Refactor the multi-host salt install page.

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

diff --git a/services/keepstore/pipe_adapters.go b/services/keepstore/pipe_adapters.go
index 91aa27094bad1a488b24feb444be06f1d0e957ba..6b555054b65ea0ed8f537401d97c7f7765186722 100644 (file)
--- a/services/keepstore/pipe_adapters.go
+++ b/services/keepstore/pipe_adapters.go
@@ -1,19 +1,24 @@
-package main
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
+package keepstore
 
 import (
        "bytes"
        "context"
        "io"
        "io/ioutil"
-       "sync"
 )
 
 // getWithPipe invokes getter and copies the resulting data into
 // buf. If ctx is done before all data is copied, getWithPipe closes
 // the pipe with an error, and returns early with an error.
-func getWithPipe(ctx context.Context, loc string, buf []byte, getter func(context.Context, string, *io.PipeWriter)) (int, error) {
+func getWithPipe(ctx context.Context, loc string, buf []byte, br BlockReader) (int, error) {
        piper, pipew := io.Pipe()
-       go getter(ctx, loc, pipew)
+       go func() {
+               pipew.CloseWithError(br.ReadBlock(ctx, loc, pipew))
+       }()
        done := make(chan struct{})
        var size int
        var err error
@@ -34,30 +39,11 @@ func getWithPipe(ctx context.Context, loc string, buf []byte, getter func(contex
        }
 }
 
-type errorReadCloser struct {
-       *io.PipeReader
-       err error
-       mtx sync.Mutex
-}
-
-func (erc *errorReadCloser) Close() error {
-       erc.mtx.Lock()
-       defer erc.mtx.Unlock()
-       erc.PipeReader.Close()
-       return erc.err
-}
-
-func (erc *errorReadCloser) SetError(err error) {
-       erc.mtx.Lock()
-       defer erc.mtx.Unlock()
-       erc.err = err
-}
-
-// putWithPipe invokes putter with a new pipe, and and copies data
+// putWithPipe invokes putter with a new pipe, and copies data
 // from buf into the pipe. If ctx is done before all data is copied,
 // putWithPipe closes the pipe with an error, and returns early with
 // an error.
-func putWithPipe(ctx context.Context, loc string, buf []byte, putter func(context.Context, string, io.ReadCloser) error) error {
+func putWithPipe(ctx context.Context, loc string, buf []byte, bw BlockWriter) error {
        piper, pipew := io.Pipe()
        copyErr := make(chan error)
        go func() {
@@ -66,13 +52,9 @@ func putWithPipe(ctx context.Context, loc string, buf []byte, putter func(contex
                close(copyErr)
        }()
 
-       erc := errorReadCloser{
-               PipeReader: piper,
-               err:        nil,
-       }
        putErr := make(chan error, 1)
        go func() {
-               putErr <- putter(ctx, loc, &erc)
+               putErr <- bw.WriteBlock(ctx, loc, piper)
                close(putErr)
        }()
 
@@ -86,10 +68,11 @@ func putWithPipe(ctx context.Context, loc string, buf []byte, putter func(contex
 
        // Ensure io.Copy goroutine isn't blocked writing to pipew
        // (otherwise, io.Copy is still using buf so it isn't safe to
-       // return). This can cause pipew to receive corrupt data, so
-       // we first ensure putter() will get an error when calling
-       // erc.Close().
-       erc.SetError(err)
+       // return). This can cause pipew to receive corrupt data if
+       // err came from copyErr or ctx.Done() before the copy
+       // finished. That's OK, though: in that case err != nil, and
+       // CloseWithErr(err) ensures putter() will get an error from
+       // piper.Read() before seeing EOF.
        go pipew.CloseWithError(err)
        go io.Copy(ioutil.Discard, piper)
        <-copyErr