20455: Use noopener everywhere on links and window.open

[arvados.git] / services / keepstore / streamwriterat.go

diff --git a/services/keepstore/streamwriterat.go b/services/keepstore/streamwriterat.go
index 365b55f233febb040f8faeb969fd0d257c804860..02dce6e216103b0976cc23d19ecaadfe2039c989 100644 (file)
--- a/services/keepstore/streamwriterat.go
+++ b/services/keepstore/streamwriterat.go
@@ -19,10 +19,16 @@ import (
 // streamWriterAt writes the data to the provided io.Writer in
 // sequential order.
 //
+// streamWriterAt can also be wrapped with an io.OffsetWriter to
+// provide an asynchronous buffer: the caller can use the io.Writer
+// interface to write into a memory buffer and return without waiting
+// for the wrapped writer to catch up.
+//
 // Close returns when all data has been written through.
 type streamWriterAt struct {
        writer     io.Writer
        buf        []byte
+       writepos   int         // target offset if Write is called
        partsize   int         // size of each part written through to writer
        endpos     int         // portion of buf actually used, judging by WriteAt calls so far
        partfilled []int       // number of bytes written to each part so far
@@ -81,7 +87,7 @@ func (swa *streamWriterAt) writeToWriter() {
        }
 }
 
-// WriteAt implements io.WriterAt.
+// WriteAt implements io.WriterAt. WriteAt is goroutine-safe.
 func (swa *streamWriterAt) WriteAt(p []byte, offset int64) (int, error) {
        pos := int(offset)
        n := 0