/image/encoders/png/nsPNGEncoder.cpp
C++ | 729 lines | 502 code | 117 blank | 110 comment | 170 complexity | 6f48ff32dd9911ea44668f0672882bfc MD5 | raw file
Possible License(s): BSD-2-Clause, MPL-2.0-no-copyleft-exception, BSD-3-Clause, JSON, Apache-2.0, LGPL-3.0, MPL-2.0, GPL-2.0, 0BSD, AGPL-1.0
- /* -*- 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/. */
- #include "nsCRT.h"
- #include "nsPNGEncoder.h"
- #include "prmem.h"
- #include "prprf.h"
- #include "nsString.h"
- #include "nsStreamUtils.h"
- using namespace mozilla;
- NS_IMPL_THREADSAFE_ISUPPORTS3(nsPNGEncoder, imgIEncoder, nsIInputStream, nsIAsyncInputStream)
- nsPNGEncoder::nsPNGEncoder() : mPNG(nullptr), mPNGinfo(nullptr),
- mIsAnimation(false),
- mFinished(false),
- mImageBuffer(nullptr), mImageBufferSize(0),
- mImageBufferUsed(0), mImageBufferReadPoint(0),
- mCallback(nullptr),
- mCallbackTarget(nullptr), mNotifyThreshold(0),
- mReentrantMonitor("nsPNGEncoder.mReentrantMonitor")
- {
- }
- nsPNGEncoder::~nsPNGEncoder()
- {
- if (mImageBuffer) {
- PR_Free(mImageBuffer);
- mImageBuffer = nullptr;
- }
- // don't leak if EndImageEncode wasn't called
- if (mPNG)
- png_destroy_write_struct(&mPNG, &mPNGinfo);
- }
- // nsPNGEncoder::InitFromData
- //
- // One output option is supported: "transparency=none" means that the
- // output PNG will not have an alpha channel, even if the input does.
- //
- // Based partially on gfx/cairo/cairo/src/cairo-png.c
- // See also modules/libimg/png/libpng.txt
- NS_IMETHODIMP nsPNGEncoder::InitFromData(const uint8_t* aData,
- uint32_t aLength, // (unused,
- // req'd by JS)
- uint32_t aWidth,
- uint32_t aHeight,
- uint32_t aStride,
- uint32_t aInputFormat,
- const nsAString& aOutputOptions)
- {
- NS_ENSURE_ARG(aData);
- nsresult rv;
- rv = StartImageEncode(aWidth, aHeight, aInputFormat, aOutputOptions);
- if (!NS_SUCCEEDED(rv))
- return rv;
- rv = AddImageFrame(aData, aLength, aWidth, aHeight, aStride,
- aInputFormat, aOutputOptions);
- if (!NS_SUCCEEDED(rv))
- return rv;
- rv = EndImageEncode();
- return rv;
- }
- // nsPNGEncoder::StartImageEncode
- //
- //
- // See ::InitFromData for other info.
- NS_IMETHODIMP nsPNGEncoder::StartImageEncode(uint32_t aWidth,
- uint32_t aHeight,
- uint32_t aInputFormat,
- const nsAString& aOutputOptions)
- {
- bool useTransparency = true, skipFirstFrame = false;
- uint32_t numFrames = 1;
- uint32_t numPlays = 0; // For animations, 0 == forever
- // can't initialize more than once
- if (mImageBuffer != nullptr)
- return NS_ERROR_ALREADY_INITIALIZED;
- // validate input format
- if (aInputFormat != INPUT_FORMAT_RGB &&
- aInputFormat != INPUT_FORMAT_RGBA &&
- aInputFormat != INPUT_FORMAT_HOSTARGB)
- return NS_ERROR_INVALID_ARG;
- // parse and check any provided output options
- nsresult rv = ParseOptions(aOutputOptions, &useTransparency, &skipFirstFrame,
- &numFrames, &numPlays, nullptr, nullptr,
- nullptr, nullptr, nullptr);
- if (rv != NS_OK)
- return rv;
- #ifdef PNG_APNG_SUPPORTED
- if (numFrames > 1)
- mIsAnimation = true;
- #endif
- // initialize
- mPNG = png_create_write_struct(PNG_LIBPNG_VER_STRING,
- nullptr,
- ErrorCallback,
- WarningCallback);
- if (! mPNG)
- return NS_ERROR_OUT_OF_MEMORY;
- mPNGinfo = png_create_info_struct(mPNG);
- if (! mPNGinfo) {
- png_destroy_write_struct(&mPNG, nullptr);
- return NS_ERROR_FAILURE;
- }
- // libpng's error handler jumps back here upon an error.
