libs/hwui/jni/ImageDecoder.cpp - platform/frameworks/base - Gitiles

 /*
  * Copyright (C) 2017 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "Bitmap.h"
 #include "BitmapFactory.h"
 #include "ByteBufferStreamAdaptor.h"
 #include "CreateJavaOutputStreamAdaptor.h"
 #include "GraphicsJNI.h"
 #include "ImageDecoder.h"
 #include "NinePatchPeeker.h"
 #include "Utils.h"

 #include <hwui/Bitmap.h>
 #include <hwui/ImageDecoder.h>
 #include <HardwareBitmapUploader.h>

 #include <SkAndroidCodec.h>
 #include <SkEncodedImageFormat.h>
 #include <SkFrontBufferedStream.h>
 #include <SkStream.h>

 #include <androidfw/Asset.h>
 #include <fcntl.h>
 #include <sys/stat.h>

 using namespace android;

 static jclass    gImageDecoder_class;
 static jclass    gSize_class;
 static jclass    gDecodeException_class;
 static jclass    gCanvas_class;
 static jmethodID gImageDecoder_constructorMethodID;
 static jmethodID gImageDecoder_postProcessMethodID;
 static jmethodID gSize_constructorMethodID;
 static jmethodID gDecodeException_constructorMethodID;
 static jmethodID gCallback_onPartialImageMethodID;
 static jmethodID gCanvas_constructorMethodID;
 static jmethodID gCanvas_releaseMethodID;

 // These need to stay in sync with ImageDecoder.java's Allocator constants.
 enum Allocator {
     kDefault_Allocator      = 0,
     kSoftware_Allocator     = 1,
     kSharedMemory_Allocator = 2,
     kHardware_Allocator     = 3,
 };

 // These need to stay in sync with ImageDecoder.java's Error constants.
 enum Error {
     kSourceException     = 1,
     kSourceIncomplete    = 2,
     kSourceMalformedData = 3,
 };

 // These need to stay in sync with PixelFormat.java's Format constants.
 enum PixelFormat {
     kUnknown     =  0,
     kTranslucent = -3,
     kOpaque      = -1,
 };

 // Clear and return any pending exception for handling other than throwing directly.
 static jthrowable get_and_clear_exception(JNIEnv* env) {
     jthrowable jexception = env->ExceptionOccurred();
     if (jexception) {
         env->ExceptionClear();
     }
     return jexception;
 }

 // Throw a new ImageDecoder.DecodeException. Returns null for convenience.
 static jobject throw_exception(JNIEnv* env, Error error, const char* msg,
                                jthrowable cause, jobject source) {
     jstring jstr = nullptr;
     if (msg) {
         jstr = env->NewStringUTF(msg);
         if (!jstr) {
             // Out of memory.
             return nullptr;
         }
     }
     jthrowable exception = (jthrowable) env->NewObject(gDecodeException_class,
             gDecodeException_constructorMethodID, error, jstr, cause, source);
     // Only throw if not out of memory.
     if (exception) {
         env->Throw(exception);
     }
     return nullptr;
 }

 static jobject native_create(JNIEnv* env, std::unique_ptr<SkStream> stream,
         jobject source, jboolean preferAnimation) {
     if (!stream.get()) {
         return throw_exception(env, kSourceMalformedData, "Failed to create a stream",
                                nullptr, source);
     }
     sk_sp<NinePatchPeeker> peeker(new NinePatchPeeker);
     SkCodec::Result result;
     auto codec = SkCodec::MakeFromStream(
             std::move(stream), &result, peeker.get(),
             preferAnimation ? SkCodec::SelectionPolicy::kPreferAnimation
                             : SkCodec::SelectionPolicy::kPreferStillImage);
     if (jthrowable jexception = get_and_clear_exception(env)) {
         return throw_exception(env, kSourceException, "", jexception, source);
     }
     if (!codec) {
         switch (result) {
             case SkCodec::kIncompleteInput:
                 return throw_exception(env, kSourceIncomplete, "", nullptr, source);
             default:
                 SkString msg;
                 msg.printf("Failed to create image decoder with message '%s'",
                            SkCodec::ResultToString(result));
                 return throw_exception(env, kSourceMalformedData,  msg.c_str(),
                                        nullptr, source);

         }
     }

     const bool animated = codec->getFrameCount() > 1;
     if (jthrowable jexception = get_and_clear_exception(env)) {
         return throw_exception(env, kSourceException, "", jexception, source);
     }

     auto androidCodec = SkAndroidCodec::MakeFromCodec(std::move(codec),
             SkAndroidCodec::ExifOrientationBehavior::kRespect);
     if (!androidCodec.get()) {
         return throw_exception(env, kSourceMalformedData, "", nullptr, source);
     }

     const auto& info = androidCodec->getInfo();
     const int width = info.width();
     const int height = info.height();
     const bool isNinePatch = peeker->mPatch != nullptr;
     ImageDecoder* decoder = new ImageDecoder(std::move(androidCodec), std::move(peeker));
     return env->NewObject(gImageDecoder_class, gImageDecoder_constructorMethodID,
                           reinterpret_cast<jlong>(decoder), width, height,
                           animated, isNinePatch);
 }

 static jobject ImageDecoder_nCreateFd(JNIEnv* env, jobject /*clazz*/,
         jobject fileDescriptor, jboolean preferAnimation, jobject source) {
 #ifndef __ANDROID__ // LayoutLib for Windows does not support F_DUPFD_CLOEXEC
     return throw_exception(env, kSourceException, "Only supported on Android", nullptr, source);
 #else
     int descriptor = jniGetFDFromFileDescriptor(env, fileDescriptor);

