Multi reader/writer cache/buffer

media/blink/url_index.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 <set>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "base/time/time.h"
+#include "media/blink/url_index.h"
+
+namespace media {
+
+const int kUrlMappingTimeoutSeconds = 300;
+
+UrlData::UrlData(const GURL& url,
+                 CORSMode cors_mode,
+                 UrlIndex* url_index) :
+    url_(url),
+    cors_mode_(cors_mode),
+    length_(kPositionNotSpecified),
+    range_supported_(false),
+    cacheable_(false),
+    last_used_(),
+    url_index_(url_index) {
+}
+
+UrlData::~UrlData() {
+  if (url_index_)
+    url_index_->RemoveUrlData(this);
+}
+
+std::pair<GURL, UrlData::CORSMode> UrlData::key() const {
+  return std::make_pair(url(), cors_mode());
+}
+
+void UrlData::set_redirects_to(const GURL& url) {
+  redirects_to_ = url;
+}
+
+void UrlData::set_valid_until(base::TimeTicks t) {
+  valid_until_ = t;
+}
+
+void UrlData::set_range_supported() {
+  range_supported_ = true;
+}
+
+void UrlData::set_cacheable(bool cacheable) {
+  cacheable_ = cacheable;
+}
+
+void UrlData::set_length(int64 length) {
+  if (length != kPositionNotSpecified) {
+    length_ = length;
+  }
+}
+
+void UrlData::Use() {
+  last_used_ = base::TimeTicks::Now();
+}
+
+bool UrlData::Valid() const {
+  base::TimeTicks now = base::TimeTicks::Now();
+  if (valid_until_ > now)
+    return true;
+  if (now - last_used_ < base::TimeDelta::FromSeconds(
+          kUrlMappingTimeoutSeconds))
+    return true;
+  return false;
+}
+
+void UrlData::set_last_modified_internal(base::Time last_modified) {
+  last_modified_ = last_modified;
+}
+
+scoped_refptr<UrlData> UrlData::set_last_modified(base::Time last_modified) {
+  if (url_index_)
+    return url_index_->SetLastModified(this, last_modified);
+  set_last_modified_internal(last_modified);
+  return this;
+}
+
+void UrlData::DisconnectFromIndex() {
+  url_index_ = nullptr;
+}
+
+UrlIndex::UrlIndex() {}
+UrlIndex::~UrlIndex() {
+  for (auto i : by_url_)
+    i.second->DisconnectFromIndex();
+  for (auto i : with_last_modified_)
+    i.second->DisconnectFromIndex();
+}
+
+void UrlIndex::RemoveUrlData(const UrlData* url_data) {
+  auto i = by_url_.find(url_data->key());
+  if (i != by_url_.end() && i->second == url_data)
+    by_url_.erase(i);
+  i = with_last_modified_.find(url_data->key());
+  if (i != with_last_modified_.end() && i->second == url_data)
+    with_last_modified_.erase(i);
+}
+
+scoped_refptr<UrlData> UrlIndex::GetByUrl(const GURL& gurl,
+                                          UrlData::CORSMode cors_mode) {
+  auto inserted = by_url_.insert(
+      std::make_pair<UrlData::KeyType,UrlData*>(
+          std::make_pair(gurl, cors_mode), nullptr));
+  if (inserted.second || !inserted.first->second->Valid()) {
+    inserted.first->second = new UrlData(gurl, cors_mode, this);
+    to_prune_.push_back(inserted.first->second);
+  }
+  DCHECK(inserted.first->second);
+  return inserted.first->second;
+}
+
+scoped_refptr<UrlData> UrlIndex::SetLastModified(
+    scoped_refptr<UrlData> url_data,
+    base::Time last_modified) {
+  DCHECK(!last_modified.is_null());
+
+  if (url_data->last_modified() == last_modified)
+    return url_data;
+
+  auto i = with_last_modified_.find(url_data->key());
+  if (i != with_last_modified_.end()) {
+    if (i->second->last_modified() == last_modified) {
+      return by_url_[i->second->key()] = i->second;
+    }
+
+    if (i->second != url_data && !url_data->last_modified().is_null())
+      return url_data;
+  }
+
+  url_data->set_last_modified_internal(last_modified);
+  with_last_modified_[url_data->key()] = url_data.get();
+  return url_data;
+}
+
+}  // namespace media