state;apiserver: Fix a race - lp bug #1067979

worker/uniter/uniter_test.go

 // Copyright 2012, 2013 Canonical Ltd.
 // Licensed under the AGPLv3, see LICENCE file for details.
 
 package uniter_test
 
 import (
         "bytes"
-        "crypto/sha256"
-        "encoding/hex"
         "fmt"
-        "io"
         "io/ioutil"
         "net/rpc"
         "net/url"
         "os"
         "os/exec"
         "path/filepath"
         "strconv"
         "strings"
         stdtesting "testing"
         "time"
@@ skipping 1170 matching lines @@
 type addCharm struct {
         dir  *charm.Dir
         curl *charm.URL
 }
 
 func (s addCharm) step(c *gc.C, ctx *context) {
         var buf bytes.Buffer
         err := s.dir.BundleTo(&buf)
         c.Assert(err, gc.IsNil)
         body := buf.Bytes()
-        hasher := sha256.New()
-        _, err = io.Copy(hasher, &buf)
+        hash, _, err := utils.ReadSHA256(&buf)
         c.Assert(err, gc.IsNil)
-        hash := hex.EncodeToString(hasher.Sum(nil))
         key := fmt.Sprintf("/charms/%s/%d", s.dir.Meta().Name, s.dir.Revision())
         hurl, err := url.Parse(coretesting.Server.URL + key)
         c.Assert(err, gc.IsNil)
         ctx.charms[key] = coretesting.Response{200, nil, body}
         ctx.sch, err = ctx.st.AddCharm(s.dir, s.curl, hurl, hash)
         c.Assert(err, gc.IsNil)
 }
 
 type serveCharm struct{}
 
@@ skipping 843 matching lines @@
 type verifyNoFile struct {
         filename string
 }
 
 func (verify verifyNoFile) step(c *gc.C, ctx *context) {
         c.Assert(verify.filename, jc.DoesNotExist)
         // Wait a short time and check again.
         time.Sleep(coretesting.ShortWait)
         c.Assert(verify.filename, jc.DoesNotExist)
 }