     struct stat fdStat;
     if (fstat(descriptor, &fdStat) == -1) {
         return throw_exception(env, kSourceMalformedData,
                                "broken file descriptor; fstat returned -1", nullptr, source);
     }

     int dupDescriptor = fcntl(descriptor, F_DUPFD_CLOEXEC, 0);
     FILE* file = fdopen(dupDescriptor, "r");
     if (file == NULL) {
         close(dupDescriptor);
         return throw_exception(env, kSourceMalformedData, "Could not open file",
                                nullptr, source);
     }

     std::unique_ptr<SkFILEStream> fileStream(new SkFILEStream(file));
     return native_create(env, std::move(fileStream), source, preferAnimation);
 #endif
 }

 static jobject ImageDecoder_nCreateInputStream(JNIEnv* env, jobject /*clazz*/,
         jobject is, jbyteArray storage, jboolean preferAnimation, jobject source) {
     std::unique_ptr<SkStream> stream(CreateJavaInputStreamAdaptor(env, is, storage, false));

     if (!stream.get()) {
         return throw_exception(env, kSourceMalformedData, "Failed to create a stream",
                                nullptr, source);
     }

     std::unique_ptr<SkStream> bufferedStream(
         SkFrontBufferedStream::Make(std::move(stream),
         SkCodec::MinBufferedBytesNeeded()));
     return native_create(env, std::move(bufferedStream), source, preferAnimation);
 }

 static jobject ImageDecoder_nCreateAsset(JNIEnv* env, jobject /*clazz*/,
         jlong assetPtr, jboolean preferAnimation, jobject source) {
     Asset* asset = reinterpret_cast<Asset*>(assetPtr);
     std::unique_ptr<SkStream> stream(new AssetStreamAdaptor(asset));
     return native_create(env, std::move(stream), source, preferAnimation);
 }

 static jobject ImageDecoder_nCreateByteBuffer(JNIEnv* env, jobject /*clazz*/,
         jobject jbyteBuffer, jint initialPosition, jint limit,
         jboolean preferAnimation, jobject source) {
     std::unique_ptr<SkStream> stream = CreateByteBufferStreamAdaptor(env, jbyteBuffer,
                                                                      initialPosition, limit);
     if (!stream) {
         return throw_exception(env, kSourceMalformedData, "Failed to read ByteBuffer",
                                nullptr, source);
     }
     return native_create(env, std::move(stream), source, preferAnimation);
 }

 static jobject ImageDecoder_nCreateByteArray(JNIEnv* env, jobject /*clazz*/,
         jbyteArray byteArray, jint offset, jint length,
         jboolean preferAnimation, jobject source) {
     std::unique_ptr<SkStream> stream(CreateByteArrayStreamAdaptor(env, byteArray, offset, length));
     return native_create(env, std::move(stream), source, preferAnimation);
 }

 jint postProcessAndRelease(JNIEnv* env, jobject jimageDecoder, std::unique_ptr<Canvas> canvas) {
     jobject jcanvas = env->NewObject(gCanvas_class, gCanvas_constructorMethodID,
                                      reinterpret_cast<jlong>(canvas.get()));
     if (!jcanvas) {
         doThrowOOME(env, "Failed to create Java Canvas for PostProcess!");
         return kUnknown;
     }

     // jcanvas now owns canvas.
     canvas.release();

     return env->CallIntMethod(jimageDecoder, gImageDecoder_postProcessMethodID, jcanvas);
 }

 static jobject ImageDecoder_nDecodeBitmap(JNIEnv* env, jobject /*clazz*/, jlong nativePtr,
                                           jobject jdecoder, jboolean jpostProcess,
                                           jint targetWidth, jint targetHeight, jobject jsubset,
                                           jboolean requireMutable, jint allocator,
                                           jboolean requireUnpremul, jboolean preferRamOverQuality,
                                           jboolean asAlphaMask, jlong colorSpaceHandle,
                                           jboolean extended) {
     auto* decoder = reinterpret_cast<ImageDecoder*>(nativePtr);
     if (!decoder->setTargetSize(targetWidth, targetHeight)) {
         doThrowISE(env, "Could not scale to target size!");
         return nullptr;
     }
     if (requireUnpremul && !decoder->setUnpremultipliedRequired(true)) {
         doThrowISE(env, "Cannot scale unpremultiplied pixels!");
         return nullptr;
     }

     SkColorType colorType = kN32_SkColorType;
     if (asAlphaMask && decoder->gray()) {
         // We have to trick Skia to decode this to a single channel.
         colorType = kGray_8_SkColorType;
     } else if (preferRamOverQuality) {
         // FIXME: The post-process might add alpha, which would make a 565
         // result incorrect. If we call the postProcess before now and record
         // to a picture, we can know whether alpha was added, and if not, we
         // can still use 565.
         if (decoder->opaque() && !jpostProcess) {
             // If the final result will be hardware, decoding to 565 and then
             // uploading to the gpu as 8888 will not save memory. This still
             // may save us from using F16, but do not go down to 565.
             if (allocator != kHardware_Allocator &&
                (allocator != kDefault_Allocator || requireMutable)) {
                 colorType = kRGB_565_SkColorType;
             }
         }
         // Otherwise, stick with N32
     } else if (extended) {
         colorType = kRGBA_F16_SkColorType;
     } else {
         colorType = decoder->mCodec->computeOutputColorType(colorType);
     }

     const bool isHardware = !requireMutable
         && (allocator == kDefault_Allocator ||
             allocator == kHardware_Allocator)
         && colorType != kGray_8_SkColorType;

     if (colorType == kRGBA_F16_SkColorType && isHardware &&
             !uirenderer::HardwareBitmapUploader::hasFP16Support()) {
         colorType = kN32_SkColorType;
     }

     if (!decoder->setOutColorType(colorType)) {
         doThrowISE(env, "Failed to set out color type!");
         return nullptr;
     }

