Add CDM allocator interface.

webkit/media/crypto/ppapi/content_decryption_module.h

 // 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.
 
 #ifndef WEBKIT_MEDIA_CRYPTO_PPAPI_CONTENT_DECRYPTION_MODULE_H_
 #define WEBKIT_MEDIA_CRYPTO_PPAPI_CONTENT_DECRYPTION_MODULE_H_
 
 #if defined(_MSC_VER)
 typedef unsigned char uint8_t;
 typedef unsigned int uint32_t;
 typedef int int32_t;
 typedef __int64 int64_t;
 #else
 #include <stdint.h>
 #endif
 
 #include "webkit/media/crypto/ppapi/cdm_export.h"
 
 namespace cdm {
+class Allocator;
+class Buffer;
 class ContentDecryptionModule;
+class KeyMessage;
+class OutputBuffer;
 }
 
 extern "C" {
-CDM_EXPORT cdm::ContentDecryptionModule* CreateCdmInstance();
+CDM_EXPORT cdm::ContentDecryptionModule* CreateCdmInstance(
+    cdm::Allocator* allocator);
 CDM_EXPORT void DestroyCdmInstance(cdm::ContentDecryptionModule* instance);
 CDM_EXPORT const char* GetCdmVersion();
 }
 
 namespace cdm {
 
 enum Status {
   kSuccess = 0,
   kNeedMoreData,  // Decoder needs more data to produce a decoded frame/sample.
   kNoKey,  // The required decryption key is not available.
   kError
 };
 
-// Represents a key message sent by the CDM. It does not own any pointers in
-// this struct.
-// TODO(xhwang): Use int32_t instead of uint32_t for sizes here and below and
-// update checks to include <0.
-struct KeyMessage {
-  KeyMessage()
-      : session_id(NULL),
-        session_id_size(0),
-        message(NULL),
-        message_size(0),
-        default_url(NULL),
-        default_url_size(0) {}
-
-  char* session_id;
-  uint32_t session_id_size;
-  uint8_t* message;
-  uint32_t message_size;
-  char* default_url;
-  uint32_t default_url_size;
-};
-
 // An input buffer can be split into several continuous subsamples.
 // A SubsampleEntry specifies the number of clear and cipher bytes in each
 // subsample. For example, the following buffer has three subsamples:
 //
 // |<----- subsample1 ----->|<----- subsample2 ----->|<----- subsample3 ----->|
 // |   clear1   |  cipher1  |  clear2  |   cipher2   | clear3 |    cipher3    |
 //
 // For decryption, all of the cipher bytes in a buffer should be concatenated
 // (in the subsample order) into a single logical stream. The clear bytes should
 // not be considered as part of decryption.
 //
 // Stream to decrypt:   |  cipher1  |   cipher2   |    cipher3    |
 // Decrypted stream:    | decrypted1|  decrypted2 |   decrypted3  |
 //
 // After decryption, the decrypted bytes should be copied over the position
 // of the corresponding cipher bytes in the original buffer to form the output
 // buffer. Following the above example, the decrypted buffer should be:
 //
 // |<----- subsample1 ----->|<----- subsample2 ----->|<----- subsample3 ----->|
 // |   clear1   | decrypted1|  clear2  |  decrypted2 | clear3 |   decrypted3  |
 //
 // TODO(xhwang): Add checks to make sure these structs have fixed layout.
 struct SubsampleEntry {
-  SubsampleEntry(uint32_t clear_bytes, uint32_t cipher_bytes)
+  SubsampleEntry(int32_t clear_bytes, int32_t cipher_bytes)
       : clear_bytes(clear_bytes), cipher_bytes(cipher_bytes) {}
 
-  uint32_t clear_bytes;
-  uint32_t cipher_bytes;
+  int32_t clear_bytes;
+  int32_t cipher_bytes;
 };
 
 // Represents an input buffer to be decrypted (and possibly decoded). It does
 // own any pointers in this struct.
 struct InputBuffer {
   InputBuffer()
       : data(NULL),
         data_size(0),
         data_offset(0),
         key_id(NULL),
         key_id_size(0),
         iv(NULL),
         iv_size(0),
         checksum(NULL),
         checksum_size(0),
         subsamples(NULL),
         num_subsamples(0),
         timestamp(0) {}
 
   const uint8_t* data;  // Pointer to the beginning of the input data.
-  uint32_t data_size;  // Size (in bytes) of |data|.
+  int32_t data_size;  // Size (in bytes) of |data|.
 
