+/**************************************************************************
+ *
+ * Copyright 2011 Zack Rusin
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ **************************************************************************/
+
+
#include "trace_snappyfile.hpp"
#include <snappy.h>
+#include <iostream>
+
#include <assert.h>
#include <string.h>
* The file is composed of a number of chunks, they are:
* chunk {
* uint32 - specifying the length of the compressed data
- * compressed data
+ * compressed data, in little endian
* }
* File can contain any number of such chunks.
* The default size of an uncompressed chunk is specified in
m_cachePtr(0),
m_cacheSize(0)
{
- m_compressedCache = new char[SNAPPY_CHUNK_SIZE];
+ size_t maxCompressedLength =
+ snappy::MaxCompressedLength(SNAPPY_CHUNK_SIZE);
+ m_compressedCache = new char[maxCompressedLength];
}
SnappyFile::~SnappyFile()
{
delete [] m_compressedCache;
+ delete [] m_cache;
}
bool SnappyFile::rawOpen(const std::string &filename, File::Mode mode)
//read in the initial buffer if we're reading
if (m_stream.is_open() && mode == File::Read) {
+ m_stream.seekg(0, std::ios::end);
+ m_endPos = m_stream.tellg();
+ m_stream.seekg(0, std::ios::beg);
+
// read the snappy file identifier
unsigned char byte1, byte2;
m_stream >> byte1;
m_stream >> byte2;
assert(byte1 == SNAPPY_BYTE1 && byte2 == SNAPPY_BYTE2);
- flushCache();
+ flushReadCache();
} else if (m_stream.is_open() && mode == File::Write) {
// write the snappy file identifier
m_stream << SNAPPY_BYTE1;
return m_stream.is_open();
}
-bool SnappyFile::rawWrite(const void *buffer, int length)
+bool SnappyFile::rawWrite(const void *buffer, size_t length)
{
if (freeCacheSize() > length) {
memcpy(m_cachePtr, buffer, length);
} else if (freeCacheSize() == length) {
memcpy(m_cachePtr, buffer, length);
m_cachePtr += length;
- flushCache();
+ flushWriteCache();
} else {
int sizeToWrite = length;
while (sizeToWrite >= freeCacheSize()) {
int endSize = freeCacheSize();
int offset = length - sizeToWrite;
- memcpy(m_cachePtr, (char*)buffer + offset, endSize);
+ memcpy(m_cachePtr, (const char*)buffer + offset, endSize);
sizeToWrite -= endSize;
m_cachePtr += endSize;
- flushCache();
+ flushWriteCache();
}
if (sizeToWrite) {
int offset = length - sizeToWrite;
- memcpy(m_cachePtr, (char*)buffer + offset, sizeToWrite);
+ memcpy(m_cachePtr, (const char*)buffer + offset, sizeToWrite);
m_cachePtr += sizeToWrite;
}
}
return true;
}
-bool SnappyFile::rawRead(void *buffer, int length)
+bool SnappyFile::rawRead(void *buffer, size_t length)
{
- if (m_stream.eof()) {
+ if (endOfData()) {
return false;
}
- if (freeCacheSize() > length) {
- memcpy(buffer, m_cachePtr, length);
- m_cachePtr += length;
- } else if (freeCacheSize() == length) {
+
+ if (freeCacheSize() >= length) {
memcpy(buffer, m_cachePtr, length);
m_cachePtr += length;
- flushCache();
} else {
- int sizeToRead = length;
- int offset = 0;
+ size_t sizeToRead = length;
+ size_t offset = 0;
while (sizeToRead) {
- int chunkSize = std::min(freeCacheSize(), sizeToRead);
+ size_t chunkSize = std::min(freeCacheSize(), sizeToRead);
offset = length - sizeToRead;
memcpy((char*)buffer + offset, m_cachePtr, chunkSize);
m_cachePtr += chunkSize;
sizeToRead -= chunkSize;
- if (sizeToRead > 0)
- flushCache();