     {
         sk_sp<SkColorSpace> colorSpace = GraphicsJNI::getNativeColorSpace(colorSpaceHandle);
         colorSpace = decoder->mCodec->computeOutputColorSpace(colorType, colorSpace);
         decoder->setOutColorSpace(std::move(colorSpace));
     }

     if (jsubset) {
         SkIRect subset;
         GraphicsJNI::jrect_to_irect(env, jsubset, &subset);
         if (!decoder->setCropRect(&subset)) {
             doThrowISE(env, "Invalid crop rect!");
             return nullptr;
         }
     }

     SkImageInfo bitmapInfo = decoder->getOutputInfo();
     if (asAlphaMask && colorType == kGray_8_SkColorType) {
         bitmapInfo = bitmapInfo.makeColorType(kAlpha_8_SkColorType);
     }

     SkBitmap bm;
     if (!bm.setInfo(bitmapInfo)) {
         doThrowIOE(env, "Failed to setInfo properly");
         return nullptr;
     }

     sk_sp<Bitmap> nativeBitmap;
     if (allocator == kSharedMemory_Allocator) {
         nativeBitmap = Bitmap::allocateAshmemBitmap(&bm);
     } else {
         nativeBitmap = Bitmap::allocateHeapBitmap(&bm);
     }
     if (!nativeBitmap) {
         SkString msg;
         msg.printf("OOM allocating Bitmap with dimensions %i x %i",
                 bitmapInfo.width(), bitmapInfo.height());
         doThrowOOME(env, msg.c_str());
         return nullptr;
     }

     SkCodec::Result result = decoder->decode(bm.getPixels(), bm.rowBytes());
     jthrowable jexception = get_and_clear_exception(env);
     int onPartialImageError = jexception ? kSourceException
                                          : 0; // No error.
     switch (result) {
         case SkCodec::kSuccess:
             // Ignore the exception, since the decode was successful anyway.
             jexception = nullptr;
             onPartialImageError = 0;
             break;
         case SkCodec::kIncompleteInput:
             if (!jexception) {
                 onPartialImageError = kSourceIncomplete;
             }
             break;
         case SkCodec::kErrorInInput:
             if (!jexception) {
                 onPartialImageError = kSourceMalformedData;
             }
             break;
         default:
             SkString msg;
             msg.printf("getPixels failed with error %s", SkCodec::ResultToString(result));
             doThrowIOE(env, msg.c_str());
             return nullptr;
     }

     if (onPartialImageError) {
         env->CallVoidMethod(jdecoder, gCallback_onPartialImageMethodID, onPartialImageError,
                 jexception);
         if (env->ExceptionCheck()) {
             return nullptr;
         }
     }

     jbyteArray ninePatchChunk = nullptr;
     jobject ninePatchInsets = nullptr;

     // Ignore ninepatch when post-processing.
     if (!jpostProcess) {
         // FIXME: Share more code with BitmapFactory.cpp.
         auto* peeker = reinterpret_cast<NinePatchPeeker*>(decoder->mPeeker.get());
         if (peeker->mPatch != nullptr) {
             size_t ninePatchArraySize = peeker->mPatch->serializedSize();
             ninePatchChunk = env->NewByteArray(ninePatchArraySize);
             if (ninePatchChunk == nullptr) {
                 doThrowOOME(env, "Failed to allocate nine patch chunk.");
                 return nullptr;
             }

             env->SetByteArrayRegion(ninePatchChunk, 0, peeker->mPatchSize,
                                     reinterpret_cast<jbyte*>(peeker->mPatch));
         }

         if (peeker->mHasInsets) {
             ninePatchInsets = peeker->createNinePatchInsets(env, 1.0f);
             if (ninePatchInsets == nullptr) {
                 doThrowOOME(env, "Failed to allocate nine patch insets.");
                 return nullptr;
             }
         }
     }

     if (jpostProcess) {
         std::unique_ptr<Canvas> canvas(Canvas::create_canvas(bm));

         jint pixelFormat = postProcessAndRelease(env, jdecoder, std::move(canvas));
         if (env->ExceptionCheck()) {
             return nullptr;
         }

         SkAlphaType newAlphaType = bm.alphaType();
         switch (pixelFormat) {
             case kUnknown:
                 break;
             case kTranslucent:
                 newAlphaType = kPremul_SkAlphaType;
                 break;
             case kOpaque:
                 newAlphaType = kOpaque_SkAlphaType;
                 break;
             default:
                 SkString msg;
                 msg.printf("invalid return from postProcess: %i", pixelFormat);
                 doThrowIAE(env, msg.c_str());
                 return nullptr;
         }

         if (newAlphaType != bm.alphaType()) {
             if (!bm.setAlphaType(newAlphaType)) {
                 SkString msg;
                 msg.printf("incompatible return from postProcess: %i", pixelFormat);
                 doThrowIAE(env, msg.c_str());
                 return nullptr;
             }
             nativeBitmap->setAlphaType(newAlphaType);
         }
     }

     int bitmapCreateFlags = 0x0;
     if (!requireUnpremul) {
         // Even if the image is opaque, setting this flag means that
         // if alpha is added (e.g. by PostProcess), it will be marked as
         // premultiplied.
         bitmapCreateFlags |= bitmap::kBitmapCreateFlag_Premultiplied;
     }

