Modified GPU command signature hash to use a binary representation.

gpu/command_buffer/service/framebuffer_manager.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/framebuffer_manager.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "gpu/command_buffer/service/renderbuffer_manager.h"
 #include "gpu/command_buffer/service/texture_manager.h"
@@ skipping 488 matching lines @@
   }
 
   // This does not mean the framebuffer is actually complete. It just means our
   // checks passed.
   return GL_FRAMEBUFFER_COMPLETE;
 }
 
 GLenum Framebuffer::GetStatus(
     TextureManager* texture_manager, GLenum target) const {
   // Check if we have this combo already.
   std::string signature;

[vmiura, 2014/09/23 20:26:47]

I think it would help to pre-reserve enough space for a typical framebuffer e.g.
1 texture for color buffer + 2 * renderbuffers for depth & stencil.

i.e. signature.reserve(xyz);

[David Yen, 2014/09/23 20:45:24]

Since I will be adding structures for the binary blobs, I'll just implement a
function to return the size of the structures.

   if (allow_framebuffer_combo_complete_map_) {
-    signature = base::StringPrintf("|FBO|target=%04x", target);
+    signature.append("|Target|");
+    signature.append(reinterpret_cast<const char*>(&target), sizeof(target));
+    signature.push_back('|');

[vmiura, 2014/09/23 20:26:47]

I think we could remove fillers like "|Target|" and "|".

[David Yen, 2014/09/23 20:45:24]

I think it's a good idea to keep marker tags to ensure the binary data will be
unique, this can be a problem especially when having binary blobs containing
enums.

[vmiura, 2014/09/23 22:37:17]

I'd think we need to keep them in the attachments to avoid collisions, but this
"|Target|" ... "|" is a constant that I think we can remove.

[David Yen, 2014/09/23 22:42:51]

Done. Removed it in the last patch.

     for (AttachmentMap::const_iterator it = attachments_.begin();
          it != attachments_.end(); ++it) {
       Attachment* attachment = it->second.get();
-      signature +=
-          base::StringPrintf("|Attachment|attachmentpoint=%04x", it->first);
+      signature.append(reinterpret_cast<const char*>(&it->first),
+                       sizeof(it->first));
       attachment->AddToSignature(texture_manager, &signature);
     }
 
     if (!framebuffer_combo_complete_map_) {
       framebuffer_combo_complete_map_ = new FramebufferComboCompleteMap();
     }
 
     FramebufferComboCompleteMap::const_iterator it =
         framebuffer_combo_complete_map_->find(signature);
     if (it != framebuffer_combo_complete_map_->end()) {
@@ skipping 208 matching lines @@
        ++it) {
     TextureDetachObserver* observer = *it;
     observer->OnTextureRefDetachedFromFramebuffer(texture);
   }
 }
 
 }  // namespace gles2
 }  // namespace gpu