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      1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "content/browser/streams/stream_registry.h"
      6 
      7 #include "content/browser/streams/stream.h"
      8 
      9 namespace content {
     10 
     11 namespace {
     12 // The maximum size of memory each StreamRegistry instance is allowed to use
     13 // for its Stream instances.
     14 const size_t kDefaultMaxMemoryUsage = 1024 * 1024 * 1024U;  // 1GiB
     15 }
     16 
     17 StreamRegistry::StreamRegistry()
     18     : total_memory_usage_(0),
     19       max_memory_usage_(kDefaultMaxMemoryUsage) {
     20 }
     21 
     22 StreamRegistry::~StreamRegistry() {
     23 }
     24 
     25 void StreamRegistry::RegisterStream(scoped_refptr<Stream> stream) {
     26   DCHECK(CalledOnValidThread());
     27   DCHECK(stream.get());
     28   DCHECK(!stream->url().is_empty());
     29   streams_[stream->url()] = stream;
     30 }
     31 
     32 scoped_refptr<Stream> StreamRegistry::GetStream(const GURL& url) {
     33   DCHECK(CalledOnValidThread());
     34   StreamMap::const_iterator stream = streams_.find(url);
     35   if (stream != streams_.end())
     36     return stream->second;
     37 
     38   return NULL;
     39 }
     40 
     41 bool StreamRegistry::CloneStream(const GURL& url, const GURL& src_url) {
     42   DCHECK(CalledOnValidThread());
     43   scoped_refptr<Stream> stream(GetStream(src_url));
     44   if (stream.get()) {
     45     streams_[url] = stream;
     46     return true;
     47   }
     48   return false;
     49 }
     50 
     51 void StreamRegistry::UnregisterStream(const GURL& url) {
     52   DCHECK(CalledOnValidThread());
     53 
     54   StreamMap::iterator iter = streams_.find(url);
     55   if (iter == streams_.end())
     56     return;
     57 
     58   // Only update |total_memory_usage_| if |url| is NOT a Stream clone because
     59   // cloned streams do not update |total_memory_usage_|.
     60   if (iter->second->url() == url) {
     61     size_t buffered_bytes = iter->second->last_total_buffered_bytes();
     62     DCHECK_LE(buffered_bytes, total_memory_usage_);
     63     total_memory_usage_ -= buffered_bytes;
     64   }
     65 
     66   streams_.erase(url);
     67 }
     68 
     69 bool StreamRegistry::UpdateMemoryUsage(const GURL& url,
     70                                        size_t current_size,
     71                                        size_t increase) {
     72   DCHECK(CalledOnValidThread());
     73 
     74   StreamMap::iterator iter = streams_.find(url);
     75   // A Stream must be registered with its parent registry to get memory.
     76   if (iter == streams_.end())
     77     return false;
     78 
     79   size_t last_size = iter->second->last_total_buffered_bytes();
     80   DCHECK_LE(last_size, total_memory_usage_);
     81   size_t usage_of_others = total_memory_usage_ - last_size;
     82   DCHECK_LE(current_size, last_size);
     83   size_t current_total_memory_usage = usage_of_others + current_size;
     84 
     85   if (increase > max_memory_usage_ - current_total_memory_usage)
     86     return false;
     87 
     88   total_memory_usage_ = current_total_memory_usage + increase;
     89   return true;
     90 }
     91 
     92 }  // namespace content
     93