From: Zack Rusin Date: Fri, 2 Sep 2011 20:02:59 +0000 (-0400) Subject: Merge remote-tracking branch 'origin/master' into on-demand-loading X-Git-Url: https://git.cworth.org/git?a=commitdiff_plain;h=2257168033b52be3094efdbd7eadff8eb77a4c4e;p=apitrace Merge remote-tracking branch 'origin/master' into on-demand-loading --- 2257168033b52be3094efdbd7eadff8eb77a4c4e diff --cc trace_file.hpp index 13b392c,c709050..4871211 --- a/trace_file.hpp +++ b/trace_file.hpp @@@ -67,15 -57,11 +67,15 @@@ public void close(); void flush(void); int getc(); + bool skip(unsigned length); + virtual bool supportsOffsets() const = 0; + virtual File::Offset currentOffset(); + virtual void setCurrentOffset(const File::Offset &offset); protected: virtual bool rawOpen(const std::string &filename, File::Mode mode) = 0; - virtual bool rawWrite(const void *buffer, int length) = 0; - virtual bool rawRead(void *buffer, int length) = 0; + virtual bool rawWrite(const void *buffer, size_t length) = 0; + virtual bool rawRead(void *buffer, size_t length) = 0; virtual int rawGetc() = 0; virtual void rawClose() = 0; virtual void rawFlush() = 0; @@@ -164,12 -141,10 +164,12 @@@ public File::Mode mode = File::Read); virtual ~ZLibFile(); + + virtual bool supportsOffsets() const; protected: virtual bool rawOpen(const std::string &filename, File::Mode mode); - virtual bool rawWrite(const void *buffer, int length); - virtual bool rawRead(void *buffer, int length); + virtual bool rawWrite(const void *buffer, size_t length); + virtual bool rawRead(void *buffer, size_t length); virtual int rawGetc(); virtual void rawClose(); virtual void rawFlush(); diff --cc trace_snappyfile.cpp index 443ebe7,7e70725..c350013 --- a/trace_snappyfile.cpp +++ b/trace_snappyfile.cpp @@@ -191,37 -190,34 +192,35 @@@ void SnappyFile::rawFlush( void SnappyFile::flushCache() { if (m_mode == File::Write) { - size_t compressedLength; + size_t inputLength = usedCacheSize(); - ::snappy::RawCompress(m_cache, SNAPPY_CHUNK_SIZE - freeCacheSize(), - m_compressedCache, &compressedLength); + if (inputLength) { + size_t compressedLength; - writeCompressedLength(compressedLength); - m_stream.write(m_compressedCache, compressedLength); - m_cachePtr = m_cache; + ::snappy::RawCompress(m_cache, inputLength, + m_compressedCache, &compressedLength); + + writeCompressedLength(compressedLength); + m_stream.write(m_compressedCache, compressedLength); + m_cachePtr = m_cache; + } + assert(m_cachePtr == m_cache); } else if (m_mode == File::Read) { - if (m_stream.eof()) - return; //assert(m_cachePtr == m_cache + m_cacheSize); + m_currentOffset.chunk = m_stream.tellg(); size_t compressedLength; compressedLength = readCompressedLength(); - m_stream.read((char*)m_compressedCache, compressedLength); - /* - * The reason we peek here is because the last read will - * read all the way until the last character, but that will not - * trigger m_stream.eof() to be set, so by calling peek - * we assure that if we in fact have read the entire stream - * then the m_stream.eof() is always set. - */ - m_stream.peek(); - ::snappy::GetUncompressedLength(m_compressedCache, compressedLength, - &m_cacheSize); - if (m_cache) - delete [] m_cache; - createCache(m_cacheSize); - ::snappy::RawUncompress(m_compressedCache, compressedLength, - m_cache); + + if (compressedLength) { + m_stream.read((char*)m_compressedCache, compressedLength); + ::snappy::GetUncompressedLength(m_compressedCache, compressedLength, + &m_cacheSize); + createCache(m_cacheSize); + ::snappy::RawUncompress(m_compressedCache, compressedLength, + m_cache); + } else { + createCache(0); + } } } @@@ -232,63 -239,29 +242,78 @@@ void SnappyFile::createCache(size_t siz m_cacheSize = size; } - void SnappyFile::writeCompressedLength(uint32_t value) + void SnappyFile::writeCompressedLength(size_t length) { - m_stream.write((const char*)&value, sizeof value); + unsigned char buf[4]; + buf[0] = length & 0xff; length >>= 8; + buf[1] = length & 0xff; length >>= 8; + buf[2] = length & 0xff; length >>= 8; + buf[3] = length & 0xff; length >>= 8; + assert(length == 0); + m_stream.write((const char *)buf, sizeof buf); } - uint32_t SnappyFile::readCompressedLength() + size_t SnappyFile::readCompressedLength() { - uint32_t len; - m_stream.read((char*)&len, sizeof len); - return len; + unsigned char buf[4]; + size_t length; + m_stream.read((char *)buf, sizeof buf); + if (m_stream.fail()) { + length = 0; + } else { + length = (size_t)buf[0]; + length |= ((size_t)buf[1] << 8); + length |= ((size_t)buf[2] << 16); + length |= ((size_t)buf[3] << 24); + } + return length; } + +bool SnappyFile::supportsOffsets() const +{ + return true; +} + +File::Offset SnappyFile::currentOffset() +{ + m_currentOffset.offsetInChunk = m_cachePtr - m_cache; + return m_currentOffset; +} + +void SnappyFile::setCurrentOffset(const File::Offset &offset) +{ + // to remove eof bit + m_stream.clear(); + // seek to the start of a chunk + m_stream.seekg(offset.chunk, std::ios::beg); + // load the chunk + flushCache(); + assert(m_cacheSize >= offset.offsetInChunk); + // seek within our cache to the correct location within the chunk + m_cachePtr = m_cache + offset.offsetInChunk; + +} + +bool SnappyFile::rawSkip(unsigned length) +{ + if (endOfData()) { + return false; + } + + if (freeCacheSize() >= length) { + m_cachePtr += length; + } else { + int sizeToRead = length; + while (sizeToRead) { + int chunkSize = std::min(freeCacheSize(), sizeToRead); + m_cachePtr += chunkSize; + sizeToRead -= chunkSize; + if (sizeToRead > 0) + flushCache(); + if (!m_cacheSize) + break; + } + } + + return true; +} diff --cc trace_snappyfile.hpp index ecf39de,61b7ab1..398ff79 --- a/trace_snappyfile.hpp +++ b/trace_snappyfile.hpp @@@ -52,25 -52,28 +52,32 @@@ public File::Mode mode = File::Read); virtual ~SnappyFile(); + virtual bool supportsOffsets() const; + virtual File::Offset currentOffset(); + virtual void setCurrentOffset(const File::Offset &offset); protected: virtual bool rawOpen(const std::string &filename, File::Mode mode); - virtual bool rawWrite(const void *buffer, int length); - virtual bool rawRead(void *buffer, int length); + virtual bool rawWrite(const void *buffer, size_t length); + virtual bool rawRead(void *buffer, size_t length); virtual int rawGetc(); virtual void rawClose(); virtual void rawFlush(); + virtual bool rawSkip(unsigned length); private: - inline int freeCacheSize() const + inline size_t usedCacheSize() const + { + assert(m_cachePtr >= m_cache); + return m_cachePtr - m_cache; + } + inline size_t freeCacheSize() const { - if (m_cacheSize > 0) - return m_cacheSize - (m_cachePtr - m_cache); - else + assert(m_cacheSize >= usedCacheSize()); + if (m_cacheSize > 0) { + return m_cacheSize - usedCacheSize(); + } else { return 0; + } } inline bool endOfData() const {