mirror of https://github.com/google/snappy.git
597 lines
20 KiB
C++
597 lines
20 KiB
C++
// Copyright 2011 Google Inc. All Rights Reserved.
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are
|
|
// met:
|
|
//
|
|
// * Redistributions of source code must retain the above copyright
|
|
// notice, this list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above
|
|
// copyright notice, this list of conditions and the following disclaimer
|
|
// in the documentation and/or other materials provided with the
|
|
// distribution.
|
|
// * Neither the name of Google Inc. nor the names of its
|
|
// contributors may be used to endorse or promote products derived from
|
|
// this software without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
//
|
|
// Various stubs for the unit tests for the open-source version of Snappy.
|
|
|
|
#include "snappy-test.h"
|
|
|
|
#ifdef HAVE_WINDOWS_H
|
|
#define WIN32_LEAN_AND_MEAN
|
|
#include <windows.h>
|
|
#endif
|
|
|
|
#include <algorithm>
|
|
|
|
DEFINE_bool(run_microbenchmarks, true,
|
|
"Run microbenchmarks before doing anything else.");
|
|
|
|
namespace snappy {
|
|
|
|
string ReadTestDataFile(const string& base) {
|
|
string contents;
|
|
const char* srcdir = getenv("srcdir"); // This is set by Automake.
|
|
if (srcdir) {
|
|
File::ReadFileToStringOrDie(
|
|
string(srcdir) + "/testdata/" + base, &contents);
|
|
} else {
|
|
File::ReadFileToStringOrDie("testdata/" + base, &contents);
|
|
}
|
|
return contents;
|
|
}
|
|
|
|
string StringPrintf(const char* format, ...) {
|
|
char buf[4096];
|
|
va_list ap;
|
|
va_start(ap, format);
|
|
vsnprintf(buf, sizeof(buf), format, ap);
|
|
va_end(ap);
|
|
return buf;
|
|
}
|
|
|
|
bool benchmark_running = false;
|
|
int64 benchmark_real_time_us = 0;
|
|
int64 benchmark_cpu_time_us = 0;
|
|
string *benchmark_label = NULL;
|
|
int64 benchmark_bytes_processed = 0;
|
|
|
|
void ResetBenchmarkTiming() {
|
|
benchmark_real_time_us = 0;
|
|
benchmark_cpu_time_us = 0;
|
|
}
|
|
|
|
#ifdef WIN32
|
|
LARGE_INTEGER benchmark_start_real;
|
|
FILETIME benchmark_start_cpu;
|
|
#else // WIN32
|
|
struct timeval benchmark_start_real;
|
|
struct rusage benchmark_start_cpu;
|
|
#endif // WIN32
|
|
|
|
void StartBenchmarkTiming() {
|
|
#ifdef WIN32
|
|
QueryPerformanceCounter(&benchmark_start_real);
|
|
FILETIME dummy;
|
|
CHECK(GetProcessTimes(
|
|
GetCurrentProcess(), &dummy, &dummy, &dummy, &benchmark_start_cpu));
|
|
#else
|
|
gettimeofday(&benchmark_start_real, NULL);
|
|
if (getrusage(RUSAGE_SELF, &benchmark_start_cpu) == -1) {
|
|
perror("getrusage(RUSAGE_SELF)");
|
|
exit(1);
|
|
}
|
|
#endif
|
|
benchmark_running = true;
|
|
}
|
|
|
|
void StopBenchmarkTiming() {
|
|
if (!benchmark_running) {
|
|
return;
|
|
}
|
|
|
|
#ifdef WIN32
|
|
