Introducing DecoderBuffer and general Buffer cleanup.

media/crypto/aes_decryptor.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 "media/crypto/aes_decryptor.h"
 
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/string_piece.h"
 #include "crypto/encryptor.h"
 #include "crypto/symmetric_key.h"
-#include "media/base/buffers.h"
-#include "media/base/data_buffer.h"
+#include "media/base/decoder_buffer.h"
 #include "media/base/decrypt_config.h"
 
 namespace media {
 
 // TODO(xhwang): Get real IV from frames.
 static const char kInitialCounter[] = "0000000000000000";
 
 // Decrypt |input| using |key|.
-// Return a scoped_refptr to a Buffer object with the decrypted data on success.
-// Return a scoped_refptr to NULL if the data could not be decrypted.
-static scoped_refptr<Buffer> DecryptData(const Buffer& input,
-                                         crypto::SymmetricKey* key) {
+// Return a DecoderBuffer with the decrypted data if decryption succeeded.
+// Return NULL if decryption failed.
+static scoped_refptr<DecoderBuffer> DecryptData(const DecoderBuffer& input,
+                                                crypto::SymmetricKey* key) {
   CHECK(input.GetDataSize());
   CHECK(key);
 
   // Initialize encryption data.
   // The IV must be exactly as long as the cipher block size.
   crypto::Encryptor encryptor;
   if (!encryptor.Init(key, crypto::Encryptor::CBC, kInitialCounter)) {
     DVLOG(1) << "Could not initialize encryptor.";
     return NULL;
   }
 
   std::string decrypted_text;
   base::StringPiece encrypted_text(
       reinterpret_cast<const char*>(input.GetData()),
       input.GetDataSize());
   if (!encryptor.Decrypt(encrypted_text, &decrypted_text)) {
     DVLOG(1) << "Could not decrypt data.";
     return NULL;
   }
 
-  // TODO(xhwang): Implement a string based Buffer implementation to avoid
-  // data copying.
-  return DataBuffer::CopyFrom(
+  // TODO(xhwang): Find a way to avoid this data copy.
+  return DecoderBuffer::CopyFrom(
       reinterpret_cast<const uint8*>(decrypted_text.data()),
       decrypted_text.size());
 }
 
 AesDecryptor::AesDecryptor() {}
 
 AesDecryptor::~AesDecryptor() {
   STLDeleteValues(&key_map_);
 }
 
@@ skipping 15 matching lines @@
 
   base::AutoLock auto_lock(lock_);
   KeyMap::iterator found = key_map_.find(key_id_string);
   if (found != key_map_.end()) {
     delete found->second;
     key_map_.erase(found);
   }
   key_map_[key_id_string] = symmetric_key;
 }
 
-scoped_refptr<Buffer> AesDecryptor::Decrypt(
-    const scoped_refptr<Buffer>& encrypted) {
+scoped_refptr<DecoderBuffer> AesDecryptor::Decrypt(
+    const scoped_refptr<DecoderBuffer>& encrypted) {
   CHECK(encrypted->GetDecryptConfig());
   const uint8* key_id = encrypted->GetDecryptConfig()->key_id();
   const int key_id_size = encrypted->GetDecryptConfig()->key_id_size();
 
   // TODO(xhwang): Avoid always constructing a string with StringPiece?
   std::string key_id_string(reinterpret_cast<const char*>(key_id), key_id_size);
 
   crypto::SymmetricKey* key = NULL;
   {
     base::AutoLock auto_lock(lock_);
     KeyMap::const_iterator found = key_map_.find(key_id_string);
     if (found == key_map_.end()) {
       DVLOG(1) << "Could not find a matching key for given key ID.";
       return NULL;
     }
     key = found->second;
   }
 
-  scoped_refptr<Buffer> decrypted = DecryptData(*encrypted, key);
+  scoped_refptr<DecoderBuffer> decrypted = DecryptData(*encrypted, key);
 
   if (decrypted) {
     decrypted->SetTimestamp(encrypted->GetTimestamp());
     decrypted->SetDuration(encrypted->GetDuration());
   }
 
   return decrypted;
 }
 
 }  // namespace media