- // Note: It's important that all png_* callers do this, or errors
- // will result in a corrupt time-warped stack.
- if (setjmp(png_jmpbuf(mPNG))) {
- png_destroy_write_struct(&mPNG, &mPNGinfo);
- return NS_ERROR_FAILURE;
- }
- // Set up to read the data into our image buffer, start out with an 8K
- // estimated size. Note: we don't have to worry about freeing this data
- // in this function. It will be freed on object destruction.
- mImageBufferSize = 8192;
- mImageBuffer = (uint8_t*)PR_Malloc(mImageBufferSize);
- if (!mImageBuffer) {
- png_destroy_write_struct(&mPNG, &mPNGinfo);
- return NS_ERROR_OUT_OF_MEMORY;
- }
- mImageBufferUsed = 0;
- // set our callback for libpng to give us the data
- png_set_write_fn(mPNG, this, WriteCallback, nullptr);
- // include alpha?
- int colorType;
- if ((aInputFormat == INPUT_FORMAT_HOSTARGB ||
- aInputFormat == INPUT_FORMAT_RGBA) &&
- useTransparency)
- colorType = PNG_COLOR_TYPE_RGB_ALPHA;
- else
- colorType = PNG_COLOR_TYPE_RGB;
- png_set_IHDR(mPNG, mPNGinfo, aWidth, aHeight, 8, colorType,
- PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
- PNG_FILTER_TYPE_DEFAULT);
- #ifdef PNG_APNG_SUPPORTED
- if (mIsAnimation) {
- png_set_first_frame_is_hidden(mPNG, mPNGinfo, skipFirstFrame);
- png_set_acTL(mPNG, mPNGinfo, numFrames, numPlays);
- }
- #endif
- // XXX: support PLTE, gAMA, tRNS, bKGD?
- png_write_info(mPNG, mPNGinfo);
- return NS_OK;
- }
- // Returns the number of bytes in the image buffer used.
- NS_IMETHODIMP nsPNGEncoder::GetImageBufferUsed(uint32_t *aOutputSize)
- {
- NS_ENSURE_ARG_POINTER(aOutputSize);
- *aOutputSize = mImageBufferUsed;
- return NS_OK;
- }
- // Returns a pointer to the start of the image buffer
- NS_IMETHODIMP nsPNGEncoder::GetImageBuffer(char **aOutputBuffer)
- {
- NS_ENSURE_ARG_POINTER(aOutputBuffer);
- *aOutputBuffer = reinterpret_cast<char*>(mImageBuffer);
- return NS_OK;
- }
- NS_IMETHODIMP nsPNGEncoder::AddImageFrame(const uint8_t* aData,
- uint32_t aLength, // (unused,
- // req'd by JS)
- uint32_t aWidth,
- uint32_t aHeight,
- uint32_t aStride,
- uint32_t aInputFormat,
- const nsAString& aFrameOptions)
- {
- bool useTransparency= true;
- uint32_t delay_ms = 500;
- #ifdef PNG_APNG_SUPPORTED
- uint32_t dispose_op = PNG_DISPOSE_OP_NONE;
- uint32_t blend_op = PNG_BLEND_OP_SOURCE;
- #else
- uint32_t dispose_op;
- uint32_t blend_op;
- #endif
- uint32_t x_offset = 0, y_offset = 0;
- // must be initialized
- if (mImageBuffer == nullptr)
- return NS_ERROR_NOT_INITIALIZED;
- // EndImageEncode was done, or some error occurred earlier
- if (!mPNG)
- return NS_BASE_STREAM_CLOSED;
- // validate input format
- if (aInputFormat != INPUT_FORMAT_RGB &&
- aInputFormat != INPUT_FORMAT_RGBA &&
- aInputFormat != INPUT_FORMAT_HOSTARGB)
- return NS_ERROR_INVALID_ARG;
- // libpng's error handler jumps back here upon an error.
