1 files changed, 175 insertions, 0 deletions
diff --git a/chromium/gpu/command_buffer/service/common_decoder.h b/chromium/gpu/command_buffer/service/common_decoder.h
new file mode 100644
index 00000000000..03002c8b06f
--- /dev/null
+++ b/chromium/gpu/command_buffer/service/common_decoder.h
@@ -0,0 +1,175 @@
+// 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 GPU_COMMAND_BUFFER_SERVICE_COMMON_DECODER_H_
+#define GPU_COMMAND_BUFFER_SERVICE_COMMON_DECODER_H_
+
+#include <map>
+#include <stack>
+#include <string>
+#include "base/memory/linked_ptr.h"
+#include "base/memory/scoped_ptr.h"
+#include "gpu/command_buffer/common/buffer.h"
+#include "gpu/command_buffer/service/cmd_parser.h"
+#include "gpu/gpu_export.h"
+
+namespace gpu {
+
+class CommandBufferEngine;
+
+// This class is a helper base class for implementing the common parts of the
+// o3d/gl2 command buffer decoder.
+class GPU_EXPORT CommonDecoder : NON_EXPORTED_BASE(public AsyncAPIInterface) {
+ public:
+  typedef error::Error Error;
+
+  static const unsigned int kMaxStackDepth = 32;
+
+  // A bucket is a buffer to help collect memory across a command buffer. When
+  // creating a command buffer implementation of an existing API, sometimes that
+  // API has functions that take a pointer to data.  A good example is OpenGL's
+  // glBufferData. Because the data is separated between client and service,
+  // there are 2 ways to get this data across. 1 is to put all the data in
+  // shared memory. The problem with this is the data can be arbitarily large
+  // and the host OS may not support that much shared memory. Another solution
+  // is to shuffle memory across a little bit at a time, collecting it on the
+  // service side and when it is all there then call glBufferData. Buckets
+  // implement this second solution. Using the common commands, SetBucketSize,
+  // SetBucketData, SetBucketDataImmediate the client can fill a bucket. It can
+  // then call a command that uses that bucket (like BufferDataBucket in the
+  // GLES2 command buffer implementation).
+  //
+  // If you are designing an API from scratch you can avoid this need for
+  // Buckets by making your API always take an offset and a size
+  // similar to glBufferSubData.
+  //
+  // Buckets also help pass strings to/from the service. To return a string of
+  // arbitary size, the service puts the string in a bucket. The client can
+  // then query the size of a bucket and request sections of the bucket to
+  // be passed across shared memory.
+  class GPU_EXPORT Bucket {
+   public:
+    Bucket();
+    ~Bucket();
+
+    size_t size() const {
+      return size_;
+    }
+
+    // Gets a pointer to a section the bucket. Returns NULL if offset or size is
+    // out of range.
+    void* GetData(size_t offset, size_t size) const;
+
+    template <typename T>
+    T GetDataAs(size_t offset, size_t size) const {
+      return reinterpret_cast<T>(GetData(offset, size));
+    }
+
+    // Sets the size of the bucket.
+    void SetSize(size_t size);
+
+    // Sets a part of the bucket.
+    // Returns false if offset or size is out of range.
+    bool SetData(const void* src, size_t offset, size_t size);
+
+    // Sets the bucket data from a string. Strings are passed NULL terminated to
+    // distinguish between empty string and no string.
+    void SetFromString(const char* str);
+
+    // Gets the bucket data as a string. Strings are passed NULL terminated to
+    // distrinquish between empty string and no string. Returns False if there
+    // is no string.
+    bool GetAsString(std::string* str);
+
+   private:
+    bool OffsetSizeValid(size_t offset, size_t size) const {
+      size_t temp = offset + size;
+      return temp <= size_ && temp >= offset;
+    }
+
+    size_t size_;
+    ::scoped_ptr<int8[]> data_;
+
+    DISALLOW_COPY_AND_ASSIGN(Bucket);
+  };
+
+  CommonDecoder();
+  virtual ~CommonDecoder();
+
+  // Sets the engine, to get shared memory buffers from, and to set the token
+  // to.
+  void set_engine(CommandBufferEngine* engine) {
+    engine_ = engine;
+  }
+  CommandBufferEngine* engine() const { return engine_; }
+
+  // Creates a bucket. If the bucket already exists returns that bucket.
+  Bucket* CreateBucket(uint32 bucket_id);
+
+  // Gets a bucket. Returns NULL if the bucket does not exist.
+  Bucket* GetBucket(uint32 bucket_id) const;
+
+  // Gets the address of shared memory data, given a shared memory ID and an
+  // offset. Also checks that the size is consistent with the shared memory
+  // size.
+  // Parameters:
+  //   shm_id: the id of the shared memory buffer.
+  //   offset: the offset of the data in the shared memory buffer.
+  //   size: the size of the data.
+  // Returns:
+  //   NULL if shm_id isn't a valid shared memory buffer ID or if the size
+  //   check fails. Return a pointer to the data otherwise.
+  void* GetAddressAndCheckSize(unsigned int shm_id,
+                               unsigned int offset,
+                               unsigned int size);
+
+  // Typed version of GetAddressAndCheckSize.
+  template <typename T>
+  T GetSharedMemoryAs(unsigned int shm_id, unsigned int offset,
+                      unsigned int size) {
+    return static_cast<T>(GetAddressAndCheckSize(shm_id, offset, size));
+  }
+
+  // Get the actual shared memory buffer.
+  Buffer GetSharedMemoryBuffer(unsigned int shm_id);
+
+ protected:
+  // Executes a common command.
+  // Parameters:
+  //    command: the command index.
+  //    arg_count: the number of CommandBufferEntry arguments.
+  //    cmd_data: the command data.
+  // Returns:
+  //   error::kNoError if no error was found, one of
+  //   error::Error otherwise.
+  error::Error DoCommonCommand(
+      unsigned int command,
+      unsigned int arg_count,
+      const void* cmd_data);
+
+  // Gets an name for a common command.
+  const char* GetCommonCommandName(cmd::CommandId command_id) const;
+
+ private:
+  // Generate a member function prototype for each command in an automated and
+  // typesafe way.
+  #define COMMON_COMMAND_BUFFER_CMD_OP(name)             \
+     error::Error Handle##name(                          \
+       uint32 immediate_data_size,                       \
+       const cmd::name& args);                           \
+
+  COMMON_COMMAND_BUFFER_CMDS(COMMON_COMMAND_BUFFER_CMD_OP)
+
+  #undef COMMON_COMMAND_BUFFER_CMD_OP
+
+  CommandBufferEngine* engine_;
+
+  typedef std::map<uint32, linked_ptr<Bucket> > BucketMap;
+  BucketMap buckets_;
+};
+
+}  // namespace gpu
+
+#endif  // GPU_COMMAND_BUFFER_SERVICE_COMMON_DECODER_H_
+