The Tor Browser: image/encoders/ico/nsICOEncoder.cpp@b8a032363ba2 (annotated)

image/encoders/ico/nsICOEncoder.cpp@b8a032363ba2 (annotated)

image/encoders/ico/nsICOEncoder.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* 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 "mozilla/Endian.h"
 #include "nsBMPEncoder.h"
 #include "nsPNGEncoder.h"
 #include "nsICOEncoder.h"
 #include "prprf.h"
 #include "nsString.h"
 #include "nsStreamUtils.h"
 #include "nsTArray.h"
 using namespace mozilla;
 using namespace mozilla::image;
 NS_IMPL_ISUPPORTS(nsICOEncoder, imgIEncoder, nsIInputStream, nsIAsyncInputStream)
 nsICOEncoder::nsICOEncoder() : mImageBufferStart(nullptr),
                                mImageBufferCurr(0),
                                mImageBufferSize(0),
                                mImageBufferReadPoint(0),
                                mFinished(false),
                                mUsePNG(true),
                                mNotifyThreshold(0)
 {
 }
 nsICOEncoder::~nsICOEncoder()
 {
   if (mImageBufferStart) {
     moz_free(mImageBufferStart);
     mImageBufferStart = nullptr;
     mImageBufferCurr = nullptr;
   }
 }
 // nsICOEncoder::InitFromData
 // Two output options are supported: format=<png|bmp>;bpp=<bpp_value>
 // format specifies whether to use png or bitmap format
 // bpp specifies the bits per pixel to use where bpp_value can be 24 or 32
 NS_IMETHODIMP nsICOEncoder::InitFromData(const uint8_t* aData,
                                          uint32_t aLength,
                                          uint32_t aWidth,
                                          uint32_t aHeight,
                                          uint32_t aStride,
                                          uint32_t aInputFormat,
                                          const nsAString& aOutputOptions)
 {
   // validate input format
   if (aInputFormat != INPUT_FORMAT_RGB &&
       aInputFormat != INPUT_FORMAT_RGBA &&
       aInputFormat != INPUT_FORMAT_HOSTARGB) {
     return NS_ERROR_INVALID_ARG;
   }
   // Stride is the padded width of each row, so it better be longer
   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");
     return NS_ERROR_INVALID_ARG;
   }
   nsresult rv;
   rv = StartImageEncode(aWidth, aHeight, aInputFormat, aOutputOptions);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = AddImageFrame(aData, aLength, aWidth, aHeight, aStride,
                      aInputFormat, aOutputOptions);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = EndImageEncode();
   return rv;
 }
 // Returns the number of bytes in the image buffer used
 // For an ICO file, this is all bytes in the buffer.
 NS_IMETHODIMP
 nsICOEncoder::GetImageBufferUsed(uint32_t *aOutputSize)
 {
   NS_ENSURE_ARG_POINTER(aOutputSize);
   *aOutputSize = mImageBufferSize;
   return NS_OK;
 }
 // Returns a pointer to the start of the image buffer
 NS_IMETHODIMP
 nsICOEncoder::GetImageBuffer(char **aOutputBuffer)
 {
   NS_ENSURE_ARG_POINTER(aOutputBuffer);
   *aOutputBuffer = reinterpret_cast<char*>(mImageBufferStart);
   return NS_OK;
 }
 NS_IMETHODIMP
 nsICOEncoder::AddImageFrame(const uint8_t* aData,
                             uint32_t aLength,
                             uint32_t aWidth,
                             uint32_t aHeight,
                             uint32_t aStride,
                             uint32_t aInputFormat,
                             const nsAString& aFrameOptions)
 {
   if (mUsePNG) {
     mContainedEncoder = new nsPNGEncoder();
     nsresult rv;
     nsAutoString noParams;
     rv = mContainedEncoder->InitFromData(aData, aLength, aWidth, aHeight,
                                          aStride, aInputFormat, noParams);
     NS_ENSURE_SUCCESS(rv, rv);
     uint32_t PNGImageBufferSize;
     mContainedEncoder->GetImageBufferUsed(&PNGImageBufferSize);
     mImageBufferSize = ICONFILEHEADERSIZE + ICODIRENTRYSIZE +
                        PNGImageBufferSize;
     mImageBufferStart = static_cast<uint8_t*>(moz_malloc(mImageBufferSize));
     if (!mImageBufferStart) {
       return NS_ERROR_OUT_OF_MEMORY;
     }
     mImageBufferCurr = mImageBufferStart;
     mICODirEntry.mBytesInRes = PNGImageBufferSize;
     EncodeFileHeader();
     EncodeInfoHeader();
     char *imageBuffer;
     rv = mContainedEncoder->GetImageBuffer(&imageBuffer);
     NS_ENSURE_SUCCESS(rv, rv);
