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diff --git a/Plugins/jingle/libjingle/talk/base/diskcache.h b/Plugins/jingle/libjingle/talk/base/diskcache.h
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+++ b/Plugins/jingle/libjingle/talk/base/diskcache.h
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+/*
+ * libjingle
+ * Copyright 2004--2005, Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef TALK_BASE_DISKCACHE_H__
+#define TALK_BASE_DISKCACHE_H__
+
+#include <map>
+#include <string>
+
+#ifdef WIN32
+#undef UnlockResource
+#endif  // WIN32
+
+namespace talk_base {
+
+class StreamInterface;
+
+///////////////////////////////////////////////////////////////////////////////
+// DiskCache - An LRU cache of streams, stored on disk.
+//
+// Streams are identified by a unique resource id.  Multiple streams can be
+// associated with each resource id, distinguished by an index.  When old
+// resources are flushed from the cache, all streams associated with those
+// resources are removed together.
+// DiskCache is designed to persist across executions of the program.  It is
+// safe for use from an arbitrary number of users on a single thread, but not
+// from multiple threads or other processes.
+///////////////////////////////////////////////////////////////////////////////
+
+class DiskCache {
+public:
+  DiskCache();
+  ~DiskCache();
+
+  bool Initialize(const std::string& folder, size_t size);
+  bool Purge();
+
+  bool LockResource(const std::string& id);
+  StreamInterface* WriteResource(const std::string& id, size_t index);
+  bool UnlockResource(const std::string& id);
+
+  StreamInterface* ReadResource(const std::string& id, size_t index) const;
+
+  bool HasResource(const std::string& id) const;
+  bool HasResourceStream(const std::string& id, size_t index) const;
+  bool DeleteResource(const std::string& id);
+
+ protected:
+  virtual bool InitializeEntries() = 0;
+  virtual bool PurgeFiles() = 0;
+
+  virtual bool FileExists(const std::string& filename) const = 0;
+  virtual bool DeleteFile(const std::string& filename) const = 0;
+
+  enum LockState { LS_UNLOCKED, LS_LOCKED, LS_UNLOCKING };
+  struct Entry {
+    LockState lock_state;
+    mutable size_t accessors;
+    size_t size;
+    size_t streams;
+    time_t last_modified;
+  };
+  typedef std::map<std::string, Entry> EntryMap;
+  friend class DiskCacheAdapter;
+
+  bool CheckLimit();
+
+  std::string IdToFilename(const std::string& id, size_t index) const;
+  bool FilenameToId(const std::string& filename, std::string* id,
+                    size_t* index) const;
+
+  const Entry* GetEntry(const std::string& id) const {
+    return const_cast<DiskCache*>(this)->GetOrCreateEntry(id, false);
+  }
+  Entry* GetOrCreateEntry(const std::string& id, bool create);
+
+  void ReleaseResource(const std::string& id, size_t index) const;
+
+  std::string folder_;
+  size_t max_cache_, total_size_;
+  EntryMap map_;
+  mutable size_t total_accessors_;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// CacheLock - Automatically manage locking and unlocking, with optional
+// rollback semantics
+///////////////////////////////////////////////////////////////////////////////
+
+class CacheLock {
+public:
+  CacheLock(DiskCache* cache, const std::string& id, bool rollback = false)
+  : cache_(cache), id_(id), rollback_(rollback)
+  {
+    locked_ = cache_->LockResource(id_);
+  }
+  ~CacheLock() {
+    if (locked_) {
+      cache_->UnlockResource(id_);
+      if (rollback_) {
+        cache_->DeleteResource(id_);
+      }
+    }
+  }
+  bool IsLocked() const { return locked_; }
+  void Commit() { rollback_ = false; }
+
+private:
+  DiskCache* cache_;
+  std::string id_;
+  bool rollback_, locked_;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+}  // namespace talk_base
+
+#endif // TALK_BASE_DISKCACHE_H__