LARGE_INTEGER benchmark_stop_real;
|
|
LARGE_INTEGER benchmark_frequency;
|
|
QueryPerformanceCounter(&benchmark_stop_real);
|
|
QueryPerformanceFrequency(&benchmark_frequency);
|
|
|
|
double elapsed_real = static_cast<double>(
|
|
benchmark_stop_real.QuadPart - benchmark_start_real.QuadPart) /
|
|
benchmark_frequency.QuadPart;
|
|
benchmark_real_time_us += elapsed_real * 1e6 + 0.5;
|
|
|
|
FILETIME benchmark_stop_cpu, dummy;
|
|
CHECK(GetProcessTimes(
|
|
GetCurrentProcess(), &dummy, &dummy, &dummy, &benchmark_stop_cpu));
|
|
|
|
ULARGE_INTEGER start_ulargeint;
|
|
start_ulargeint.LowPart = benchmark_start_cpu.dwLowDateTime;
|
|
start_ulargeint.HighPart = benchmark_start_cpu.dwHighDateTime;
|
|
|
|
ULARGE_INTEGER stop_ulargeint;
|
|
stop_ulargeint.LowPart = benchmark_stop_cpu.dwLowDateTime;
|
|
stop_ulargeint.HighPart = benchmark_stop_cpu.dwHighDateTime;
|
|
|
|
benchmark_cpu_time_us +=
|
|
(stop_ulargeint.QuadPart - start_ulargeint.QuadPart + 5) / 10;
|
|
#else // WIN32
|
|
struct timeval benchmark_stop_real;
|
|
gettimeofday(&benchmark_stop_real, NULL);
|
|
benchmark_real_time_us +=
|
|
1000000 * (benchmark_stop_real.tv_sec - benchmark_start_real.tv_sec);
|
|
benchmark_real_time_us +=
|
|
(benchmark_stop_real.tv_usec - benchmark_start_real.tv_usec);
|
|
|
|
struct rusage benchmark_stop_cpu;
|
|
if (getrusage(RUSAGE_SELF, &benchmark_stop_cpu) == -1) {
|
|
perror("getrusage(RUSAGE_SELF)");
|
|
exit(1);
|
|
}
|
|
benchmark_cpu_time_us += 1000000 * (benchmark_stop_cpu.ru_utime.tv_sec -
|
|
benchmark_start_cpu.ru_utime.tv_sec);
|
|
benchmark_cpu_time_us += (benchmark_stop_cpu.ru_utime.tv_usec -
|
|
benchmark_start_cpu.ru_utime.tv_usec);
|
|
#endif // WIN32
|
|
|
|
benchmark_running = false;
|
|
}
|
|
|
|
void SetBenchmarkLabel(const string& str) {
|
|
if (benchmark_label) {
|
|
delete benchmark_label;
|
|
}
|
|
benchmark_label = new string(str);
|
|
}
|
|
|
|
void SetBenchmarkBytesProcessed(int64 bytes) {
|
|
benchmark_bytes_processed = bytes;
|
|
}
|
|
|
|
struct BenchmarkRun {
|
|
int64 real_time_us;
|
|
int64 cpu_time_us;
|
|
};
|
|
|
|
struct BenchmarkCompareCPUTime {
|
|
bool operator() (const BenchmarkRun& a, const BenchmarkRun& b) const {
|
|
return a.cpu_time_us < b.cpu_time_us;
|
|
}
|
|
};
|
|
|
|
void Benchmark::Run() {
|
|
for (int test_case_num = start_; test_case_num <= stop_; ++test_case_num) {
|
|
// Run a few iterations first to find out approximately how fast
|
|
// the benchmark is.
|
|
const int kCalibrateIterations = 100;
|
|
ResetBenchmarkTiming();
|
|
StartBenchmarkTiming();
|
|
(*function_)(kCalibrateIterations, test_case_num);
|
|
StopBenchmarkTiming();
|
|
|
|
// Let each test case run for about 200ms, but at least as many
|
|
// as we used to calibrate.
|
|
// Run five times and pick the median.