- if (setjmp(png_jmpbuf(mPNG))) {
- png_destroy_write_struct(&mPNG, &mPNGinfo);
- return NS_ERROR_FAILURE;
- }
- // parse and check any provided output options
- nsresult rv = ParseOptions(aFrameOptions, &useTransparency, nullptr,
- nullptr, nullptr, &dispose_op, &blend_op,
- &delay_ms, &x_offset, &y_offset);
- if (rv != NS_OK)
- return rv;
- #ifdef PNG_APNG_SUPPORTED
- if (mIsAnimation) {
- // XXX the row pointers arg (#3) is unused, can it be removed?
- png_write_frame_head(mPNG, mPNGinfo, nullptr,
- aWidth, aHeight, x_offset, y_offset,
- delay_ms, 1000, dispose_op, blend_op);
- }
- #endif
- // Stride is the padded width of each row, so it better be longer
- // (I'm afraid people will not understand what stride means, so
- // check it well)
- if ((aInputFormat == INPUT_FORMAT_RGB &&
- aStride < aWidth * 3) ||
- ((aInputFormat == INPUT_FORMAT_RGBA ||
- aInputFormat == INPUT_FORMAT_HOSTARGB) &&
- aStride < aWidth * 4)) {
- NS_WARNING("Invalid stride for InitFromData/AddImageFrame");
- return NS_ERROR_INVALID_ARG;
- }
- #ifdef PNG_WRITE_FILTER_SUPPORTED
- png_set_filter(mPNG, PNG_FILTER_TYPE_BASE, PNG_FILTER_VALUE_NONE);
- #endif
- // write each row: if we add more input formats, we may want to
- // generalize the conversions
- if (aInputFormat == INPUT_FORMAT_HOSTARGB) {
- // PNG requires RGBA with post-multiplied alpha, so we need to
- // convert
- uint8_t* row = new uint8_t[aWidth * 4];
- for (uint32_t y = 0; y < aHeight; y ++) {
- ConvertHostARGBRow(&aData[y * aStride], row, aWidth, useTransparency);
- png_write_row(mPNG, row);
- }
- delete[] row;
- } else if (aInputFormat == INPUT_FORMAT_RGBA && ! useTransparency) {
- // RBGA, but we need to strip the alpha
- uint8_t* row = new uint8_t[aWidth * 4];
- for (uint32_t y = 0; y < aHeight; y ++) {
- StripAlpha(&aData[y * aStride], row, aWidth);
- png_write_row(mPNG, row);
- }
- delete[] row;
- } else if (aInputFormat == INPUT_FORMAT_RGB ||
- aInputFormat == INPUT_FORMAT_RGBA) {
- // simple RBG(A), no conversion needed
- for (uint32_t y = 0; y < aHeight; y ++) {
- png_write_row(mPNG, (uint8_t*)&aData[y * aStride]);
- }
- } else {
- NS_NOTREACHED("Bad format type");
- return NS_ERROR_INVALID_ARG;
- }
- #ifdef PNG_APNG_SUPPORTED
- if (mIsAnimation) {
- png_write_frame_tail(mPNG, mPNGinfo);
- }
- #endif
- return NS_OK;
- }
- NS_IMETHODIMP nsPNGEncoder::EndImageEncode()
- {
- // must be initialized
- if (mImageBuffer == nullptr)
- return NS_ERROR_NOT_INITIALIZED;
- // EndImageEncode has already been called, or some error
- // occurred earlier
- if (!mPNG)
- return NS_BASE_STREAM_CLOSED;
- // libpng's error handler jumps back here upon an error.
- if (setjmp(png_jmpbuf(mPNG))) {
- png_destroy_write_struct(&mPNG, &mPNGinfo);
- return NS_ERROR_FAILURE;
- }
- png_write_end(mPNG, mPNGinfo);
- png_destroy_write_struct(&mPNG, &mPNGinfo);
- mFinished = true;
- NotifyListener();
- // if output callback can't get enough memory, it will free our buffer
- if (!mImageBuffer)
- return NS_ERROR_OUT_OF_MEMORY;
- return NS_OK;
- }
- nsresult
- nsPNGEncoder::ParseOptions(const nsAString& aOptions,
- bool* useTransparency,
- bool* skipFirstFrame,
- uint32_t* numFrames,
- uint32_t* numPlays,
- uint32_t* frameDispose,
- uint32_t* frameBlend,
- uint32_t* frameDelay,
- uint32_t* offsetX,
- uint32_t* offsetY)
- {
- #ifdef PNG_APNG_SUPPORTED
- // Make a copy of aOptions, because strtok() will modify it.