     if (requireMutable) {
         bitmapCreateFlags |= bitmap::kBitmapCreateFlag_Mutable;
     } else {
         if (isHardware) {
             sk_sp<Bitmap> hwBitmap = Bitmap::allocateHardwareBitmap(bm);
             if (hwBitmap) {
                 hwBitmap->setImmutable();
                 return bitmap::createBitmap(env, hwBitmap.release(), bitmapCreateFlags,
                                             ninePatchChunk, ninePatchInsets);
             }
             if (allocator == kHardware_Allocator) {
                 doThrowOOME(env, "failed to allocate hardware Bitmap!");
                 return nullptr;
             }
             // If we failed to create a hardware bitmap, go ahead and create a
             // software one.
         }

         nativeBitmap->setImmutable();
     }
     return bitmap::createBitmap(env, nativeBitmap.release(), bitmapCreateFlags, ninePatchChunk,
                                 ninePatchInsets);
 }

 static jobject ImageDecoder_nGetSampledSize(JNIEnv* env, jobject /*clazz*/, jlong nativePtr,
                                             jint sampleSize) {
     auto* decoder = reinterpret_cast<ImageDecoder*>(nativePtr);
     SkISize size = decoder->mCodec->getSampledDimensions(sampleSize);
     return env->NewObject(gSize_class, gSize_constructorMethodID, size.width(), size.height());
 }

 static void ImageDecoder_nGetPadding(JNIEnv* env, jobject /*clazz*/, jlong nativePtr,
                                      jobject outPadding) {
     auto* decoder = reinterpret_cast<ImageDecoder*>(nativePtr);
     reinterpret_cast<NinePatchPeeker*>(decoder->mPeeker.get())->getPadding(env, outPadding);
 }

 static void ImageDecoder_nClose(JNIEnv* /*env*/, jobject /*clazz*/, jlong nativePtr) {
     delete reinterpret_cast<ImageDecoder*>(nativePtr);
 }

 static jstring ImageDecoder_nGetMimeType(JNIEnv* env, jobject /*clazz*/, jlong nativePtr) {
     auto* decoder = reinterpret_cast<ImageDecoder*>(nativePtr);
     return getMimeTypeAsJavaString(env, decoder->mCodec->getEncodedFormat());
 }

 static jobject ImageDecoder_nGetColorSpace(JNIEnv* env, jobject /*clazz*/, jlong nativePtr) {
     auto* codec = reinterpret_cast<ImageDecoder*>(nativePtr)->mCodec.get();
     auto colorType = codec->computeOutputColorType(kN32_SkColorType);
     sk_sp<SkColorSpace> colorSpace = codec->computeOutputColorSpace(colorType);
     return GraphicsJNI::getColorSpace(env, colorSpace.get(), colorType);
 }

 static const JNINativeMethod gImageDecoderMethods[] = {
     { "nCreate",        "(JZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;",    (void*) ImageDecoder_nCreateAsset },
     { "nCreate",        "(Ljava/nio/ByteBuffer;IIZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;", (void*) ImageDecoder_nCreateByteBuffer },
     { "nCreate",        "([BIIZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;", (void*) ImageDecoder_nCreateByteArray },
     { "nCreate",        "(Ljava/io/InputStream;[BZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;", (void*) ImageDecoder_nCreateInputStream },
     { "nCreate",        "(Ljava/io/FileDescriptor;ZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;", (void*) ImageDecoder_nCreateFd },
     { "nDecodeBitmap",  "(JLandroid/graphics/ImageDecoder;ZIILandroid/graphics/Rect;ZIZZZJZ)Landroid/graphics/Bitmap;",
                                                                  (void*) ImageDecoder_nDecodeBitmap },
     { "nGetSampledSize","(JI)Landroid/util/Size;",               (void*) ImageDecoder_nGetSampledSize },
     { "nGetPadding",    "(JLandroid/graphics/Rect;)V",           (void*) ImageDecoder_nGetPadding },
     { "nClose",         "(J)V",                                  (void*) ImageDecoder_nClose},
     { "nGetMimeType",   "(J)Ljava/lang/String;",                 (void*) ImageDecoder_nGetMimeType },
     { "nGetColorSpace", "(J)Landroid/graphics/ColorSpace;",      (void*) ImageDecoder_nGetColorSpace },
 };

 int register_android_graphics_ImageDecoder(JNIEnv* env) {
     gImageDecoder_class = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/graphics/ImageDecoder"));
     gImageDecoder_constructorMethodID = GetMethodIDOrDie(env, gImageDecoder_class, "<init>", "(JIIZZ)V");
     gImageDecoder_postProcessMethodID = GetMethodIDOrDie(env, gImageDecoder_class, "postProcessAndRelease", "(Landroid/graphics/Canvas;)I");

     gSize_class = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/util/Size"));
     gSize_constructorMethodID = GetMethodIDOrDie(env, gSize_class, "<init>", "(II)V");

     gDecodeException_class = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/graphics/ImageDecoder$DecodeException"));
     gDecodeException_constructorMethodID = GetMethodIDOrDie(env, gDecodeException_class, "<init>", "(ILjava/lang/String;Ljava/lang/Throwable;Landroid/graphics/ImageDecoder$Source;)V");

     gCallback_onPartialImageMethodID = GetMethodIDOrDie(env, gImageDecoder_class, "onPartialImage", "(ILjava/lang/Throwable;)V");

     gCanvas_class = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/graphics/Canvas"));
     gCanvas_constructorMethodID = GetMethodIDOrDie(env, gCanvas_class, "<init>", "(J)V");
     gCanvas_releaseMethodID = GetMethodIDOrDie(env, gCanvas_class, "release", "()V");

     return android::RegisterMethodsOrDie(env, "android/graphics/ImageDecoder", gImageDecoderMethods,
                                          NELEM(gImageDecoderMethods));
 }
	/*
	* Copyright (C) 2017 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "Bitmap.h"
	#include "BitmapFactory.h"
	#include "ByteBufferStreamAdaptor.h"
	#include "CreateJavaOutputStreamAdaptor.h"
	#include "GraphicsJNI.h"
	#include "ImageDecoder.h"
	#include "NinePatchPeeker.h"
	#include "Utils.h"