|
|
const int kNumRuns = 5;
|
|
const int kMedianPos = kNumRuns / 2;
|
|
int num_iterations = 0;
|
|
if (benchmark_real_time_us > 0) {
|
|
num_iterations = 200000 * kCalibrateIterations / benchmark_real_time_us;
|
|
}
|
|
num_iterations = max(num_iterations, kCalibrateIterations);
|
|
BenchmarkRun benchmark_runs[kNumRuns];
|
|
|
|
for (int run = 0; run < kNumRuns; ++run) {
|
|
ResetBenchmarkTiming();
|
|
StartBenchmarkTiming();
|
|
(*function_)(num_iterations, test_case_num);
|
|
StopBenchmarkTiming();
|
|
|
|
benchmark_runs[run].real_time_us = benchmark_real_time_us;
|
|
benchmark_runs[run].cpu_time_us = benchmark_cpu_time_us;
|
|
}
|
|
|
|
nth_element(benchmark_runs,
|
|
benchmark_runs + kMedianPos,
|
|
benchmark_runs + kNumRuns,
|
|
BenchmarkCompareCPUTime());
|
|
int64 real_time_us = benchmark_runs[kMedianPos].real_time_us;
|
|
int64 cpu_time_us = benchmark_runs[kMedianPos].cpu_time_us;
|
|
int64 bytes_per_second = benchmark_bytes_processed * 1000000 / cpu_time_us;
|
|
|
|
string heading = StringPrintf("%s/%d", name_.c_str(), test_case_num);
|
|
string human_readable_speed;
|
|
if (bytes_per_second < 1024) {
|
|
human_readable_speed = StringPrintf("%dB/s", bytes_per_second);
|
|
} else if (bytes_per_second < 1024 * 1024) {
|
|
human_readable_speed = StringPrintf(
|
|
"%.1fkB/s", bytes_per_second / 1024.0f);
|
|
} else if (bytes_per_second < 1024 * 1024 * 1024) {
|
|
human_readable_speed = StringPrintf(
|
|
"%.1fMB/s", bytes_per_second / (1024.0f * 1024.0f));
|
|
} else {
|
|
human_readable_speed = StringPrintf(
|
|
"%.1fGB/s", bytes_per_second / (1024.0f * 1024.0f * 1024.0f));
|
|
}
|
|
|
|
fprintf(stderr,
|
|
#ifdef WIN32
|
|
"%-18s %10I64d %10I64d %10d %s %s\n",
|
|
#else
|
|
"%-18s %10lld %10lld %10d %s %s\n",
|
|
#endif
|
|
heading.c_str(),
|
|
static_cast<long long>(real_time_us * 1000 / num_iterations),
|
|
static_cast<long long>(cpu_time_us * 1000 / num_iterations),
|
|
num_iterations,
|
|
human_readable_speed.c_str(),
|
|
benchmark_label->c_str());
|
|
}
|
|
}
|
|
|
|
#ifdef HAVE_LIBZ
|
|
|
|
ZLib::ZLib()
|
|
: comp_init_(false),
|
|
uncomp_init_(false) {
|
|
Reinit();
|
|
}
|
|
|
|
ZLib::~ZLib() {
|
|
if (comp_init_) { deflateEnd(&comp_stream_); }
|
|
if (uncomp_init_) { inflateEnd(&uncomp_stream_); }
|
|
}
|
|
|
|
void ZLib::Reinit() {
|
|
compression_level_ = Z_DEFAULT_COMPRESSION;
|
|
window_bits_ = MAX_WBITS;
|
|
mem_level_ = 8; // DEF_MEM_LEVEL
|
|
if (comp_init_) {
|
|
deflateEnd(&comp_stream_);
|
|
comp_init_ = false;
|
|
}
|
|
if (uncomp_init_) {
|
|
inflateEnd(&uncomp_stream_);
|
|
uncomp_init_ = false;
|
|
}
|
|
first_chunk_ = true;
|
|
}
|
|
|
|
void ZLib::Reset() {
|
|
first_chunk_ = true;
|
|
}
|
|
|
|
// --------- COMPRESS MODE
|
|
|
|
// Initialization method to be called if we hit an error while
|
|
// compressing. On hitting an error, call this method before returning
|
|
// the error.
