hopp: Add SetDeadline methods to Conn and Trans

metadapta.go

@@ -1,9 +1,11 @@
 package hopp
 
 import "io"
+import "os"
 import "fmt"
 import "net"
 import "sync"
+import "time"
 import "sync/atomic"
 import "git.tebibyte.media/sashakoshka/go-util/sync"
 
@@ -108,6 +110,10 @@ func (this *a) AcceptTrans() (Trans, error) {
 	}
 }
 
+func (this *a) SetDeadline(t time.Time) error {
+	return this.underlying.SetDeadline(t)
+}
+
 func (this *a) SetSizeLimit(limit int64) {
 	this.sizeLimit = limit
 }
@@ -212,6 +218,10 @@ type transA struct {
 	currentWriter io.Closer
 	writeBuffer   []byte
 	closed        atomic.Bool
+	closeErr      error
+	
+	deadline      *time.Timer
+	deadlineLock  sync.Mutex
 }
 
 func (this *transA) Close() error {
@@ -221,6 +231,11 @@ func (this *transA) Close() error {
 	return err
 }
 
+func (this *transA) closeWithError(err error) error {
+	this.closeErr = err
+	return this.Close()
+}
+
 func (this *transA) closeDontUnlist() (err error) {
 	// MUST be goroutine safe
 	this.incoming.Close()
@@ -269,9 +284,9 @@ func (this *transA) Receive() (method uint16, data []byte, err error) {
 }
 
 func (this *transA) ReceiveReader() (uint16, io.Reader, error) {
-	// if the transaction has been closed, return an io.EOF
-	if this.closed.Load() {
-		return 0, nil, io.EOF
+	// if the transaction has been closed, return an appropriate error.
+	if err := this.errIfClosed(); err != nil {
+		return 0, nil, err
 	}
 
 	// drain previous reader if necessary
@@ -289,6 +304,54 @@ func (this *transA) ReceiveReader() (uint16, io.Reader, error) {
 	return method, reader, nil
 }
 
+func (this *transA) SetDeadline(t time.Time) error {
+	this.deadlineLock.Lock()
+	defer this.deadlineLock.Unlock()
+
+	if t == (time.Time { }) {
+		if this.deadline != nil {
+			this.deadline.Stop()
+		}
+		return nil
+	}
+	
+	until := time.Until(t)
+	if this.deadline == nil {
+		this.deadline.Reset(until)
+		return nil
+	}
+	this.deadline = time.AfterFunc(until, func () {
+		this.closeWithError(os.ErrDeadlineExceeded)
+	})
+	return nil
+}
+
+// TODO
+// func (this *transA) SetReadDeadline(t time.Time) error {
+// 	// TODO
+// }
+// 
+// func (this *transA) SetWriteDeadline(t time.Time) error {
+// 	// TODO
+// }
+
+func (this *transA) errIfClosed() error {
+	if !this.closed.Load() {
+		return nil
+	}
+	return this.bestErr()
+}
+
+func (this *transA) bestErr() error {
+	if this.parent.err != nil {
+		return this.parent.err
+	}
+	if this.closeErr != nil {
+		return this.closeErr
+	}
+	return io.EOF
+}
+
 type readerA struct {
 	parent   *transA
 	leftover []byte
@@ -319,11 +382,7 @@ func (this *readerA) pull() (uint16, error) {
 	// close and return error on failure
 	this.eof = true
 	this.parent.Close()
-	if this.parent.parent.err == nil {
-		return 0, fmt.Errorf("could not receive message: %w", io.EOF)
-	} else {
-		return 0, this.parent.parent.err
-	}
+	return 0, fmt.Errorf("could not receive message: %w", this.parent.bestErr())
 }
 
 func (this *readerA) Read(buffer []byte) (int, error) {