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author | Mathias Agopian <mathias@google.com> | 2012-02-17 18:27:36 -0800 |
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committer | Mathias Agopian <mathias@google.com> | 2012-02-17 19:01:26 -0800 |
commit | b13b9bdad2baf6ad1ec2e56b6b7598fa20f55fc4 (patch) | |
tree | 2b90dc39a35d8081ea47b038893624b69a01202d /include/androidfw/StreamingZipInflater.h | |
parent | 6db0608dff408130b35e6f21abe746a635648b18 (diff) | |
download | frameworks_base-b13b9bdad2baf6ad1ec2e56b6b7598fa20f55fc4.zip frameworks_base-b13b9bdad2baf6ad1ec2e56b6b7598fa20f55fc4.tar.gz frameworks_base-b13b9bdad2baf6ad1ec2e56b6b7598fa20f55fc4.tar.bz2 |
frameworks/base refactoring.
step 2: move libutils headers to their new home: androidfw
Change-Id: I14624ba23db92a81f2cb929f104386e1fab293ef
Diffstat (limited to 'include/androidfw/StreamingZipInflater.h')
-rw-r--r-- | include/androidfw/StreamingZipInflater.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/include/androidfw/StreamingZipInflater.h b/include/androidfw/StreamingZipInflater.h new file mode 100644 index 0000000..3ace5d5 --- /dev/null +++ b/include/androidfw/StreamingZipInflater.h @@ -0,0 +1,84 @@ +/* + * Copyright (C) 2010 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. + */ + +#ifndef __LIBS_STREAMINGZIPINFLATER_H +#define __LIBS_STREAMINGZIPINFLATER_H + +#include <unistd.h> +#include <inttypes.h> +#include <zlib.h> + +#include <utils/Compat.h> + +namespace android { + +class StreamingZipInflater { +public: + static const size_t INPUT_CHUNK_SIZE = 64 * 1024; + static const size_t OUTPUT_CHUNK_SIZE = 64 * 1024; + + // Flavor that pages in the compressed data from a fd + StreamingZipInflater(int fd, off64_t compDataStart, size_t uncompSize, size_t compSize); + + // Flavor that gets the compressed data from an in-memory buffer + StreamingZipInflater(class FileMap* dataMap, size_t uncompSize); + + ~StreamingZipInflater(); + + // read 'count' bytes of uncompressed data from the current position. outBuf may + // be NULL, in which case the data is consumed and discarded. + ssize_t read(void* outBuf, size_t count); + + // seeking backwards requires uncompressing fom the beginning, so is very + // expensive. seeking forwards only requires uncompressing from the current + // position to the destination. + off64_t seekAbsolute(off64_t absoluteInputPosition); + +private: + void initInflateState(); + int readNextChunk(); + + // where to find the uncompressed data + int mFd; + off64_t mInFileStart; // where the compressed data lives in the file + class FileMap* mDataMap; + + z_stream mInflateState; + bool mStreamNeedsInit; + + // output invariants for this asset + uint8_t* mOutBuf; // output buf for decompressed bytes + size_t mOutBufSize; // allocated size of mOutBuf + size_t mOutTotalSize; // total uncompressed size of the blob + + // current output state bookkeeping + off64_t mOutCurPosition; // current position in total offset + size_t mOutLastDecoded; // last decoded byte + 1 in mOutbuf + size_t mOutDeliverable; // next undelivered byte of decoded output in mOutBuf + + // input invariants + uint8_t* mInBuf; + size_t mInBufSize; // allocated size of mInBuf; + size_t mInTotalSize; // total size of compressed data for this blob + + // input state bookkeeping + size_t mInNextChunkOffset; // offset from start of blob at which the next input chunk lies + // the z_stream contains state about input block consumption +}; + +} + +#endif |