package database
import (
"context"
"database/sql"
"fmt"
"github.com/ZanzyTHEbar/mcp-memory-libsql-go/internal/metrics"
)
// getPreparedStmt returns or prepares and caches a statement for the given project DB
func (dm *DBManager) getPreparedStmt(ctx context.Context, projectName string, db *sql.DB, sqlText string) (*sql.Stmt, error) {
// fast path read
dm.stmtMu.RLock()
if projCache, ok := dm.stmtCache[projectName]; ok {
if stmt, ok2 := projCache[sqlText]; ok2 {
dm.stmtMu.RUnlock()
metrics.Default().IncStmtCacheHit("prepare")
return stmt, nil
}
}
dm.stmtMu.RUnlock()
metrics.Default().IncStmtCacheMiss("prepare")
// prepare and store
stmt, err := db.PrepareContext(ctx, sqlText)
if err != nil {
return nil, fmt.Errorf("failed to prepare statement: %w", err)
}
dm.stmtMu.Lock()
if _, ok := dm.stmtCache[projectName]; !ok {
dm.stmtCache[projectName] = make(map[string]*sql.Stmt)
}
dm.stmtCache[projectName][sqlText] = stmt
dm.stmtMu.Unlock()
return stmt, nil
}