-  uint32_t data_offset;  // Number of bytes to be discarded before decryption.
+  int32_t data_offset;  // Number of bytes to be discarded before decryption.
 
   const uint8_t* key_id;  // Key ID to identify the decryption key.
-  uint32_t key_id_size;  // Size (in bytes) of |key_id|.
+  int32_t key_id_size;  // Size (in bytes) of |key_id|.
 
   const uint8_t* iv;  // Initialization vector.
-  uint32_t iv_size;  // Size (in bytes) of |iv|.
+  int32_t iv_size;  // Size (in bytes) of |iv|.
 
   const uint8_t* checksum;
-  uint32_t checksum_size;  // Size (in bytes) of the |checksum|.
+  int32_t checksum_size;  // Size (in bytes) of the |checksum|.
 
   const struct SubsampleEntry* subsamples;
-  uint32_t num_subsamples;  // Number of subsamples in |subsamples|.
+  int32_t num_subsamples;  // Number of subsamples in |subsamples|.
 
   int64_t timestamp;  // Presentation timestamp in microseconds.
 };
-
-// Represents an output decrypted buffer. It does not own |data|.
-struct OutputBuffer {
-  OutputBuffer()
-      : data(NULL),
-        data_size(0),
-        timestamp(0) {}
-
-  const uint8_t* data;  // Pointer to the beginning of the output data.
-  uint32_t data_size;  // Size (in bytes) of |data|.
-
-  int64_t timestamp;  // Presentation timestamp in microseconds.
-};
 
 // Surface formats based on FOURCC labels, see:
 // http://www.fourcc.org/yuv.php
 enum VideoFormat {
   kUnknownVideoFormat = 0,  // Unknown format value.  Used for error reporting.
   kEmptyVideoFrame,  // An empty frame.
   kYv12,  // 12bpp YVU planar 1x1 Y, 2x2 VU samples.
   kI420  // 12bpp YVU planar 1x1 Y, 2x2 UV samples.
 };
 
@@ skipping 153 matching lines @@
 
   // Stops the CDM video decoder and sets it to an uninitialized state. The
   // caller can call InitializeVideoDecoder() again after this call to
   // re-initialize the video decoder. This can be used to reconfigure the
   // video decoder if the config changes.
   virtual void StopVideoDecoder() = 0;
 
   virtual ~ContentDecryptionModule() {}
 };
 
+// Represents a buffer created by Allocator implementations.
+class Buffer {
+ public:
+  virtual ~Buffer() {}

[ddorwin, 2012/09/17 21:19:23]

protected.
Don't let the CDM delete Buffers.

[Tom Finegan, 2012/09/18 01:08:02]

Done.

+  virtual uint8_t* buffer() = 0;
+  virtual int32_t size() const = 0;
+
+ protected:
+  Buffer() {}
+
+ private:
+  Buffer(const Buffer&);
+  void operator=(const Buffer&);
+};
+
+// Interface class that hides cross object memory allocation details from CDMs.
+// Allocated buffers should only be freed by the CDM wrapper with the single
+// exception noted by the |ReleaseBuffer()| comment.
+class Allocator {
+ public:
+  Allocator() {}

[ddorwin, 2012/09/17 21:19:23]

protected for these two.

[Tom Finegan, 2012/09/18 01:08:02]

Done.

+  virtual ~Allocator() {}
+
+  // Returns a Buffer* containing non-zero members upon success, or NULL on
+  // failure. The caller owns the Buffer* until it is passed back to the CDM
+  // wrapper.
+  virtual Buffer* Allocate(int32_t size) = 0;
+
+  // Release a Buffer returned by Allocate(). The |buffer| pointer is no longer

[ddorwin, 2012/09/17 21:19:23]

Correcting myself: I think we should just say "|buffer| is no..."

[Tom Finegan, 2012/09/18 01:08:02]

Done.

+  // valid after calling this method.
+  virtual void Release(const Buffer* buffer) = 0;
+};
+
+// Represents a key message sent by the CDM.
+class KeyMessage {
+ public:
+  virtual bool set_session_id(const char* session_id, int32_t length) = 0;
+  virtual const char* session_id() const = 0;
+  virtual int32_t session_id_length() const = 0;
+
+  virtual bool set_message(Buffer* message) = 0;
+  virtual Buffer* message() const = 0;
+
+  virtual bool set_default_url(const char* default_url, int32_t length) = 0;
+  virtual const char* default_url() const = 0;
+  virtual int32_t default_url_length() const = 0;
+
+ protected:
+  KeyMessage() {}
+  virtual ~KeyMessage() {}
+};
+
+// Represents an output decrypted buffer.
+class OutputBuffer {
+ public:
+  virtual bool set_buffer(Buffer* buffer) = 0;
+  virtual Buffer* buffer() const = 0;
+
+  virtual void set_timestamp(int64_t timestamp) = 0;
+  virtual int64_t timestamp() const = 0;

[ddorwin, 2012/09/17 21:19:23]

TODO: Figure out if we need timestamp() here. If not, just replace use with
Buffer.

[Tom Finegan, 2012/09/18 01:08:02]

Done.

+
+ protected:
+  OutputBuffer() {}
+  virtual ~OutputBuffer() {}
+};
+
 }  // namespace cdm
 
 #endif  // WEBKIT_MEDIA_CRYPTO_PPAPI_CONTENT_DECRYPTION_MODULE_H_