- nsAutoCString optionsCopy;
- optionsCopy.Assign(NS_ConvertUTF16toUTF8(aOptions));
- char* options = optionsCopy.BeginWriting();
- while (char* token = nsCRT::strtok(options, ";", &options)) {
- // If there's an '=' character, split the token around it.
- char* equals = token, *value = nullptr;
- while(*equals != '=' && *equals) {
- ++equals;
- }
- if (*equals == '=')
- value = equals + 1;
- if (value)
- *equals = '\0'; // temporary null
- // transparency=[yes|no|none]
- if (nsCRT::strcmp(token, "transparency") == 0 && useTransparency) {
- if (!value)
- return NS_ERROR_INVALID_ARG;
- if (nsCRT::strcmp(value, "none") == 0 ||
- nsCRT::strcmp(value, "no") == 0) {
- *useTransparency = false;
- } else if (nsCRT::strcmp(value, "yes") == 0) {
- *useTransparency = true;
- } else {
- return NS_ERROR_INVALID_ARG;
- }
- // skipfirstframe=[yes|no]
- } else if (nsCRT::strcmp(token, "skipfirstframe") == 0 &&
- skipFirstFrame) {
- if (!value)
- return NS_ERROR_INVALID_ARG;
- if (nsCRT::strcmp(value, "no") == 0) {
- *skipFirstFrame = false;
- } else if (nsCRT::strcmp(value, "yes") == 0) {
- *skipFirstFrame = true;
- } else {
- return NS_ERROR_INVALID_ARG;
- }
- // frames=#
- } else if (nsCRT::strcmp(token, "frames") == 0 && numFrames) {
- if (!value)
- return NS_ERROR_INVALID_ARG;
- if (PR_sscanf(value, "%u", numFrames) != 1) {
- return NS_ERROR_INVALID_ARG;
- }
- // frames=0 is nonsense.
- if (*numFrames == 0)
- return NS_ERROR_INVALID_ARG;
- // plays=#
- } else if (nsCRT::strcmp(token, "plays") == 0 && numPlays) {
- if (!value)
- return NS_ERROR_INVALID_ARG;
- // plays=0 to loop forever, otherwise play sequence specified
- // number of times
- if (PR_sscanf(value, "%u", numPlays) != 1)
- return NS_ERROR_INVALID_ARG;
- // dispose=[none|background|previous]
- } else if (nsCRT::strcmp(token, "dispose") == 0 && frameDispose) {
- if (!value)
- return NS_ERROR_INVALID_ARG;
- if (nsCRT::strcmp(value, "none") == 0) {
- *frameDispose = PNG_DISPOSE_OP_NONE;
- } else if (nsCRT::strcmp(value, "background") == 0) {
- *frameDispose = PNG_DISPOSE_OP_BACKGROUND;
- } else if (nsCRT::strcmp(value, "previous") == 0) {
- *frameDispose = PNG_DISPOSE_OP_PREVIOUS;
- } else {
- return NS_ERROR_INVALID_ARG;
- }
- // blend=[source|over]
- } else if (nsCRT::strcmp(token, "blend") == 0 && frameBlend) {
- if (!value)
- return NS_ERROR_INVALID_ARG;
- if (nsCRT::strcmp(value, "source") == 0) {
- *frameBlend = PNG_BLEND_OP_SOURCE;
- } else if (nsCRT::strcmp(value, "over") == 0) {
- *frameBlend = PNG_BLEND_OP_OVER;
- } else {
- return NS_ERROR_INVALID_ARG;
- }
- // delay=# (in ms)
- } else if (nsCRT::strcmp(token, "delay") == 0 && frameDelay) {
- if (!value)
- return NS_ERROR_INVALID_ARG;
- if (PR_sscanf(value, "%u", frameDelay) != 1)
- return NS_ERROR_INVALID_ARG;
- // xoffset=#
- } else if (nsCRT::strcmp(token, "xoffset") == 0 && offsetX) {
- if (!value)
- return NS_ERROR_INVALID_ARG;
- if (PR_sscanf(value, "%u", offsetX) != 1)
- return NS_ERROR_INVALID_ARG;
- // yoffset=#
- } else if (nsCRT::strcmp(token, "yoffset") == 0 && offsetY) {
- if (!value)
- return NS_ERROR_INVALID_ARG;
- if (PR_sscanf(value, "%u", offsetY) != 1)