     memcpy(mImageBufferCurr, imageBuffer, PNGImageBufferSize);
     mImageBufferCurr += PNGImageBufferSize;
   } else {
     mContainedEncoder = new nsBMPEncoder();
     nsresult rv;
     nsAutoString params;
     params.AppendLiteral("bpp=");
     params.AppendInt(mICODirEntry.mBitCount);
     rv = mContainedEncoder->InitFromData(aData, aLength, aWidth, aHeight,
                                          aStride, aInputFormat, params);
     NS_ENSURE_SUCCESS(rv, rv);
     uint32_t andMaskSize = ((GetRealWidth() + 31) / 32) * 4 * // row AND mask
                            GetRealHeight(); // num rows
     uint32_t BMPImageBufferSize;
     mContainedEncoder->GetImageBufferUsed(&BMPImageBufferSize);
     mImageBufferSize = ICONFILEHEADERSIZE + ICODIRENTRYSIZE +
                        BMPImageBufferSize + andMaskSize;
     mImageBufferStart = static_cast<uint8_t*>(moz_malloc(mImageBufferSize));
     if (!mImageBufferStart) {
       return NS_ERROR_OUT_OF_MEMORY;
     }
     mImageBufferCurr = mImageBufferStart;
     // The icon buffer does not include the BFH at all.
     mICODirEntry.mBytesInRes = BMPImageBufferSize - BFH_LENGTH + andMaskSize;
     // Encode the icon headers
     EncodeFileHeader();
     EncodeInfoHeader();
     char *imageBuffer;
     rv = mContainedEncoder->GetImageBuffer(&imageBuffer);
     NS_ENSURE_SUCCESS(rv, rv);
     memcpy(mImageBufferCurr, imageBuffer + BFH_LENGTH,
            BMPImageBufferSize - BFH_LENGTH);
     // We need to fix the BMP height to be *2 for the AND mask
     uint32_t fixedHeight = GetRealHeight() * 2;
     NativeEndian::swapToLittleEndianInPlace(&fixedHeight, 1);
     // The height is stored at an offset of 8 from the DIB header
     memcpy(mImageBufferCurr + 8, &fixedHeight, sizeof(fixedHeight));
     mImageBufferCurr += BMPImageBufferSize - BFH_LENGTH;
     // Calculate rowsize in DWORD's
     uint32_t rowSize = ((GetRealWidth() + 31) / 32) * 4; // + 31 to round up
     int32_t currentLine = GetRealHeight();
     // Write out the AND mask
     while (currentLine > 0) {
       currentLine--;
       uint8_t* encoded = mImageBufferCurr + currentLine * rowSize;
       uint8_t* encodedEnd = encoded + rowSize;
       while (encoded != encodedEnd) {
         *encoded = 0; // make everything visible
         encoded++;
       }
     }
     mImageBufferCurr += andMaskSize;
   }
   return NS_OK;
 }
 // See ::InitFromData for other info.
 NS_IMETHODIMP nsICOEncoder::StartImageEncode(uint32_t aWidth,
                                              uint32_t aHeight,
                                              uint32_t aInputFormat,
                                              const nsAString& aOutputOptions)
 {
   // can't initialize more than once
   if (mImageBufferStart || mImageBufferCurr) {
     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;
   }
   // Icons are only 1 byte, so make sure our bitmap is in range
   if (aWidth > 256 || aHeight > 256) {
     return NS_ERROR_INVALID_ARG;
   }
   // parse and check any provided output options
   uint32_t bpp = 24;
   bool usePNG = true;
   nsresult rv = ParseOptions(aOutputOptions, &bpp, &usePNG);
   NS_ENSURE_SUCCESS(rv, rv);
   mUsePNG = usePNG;
   InitFileHeader();
   // The width and height are stored as 0 when we have a value of 256
   InitInfoHeader(bpp, aWidth == 256 ? 0 : (uint8_t)aWidth,
                  aHeight == 256 ? 0 : (uint8_t)aHeight);
   return NS_OK;
 }
 NS_IMETHODIMP nsICOEncoder::EndImageEncode()
 {
   // must be initialized
   if (!mImageBufferStart || !mImageBufferCurr) {
     return NS_ERROR_NOT_INITIALIZED;
   }
   mFinished = true;
   NotifyListener();
   // if output callback can't get enough memory, it will free our buffer
   if (!mImageBufferStart || !mImageBufferCurr) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
   return NS_OK;
 }
 // Parses the encoder options and sets the bits per pixel to use and PNG or BMP
 // See InitFromData for a description of the parse options
 nsresult
 nsICOEncoder::ParseOptions(const nsAString& aOptions, uint32_t* bpp,
                            bool *usePNG)
 {
   // If no parsing options just use the default of 24BPP and PNG yes
   if (aOptions.Length() == 0) {
     if (usePNG) {
       *usePNG = true;
     }
     if (bpp) {
       *bpp = 24;
     }
   }
   // Parse the input string into a set of name/value pairs.
