diff options
Diffstat (limited to 'vendor/github.com/lib/pq/conn_go18.go')
-rw-r--r-- | vendor/github.com/lib/pq/conn_go18.go | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/vendor/github.com/lib/pq/conn_go18.go b/vendor/github.com/lib/pq/conn_go18.go new file mode 100644 index 0000000..ab97a10 --- /dev/null +++ b/vendor/github.com/lib/pq/conn_go18.go @@ -0,0 +1,128 @@ +// +build go1.8 + +package pq + +import ( + "context" + "database/sql" + "database/sql/driver" + "fmt" + "io" + "io/ioutil" +) + +// Implement the "QueryerContext" interface +func (cn *conn) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) { + list := make([]driver.Value, len(args)) + for i, nv := range args { + list[i] = nv.Value + } + finish := cn.watchCancel(ctx) + r, err := cn.query(query, list) + if err != nil { + if finish != nil { + finish() + } + return nil, err + } + r.finish = finish + return r, nil +} + +// Implement the "ExecerContext" interface +func (cn *conn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) { + list := make([]driver.Value, len(args)) + for i, nv := range args { + list[i] = nv.Value + } + + if finish := cn.watchCancel(ctx); finish != nil { + defer finish() + } + + return cn.Exec(query, list) +} + +// Implement the "ConnBeginTx" interface +func (cn *conn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) { + var mode string + + switch sql.IsolationLevel(opts.Isolation) { + case sql.LevelDefault: + // Don't touch mode: use the server's default + case sql.LevelReadUncommitted: + mode = " ISOLATION LEVEL READ UNCOMMITTED" + case sql.LevelReadCommitted: + mode = " ISOLATION LEVEL READ COMMITTED" + case sql.LevelRepeatableRead: + mode = " ISOLATION LEVEL REPEATABLE READ" + case sql.LevelSerializable: + mode = " ISOLATION LEVEL SERIALIZABLE" + default: + return nil, fmt.Errorf("pq: isolation level not supported: %d", opts.Isolation) + } + + if opts.ReadOnly { + mode += " READ ONLY" + } else { + mode += " READ WRITE" + } + + tx, err := cn.begin(mode) + if err != nil { + return nil, err + } + cn.txnFinish = cn.watchCancel(ctx) + return tx, nil +} + +func (cn *conn) watchCancel(ctx context.Context) func() { + if done := ctx.Done(); done != nil { + finished := make(chan struct{}) + go func() { + select { + case <-done: + _ = cn.cancel() + finished <- struct{}{} + case <-finished: + } + }() + return func() { + select { + case <-finished: + case finished <- struct{}{}: + } + } + } + return nil +} + +func (cn *conn) cancel() error { + c, err := dial(cn.dialer, cn.opts) + if err != nil { + return err + } + defer c.Close() + + { + can := conn{ + c: c, + } + can.ssl(cn.opts) + + w := can.writeBuf(0) + w.int32(80877102) // cancel request code + w.int32(cn.processID) + w.int32(cn.secretKey) + + if err := can.sendStartupPacket(w); err != nil { + return err + } + } + + // Read until EOF to ensure that the server received the cancel. + { + _, err := io.Copy(ioutil.Discard, c) + return err + } +} |