/*static*/ uint64_t SkBitmapChecksummer::Compute64Internal(
const SkBitmap& bitmap, const SkBitmapTransformer& transformer) {
size_t pixelBufferSize = transformer.bytesNeededTotal();
size_t totalBufferSize = pixelBufferSize + 8; // leave room for x/y dimensions
SkAutoMalloc bufferManager(totalBufferSize);
char *bufferStart = static_cast<char *>(bufferManager.get());
char *bufPtr = bufferStart;
// start with the x/y dimensions
write_int_to_buffer(bitmap.width(), bufPtr);
bufPtr += 4;
write_int_to_buffer(bitmap.height(), bufPtr);
bufPtr += 4;
// add all the pixel data
if (!transformer.copyBitmapToPixelBuffer(bufPtr, pixelBufferSize)) {
return 0;
}
return SkCityHash::Compute64(bufferStart, totalBufferSize);
}
/*static*/ bool SkBitmapHasher::ComputeDigestInternal(const SkBitmap& bitmap,
SkHashDigest *result) {
size_t pixelBufferSize = bitmap.width() * bitmap.height() * 4;
size_t totalBufferSize = pixelBufferSize + 2 * sizeof(uint32_t);
SkAutoMalloc bufferManager(totalBufferSize);
char *bufferStart = static_cast<char *>(bufferManager.get());
SkMemoryWStream out(bufferStart, totalBufferSize);
// start with the x/y dimensions
write_int_to_buffer(SkToU32(bitmap.width()), &out);
write_int_to_buffer(SkToU32(bitmap.height()), &out);
// add all the pixel data
SkAutoTDelete<SkImageEncoder> enc(CreateARGBImageEncoder());
if (!enc->encodeStream(&out, bitmap, SkImageEncoder::kDefaultQuality)) {
return false;
}
*result = SkCityHash::Compute64(bufferStart, totalBufferSize);
return true;
}