- return NS_ERROR_INVALID_ARG;
- // unknown token name
- } else
- return NS_ERROR_INVALID_ARG;
- if (value)
- *equals = '='; // restore '=' so strtok doesn't get lost
- }
- #endif
- return NS_OK;
- }
- /* void close (); */
- NS_IMETHODIMP nsPNGEncoder::Close()
- {
- if (mImageBuffer != nullptr) {
- PR_Free(mImageBuffer);
- mImageBuffer = nullptr;
- mImageBufferSize = 0;
- mImageBufferUsed = 0;
- mImageBufferReadPoint = 0;
- }
- return NS_OK;
- }
- /* unsigned long available (); */
- NS_IMETHODIMP nsPNGEncoder::Available(uint64_t *_retval)
- {
- if (!mImageBuffer)
- return NS_BASE_STREAM_CLOSED;
- *_retval = mImageBufferUsed - mImageBufferReadPoint;
- return NS_OK;
- }
- /* [noscript] unsigned long read (in charPtr aBuf,
- in unsigned long aCount); */
- NS_IMETHODIMP nsPNGEncoder::Read(char * aBuf, uint32_t aCount,
- uint32_t *_retval)
- {
- return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, _retval);
- }
- /* [noscript] unsigned long readSegments (in nsWriteSegmentFun aWriter,
- in voidPtr aClosure,
- in unsigned long aCount); */
- NS_IMETHODIMP nsPNGEncoder::ReadSegments(nsWriteSegmentFun aWriter,
- void *aClosure, uint32_t aCount,
- uint32_t *_retval)
- {
- // Avoid another thread reallocing the buffer underneath us
- ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
- uint32_t maxCount = mImageBufferUsed - mImageBufferReadPoint;
- if (maxCount == 0) {
- *_retval = 0;
- return mFinished ? NS_OK : NS_BASE_STREAM_WOULD_BLOCK;
- }
- if (aCount > maxCount)
- aCount = maxCount;
- nsresult rv =
- aWriter(this, aClosure,
- reinterpret_cast<const char*>(mImageBuffer+mImageBufferReadPoint),
- 0, aCount, _retval);
- if (NS_SUCCEEDED(rv)) {
- NS_ASSERTION(*_retval <= aCount, "bad write count");
- mImageBufferReadPoint += *_retval;
- }
- // errors returned from the writer end here!
- return NS_OK;
- }
- /* boolean isNonBlocking (); */
- NS_IMETHODIMP nsPNGEncoder::IsNonBlocking(bool *_retval)
- {
- *_retval = true;
- return NS_OK;
- }
- NS_IMETHODIMP nsPNGEncoder::AsyncWait(nsIInputStreamCallback *aCallback,
- uint32_t aFlags,
- uint32_t aRequestedCount,
- nsIEventTarget *aTarget)
- {
- if (aFlags != 0)
- return NS_ERROR_NOT_IMPLEMENTED;
- if (mCallback || mCallbackTarget)
- return NS_ERROR_UNEXPECTED;
- mCallbackTarget = aTarget;
- // 0 means "any number of bytes except 0"
- mNotifyThreshold = aRequestedCount;
- if (!aRequestedCount)
- mNotifyThreshold = 1024; // We don't want to notify incessantly
- // We set the callback absolutely last, because NotifyListener uses it to
- // determine if someone needs to be notified. If we don't set it last,
- // NotifyListener might try to fire off a notification to a null target
- // which will generally cause non-threadsafe objects to be used off the main thread
- mCallback = aCallback;
- // What we are being asked for may be present already
- NotifyListener();
- return NS_OK;
- }
- NS_IMETHODIMP nsPNGEncoder::CloseWithStatus(nsresult aStatus)
- {
- return Close();
- }
- // nsPNGEncoder::ConvertHostARGBRow
- //
- // Our colors are stored with premultiplied alphas, but PNGs use
- // post-multiplied alpha. This swaps to PNG-style alpha.
