Update dependencies (#5518)

vendor/github.com/Masterminds/squirrel/stmtcacher_ctx.go

@@ -0,0 +1,86 @@
+// +build go1.8
+
+package squirrel
+
+import (
+	"context"
+	"database/sql"
+)
+
+// PrepareerContext is the interface that wraps the Prepare and PrepareContext methods.
+//
+// Prepare executes the given query as implemented by database/sql.Prepare.
+// PrepareContext executes the given query as implemented by database/sql.PrepareContext.
+type PreparerContext interface {
+	Preparer
+	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
+}
+
+// DBProxyContext groups the Execer, Queryer, QueryRower and PreparerContext interfaces.
+type DBProxyContext interface {
+	Execer
+	Queryer
+	QueryRower
+	PreparerContext
+}
+
+// NewStmtCache returns a *StmtCache wrapping a PreparerContext that caches Prepared Stmts.
+//
+// Stmts are cached based on the string value of their queries.
+func NewStmtCache(prep PreparerContext) *StmtCache {
+	return &StmtCache{prep: prep, cache: make(map[string]*sql.Stmt)}
+}
+
+// NewStmtCacher is deprecated
+//
+// Use NewStmtCache instead
+func NewStmtCacher(prep PreparerContext) DBProxyContext {
+	return NewStmtCache(prep)
+}
+
+// PrepareContext delegates down to the underlying PreparerContext and caches the result
+// using the provided query as a key
+func (sc *StmtCache) PrepareContext(ctx context.Context, query string) (*sql.Stmt, error) {
+	ctxPrep, ok := sc.prep.(PreparerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+	stmt, ok := sc.cache[query]
+	if ok {
+		return stmt, nil
+	}
+	stmt, err := ctxPrep.PrepareContext(ctx, query)
+	if err == nil {
+		sc.cache[query] = stmt
+	}
+	return stmt, err
+}
+
+// ExecContext delegates down to the underlying PreparerContext using a prepared statement
+func (sc *StmtCache) ExecContext(ctx context.Context, query string, args ...interface{}) (res sql.Result, err error) {
+	stmt, err := sc.PrepareContext(ctx, query)
+	if err != nil {
+		return
+	}
+	return stmt.ExecContext(ctx, args...)
+}
+
+// QueryContext delegates down to the underlying PreparerContext using a prepared statement
+func (sc *StmtCache) QueryContext(ctx context.Context, query string, args ...interface{}) (rows *sql.Rows, err error) {
+	stmt, err := sc.PrepareContext(ctx, query)
+	if err != nil {
+		return
+	}
+	return stmt.QueryContext(ctx, args...)
+}
+
+// QueryRowContext delegates down to the underlying PreparerContext using a prepared statement
+func (sc *StmtCache) QueryRowContext(ctx context.Context, query string, args ...interface{}) RowScanner {
+	stmt, err := sc.PrepareContext(ctx, query)
+	if err != nil {
+		return &Row{err: err}
+	}
+	return stmt.QueryRowContext(ctx, args...)
+}