87 lines
2.5 KiB
Go
87 lines
2.5 KiB
Go
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// +build go1.8
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package squirrel
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import (
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"context"
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"database/sql"
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)
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// PrepareerContext is the interface that wraps the Prepare and PrepareContext methods.
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//
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// Prepare executes the given query as implemented by database/sql.Prepare.
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// PrepareContext executes the given query as implemented by database/sql.PrepareContext.
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type PreparerContext interface {
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Preparer
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PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
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}
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// DBProxyContext groups the Execer, Queryer, QueryRower and PreparerContext interfaces.
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type DBProxyContext interface {
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Execer
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Queryer
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QueryRower
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PreparerContext
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}
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// NewStmtCache returns a *StmtCache wrapping a PreparerContext that caches Prepared Stmts.
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//
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// Stmts are cached based on the string value of their queries.
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func NewStmtCache(prep PreparerContext) *StmtCache {
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return &StmtCache{prep: prep, cache: make(map[string]*sql.Stmt)}
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}
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// NewStmtCacher is deprecated
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//
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// Use NewStmtCache instead
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func NewStmtCacher(prep PreparerContext) DBProxyContext {
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return NewStmtCache(prep)
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}
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// PrepareContext delegates down to the underlying PreparerContext and caches the result
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// using the provided query as a key
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func (sc *StmtCache) PrepareContext(ctx context.Context, query string) (*sql.Stmt, error) {
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ctxPrep, ok := sc.prep.(PreparerContext)
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if !ok {
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return nil, NoContextSupport
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}
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sc.mu.Lock()
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defer sc.mu.Unlock()
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stmt, ok := sc.cache[query]
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if ok {
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return stmt, nil
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}
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stmt, err := ctxPrep.PrepareContext(ctx, query)
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if err == nil {
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sc.cache[query] = stmt
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}
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return stmt, err
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}
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// ExecContext delegates down to the underlying PreparerContext using a prepared statement
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func (sc *StmtCache) ExecContext(ctx context.Context, query string, args ...interface{}) (res sql.Result, err error) {
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stmt, err := sc.PrepareContext(ctx, query)
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if err != nil {
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return
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}
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return stmt.ExecContext(ctx, args...)
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}
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// QueryContext delegates down to the underlying PreparerContext using a prepared statement
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func (sc *StmtCache) QueryContext(ctx context.Context, query string, args ...interface{}) (rows *sql.Rows, err error) {
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stmt, err := sc.PrepareContext(ctx, query)
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if err != nil {
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return
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}
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return stmt.QueryContext(ctx, args...)
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}
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// QueryRowContext delegates down to the underlying PreparerContext using a prepared statement
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func (sc *StmtCache) QueryRowContext(ctx context.Context, query string, args ...interface{}) RowScanner {
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stmt, err := sc.PrepareContext(ctx, query)
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if err != nil {
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return &Row{err: err}
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}
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return stmt.QueryRowContext(ctx, args...)
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}
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