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[golang] rewrite database handling

This commit is contained in:
Julien Dessaux 2025-02-12 20:20:02 +01:00
parent db07815736
commit 5611f5b468
Signed by: adyxax
GPG key ID: F92E51B86E07177E
3 changed files with 134 additions and 54 deletions

View file

@ -26,7 +26,10 @@ func main() {
ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
defer cancel()
db, err := database.DBInit(ctx, "./spacetraders.db")
db, err := database.NewDB(
ctx,
"./spacetraders.db?_txlock=immediate",
)
if err != nil {
fmt.Fprintf(os.Stderr, "DbInit error %+v\n", err)
os.Exit(1)

View file

@ -3,17 +3,123 @@ package database
import (
"context"
"database/sql"
"fmt"
"runtime"
)
func initDB(ctx context.Context, url string) (*sql.DB, error) {
db, err := sql.Open("sqlite3", url)
if err != nil {
return nil, fmt.Errorf("failed to open database: %w", err)
}
defer func() {
if err != nil {
_ = db.Close()
}
}()
if _, err = db.ExecContext(ctx, "PRAGMA busy_timeout = 5000"); err != nil {
return nil, fmt.Errorf("failed to set pragma: %w", err)
}
return db, nil
}
type DB struct {
ctx context.Context
db *sql.DB
ctx context.Context
readDB *sql.DB
writeDB *sql.DB
}
func NewDB(ctx context.Context, url string) (*DB, error) {
readDB, err := initDB(ctx, url)
if err != nil {
return nil, fmt.Errorf("failed to init read database connection: %w", err)
}
defer func() {
if err != nil {
_ = readDB.Close()
}
}()
readDB.SetMaxOpenConns(max(4, runtime.NumCPU()))
writeDB, err := initDB(ctx, url)
if err != nil {
return nil, fmt.Errorf("failed to init write database connection: %w", err)
}
defer func() {
if err != nil {
_ = writeDB.Close()
}
}()
writeDB.SetMaxOpenConns(1)
db := DB{
ctx: ctx,
readDB: readDB,
writeDB: writeDB,
}
pragmas := []struct {
key string
value string
}{
{"foreign_keys", "ON"},
{"cache_size", "10000000"},
{"journal_mode", "WAL"},
{"synchronous", "NORMAL"},
}
for _, pragma := range pragmas {
if _, err = db.Exec(fmt.Sprintf("PRAGMA %s = %s", pragma.key, pragma.value)); err != nil {
return nil, fmt.Errorf("failed to set pragma: %w", err)
}
}
if err = db.migrate(); err != nil {
return nil, fmt.Errorf("failed to migrate: %w", err)
}
return &db, nil
}
func (db *DB) Close() error {
if err := db.readDB.Close(); err != nil {
_ = db.writeDB.Close()
return fmt.Errorf("failed to close read database connection: %w", err)
}
if err := db.writeDB.Close(); err != nil {
return fmt.Errorf("failed to close write database connection: %w", err)
}
return nil
}
func (db *DB) Exec(query string, args ...any) (sql.Result, error) {
return db.db.ExecContext(db.ctx, query, args...)
return db.writeDB.ExecContext(db.ctx, query, args...)
}
func (db *DB) Query(query string, args ...any) (*sql.Rows, error) {
return db.readDB.QueryContext(db.ctx, query, args...)
}
func (db *DB) QueryRow(query string, args ...any) *sql.Row {
return db.db.QueryRowContext(db.ctx, query, args...)
return db.readDB.QueryRowContext(db.ctx, query, args...)
}
func (db *DB) WithTransaction(f func(tx *sql.Tx) error) error {
tx, err := db.writeDB.Begin()
if err != nil {
return fmt.Errorf("failed to begin transaction: %w", err)
}
defer func() {
if err != nil {
if err2 := tx.Rollback(); err2 != nil {
panic(fmt.Sprintf("failed to rollback transaction: %+v. Reason for rollback: %+v", err2, err))
}
}
}()
if err = f(tx); err != nil {
return fmt.Errorf("failed to execute function inside transaction: %w", err)
} else {
if err = tx.Commit(); err != nil {
err = fmt.Errorf("failed to commit transaction: %w", err)
}
}
return err
}

View file

@ -1,7 +1,6 @@
package database
import (
"context"
"database/sql"
"embed"
"io/fs"
@ -12,35 +11,9 @@ import (
//go:embed sql/*.sql
var schemaFiles embed.FS
func DBInit(ctx context.Context, url string) (myDB *DB, err error) {
var db *sql.DB
if db, err = sql.Open("sqlite3", url); err != nil {
return nil, err
}
defer func() {
if err != nil {
_ = db.Close()
}
}()
if _, err = db.ExecContext(ctx, "PRAGMA foreign_keys = ON"); err != nil {
return nil, err
}
if _, err = db.ExecContext(ctx, "PRAGMA journal_mode = WAL"); err != nil {
return nil, err
}
var version int
if err = db.QueryRowContext(ctx, `SELECT version FROM schema_version;`).Scan(&version); err != nil {
if err.Error() == "no such table: schema_version" {
version = 0
} else {
return nil, err
}
}
func (db *DB) migrate() error {
statements := make([]string, 0)
err = fs.WalkDir(schemaFiles, ".", func(path string, d fs.DirEntry, err error) error {
err := fs.WalkDir(schemaFiles, ".", func(path string, d fs.DirEntry, err error) error {
if d.IsDir() || err != nil {
return err
}
@ -53,28 +26,26 @@ func DBInit(ctx context.Context, url string) (myDB *DB, err error) {
return nil
})
if err != nil {
return nil, err
return err
}
tx, err := db.Begin()
if err != nil {
return nil, err
}
for version < len(statements) {
if _, err = tx.ExecContext(ctx, statements[version]); err != nil {
tx.Rollback()
return nil, err
return db.WithTransaction(func(tx *sql.Tx) error {
var version int
if err = tx.QueryRowContext(db.ctx, `SELECT version FROM schema_version;`).Scan(&version); err != nil {
if err.Error() == "no such table: schema_version" {
version = 0
} else {
return err
}
}
version++
}
if _, err = tx.ExecContext(ctx, `DELETE FROM schema_version; INSERT INTO schema_version (version) VALUES (?);`, version); err != nil {
tx.Rollback()
return nil, err
}
tx.Commit()
return &DB{ctx: ctx, db: db}, nil
}
func (db *DB) Close() error {
return db.db.Close()
for version < len(statements) {
if _, err = tx.ExecContext(db.ctx, statements[version]); err != nil {
return err
}
version++
}
_, err = tx.ExecContext(db.ctx, `DELETE FROM schema_version; INSERT INTO schema_version (version) VALUES (?);`, version)
return err
})
}