Create AAssetStreamAdaptor, for reading from AAssets (9732e29b) · Commits · e / os / android_frameworks_base

native/graphics/jni/Android.bp

+6 −1

Original line number	Diff line number	Diff line
		@@ -24,10 +24,15 @@ cc_library_shared {

		// our source files
		//
		srcs: ["bitmap.cpp"],
		srcs: [
		"bitmap.cpp",
		"aassetstreamadaptor.cpp",
		],

		shared_libs: [
		"libandroid",
		"libandroid_runtime",
		"liblog",
		],

		arch: {

native/graphics/jni/aassetstreamadaptor.cpp

0 → 100644

+117 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2019 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 "aassetstreamadaptor.h"

		#include <log/log.h>

		AAssetStreamAdaptor::AAssetStreamAdaptor(AAsset* asset)
		: mAAsset(asset)
		{
		}

		bool AAssetStreamAdaptor::rewind() {
		off64_t pos = AAsset_seek64(mAAsset, 0, SEEK_SET);
		if (pos == (off64_t)-1) {
		ALOGE("rewind failed!");
		return false;
		}
		return true;
		}

		size_t AAssetStreamAdaptor::getLength() const {
		return AAsset_getLength64(mAAsset);
		}

		bool AAssetStreamAdaptor::isAtEnd() const {
		return AAsset_getRemainingLength64(mAAsset) == 0;
		}

		SkStreamRewindable* AAssetStreamAdaptor::onDuplicate() const {
		// Cannot sensibly create a duplicate, since each AAssetStreamAdaptor
		// would be modifying the same AAsset.
		//return new AAssetStreamAdaptor(mAAsset);
		return nullptr;
		}

		bool AAssetStreamAdaptor::hasPosition() const {
		return AAsset_seek64(mAAsset, 0, SEEK_CUR) != -1;
		}

		size_t AAssetStreamAdaptor::getPosition() const {
		const off64_t offset = AAsset_seek64(mAAsset, 0, SEEK_CUR);
		if (offset == -1) {
		ALOGE("getPosition failed!");
		return 0;
		}

		return offset;
		}

		bool AAssetStreamAdaptor::seek(size_t position) {
		if (AAsset_seek64(mAAsset, position, SEEK_SET) == -1) {
		ALOGE("seek failed!");
		return false;
		}

		return true;
		}

		bool AAssetStreamAdaptor::move(long offset) {
		if (AAsset_seek64(mAAsset, offset, SEEK_CUR) == -1) {
		ALOGE("move failed!");
		return false;
		}

		return true;
		}

		size_t AAssetStreamAdaptor::read(void* buffer, size_t size) {
		ssize_t amount;

		if (!buffer) {
		if (!size) {
		return 0;
		}

		// asset->seek returns new total offset
		// we want to return amount that was skipped
		const off64_t oldOffset = AAsset_seek64(mAAsset, 0, SEEK_CUR);
		if (oldOffset == -1) {
		ALOGE("seek(oldOffset) failed!");
		return 0;
		}

		const off64_t newOffset = AAsset_seek64(mAAsset, size, SEEK_CUR);
		if (-1 == newOffset) {
		ALOGE("seek(%zu) failed!", size);
		return 0;
		}
		amount = newOffset - oldOffset;
		} else {
		amount = AAsset_read(mAAsset, buffer, size);
		}

		if (amount < 0) {
		amount = 0;
		}
		return amount;
		}

		const void* AAssetStreamAdaptor::getMemoryBase() {
		return AAsset_getBuffer(mAAsset);
		}

native/graphics/jni/aassetstreamadaptor.h

0 → 100644

+50 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2019 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.
		*/

		#pragma once

		#include "SkStream.h"

		#include <android/asset_manager.h>

		// Like AssetStreamAdaptor, but operates on AAsset, a public NDK API.
		class AAssetStreamAdaptor : public SkStreamRewindable {
		public:
		/**
		* Create an SkStream that reads from an AAsset.
		*
		* The AAsset must remain open for the lifetime of the Adaptor. The Adaptor
		* does not close the AAsset.
		*/
		explicit AAssetStreamAdaptor(AAsset*);

		bool rewind() override;
		size_t read(void* buffer, size_t size) override;
		bool hasLength() const override { return true; }
		size_t getLength() const override;
		bool hasPosition() const override;
		size_t getPosition() const override;
		bool seek(size_t position) override;
		bool move(long offset) override;
		bool isAtEnd() const override;
		const void* getMemoryBase() override;
		protected:
		SkStreamRewindable* onDuplicate() const override;

		private:
		AAsset* mAAsset;
		};