diff options
Diffstat (limited to '')
-rw-r--r-- | dependencies/pkg/mod/github.com/lib/pq@v1.10.7/conn_go18.go | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/github.com/lib/pq@v1.10.7/conn_go18.go b/dependencies/pkg/mod/github.com/lib/pq@v1.10.7/conn_go18.go new file mode 100644 index 0000000..63d4ca6 --- /dev/null +++ b/dependencies/pkg/mod/github.com/lib/pq@v1.10.7/conn_go18.go @@ -0,0 +1,247 @@ +package pq + +import ( + "context" + "database/sql" + "database/sql/driver" + "fmt" + "io" + "io/ioutil" + "time" +) + +const ( + watchCancelDialContextTimeout = time.Second * 10 +) + +// 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 "ConnPrepareContext" interface +func (cn *conn) PrepareContext(ctx context.Context, query string) (driver.Stmt, error) { + if finish := cn.watchCancel(ctx); finish != nil { + defer finish() + } + return cn.Prepare(query) +} + +// 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) Ping(ctx context.Context) error { + if finish := cn.watchCancel(ctx); finish != nil { + defer finish() + } + rows, err := cn.simpleQuery(";") + if err != nil { + return driver.ErrBadConn // https://golang.org/pkg/database/sql/driver/#Pinger + } + rows.Close() + return nil +} + +func (cn *conn) watchCancel(ctx context.Context) func() { + if done := ctx.Done(); done != nil { + finished := make(chan struct{}, 1) + go func() { + select { + case <-done: + select { + case finished <- struct{}{}: + default: + // We raced with the finish func, let the next query handle this with the + // context. + return + } + + // Set the connection state to bad so it does not get reused. + cn.err.set(ctx.Err()) + + // At this point the function level context is canceled, + // so it must not be used for the additional network + // request to cancel the query. + // Create a new context to pass into the dial. + ctxCancel, cancel := context.WithTimeout(context.Background(), watchCancelDialContextTimeout) + defer cancel() + + _ = cn.cancel(ctxCancel) + case <-finished: + } + }() + return func() { + select { + case <-finished: + cn.err.set(ctx.Err()) + cn.Close() + case finished <- struct{}{}: + } + } + } + return nil +} + +func (cn *conn) cancel(ctx context.Context) error { + // Create a new values map (copy). This makes sure the connection created + // in this method cannot write to the same underlying data, which could + // cause a concurrent map write panic. This is necessary because cancel + // is called from a goroutine in watchCancel. + o := make(values) + for k, v := range cn.opts { + o[k] = v + } + + c, err := dial(ctx, cn.dialer, o) + if err != nil { + return err + } + defer c.Close() + + { + can := conn{ + c: c, + } + err = can.ssl(o) + if err != nil { + return err + } + + 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 + } +} + +// Implement the "StmtQueryContext" interface +func (st *stmt) QueryContext(ctx context.Context, args []driver.NamedValue) (driver.Rows, error) { + list := make([]driver.Value, len(args)) + for i, nv := range args { + list[i] = nv.Value + } + finish := st.watchCancel(ctx) + r, err := st.query(list) + if err != nil { + if finish != nil { + finish() + } + return nil, err + } + r.finish = finish + return r, nil +} + +// Implement the "StmtExecContext" interface +func (st *stmt) ExecContext(ctx context.Context, args []driver.NamedValue) (driver.Result, error) { + list := make([]driver.Value, len(args)) + for i, nv := range args { + list[i] = nv.Value + } + + if finish := st.watchCancel(ctx); finish != nil { + defer finish() + } + + return st.Exec(list) +} + +// watchCancel is implemented on stmt in order to not mark the parent conn as bad +func (st *stmt) watchCancel(ctx context.Context) func() { + if done := ctx.Done(); done != nil { + finished := make(chan struct{}) + go func() { + select { + case <-done: + // At this point the function level context is canceled, + // so it must not be used for the additional network + // request to cancel the query. + // Create a new context to pass into the dial. + ctxCancel, cancel := context.WithTimeout(context.Background(), watchCancelDialContextTimeout) + defer cancel() + + _ = st.cancel(ctxCancel) + finished <- struct{}{} + case <-finished: + } + }() + return func() { + select { + case <-finished: + case finished <- struct{}{}: + } + } + } + return nil +} + +func (st *stmt) cancel(ctx context.Context) error { + return st.cn.cancel(ctx) +} |