	#include <hwui/Bitmap.h>
	#include <hwui/ImageDecoder.h>
	#include <HardwareBitmapUploader.h>

	#include <SkAndroidCodec.h>
	#include <SkEncodedImageFormat.h>
	#include <SkFrontBufferedStream.h>
	#include <SkStream.h>

	#include <androidfw/Asset.h>
	#include <fcntl.h>
	#include <sys/stat.h>

	using namespace android;

	static jclass gImageDecoder_class;
	static jclass gSize_class;
	static jclass gDecodeException_class;
	static jclass gCanvas_class;
	static jmethodID gImageDecoder_constructorMethodID;
	static jmethodID gImageDecoder_postProcessMethodID;
	static jmethodID gSize_constructorMethodID;
	static jmethodID gDecodeException_constructorMethodID;
	static jmethodID gCallback_onPartialImageMethodID;
	static jmethodID gCanvas_constructorMethodID;
	static jmethodID gCanvas_releaseMethodID;

	// These need to stay in sync with ImageDecoder.java's Allocator constants.
	enum Allocator {
	kDefault_Allocator = 0,
	kSoftware_Allocator = 1,
	kSharedMemory_Allocator = 2,
	kHardware_Allocator = 3,
	};

	// These need to stay in sync with ImageDecoder.java's Error constants.
	enum Error {
	kSourceException = 1,
	kSourceIncomplete = 2,
	kSourceMalformedData = 3,
	};

	// These need to stay in sync with PixelFormat.java's Format constants.
	enum PixelFormat {
	kUnknown = 0,
	kTranslucent = -3,
	kOpaque = -1,
	};

	// Clear and return any pending exception for handling other than throwing directly.
	static jthrowable get_and_clear_exception(JNIEnv* env) {
	jthrowable jexception = env->ExceptionOccurred();
	if (jexception) {
	env->ExceptionClear();
	}
	return jexception;
	}

	// Throw a new ImageDecoder.DecodeException. Returns null for convenience.
	static jobject throw_exception(JNIEnv* env, Error error, const char* msg,
	jthrowable cause, jobject source) {
	jstring jstr = nullptr;
	if (msg) {
	jstr = env->NewStringUTF(msg);
	if (!jstr) {
	// Out of memory.
	return nullptr;
	}
	}
	jthrowable exception = (jthrowable) env->NewObject(gDecodeException_class,
	gDecodeException_constructorMethodID, error, jstr, cause, source);
	// Only throw if not out of memory.
	if (exception) {
	env->Throw(exception);
	}
	return nullptr;
	}

	static jobject native_create(JNIEnv* env, std::unique_ptr<SkStream> stream,
	jobject source, jboolean preferAnimation) {
	if (!stream.get()) {
	return throw_exception(env, kSourceMalformedData, "Failed to create a stream",
	nullptr, source);
	}
	sk_sp<NinePatchPeeker> peeker(new NinePatchPeeker);
	SkCodec::Result result;
	auto codec = SkCodec::MakeFromStream(
	std::move(stream), &result, peeker.get(),
	preferAnimation ? SkCodec::SelectionPolicy::kPreferAnimation
	: SkCodec::SelectionPolicy::kPreferStillImage);
	if (jthrowable jexception = get_and_clear_exception(env)) {
	return throw_exception(env, kSourceException, "", jexception, source);
	}
	if (!codec) {
	switch (result) {
	case SkCodec::kIncompleteInput:
	return throw_exception(env, kSourceIncomplete, "", nullptr, source);
	default:
	SkString msg;
	msg.printf("Failed to create image decoder with message '%s'",
	SkCodec::ResultToString(result));
	return throw_exception(env, kSourceMalformedData, msg.c_str(),
	nullptr, source);

	}
	}

	const bool animated = codec->getFrameCount() > 1;
	if (jthrowable jexception = get_and_clear_exception(env)) {
	return throw_exception(env, kSourceException, "", jexception, source);
	}

	auto androidCodec = SkAndroidCodec::MakeFromCodec(std::move(codec),
	SkAndroidCodec::ExifOrientationBehavior::kRespect);
	if (!androidCodec.get()) {
	return throw_exception(env, kSourceMalformedData, "", nullptr, source);
	}

	const auto& info = androidCodec->getInfo();
	const int width = info.width();
	const int height = info.height();
	const bool isNinePatch = peeker->mPatch != nullptr;
	ImageDecoder* decoder = new ImageDecoder(std::move(androidCodec), std::move(peeker));
	return env->NewObject(gImageDecoder_class, gImageDecoder_constructorMethodID,
	reinterpret_cast<jlong>(decoder), width, height,
	animated, isNinePatch);
	}

	static jobject ImageDecoder_nCreateFd(JNIEnv* env, jobject /clazz/,
	jobject fileDescriptor, jboolean preferAnimation, jobject source) {
	#ifndef __ANDROID__ // LayoutLib for Windows does not support F_DUPFD_CLOEXEC
	return throw_exception(env, kSourceException, "Only supported on Android", nullptr, source);
	#else
	int descriptor = jniGetFDFromFileDescriptor(env, fileDescriptor);