|
|
void ZLib::CompressErrorInit() {
|
|
deflateEnd(&comp_stream_);
|
|
comp_init_ = false;
|
|
Reset();
|
|
}
|
|
|
|
int ZLib::DeflateInit() {
|
|
return deflateInit2(&comp_stream_,
|
|
compression_level_,
|
|
Z_DEFLATED,
|
|
window_bits_,
|
|
mem_level_,
|
|
Z_DEFAULT_STRATEGY);
|
|
}
|
|
|
|
int ZLib::CompressInit(Bytef *dest, uLongf *destLen,
|
|
const Bytef *source, uLong *sourceLen) {
|
|
int err;
|
|
|
|
comp_stream_.next_in = (Bytef*)source;
|
|
comp_stream_.avail_in = (uInt)*sourceLen;
|
|
if ((uLong)comp_stream_.avail_in != *sourceLen) return Z_BUF_ERROR;
|
|
comp_stream_.next_out = dest;
|
|
comp_stream_.avail_out = (uInt)*destLen;
|
|
if ((uLong)comp_stream_.avail_out != *destLen) return Z_BUF_ERROR;
|
|
|
|
if ( !first_chunk_ ) // only need to set up stream the first time through
|
|
return Z_OK;
|
|
|
|
if (comp_init_) { // we've already initted it
|
|
err = deflateReset(&comp_stream_);
|
|
if (err != Z_OK) {
|
|
LOG(WARNING) << "ERROR: Can't reset compress object; creating a new one";
|
|
deflateEnd(&comp_stream_);
|
|
comp_init_ = false;
|
|
}
|
|
}
|
|
if (!comp_init_) { // first use
|
|
comp_stream_.zalloc = (alloc_func)0;
|
|
comp_stream_.zfree = (free_func)0;
|
|
comp_stream_.opaque = (voidpf)0;
|
|
err = DeflateInit();
|
|
if (err != Z_OK) return err;
|
|
comp_init_ = true;
|
|
}
|
|
return Z_OK;
|
|
}
|
|
|
|
// In a perfect world we'd always have the full buffer to compress
|
|
// when the time came, and we could just call Compress(). Alas, we
|
|
// want to do chunked compression on our webserver. In this
|
|
// application, we compress the header, send it off, then compress the
|
|
// results, send them off, then compress the footer. Thus we need to
|
|
// use the chunked compression features of zlib.
|
|
int ZLib::CompressAtMostOrAll(Bytef *dest, uLongf *destLen,
|
|
const Bytef *source, uLong *sourceLen,
|
|
int flush_mode) { // Z_FULL_FLUSH or Z_FINISH
|
|
int err;
|
|
|
|
if ( (err=CompressInit(dest, destLen, source, sourceLen)) != Z_OK )
|
|
return err;
|
|
|
|
// This is used to figure out how many bytes we wrote *this chunk*
|
|
int compressed_size = comp_stream_.total_out;
|
|
|
|
// Some setup happens only for the first chunk we compress in a run
|
|
if ( first_chunk_ ) {
|
|
first_chunk_ = false;
|
|
}
|
|
|
|
// flush_mode is Z_FINISH for all mode, Z_SYNC_FLUSH for incremental
|
|
// compression.
|
|
err = deflate(&comp_stream_, flush_mode);
|
|
|
|
const uLong source_bytes_consumed = *sourceLen - comp_stream_.avail_in;
|
|
*sourceLen = comp_stream_.avail_in;
|
|
|
|
if ((err == Z_STREAM_END || err == Z_OK)
|
|
&& comp_stream_.avail_in == 0
|
|
&& comp_stream_.avail_out != 0 ) {
|
|
// we processed everything ok and the output buffer was large enough.
|
|
;
|
|
} else if (err == Z_STREAM_END && comp_stream_.avail_in > 0) {
|
|
return Z_BUF_ERROR; // should never happen
|
|
} else if (err != Z_OK && err != Z_STREAM_END && err != Z_BUF_ERROR) {
|
|
// an error happened
|
|
CompressErrorInit();
|
|
return err;
|
|
} else if (comp_stream_.avail_out == 0) { // not enough space
|
|
err = Z_BUF_ERROR;
|
|
}
|
|
|
|
assert(err == Z_OK || err == Z_STREAM_END || err == Z_BUF_ERROR);
|
|
if (err == Z_STREAM_END)
|
|
err = Z_OK;
|
|
|
|
// update the crc and other metadata
|
|
compressed_size = comp_stream_.total_out - compressed_size; // delta
|
|
*destLen = compressed_size;
|
|
|
|
return err;
|
|
}
|
|
|
|
int ZLib::CompressChunkOrAll(Bytef *dest, uLongf *destLen,
|
|
const Bytef *source, uLong sourceLen,
|
|
int flush_mode) { // Z_FULL_FLUSH or Z_FINISH
|
|
const int ret =
|
|
CompressAtMostOrAll(dest, destLen, source, &sourceLen, flush_mode);
|
|
if (ret == Z_BUF_ERROR)
|
|
CompressErrorInit();
|
|
return ret;
|
|
}
|
|
|
|
// This routine only initializes the compression stream once. Thereafter, it
|
|
// just does a deflateReset on the stream, which should be faster.