   // From format: format=<png|bmp>;bpp=<bpp_value>
   // to format: [0] = format=<png|bmp>, [1] = bpp=<bpp_value>
   nsTArray<nsCString> nameValuePairs;
   if (!ParseString(NS_ConvertUTF16toUTF8(aOptions), ';', nameValuePairs)) {
     return NS_ERROR_INVALID_ARG;
   }
   // For each name/value pair in the set
   for (unsigned i = 0; i < nameValuePairs.Length(); ++i) {
     // Split the name value pair [0] = name, [1] = value
     nsTArray<nsCString> nameValuePair;
     if (!ParseString(nameValuePairs[i], '=', nameValuePair)) {
       return NS_ERROR_INVALID_ARG;
     }
     if (nameValuePair.Length() != 2) {
       return NS_ERROR_INVALID_ARG;
     }
     // Parse the format portion of the string format=<png|bmp>;bpp=<bpp_value>
     if (nameValuePair[0].Equals("format", nsCaseInsensitiveCStringComparator())) {
       if (nameValuePair[1].Equals("png", nsCaseInsensitiveCStringComparator())) {
         *usePNG = true;
       }
       else if (nameValuePair[1].Equals("bmp", nsCaseInsensitiveCStringComparator())) {
         *usePNG = false;
       }
       else {
         return NS_ERROR_INVALID_ARG;
       }
     }
     // Parse the bpp portion of the string format=<png|bmp>;bpp=<bpp_value>
     if (nameValuePair[0].Equals("bpp", nsCaseInsensitiveCStringComparator())) {
       if (nameValuePair[1].Equals("24")) {
         *bpp = 24;
       }
       else if (nameValuePair[1].Equals("32")) {
         *bpp = 32;
       }
       else {
         return NS_ERROR_INVALID_ARG;
       }
     }
   }
   return NS_OK;
 }
 NS_IMETHODIMP nsICOEncoder::Close()
 {
   if (mImageBufferStart) {
     moz_free(mImageBufferStart);
     mImageBufferStart = nullptr;
     mImageBufferSize = 0;
     mImageBufferReadPoint = 0;
     mImageBufferCurr = nullptr;
   }
   return NS_OK;
 }
 // Obtains the available bytes to read
 NS_IMETHODIMP nsICOEncoder::Available(uint64_t *_retval)
 {
   if (!mImageBufferStart || !mImageBufferCurr) {
     return NS_BASE_STREAM_CLOSED;
   }
   *_retval = GetCurrentImageBufferOffset() - mImageBufferReadPoint;
   return NS_OK;
 }
 // [noscript] Reads bytes which are available
 NS_IMETHODIMP nsICOEncoder::Read(char *aBuf, uint32_t aCount,
                                  uint32_t *_retval)
 {
   return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, _retval);
 }
 // [noscript] Reads segments
 NS_IMETHODIMP nsICOEncoder::ReadSegments(nsWriteSegmentFun aWriter,
                                          void *aClosure, uint32_t aCount,
                                          uint32_t *_retval)
 {
   uint32_t maxCount = GetCurrentImageBufferOffset() - 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*>(mImageBufferStart +
                                                       mImageBufferReadPoint),
 , 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;
 }
 NS_IMETHODIMP
 nsICOEncoder::IsNonBlocking(bool *_retval)
 {
   *_retval = true;
   return NS_OK;
 }
 NS_IMETHODIMP
 nsICOEncoder::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 nsICOEncoder::CloseWithStatus(nsresult aStatus)
 {
   return Close();
 }
 void
 nsICOEncoder::NotifyListener()
 {
   if (mCallback &&
       (GetCurrentImageBufferOffset() - mImageBufferReadPoint >= mNotifyThreshold ||
        mFinished)) {
     nsCOMPtr<nsIInputStreamCallback> callback;
     if (mCallbackTarget) {
       callback = NS_NewInputStreamReadyEvent(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);
   }
 }