- //
- // Copied from gfx/cairo/cairo/src/cairo-png.c
- void
- nsPNGEncoder::ConvertHostARGBRow(const uint8_t* aSrc, uint8_t* aDest,
- uint32_t aPixelWidth,
- bool aUseTransparency)
- {
- uint32_t pixelStride = aUseTransparency ? 4 : 3;
- for (uint32_t x = 0; x < aPixelWidth; x ++) {
- const uint32_t& pixelIn = ((const uint32_t*)(aSrc))[x];
- uint8_t *pixelOut = &aDest[x * pixelStride];
- uint8_t alpha = (pixelIn & 0xff000000) >> 24;
- if (alpha == 0) {
- pixelOut[0] = pixelOut[1] = pixelOut[2] = pixelOut[3] = 0;
- } else {
- pixelOut[0] = (((pixelIn & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
- pixelOut[1] = (((pixelIn & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
- pixelOut[2] = (((pixelIn & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha;
- if (aUseTransparency)
- pixelOut[3] = alpha;
- }
- }
- }
- // nsPNGEncoder::StripAlpha
- //
- // Input is RGBA, output is RGB
- void
- nsPNGEncoder::StripAlpha(const uint8_t* aSrc, uint8_t* aDest,
- uint32_t aPixelWidth)
- {
- for (uint32_t x = 0; x < aPixelWidth; x ++) {
- const uint8_t* pixelIn = &aSrc[x * 4];
- uint8_t* pixelOut = &aDest[x * 3];
- pixelOut[0] = pixelIn[0];
- pixelOut[1] = pixelIn[1];
- pixelOut[2] = pixelIn[2];
- }
- }
- // nsPNGEncoder::WarningCallback
- void // static
- nsPNGEncoder::WarningCallback(png_structp png_ptr,
- png_const_charp warning_msg)
- {
- #ifdef DEBUG
- // XXX: these messages are probably useful callers...
- // use nsIConsoleService?
- PR_fprintf(PR_STDERR, "PNG Encoder: %s\n", warning_msg);;
- #endif
- }
- // nsPNGEncoder::ErrorCallback
- void // static
- nsPNGEncoder::ErrorCallback(png_structp png_ptr,
- png_const_charp error_msg)
- {
- #ifdef DEBUG
- // XXX: these messages are probably useful callers...
- // use nsIConsoleService?
- PR_fprintf(PR_STDERR, "PNG Encoder: %s\n", error_msg);;
- #endif
- #if PNG_LIBPNG_VER < 10500
- longjmp(png_ptr->jmpbuf, 1);
- #else
- png_longjmp(png_ptr, 1);
- #endif
- }
- // nsPNGEncoder::WriteCallback
- void // static
- nsPNGEncoder::WriteCallback(png_structp png, png_bytep data,
- png_size_t size)
- {
- nsPNGEncoder* that = static_cast<nsPNGEncoder*>(png_get_io_ptr(png));
- if (! that->mImageBuffer)
- return;
- if (that->mImageBufferUsed + size > that->mImageBufferSize) {
- // When we're reallocing the buffer we need to take the lock to ensure
- // that nobody is trying to read from the buffer we are destroying
- ReentrantMonitorAutoEnter autoEnter(that->mReentrantMonitor);
- // expand buffer, just double each time
- that->mImageBufferSize *= 2;
- uint8_t* newBuf = (uint8_t*)PR_Realloc(that->mImageBuffer,
- that->mImageBufferSize);
- if (! newBuf) {
- // can't resize, just zero (this will keep us from writing more)
- PR_Free(that->mImageBuffer);
- that->mImageBuffer = nullptr;
- that->mImageBufferSize = 0;
- that->mImageBufferUsed = 0;
- return;
- }
- that->mImageBuffer = newBuf;
- }
- memcpy(&that->mImageBuffer[that->mImageBufferUsed], data, size);
- that->mImageBufferUsed += size;
- that->NotifyListener();
- }
- void
- nsPNGEncoder::NotifyListener()
- {
- // We might call this function on multiple threads (any threads that call
- // AsyncWait and any that do encoding) so we lock to avoid notifying the
- // listener twice about the same data (which generally leads to a truncated
- // image).
- ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
- if (mCallback &&
- (mImageBufferUsed - mImageBufferReadPoint >= mNotifyThreshold ||
- mFinished)) {
- nsCOMPtr<nsIInputStreamCallback> callback;
- if (mCallbackTarget) {
- NS_NewInputStreamReadyEvent(getter_AddRefs(callback),
- mCallback,
- mCallbackTarget);
- } else {
- callback = mCallback;
- }
- NS_ASSERTION(callback, "Shouldn't fail to make the callback");
- // Null the callback first because OnInputStreamReady could reenter
- // AsyncWait
- mCallback = nullptr;
- mCallbackTarget = nullptr;
- mNotifyThreshold = 0;
- callback->OnInputStreamReady(this);
- }
- }