returns the Resource associated with the Tracer that created this
+// span.
+func (s *recordingSpan) Resource() *resource.Resource {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.tracer.provider.resource
+}
+
+func (s *recordingSpan) addLink(link trace.Link) {
+	if !s.IsRecording() || !link.SpanContext.IsValid() {
+		return
+	}
+
+	l := Link{SpanContext: link.SpanContext, Attributes: link.Attributes}
+
+	// Discard attributes over limit.
+	limit := s.tracer.provider.spanLimits.AttributePerLinkCountLimit
+	if limit == 0 {
+		// Drop all attributes.
+		l.DroppedAttributeCount = len(l.Attributes)
+		l.Attributes = nil
+	} else if limit > 0 && len(l.Attributes) > limit {
+		l.DroppedAttributeCount = len(l.Attributes) - limit
+		l.Attributes = l.Attributes[:limit]
+	}
+
+	s.mu.Lock()
+	s.links.add(l)
+	s.mu.Unlock()
+}
+
+// DroppedAttributes returns the number of attributes dropped by the span
+// due to limits being reached.
+func (s *recordingSpan) DroppedAttributes() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.droppedAttributes
+}
+
+// DroppedLinks returns the number of links dropped by the span due to limits
+// being reached.
+func (s *recordingSpan) DroppedLinks() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.links.droppedCount
+}
+
+// DroppedEvents returns the number of events dropped by the span due to
+// limits being reached.
+func (s *recordingSpan) DroppedEvents() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.events.droppedCount
+}
+
+// ChildSpanCount returns the count of spans that consider the span a
+// direct parent.
+func (s *recordingSpan) ChildSpanCount() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.childSpanCount
+}
+
+// TracerProvider returns a trace.TracerProvider that can be used to generate
+// additional Spans on the same telemetry pipeline as the current Span.
+func (s *recordingSpan) TracerProvider() trace.TracerProvider {
+	return s.tracer.provider
+}
+
+// snapshot creates a read-only copy of the current state of the span.
+func (s *recordingSpan) snapshot() ReadOnlySpan {
+	var sd snapshot
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	sd.endTime = s.endTime
+	sd.instrumentationScope = s.tracer.instrumentationScope
+	sd.name = s.name
+	sd.parent = s.parent
+	sd.resource = s.tracer.provider.resource
+	sd.spanContext = s.spanContext
+	sd.spanKind = s.spanKind
+	sd.startTime = s.startTime
+	sd.status = s.status
+	sd.childSpanCount = s.childSpanCount
+
+	if len(s.attributes) > 0 {
+		s.dedupeAttrs()
+		sd.attributes = s.attributes
+	}
+	sd.droppedAttributeCount = s.droppedAttributes
+	if len(s.events.queue) > 0 {
+		sd.events = s.interfaceArrayToEventArray()
+		sd.droppedEventCount = s.events.droppedCount
+	}
+	if len(s.links.queue) > 0 {
+		sd.links = s.interfaceArrayToLinksArray()
+		sd.droppedLinkCount = s.links.droppedCount
+	}
+	return &sd
+}
+
+func (s *recordingSpan) interfaceArrayToLinksArray() []Link {
+	linkArr := make([]Link, 0)
+	for _, value := range s.links.queue {
+		linkArr = append(linkArr, value.(Link))
+	}
+	return linkArr
+}
+
+func (s *recordingSpan) interfaceArrayToEventArray() []Event {
+	eventArr := make([]Event, 0)
+	for _, value := range s.events.queue {
+		eventArr = append(eventArr, value.(Event))
+	}
+	return eventArr
+}
+
+func (s *recordingSpan) addChild() {
+	if !s.IsRecording() {
+		return
+	}
+	s.mu.Lock()
+	s.childSpanCount++
+	s.mu.Unlock()
+}
+
+func (*recordingSpan) private() {}
+
+// runtimeTrace starts a "runtime/trace".Task for the span and returns a
+// context containing the task.
+func (s *recordingSpan) runtimeTrace(ctx context.Context) context.Context {
+	if !rt.IsEnabled() {
+		// Avoid additional overhead if runtime/trace is not enabled.
+		return ctx
+	}
+	nctx, task := rt.NewTask(ctx, s.name)
+
+	s.mu.Lock()
+	s.executionTracerTaskEnd = task.End
+	s.mu.Unlock()
+
+	return nctx
+}
+
+// nonRecordingSpan is a minimal implementation of the OpenTelemetry Span API
+// that wraps a SpanContext. It performs no operations other than to return
+// the wrapped SpanContext or TracerProvider that created it.
+type nonRecordingSpan struct {
+	// tracer is the SDK tracer that created this span.
+	tracer *tracer
+	sc     trace.SpanContext
+}
+
+var _ trace.Span = nonRecordingSpan{}
+
+// SpanContext returns the wrapped SpanContext.
+func (s nonRecordingSpan) SpanContext() trace.SpanContext { return s.sc }
+
+// IsRecording always returns false.
+func (nonRecordingSpan) IsRecording() bool { return false }
+
+// SetStatus does nothing.
+func (nonRecordingSpan) SetStatus(codes.Code, string) {}
+
+// SetError does nothing.
+func (nonRecordingSpan) SetError(bool) {}
+
+// SetAttributes does nothing.
+func (nonRecordingSpan) SetAttributes(...attribute.KeyValue) {}
+
+// End does nothing.
+func (nonRecordingSpan) End(...trace.SpanEndOption) {}
+
+// RecordError does nothing.
+func (nonRecordingSpan) RecordError(error, ...trace.EventOption) {}
+
+// AddEvent does nothing.
+func (nonRecordingSpan) AddEvent(string, ...trace.EventOption) {}
+
+// SetName does nothing.
+func (nonRecordingSpan) SetName(string) {}
+
+// TracerProvider returns the trace.TracerProvider that provided the Tracer
+// that created this span.
+func (s nonRecordingSpan) TracerProvider() trace.TracerProvider { return s.tracer.provider }
+
+func isRecording(s SamplingResult) bool {
+	return s.Decision == RecordOnly || s.Decision == RecordAndSample
+}
+
+func isSampled(s SamplingResult) bool {
+	return s.Decision == RecordAndSample
+}
+
+// Status is the classified state of a Span.
+type Status struct {
+	// Code is an identifier of a Spans state classification.
+	Code codes.Code
+	// Description is a user hint about why that status was set. It is only
+	// applicable when Code is Error.
+	Description string
+}