[NaCl SDK] Used cached size when calling MountNodeHttp::GetSize.

Without this change, every call to seek will perform 2 HEAD requests.

BUG=none
R=sbc@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/12070007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@179702 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 7 insertions, 10 deletions

diff --git a/native_client_sdk/src/libraries/nacl_mounts/kernel_handle.cc b/native_client_sdk/src/libraries/nacl_mounts/kernel_handle.cc
index 5103542..f1f2600 100644
--- a/native_client_sdk/src/libraries/nacl_mounts/kernel_handle.cc
+++ b/native_client_sdk/src/libraries/nacl_mounts/kernel_handle.cc
@@ -27,12 +27,13 @@ KernelHandle::KernelHandle(Mount* mnt, MountNode* node, int mode)
 
 off_t KernelHandle::Seek(off_t offset, int whence) {
   size_t base;
+  size_t node_size = node_->GetSize();
 
   switch (whence) {
     default: return -1;
     case SEEK_SET: base = 0; break;
     case SEEK_CUR: base = offs_; break;
-    case SEEK_END: base = node_->GetSize(); break;
+    case SEEK_END: base = node_size; break;
   }
 
   if (base + offset < 0) {
@@ -44,7 +45,7 @@ off_t KernelHandle::Seek(off_t offset, int whence) {
 
   // Seeking past the end of the file will zero out the space between the old
   // end and the new end.
-  if (offs_ > node_->GetSize()) {
+  if (offs_ > node_size) {
     if (node_->Truncate(offs_) < 0) {
       errno = EINVAL;
       return -1;
diff --git a/native_client_sdk/src/libraries/nacl_mounts/mount_http.cc b/native_client_sdk/src/libraries/nacl_mounts/mount_http.cc
index bd5fc40..f269a41 100644
--- a/native_client_sdk/src/libraries/nacl_mounts/mount_http.cc
+++ b/native_client_sdk/src/libraries/nacl_mounts/mount_http.cc
@@ -328,19 +328,15 @@ int MountNodeHttp::Truncate(size_t size) {
 }
 
 int MountNodeHttp::Write(size_t offs, const void* buf, size_t count) {
-  // TODO(binji): supprt POST?
+  // TODO(binji): support POST?
   errno = ENOSYS;
   return -1;
 }
 
 size_t MountNodeHttp::GetSize() {
-  struct stat stat;
-  if (GetStat(&stat) == -1) {
-    // errno is already set by GetStat.
-    return -1;
-  }
-
-  return stat.st_size;
+  // TODO(binji): This value should be cached properly; i.e. obey the caching
+  // headers returned by the server.
+  return stat_.st_size;
 }
 
 MountNodeHttp::MountNodeHttp(Mount* mount, int ino, int dev,