Do not unnecessarily prepare SQL statements

db/sqlite/driver.go

@@ -8,26 +8,8 @@ import (
 	ippb "git.autistici.org/ai3/tools/iprep/proto"
 )
 
-var statements = map[string]string{
-	"insert_event": `
-INSERT INTO events (ip, event_type, count, timestamp) VALUES (?, ?, ?, ?)
-`,
-	"scan_by_ip": `
-SELECT
-  event_type, SUM(count) AS sum
-FROM
-  events
-WHERE
-  ip = ?
-  AND timestamp > ?
-GROUP BY
-  event_type
-`,
-}
-
 type DB struct {
 	db *sql.DB
-	stmts StatementMap
 }
 
 func Open(path string) (*DB, error) {
@@ -40,15 +22,8 @@ func Open(path string) (*DB, error) {
 		return nil, err
 	}
 
-	stmts, err := NewStatementMap(db, statements)
-	if err != nil {
-		db.Close()
-		return nil, err
-	}
-
 	return &DB{
 		db: db,
-		stmts: stmts,
 	}, nil
 }
 
@@ -61,7 +36,14 @@ func (db *DB) AddAggregate(aggr *ippb.Aggregate) error {
 	if err != nil {
 		return err
 	}
-	stmt := db.stmts.Get(tx, "insert_event")
+
+	stmt, err := tx.Prepare(
+		"INSERT INTO events (ip, event_type, count, timestamp) VALUES (?, ?, ?, ?)")
+	if err != nil {
+		tx.Rollback()
+		return err
+	}
+
 	now := time.Now()
 
 	for _, bt := range aggr.ByType {
@@ -90,7 +72,11 @@ func (db *DB) ScanIP(startTime time.Time, ip string) (map[string]int64, error) {
 	}
 	defer tx.Rollback() // nolint
 
-	rows, err := db.stmts.Get(tx, "scan_by_ip").Query(ip, startTime)
+	rows, err := tx.Query(
+		`SELECT event_type, SUM(count) AS sum FROM events
+                 WHERE ip = ? AND timestamp > ?
+                 GROUP BY event_type`,
+		ip, startTime)
 	if err != nil {
 		return nil, err
 	}

db/sqlite/sql.go

@@ -3,7 +3,6 @@ package sqlite
 
 import (
 	"database/sql"
-	"fmt"
 	"log"
 
 	migrate "github.com/golang-migrate/migrate/v4"
@@ -71,33 +70,3 @@ func runDatabaseMigrations(db *sql.DB) error {
 	}
 	return nil
 }
-
-// A StatementMap holds named compiled statements.
-type StatementMap map[string]*sql.Stmt
-
-// NewStatementMap compiles the given named statements and returns a
-// new StatementMap.
-func NewStatementMap(db *sql.DB, statements map[string]string) (StatementMap, error) {
-	stmts := make(map[string]*sql.Stmt)
-	for name, qstr := range statements {
-		stmt, err := db.Prepare(qstr)
-		if err != nil {
-			return nil, fmt.Errorf("error compiling statement '%s': %v", name, err)
-		}
-		stmts[name] = stmt
-	}
-	return StatementMap(stmts), nil
-}
-
-// Close all resources associated with the StatementMap.
-func (m StatementMap) Close() {
-	for _, s := range m {
-		s.Close() // nolint
-	}
-}
-
-// Get a named compiled statement (or nil if not found), and associate
-// it with the given transaction.
-func (m StatementMap) Get(tx *sql.Tx, name string) *sql.Stmt {
-	return tx.Stmt(m[name])
-}