	struct stat fdStat;
	if (fstat(descriptor, &fdStat) == -1) {
	return throw_exception(env, kSourceMalformedData,
	"broken file descriptor; fstat returned -1", nullptr, source);
	}

	int dupDescriptor = fcntl(descriptor, F_DUPFD_CLOEXEC, 0);
	FILE* file = fdopen(dupDescriptor, "r");
	if (file == NULL) {
	close(dupDescriptor);
	return throw_exception(env, kSourceMalformedData, "Could not open file",
	nullptr, source);
	}

	std::unique_ptr<SkFILEStream> fileStream(new SkFILEStream(file));
	return native_create(env, std::move(fileStream), source, preferAnimation);
	#endif
	}

	static jobject ImageDecoder_nCreateInputStream(JNIEnv* env, jobject /clazz/,
	jobject is, jbyteArray storage, jboolean preferAnimation, jobject source) {
	std::unique_ptr<SkStream> stream(CreateJavaInputStreamAdaptor(env, is, storage, false));

	if (!stream.get()) {
	return throw_exception(env, kSourceMalformedData, "Failed to create a stream",
	nullptr, source);
	}

	std::unique_ptr<SkStream> bufferedStream(
	SkFrontBufferedStream::Make(std::move(stream),
	SkCodec::MinBufferedBytesNeeded()));
	return native_create(env, std::move(bufferedStream), source, preferAnimation);
	}

	static jobject ImageDecoder_nCreateAsset(JNIEnv* env, jobject /clazz/,
	jlong assetPtr, jboolean preferAnimation, jobject source) {
	Asset* asset = reinterpret_cast<Asset*>(assetPtr);
	std::unique_ptr<SkStream> stream(new AssetStreamAdaptor(asset));
	return native_create(env, std::move(stream), source, preferAnimation);
	}

	static jobject ImageDecoder_nCreateByteBuffer(JNIEnv* env, jobject /clazz/,
	jobject jbyteBuffer, jint initialPosition, jint limit,
	jboolean preferAnimation, jobject source) {
	std::unique_ptr<SkStream> stream = CreateByteBufferStreamAdaptor(env, jbyteBuffer,
	initialPosition, limit);
	if (!stream) {
	return throw_exception(env, kSourceMalformedData, "Failed to read ByteBuffer",
	nullptr, source);
	}
	return native_create(env, std::move(stream), source, preferAnimation);
	}

	static jobject ImageDecoder_nCreateByteArray(JNIEnv* env, jobject /clazz/,
	jbyteArray byteArray, jint offset, jint length,
	jboolean preferAnimation, jobject source) {
	std::unique_ptr<SkStream> stream(CreateByteArrayStreamAdaptor(env, byteArray, offset, length));
	return native_create(env, std::move(stream), source, preferAnimation);
	}

	jint postProcessAndRelease(JNIEnv* env, jobject jimageDecoder, std::unique_ptr<Canvas> canvas) {
	jobject jcanvas = env->NewObject(gCanvas_class, gCanvas_constructorMethodID,
	reinterpret_cast<jlong>(canvas.get()));
	if (!jcanvas) {
	doThrowOOME(env, "Failed to create Java Canvas for PostProcess!");
	return kUnknown;
	}

	// jcanvas now owns canvas.
	canvas.release();

	return env->CallIntMethod(jimageDecoder, gImageDecoder_postProcessMethodID, jcanvas);
	}

	static jobject ImageDecoder_nDecodeBitmap(JNIEnv* env, jobject /clazz/, jlong nativePtr,
	jobject jdecoder, jboolean jpostProcess,
	jint targetWidth, jint targetHeight, jobject jsubset,
	jboolean requireMutable, jint allocator,
	jboolean requireUnpremul, jboolean preferRamOverQuality,
	jboolean asAlphaMask, jlong colorSpaceHandle,
	jboolean extended) {
	auto* decoder = reinterpret_cast<ImageDecoder*>(nativePtr);
	if (!decoder->setTargetSize(targetWidth, targetHeight)) {
	doThrowISE(env, "Could not scale to target size!");
	return nullptr;
	}
	if (requireUnpremul && !decoder->setUnpremultipliedRequired(true)) {
	doThrowISE(env, "Cannot scale unpremultiplied pixels!");
	return nullptr;
	}

	SkColorType colorType = kN32_SkColorType;
	if (asAlphaMask && decoder->gray()) {
	// We have to trick Skia to decode this to a single channel.
	colorType = kGray_8_SkColorType;
	} else if (preferRamOverQuality) {
	// FIXME: The post-process might add alpha, which would make a 565
	// result incorrect. If we call the postProcess before now and record
	// to a picture, we can know whether alpha was added, and if not, we
	// can still use 565.
	if (decoder->opaque() && !jpostProcess) {
	// If the final result will be hardware, decoding to 565 and then
	// uploading to the gpu as 8888 will not save memory. This still
	// may save us from using F16, but do not go down to 565.
	if (allocator != kHardware_Allocator &&
	(allocator != kDefault_Allocator \|\| requireMutable)) {
	colorType = kRGB_565_SkColorType;
	}
	}
	// Otherwise, stick with N32
	} else if (extended) {
	colorType = kRGBA_F16_SkColorType;
	} else {
	colorType = decoder->mCodec->computeOutputColorType(colorType);
	}

	const bool isHardware = !requireMutable
	&& (allocator == kDefault_Allocator \|\|
	allocator == kHardware_Allocator)
	&& colorType != kGray_8_SkColorType;

	if (colorType == kRGBA_F16_SkColorType && isHardware &&
	!uirenderer::HardwareBitmapUploader::hasFP16Support()) {
	colorType = kN32_SkColorType;
	}

	if (!decoder->setOutColorType(colorType)) {
	doThrowISE(env, "Failed to set out color type!");
	return nullptr;
	}

