14199: Rename (*remoteResponseCacher)Flush -> Close.

Finalizing the caching writer is more like Close: it can only happen
once, and only after all Writes are done.  Flush means something
different, especially in http.ResponseWriter context.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tclegg@veritasgenetics.com>

diff --git a/services/keepstore/proxy_remote.go b/services/keepstore/proxy_remote.go
index 4b5c1cc7ede9a1744c3c6ec9468e873ac22d6734..66bfce16e2b4578893419508513d72e836f090d4 100644 (file)
--- a/services/keepstore/proxy_remote.go
+++ b/services/keepstore/proxy_remote.go
@@ -48,8 +48,9 @@ func (rp *remoteProxy) Get(ctx context.Context, w http.ResponseWriter, r *http.R
                        Token:          token,
                        Buffer:         buf[:0],
                        ResponseWriter: w,
+                       Context:        ctx,
                }
-               defer rrc.Flush(ctx)
+               defer rrc.Close()
                w = rrc
        }
        var remoteClient *keepclient.KeepClient
@@ -147,6 +148,7 @@ type remoteResponseCacher struct {
        Locator string
        Token   string
        Buffer  []byte
+       Context context.Context
        http.ResponseWriter
        statusCode int
 }
@@ -163,35 +165,37 @@ func (rrc *remoteResponseCacher) WriteHeader(statusCode int) {
        rrc.statusCode = statusCode
 }
 
-func (rrc *remoteResponseCacher) Flush(ctx context.Context) {
+func (rrc *remoteResponseCacher) Close() error {
        if rrc.statusCode == 0 {
                rrc.statusCode = http.StatusOK
        } else if rrc.statusCode != http.StatusOK {
                rrc.ResponseWriter.WriteHeader(rrc.statusCode)
                rrc.ResponseWriter.Write(rrc.Buffer)
-               return
+               return nil
        }
-       _, err := PutBlock(ctx, rrc.Buffer, rrc.Locator[:32])
+       _, err := PutBlock(rrc.Context, rrc.Buffer, rrc.Locator[:32])
        if err == RequestHashError {
                http.Error(rrc.ResponseWriter, "checksum mismatch in remote response", http.StatusBadGateway)
-               return
+               return err
        }
        if err, ok := err.(*KeepError); ok {
                http.Error(rrc.ResponseWriter, err.Error(), err.HTTPCode)
-               return
+               return err
        }
        if err != nil {
                http.Error(rrc.ResponseWriter, err.Error(), http.StatusBadGateway)
-               return
+               return err
        }
 
        unsigned := localOrRemoteSignature.ReplaceAllLiteralString(rrc.Locator, "")
        signed := SignLocator(unsigned, rrc.Token, time.Now().Add(theConfig.BlobSignatureTTL.Duration()))
        if signed == unsigned {
-               http.Error(rrc.ResponseWriter, "could not sign locator", http.StatusInternalServerError)
-               return
+               err = errors.New("could not sign locator")
+               http.Error(rrc.ResponseWriter, err.Error(), http.StatusInternalServerError)
+               return err
        }
        rrc.Header().Set("X-Keep-Locator", signed)
        rrc.ResponseWriter.WriteHeader(rrc.statusCode)
-       rrc.ResponseWriter.Write(rrc.Buffer)
+       _, err = rrc.ResponseWriter.Write(rrc.Buffer)
+       return err
 }