nsPNGEncoder.h - mozsearch

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_image_encoders_png_nsPNGEncoder_h

#define mozilla_image_encoders_png_nsPNGEncoder_h

#include <png.h>

#include "imgIEncoder.h"

#include "nsCOMPtr.h"

#include "mozilla/Attributes.h"

#include "mozilla/ReentrantMonitor.h"

#define NS_PNGENCODER_CID                            \

  { /* 38d1592e-b81e-432b-86f8-471878bbfe07 */       \

    0x38d1592e, 0xb81e, 0x432b, {                    \

      0x86, 0xf8, 0x47, 0x18, 0x78, 0xbb, 0xfe, 0x07 \

    }                                                \

// Provides PNG encoding functionality. Use InitFromData() to do the

// encoding. See that function definition for encoding options.

class nsPNGEncoder final : public imgIEncoder {

  typedef mozilla::ReentrantMonitor ReentrantMonitor;

 public:

  NS_DECL_THREADSAFE_ISUPPORTS

  NS_DECL_IMGIENCODER

  NS_DECL_NSIINPUTSTREAM

  NS_DECL_NSIASYNCINPUTSTREAM

  nsPNGEncoder();

 protected:

  ~nsPNGEncoder();

  nsresult ParseOptions(const nsAString& aOptions, bool* useTransparency,

                        bool* skipFirstFrame, uint32_t* numAnimatedFrames,

                        uint32_t* numIterations, int* zlibLevel, int* filters,

                        uint32_t* frameDispose, uint32_t* frameBlend,

                        uint32_t* frameDelay, uint32_t* offsetX,

                        uint32_t* offsetY);

  void ConvertHostARGBRow(const uint8_t* aSrc, uint8_t* aDest,

                          uint32_t aPixelWidth, bool aUseTransparency);

  void StripAlpha(const uint8_t* aSrc, uint8_t* aDest, uint32_t aPixelWidth);

  static void WarningCallback(png_structp png_ptr, png_const_charp warning_msg);

  static void ErrorCallback(png_structp png_ptr, png_const_charp error_msg);

  static void WriteCallback(png_structp png, png_bytep data, png_size_t size);

  void NullOutImageBuffer();

  void NotifyListener();

  png_struct* mPNG;

  png_info* mPNGinfo;

  bool mIsAnimation;

  bool mFinished;

  // image buffer

  uint8_t* mImageBuffer;

  uint32_t mImageBufferSize;

  uint32_t mImageBufferUsed;

  uint32_t mImageBufferReadPoint;

  nsCOMPtr<nsIInputStreamCallback> mCallback;

  nsCOMPtr<nsIEventTarget> mCallbackTarget;

  uint32_t mNotifyThreshold;

  // nsPNGEncoder is designed to allow one thread to pump data into it while

  // another reads from it.  We lock to ensure that the buffer remains

  // append-only while we read from it (that it is not realloced) and to

  // ensure that only one thread dispatches a callback for each call to

  // AsyncWait.

  ReentrantMonitor mReentrantMonitor MOZ_UNANNOTATED;

};

#endif  // mozilla_image_encoders_png_nsPNGEncoder_h