Initial commit

sqlitestore.go

@@ -0,0 +1,160 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"fmt"
+
+	"github.com/gopatchy/metadata"
+	// Register sqlite3 db handler.
+	_ "github.com/mattn/go-sqlite3"
+)
+
+type SQLiteStore struct {
+	db *sql.DB
+}
+
+func NewSQLiteStore(conn string) (*SQLiteStore, error) {
+	db, err := sql.Open("sqlite3", conn)
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: Keep a set of prepared statements with PrepareContext()
+	// TODO: Consider tuning per https://phiresky.github.io/blog/2020/sqlite-performance-tuning/
+
+	return &SQLiteStore{
+		db: db,
+	}, nil
+}
+
+func (sls *SQLiteStore) Close() {
+	sls.db.Close()
+}
+
+func (sls *SQLiteStore) Write(ctx context.Context, t string, obj any) error {
+	id := metadata.GetMetadata(obj).ID
+
+	js, err := json.Marshal(obj)
+	if err != nil {
+		return err
+	}
+
+	err = sls.exec(ctx, "INSERT INTO `%s` (id, obj) VALUES (?,?) ON CONFLICT(id) DO UPDATE SET obj=?;", t, id, js, js)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (sls *SQLiteStore) Delete(ctx context.Context, t, id string) error {
+	err := sls.exec(ctx, "DELETE FROM `%s` WHERE id=?", t, id)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (sls *SQLiteStore) Read(ctx context.Context, t, id string, factory func() any) (any, error) {
+	rows, err := sls.query(ctx, "SELECT obj FROM `%s` WHERE id=?;", t, id)
+	if err != nil {
+		return nil, err
+	}
+
+	defer rows.Close()
+
+	if !rows.Next() {
+		return nil, nil
+	}
+
+	var js []byte
+
+	err = rows.Scan(&js)
+	if err != nil {
+		return nil, err
+	}
+
+	obj := factory()
+
+	err = json.Unmarshal(js, obj)
+	if err != nil {
+		return nil, err
+	}
+
+	return obj, nil
+}
+
+func (sls *SQLiteStore) List(ctx context.Context, t string, factory func() any) ([]any, error) {
+	rows, err := sls.query(ctx, "SELECT obj FROM `%s`;", t)
+	if err != nil {
+		return nil, err
+	}
+
+	defer rows.Close()
+
+	ret := []any{}
+
+	for rows.Next() {
+		var js []byte
+
+		err = rows.Scan(&js)
+		if err != nil {
+			return nil, err
+		}
+
+		obj := factory()
+
+		err = json.Unmarshal(js, obj)
+		if err != nil {
+			return nil, err
+		}
+
+		ret = append(ret, obj)
+	}
+
+	return ret, nil
+}
+
+func (sls *SQLiteStore) exec(ctx context.Context, query, t string, args ...any) error {
+	query = fmt.Sprintf(query, t)
+
+	_, err := sls.db.ExecContext(ctx, query, args...)
+	if err == nil {
+		return nil
+	}
+
+	_, err = sls.db.ExecContext(ctx, sls.tableSQL(t))
+	if err != nil {
+		return err
+	}
+
+	_, err = sls.db.ExecContext(ctx, query, args...)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (sls *SQLiteStore) query(ctx context.Context, query, t string, args ...any) (*sql.Rows, error) {
+	query = fmt.Sprintf(query, t)
+
+	rows, err := sls.db.QueryContext(ctx, query, args...)
+	if err == nil {
+		return rows, nil
+	}
+
+	_, err = sls.db.ExecContext(ctx, sls.tableSQL(t))
+	if err != nil {
+		return nil, err
+	}
+
+	return sls.db.QueryContext(ctx, query, args...)
+}
+
+func (sls *SQLiteStore) tableSQL(t string) string {
+	return fmt.Sprintf("CREATE TABLE IF NOT EXISTS `%s` (id TEXT NOT NULL PRIMARY KEY, obj TEXT NOT NULL);", t)
+}