	{
	sk_sp<SkColorSpace> colorSpace = GraphicsJNI::getNativeColorSpace(colorSpaceHandle);
	colorSpace = decoder->mCodec->computeOutputColorSpace(colorType, colorSpace);
	decoder->setOutColorSpace(std::move(colorSpace));
	}

	if (jsubset) {
	SkIRect subset;
	GraphicsJNI::jrect_to_irect(env, jsubset, &subset);
	if (!decoder->setCropRect(&subset)) {
	doThrowISE(env, "Invalid crop rect!");
	return nullptr;
	}
	}

	SkImageInfo bitmapInfo = decoder->getOutputInfo();
	if (asAlphaMask && colorType == kGray_8_SkColorType) {
	bitmapInfo = bitmapInfo.makeColorType(kAlpha_8_SkColorType);
	}

	SkBitmap bm;
	if (!bm.setInfo(bitmapInfo)) {
	doThrowIOE(env, "Failed to setInfo properly");
	return nullptr;
	}

	sk_sp<Bitmap> nativeBitmap;
	if (allocator == kSharedMemory_Allocator) {
	nativeBitmap = Bitmap::allocateAshmemBitmap(&bm);
	} else {
	nativeBitmap = Bitmap::allocateHeapBitmap(&bm);
	}
	if (!nativeBitmap) {
	SkString msg;
	msg.printf("OOM allocating Bitmap with dimensions %i x %i",
	bitmapInfo.width(), bitmapInfo.height());
	doThrowOOME(env, msg.c_str());
	return nullptr;
	}

	SkCodec::Result result = decoder->decode(bm.getPixels(), bm.rowBytes());
	jthrowable jexception = get_and_clear_exception(env);
	int onPartialImageError = jexception ? kSourceException
	: 0; // No error.
	switch (result) {
	case SkCodec::kSuccess:
	// Ignore the exception, since the decode was successful anyway.
	jexception = nullptr;
	onPartialImageError = 0;
	break;
	case SkCodec::kIncompleteInput:
	if (!jexception) {
	onPartialImageError = kSourceIncomplete;
	}
	break;
	case SkCodec::kErrorInInput:
	if (!jexception) {
	onPartialImageError = kSourceMalformedData;
	}
	break;
	default:
	SkString msg;
	msg.printf("getPixels failed with error %s", SkCodec::ResultToString(result));
	doThrowIOE(env, msg.c_str());
	return nullptr;
	}

	if (onPartialImageError) {
	env->CallVoidMethod(jdecoder, gCallback_onPartialImageMethodID, onPartialImageError,
	jexception);
	if (env->ExceptionCheck()) {
	return nullptr;
	}
	}

	jbyteArray ninePatchChunk = nullptr;
	jobject ninePatchInsets = nullptr;

	// Ignore ninepatch when post-processing.
	if (!jpostProcess) {
	// FIXME: Share more code with BitmapFactory.cpp.
	auto* peeker = reinterpret_cast<NinePatchPeeker*>(decoder->mPeeker.get());
	if (peeker->mPatch != nullptr) {
	size_t ninePatchArraySize = peeker->mPatch->serializedSize();
	ninePatchChunk = env->NewByteArray(ninePatchArraySize);
	if (ninePatchChunk == nullptr) {
	doThrowOOME(env, "Failed to allocate nine patch chunk.");
	return nullptr;
	}

	env->SetByteArrayRegion(ninePatchChunk, 0, peeker->mPatchSize,
	reinterpret_cast<jbyte*>(peeker->mPatch));
	}

	if (peeker->mHasInsets) {
	ninePatchInsets = peeker->createNinePatchInsets(env, 1.0f);
	if (ninePatchInsets == nullptr) {
	doThrowOOME(env, "Failed to allocate nine patch insets.");
	return nullptr;
	}
	}
	}

	if (jpostProcess) {
	std::unique_ptr<Canvas> canvas(Canvas::create_canvas(bm));

	jint pixelFormat = postProcessAndRelease(env, jdecoder, std::move(canvas));
	if (env->ExceptionCheck()) {
	return nullptr;
	}

	SkAlphaType newAlphaType = bm.alphaType();
	switch (pixelFormat) {
	case kUnknown:
	break;
	case kTranslucent:
	newAlphaType = kPremul_SkAlphaType;
	break;
	case kOpaque:
	newAlphaType = kOpaque_SkAlphaType;
	break;
	default:
	SkString msg;
	msg.printf("invalid return from postProcess: %i", pixelFormat);
	doThrowIAE(env, msg.c_str());
	return nullptr;
	}

	if (newAlphaType != bm.alphaType()) {
	if (!bm.setAlphaType(newAlphaType)) {
	SkString msg;
	msg.printf("incompatible return from postProcess: %i", pixelFormat);
	doThrowIAE(env, msg.c_str());
	return nullptr;
	}
	nativeBitmap->setAlphaType(newAlphaType);
	}
	}

	int bitmapCreateFlags = 0x0;
	if (!requireUnpremul) {
	// Even if the image is opaque, setting this flag means that
	// if alpha is added (e.g. by PostProcess), it will be marked as
	// premultiplied.
	bitmapCreateFlags \|= bitmap::kBitmapCreateFlag_Premultiplied;
	}