|
|
int ZLib::Compress(Bytef *dest, uLongf *destLen,
|
|
const Bytef *source, uLong sourceLen) {
|
|
int err;
|
|
const uLongf orig_destLen = *destLen;
|
|
if ( (err=CompressChunkOrAll(dest, destLen, source, sourceLen,
|
|
Z_FINISH)) != Z_OK )
|
|
return err;
|
|
Reset(); // reset for next call to Compress
|
|
|
|
return Z_OK;
|
|
}
|
|
|
|
|
|
// --------- UNCOMPRESS MODE
|
|
|
|
int ZLib::InflateInit() {
|
|
return inflateInit2(&uncomp_stream_, MAX_WBITS);
|
|
}
|
|
|
|
// Initialization method to be called if we hit an error while
|
|
// uncompressing. On hitting an error, call this method before
|
|
// returning the error.
|
|
void ZLib::UncompressErrorInit() {
|
|
inflateEnd(&uncomp_stream_);
|
|
uncomp_init_ = false;
|
|
Reset();
|
|
}
|
|
|
|
int ZLib::UncompressInit(Bytef *dest, uLongf *destLen,
|
|
const Bytef *source, uLong *sourceLen) {
|
|
int err;
|
|
|
|
uncomp_stream_.next_in = (Bytef*)source;
|
|
uncomp_stream_.avail_in = (uInt)*sourceLen;
|
|
// Check for source > 64K on 16-bit machine:
|
|
if ((uLong)uncomp_stream_.avail_in != *sourceLen) return Z_BUF_ERROR;
|
|
|
|
uncomp_stream_.next_out = dest;
|
|
uncomp_stream_.avail_out = (uInt)*destLen;
|
|
if ((uLong)uncomp_stream_.avail_out != *destLen) return Z_BUF_ERROR;
|
|
|
|
if ( !first_chunk_ ) // only need to set up stream the first time through
|
|
return Z_OK;
|
|
|
|
if (uncomp_init_) { // we've already initted it
|
|
err = inflateReset(&uncomp_stream_);
|
|
if (err != Z_OK) {
|
|
LOG(WARNING)
|
|
<< "ERROR: Can't reset uncompress object; creating a new one";
|
|
UncompressErrorInit();
|
|
}
|
|
}
|
|
if (!uncomp_init_) {
|
|
uncomp_stream_.zalloc = (alloc_func)0;
|
|
uncomp_stream_.zfree = (free_func)0;
|
|
uncomp_stream_.opaque = (voidpf)0;
|
|
err = InflateInit();
|
|
if (err != Z_OK) return err;
|
|
uncomp_init_ = true;
|
|
}
|
|
return Z_OK;
|
|
}
|
|
|
|
// If you compressed your data a chunk at a time, with CompressChunk,
|
|
// you can uncompress it a chunk at a time with UncompressChunk.
|
|
// Only difference bewteen chunked and unchunked uncompression
|
|
// is the flush mode we use: Z_SYNC_FLUSH (chunked) or Z_FINISH (unchunked).
|
|
int ZLib::UncompressAtMostOrAll(Bytef *dest, uLongf *destLen,
|
|
const Bytef *source, uLong *sourceLen,
|
|
int flush_mode) { // Z_SYNC_FLUSH or Z_FINISH
|
|
int err = Z_OK;
|
|
|
|
if ( (err=UncompressInit(dest, destLen, source, sourceLen)) != Z_OK ) {
|
|
LOG(WARNING) << "UncompressInit: Error: " << err << " SourceLen: "
|
|
<< *sourceLen;
|
|
return err;
|
|
}
|
|
|
|
// This is used to figure out how many output bytes we wrote *this chunk*:
|
|
const uLong old_total_out = uncomp_stream_.total_out;
|
|
|
|
// This is used to figure out how many input bytes we read *this chunk*:
|
|
const uLong old_total_in = uncomp_stream_.total_in;
|
|
|
|
// Some setup happens only for the first chunk we compress in a run
|
|
if ( first_chunk_ ) {
|
|
first_chunk_ = false; // so we don't do this again
|
|
|
|
// For the first chunk *only* (to avoid infinite troubles), we let
|
|
// there be no actual data to uncompress. This sometimes triggers
|
|
// when the input is only the gzip header, say.
|
|
if ( *sourceLen == 0 ) {
|
|
*destLen = 0;
|
|
return Z_OK;
|
|
}
|
|
}
|
|
|
|
// We'll uncompress as much as we can. If we end OK great, otherwise
|
|
// if we get an error that seems to be the gzip footer, we store the
|
|
// gzip footer and return OK, otherwise we return the error.