 // Initializes the icon file header mICOFileHeader
 void
 nsICOEncoder::InitFileHeader()
 {
   memset(&mICOFileHeader, 0, sizeof(mICOFileHeader));
   mICOFileHeader.mReserved = 0;
   mICOFileHeader.mType = 1;
   mICOFileHeader.mCount = 1;
 }
 // Initializes the icon directory info header mICODirEntry
 void
 nsICOEncoder::InitInfoHeader(uint32_t aBPP, uint8_t aWidth, uint8_t aHeight)
 {
   memset(&mICODirEntry, 0, sizeof(mICODirEntry));
   mICODirEntry.mBitCount = aBPP;
   mICODirEntry.mBytesInRes = 0;
   mICODirEntry.mColorCount = 0;
   mICODirEntry.mWidth = aWidth;
   mICODirEntry.mHeight = aHeight;
   mICODirEntry.mImageOffset = ICONFILEHEADERSIZE + ICODIRENTRYSIZE;
   mICODirEntry.mPlanes = 1;
   mICODirEntry.mReserved = 0;
 }
 // Encodes the icon file header mICOFileHeader
 void
 nsICOEncoder::EncodeFileHeader()
 {
   IconFileHeader littleEndianIFH = mICOFileHeader;
   NativeEndian::swapToLittleEndianInPlace(&littleEndianIFH.mReserved, 1);
   NativeEndian::swapToLittleEndianInPlace(&littleEndianIFH.mType, 1);
   NativeEndian::swapToLittleEndianInPlace(&littleEndianIFH.mCount, 1);
   memcpy(mImageBufferCurr, &littleEndianIFH.mReserved,
          sizeof(littleEndianIFH.mReserved));
   mImageBufferCurr += sizeof(littleEndianIFH.mReserved);
   memcpy(mImageBufferCurr, &littleEndianIFH.mType,
          sizeof(littleEndianIFH.mType));
   mImageBufferCurr += sizeof(littleEndianIFH.mType);
   memcpy(mImageBufferCurr, &littleEndianIFH.mCount,
          sizeof(littleEndianIFH.mCount));
   mImageBufferCurr += sizeof(littleEndianIFH.mCount);
 }
 // Encodes the icon directory info header mICODirEntry
 void
 nsICOEncoder::EncodeInfoHeader()
 {
   IconDirEntry littleEndianmIDE = mICODirEntry;
   NativeEndian::swapToLittleEndianInPlace(&littleEndianmIDE.mPlanes, 1);
   NativeEndian::swapToLittleEndianInPlace(&littleEndianmIDE.mBitCount, 1);
   NativeEndian::swapToLittleEndianInPlace(&littleEndianmIDE.mBytesInRes, 1);
   NativeEndian::swapToLittleEndianInPlace(&littleEndianmIDE.mImageOffset, 1);
   memcpy(mImageBufferCurr, &littleEndianmIDE.mWidth,
          sizeof(littleEndianmIDE.mWidth));
   mImageBufferCurr += sizeof(littleEndianmIDE.mWidth);
   memcpy(mImageBufferCurr, &littleEndianmIDE.mHeight,
          sizeof(littleEndianmIDE.mHeight));
   mImageBufferCurr += sizeof(littleEndianmIDE.mHeight);
   memcpy(mImageBufferCurr, &littleEndianmIDE.mColorCount,
          sizeof(littleEndianmIDE.mColorCount));
   mImageBufferCurr += sizeof(littleEndianmIDE.mColorCount);
   memcpy(mImageBufferCurr, &littleEndianmIDE.mReserved,
          sizeof(littleEndianmIDE.mReserved));
   mImageBufferCurr += sizeof(littleEndianmIDE.mReserved);
   memcpy(mImageBufferCurr, &littleEndianmIDE.mPlanes,
          sizeof(littleEndianmIDE.mPlanes));
   mImageBufferCurr += sizeof(littleEndianmIDE.mPlanes);
   memcpy(mImageBufferCurr, &littleEndianmIDE.mBitCount,
          sizeof(littleEndianmIDE.mBitCount));
   mImageBufferCurr += sizeof(littleEndianmIDE.mBitCount);
   memcpy(mImageBufferCurr, &littleEndianmIDE.mBytesInRes,
          sizeof(littleEndianmIDE.mBytesInRes));
   mImageBufferCurr += sizeof(littleEndianmIDE.mBytesInRes);
   memcpy(mImageBufferCurr, &littleEndianmIDE.mImageOffset,
          sizeof(littleEndianmIDE.mImageOffset));
   mImageBufferCurr += sizeof(littleEndianmIDE.mImageOffset);
 }

The Tor Browser / annotate

image/encoders/ico/nsICOEncoder.cpp@b8a032363ba2 (annotated)

image/encoders/ico/nsICOEncoder.cpp