	if (requireMutable) {
	bitmapCreateFlags \|= bitmap::kBitmapCreateFlag_Mutable;
	} else {
	if (isHardware) {
	sk_sp<Bitmap> hwBitmap = Bitmap::allocateHardwareBitmap(bm);
	if (hwBitmap) {
	hwBitmap->setImmutable();
	return bitmap::createBitmap(env, hwBitmap.release(), bitmapCreateFlags,
	ninePatchChunk, ninePatchInsets);
	}
	if (allocator == kHardware_Allocator) {
	doThrowOOME(env, "failed to allocate hardware Bitmap!");
	return nullptr;
	}
	// If we failed to create a hardware bitmap, go ahead and create a
	// software one.
	}

	nativeBitmap->setImmutable();
	}
	return bitmap::createBitmap(env, nativeBitmap.release(), bitmapCreateFlags, ninePatchChunk,
	ninePatchInsets);
	}

	static jobject ImageDecoder_nGetSampledSize(JNIEnv* env, jobject /clazz/, jlong nativePtr,
	jint sampleSize) {
	auto* decoder = reinterpret_cast<ImageDecoder*>(nativePtr);
	SkISize size = decoder->mCodec->getSampledDimensions(sampleSize);
	return env->NewObject(gSize_class, gSize_constructorMethodID, size.width(), size.height());
	}

	static void ImageDecoder_nGetPadding(JNIEnv* env, jobject /clazz/, jlong nativePtr,
	jobject outPadding) {
	auto* decoder = reinterpret_cast<ImageDecoder*>(nativePtr);
	reinterpret_cast<NinePatchPeeker*>(decoder->mPeeker.get())->getPadding(env, outPadding);
	}

	static void ImageDecoder_nClose(JNIEnv* /env/, jobject /clazz/, jlong nativePtr) {
	delete reinterpret_cast<ImageDecoder*>(nativePtr);
	}

	static jstring ImageDecoder_nGetMimeType(JNIEnv* env, jobject /clazz/, jlong nativePtr) {
	auto* decoder = reinterpret_cast<ImageDecoder*>(nativePtr);
	return getMimeTypeAsJavaString(env, decoder->mCodec->getEncodedFormat());
	}

	static jobject ImageDecoder_nGetColorSpace(JNIEnv* env, jobject /clazz/, jlong nativePtr) {
	auto* codec = reinterpret_cast<ImageDecoder*>(nativePtr)->mCodec.get();
	auto colorType = codec->computeOutputColorType(kN32_SkColorType);
	sk_sp<SkColorSpace> colorSpace = codec->computeOutputColorSpace(colorType);
	return GraphicsJNI::getColorSpace(env, colorSpace.get(), colorType);
	}

	static const JNINativeMethod gImageDecoderMethods[] = {
	{ "nCreate", "(JZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;", (void*) ImageDecoder_nCreateAsset },
	{ "nCreate", "(Ljava/nio/ByteBuffer;IIZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;", (void*) ImageDecoder_nCreateByteBuffer },
	{ "nCreate", "([BIIZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;", (void*) ImageDecoder_nCreateByteArray },
	{ "nCreate", "(Ljava/io/InputStream;[BZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;", (void*) ImageDecoder_nCreateInputStream },
	{ "nCreate", "(Ljava/io/FileDescriptor;ZLandroid/graphics/ImageDecoder$Source;)Landroid/graphics/ImageDecoder;", (void*) ImageDecoder_nCreateFd },
	{ "nDecodeBitmap", "(JLandroid/graphics/ImageDecoder;ZIILandroid/graphics/Rect;ZIZZZJZ)Landroid/graphics/Bitmap;",
	(void*) ImageDecoder_nDecodeBitmap },
	{ "nGetSampledSize","(JI)Landroid/util/Size;", (void*) ImageDecoder_nGetSampledSize },
	{ "nGetPadding", "(JLandroid/graphics/Rect;)V", (void*) ImageDecoder_nGetPadding },
	{ "nClose", "(J)V", (void*) ImageDecoder_nClose},
	{ "nGetMimeType", "(J)Ljava/lang/String;", (void*) ImageDecoder_nGetMimeType },
	{ "nGetColorSpace", "(J)Landroid/graphics/ColorSpace;", (void*) ImageDecoder_nGetColorSpace },
	};

	int register_android_graphics_ImageDecoder(JNIEnv* env) {
	gImageDecoder_class = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/graphics/ImageDecoder"));
	gImageDecoder_constructorMethodID = GetMethodIDOrDie(env, gImageDecoder_class, "<init>", "(JIIZZ)V");
	gImageDecoder_postProcessMethodID = GetMethodIDOrDie(env, gImageDecoder_class, "postProcessAndRelease", "(Landroid/graphics/Canvas;)I");

	gSize_class = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/util/Size"));
	gSize_constructorMethodID = GetMethodIDOrDie(env, gSize_class, "<init>", "(II)V");

	gDecodeException_class = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/graphics/ImageDecoder$DecodeException"));
	gDecodeException_constructorMethodID = GetMethodIDOrDie(env, gDecodeException_class, "<init>", "(ILjava/lang/String;Ljava/lang/Throwable;Landroid/graphics/ImageDecoder$Source;)V");

	gCallback_onPartialImageMethodID = GetMethodIDOrDie(env, gImageDecoder_class, "onPartialImage", "(ILjava/lang/Throwable;)V");

	gCanvas_class = MakeGlobalRefOrDie(env, FindClassOrDie(env, "android/graphics/Canvas"));
	gCanvas_constructorMethodID = GetMethodIDOrDie(env, gCanvas_class, "<init>", "(J)V");
	gCanvas_releaseMethodID = GetMethodIDOrDie(env, gCanvas_class, "release", "()V");

	return android::RegisterMethodsOrDie(env, "android/graphics/ImageDecoder", gImageDecoderMethods,
	NELEM(gImageDecoderMethods));
	}