- if (!m_cacheSize)
+ if (sizeToRead > 0) {
+ flushReadCache();
+ }
+ if (!m_cacheSize) {
break;
+ }
}
}
void SnappyFile::rawClose()
{
- flushCache();
+ if (m_mode == File::Write) {
+ flushWriteCache();
+ }
m_stream.close();
delete [] m_cache;
m_cache = NULL;
m_cachePtr = NULL;
}
-void SnappyFile::rawFlush(FlushType type)
+void SnappyFile::rawFlush()
{
- if (type == FlushDeep) {
- flushCache();
- }
+ assert(m_mode == File::Write);
+ flushWriteCache();
m_stream.flush();
}
-void SnappyFile::flushCache()
+void SnappyFile::flushWriteCache()
{
- if (m_mode == File::Write) {
+ size_t inputLength = usedCacheSize();
+
+ if (inputLength) {
size_t compressedLength;
- ::snappy::RawCompress(m_cache, SNAPPY_CHUNK_SIZE - freeCacheSize(),
+ ::snappy::RawCompress(m_cache, inputLength,
m_compressedCache, &compressedLength);
writeCompressedLength(compressedLength);
m_stream.write(m_compressedCache, compressedLength);
m_cachePtr = m_cache;
- } else if (m_mode == File::Read) {
- if (m_stream.eof())
- return;
- //assert(m_cachePtr == m_cache + m_cacheSize);
- size_t compressedLength;
- compressedLength = readCompressedLength();
+ }
+ assert(m_cachePtr == m_cache);
+}
+
+void SnappyFile::flushReadCache(size_t skipLength)
+{
+ //assert(m_cachePtr == m_cache + m_cacheSize);
+ m_currentOffset.chunk = m_stream.tellg();
+ size_t compressedLength;
+ compressedLength = readCompressedLength();
+
+ if (compressedLength) {
m_stream.read((char*)m_compressedCache, compressedLength);
::snappy::GetUncompressedLength(m_compressedCache, compressedLength,
&m_cacheSize);
- if (m_cache)
- delete [] m_cache;
createCache(m_cacheSize);
- ::snappy::RawUncompress(m_compressedCache, compressedLength,
- m_cache);
+ if (skipLength < m_cacheSize) {
+ ::snappy::RawUncompress(m_compressedCache, compressedLength,
+ m_cache);
+ }
+ } else {
+ createCache(0);
}
}
void SnappyFile::createCache(size_t size)
{
- m_cache = new char[size];
+ // TODO: only re-allocate if the current buffer is not big enough
+
+ if (m_cache) {
+ delete [] m_cache;
+ }
+
+ if (size) {
+ m_cache = new char[size];
+ } else {
+ m_cache = NULL;
+ }
+
m_cachePtr = m_cache;
m_cacheSize = size;
}
-void SnappyFile::writeCompressedLength(uint32_t value)
+void SnappyFile::writeCompressedLength(size_t length)
+{
+ 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);
+}
+
+size_t SnappyFile::readCompressedLength()
+{
+ 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
{
- m_stream.write((char*)&value, sizeof value);
+ 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
+ flushReadCache();
+ 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(size_t length)
+{
+ if (endOfData()) {
+ return false;
+ }
+
+ if (freeCacheSize() >= length) {
+ m_cachePtr += length;
+ } else {
+ size_t sizeToRead = length;
+ while (sizeToRead) {
+ size_t chunkSize = std::min(freeCacheSize(), sizeToRead);
+ m_cachePtr += chunkSize;
+ sizeToRead -= chunkSize;
+ if (sizeToRead > 0) {
+ flushReadCache(sizeToRead);
+ }
+ if (!m_cacheSize) {
+ break;
+ }
+ }
+ }
+
+ return true;
}
-uint32_t SnappyFile::readCompressedLength()
+int SnappyFile::rawPercentRead()
{
- uint32_t len;
- m_stream.read((char*)&len, sizeof len);
- return len;
+ return 100 * (double(m_stream.tellg()) / double(m_endPos));
}
projects / apitrace / blobdiff