diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/utils/Asset.h | 11 | ||||
| -rw-r--r-- | include/utils/StreamingZipInflater.h | 82 |
2 files changed, 84 insertions, 9 deletions
diff --git a/include/utils/Asset.h b/include/utils/Asset.h index 5908bcc..2a09095 100644 --- a/include/utils/Asset.h +++ b/include/utils/Asset.h @@ -61,15 +61,6 @@ public: ACCESS_BUFFER, } AccessMode; - enum { - /* data larger than this does not get uncompressed into a buffer */ -#ifdef HAVE_ANDROID_OS - UNCOMPRESS_DATA_MAX = 1 * 1024 * 1024 -#else - UNCOMPRESS_DATA_MAX = 2 * 1024 * 1024 -#endif - }; - /* * Read data from the current offset. Returns the actual number of * bytes read, 0 on EOF, or -1 on error. @@ -317,6 +308,8 @@ private: FileMap* mMap; // for memory-mapped input int mFd; // for file input + class StreamingZipInflater* mZipInflater; // for streaming large compressed assets + unsigned char* mBuf; // for getBuffer() }; diff --git a/include/utils/StreamingZipInflater.h b/include/utils/StreamingZipInflater.h new file mode 100644 index 0000000..16867d8 --- /dev/null +++ b/include/utils/StreamingZipInflater.h @@ -0,0 +1,82 @@ +/* + * 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> + +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, off_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. + off_t seekAbsolute(off_t absoluteInputPosition); + +private: + void initInflateState(); + int readNextChunk(); + + // where to find the uncompressed data + int mFd; + off_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 + off_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 |