Tie multibuffers to URLs

media/blink/multibuffer.cc

 // Copyright 2015 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 "media/blink/multibuffer.h"
 
 #include "base/bind.h"
 
 namespace media {
 
@@ skipping 144 matching lines @@
     // Make sure that there are no present blocks between the writer and
     // the requested position, as that will cause the writer to quit.
     if (closest_writer > closest_block) {
       provider = writer_index_[closest_writer];
       DCHECK(provider);
     }
   }
   if (!provider) {
     DCHECK(writer_index_.find(pos) == writer_index_.end());
     provider = writer_index_[pos] = CreateWriter(pos);
-    provider->SetAvailableCallback(base::Bind(
-        &MultiBuffer::DataProviderEvent, base::Unretained(this), provider));
   }
   provider->SetDeferred(false);
 }
 
 void MultiBuffer::RemoveReader(const BlockId& pos, Reader* reader) {
   auto i = readers_.find(pos);
   if (i == readers_.end())
     return;
   i->second.erase(reader);
   if (i->second.empty()) {
@@ skipping 74 matching lines @@
       }
       if (i.interval_end() == freed_range.first.end) {
         // Notify the following range that it contains fewer blocks.
         auto j = i;
         ++j;
         DCHECK_EQ(j.value(), 1);
         NotifyAvailableRange(j.interval(), j.interval());
       }
     }
   }
+  if (data_.empty()) {
+    OnEmpty();
+  }

[xhwang, 2015/11/19 23:34:17]

tiny nit: braces can be omitted here. I actually saw mixed style in this file.
Is there any special rule you are following?

[hubbe, 2015/11/20 23:24:22]

No, unfortunately I'm still all mixed up since I used to work in a group where
we required braces everywhere.

Done.

 }
 
+void MultiBuffer::OnEmpty() {}

[xhwang, 2015/11/19 23:34:17]

What's the purpose of this? Will some test class override this?

[hubbe, 2015/11/20 23:24:22]

Comment added in multibuffer.h
See ResourceMultiBuffer::OnEmpty in url_index.h/cc

+
 void MultiBuffer::AddProvider(scoped_ptr<DataProvider> provider) {
   // If there is already a provider in the same location, we delete it.
   DCHECK(!provider->Available());
   BlockId pos = provider->Tell();
   DataProvider** place = &writer_index_[pos];
   DCHECK_NE(*place, provider.get());
   if (*place)
     delete *place;
   *place = provider.release();
 }
@@ skipping 198 matching lines @@
 }
 
 void MultiBuffer::IncrementMaxSize(int32_t size) {
   max_size_ += size;
   lru_->IncrementMaxSize(size);
   DCHECK_GE(max_size_, 0);
   // Pruning only happens when blocks are added.
 }
 
 }  // namespace media