|
|
|
|
// flush_mode is Z_SYNC_FLUSH for chunked mode, Z_FINISH for all mode.
|
|
err = inflate(&uncomp_stream_, flush_mode);
|
|
|
|
// Figure out how many bytes of the input zlib slurped up:
|
|
const uLong bytes_read = uncomp_stream_.total_in - old_total_in;
|
|
CHECK_LE(source + bytes_read, source + *sourceLen);
|
|
*sourceLen = uncomp_stream_.avail_in;
|
|
|
|
if ((err == Z_STREAM_END || err == Z_OK) // everything went ok
|
|
&& uncomp_stream_.avail_in == 0) { // and we read it all
|
|
;
|
|
} else if (err == Z_STREAM_END && uncomp_stream_.avail_in > 0) {
|
|
LOG(WARNING)
|
|
<< "UncompressChunkOrAll: Received some extra data, bytes total: "
|
|
<< uncomp_stream_.avail_in << " bytes: "
|
|
<< string(reinterpret_cast<const char *>(uncomp_stream_.next_in),
|
|
min(int(uncomp_stream_.avail_in), 20));
|
|
UncompressErrorInit();
|
|
return Z_DATA_ERROR; // what's the extra data for?
|
|
} else if (err != Z_OK && err != Z_STREAM_END && err != Z_BUF_ERROR) {
|
|
// an error happened
|
|
LOG(WARNING) << "UncompressChunkOrAll: Error: " << err
|
|
<< " avail_out: " << uncomp_stream_.avail_out;
|
|
UncompressErrorInit();
|
|
return err;
|
|
} else if (uncomp_stream_.avail_out == 0) {
|
|
err = Z_BUF_ERROR;
|
|
}
|
|
|
|
assert(err == Z_OK || err == Z_BUF_ERROR || err == Z_STREAM_END);
|
|
if (err == Z_STREAM_END)
|
|
err = Z_OK;
|
|
|
|
*destLen = uncomp_stream_.total_out - old_total_out; // size for this call
|
|
|
|
return err;
|
|
}
|
|
|
|
int ZLib::UncompressChunkOrAll(Bytef *dest, uLongf *destLen,
|
|
const Bytef *source, uLong sourceLen,
|
|
int flush_mode) { // Z_SYNC_FLUSH or Z_FINISH
|
|
const int ret =
|
|
UncompressAtMostOrAll(dest, destLen, source, &sourceLen, flush_mode);
|
|
if (ret == Z_BUF_ERROR)
|
|
UncompressErrorInit();
|
|
return ret;
|
|
}
|
|
|
|
int ZLib::UncompressAtMost(Bytef *dest, uLongf *destLen,
|
|
const Bytef *source, uLong *sourceLen) {
|
|
return UncompressAtMostOrAll(dest, destLen, source, sourceLen, Z_SYNC_FLUSH);
|
|
}
|
|
|
|
// We make sure we've uncompressed everything, that is, the current
|
|
// uncompress stream is at a compressed-buffer-EOF boundary. In gzip
|
|
// mode, we also check the gzip footer to make sure we pass the gzip
|
|
// consistency checks. We RETURN true iff both types of checks pass.
|
|
bool ZLib::UncompressChunkDone() {
|
|
assert(!first_chunk_ && uncomp_init_);
|
|
// Make sure we're at the end-of-compressed-data point. This means
|
|
// if we call inflate with Z_FINISH we won't consume any input or
|
|
// write any output
|
|
Bytef dummyin, dummyout;
|
|
uLongf dummylen = 0;
|
|
if ( UncompressChunkOrAll(&dummyout, &dummylen, &dummyin, 0, Z_FINISH)
|
|
!= Z_OK ) {
|
|
return false;
|
|
}
|
|
|
|
// Make sure that when we exit, we can start a new round of chunks later
|
|
Reset();
|
|
|
|
return true;
|
|
}
|
|
|
|
// Uncompresses the source buffer into the destination buffer.
|
|
// The destination buffer must be long enough to hold the entire
|
|
// decompressed contents.
|
|
//
|
|
// We only initialize the uncomp_stream once. Thereafter, we use
|
|
// inflateReset, which should be faster.
|
|
//
|
|
// Returns Z_OK on success, otherwise, it returns a zlib error code.
|
|
int ZLib::Uncompress(Bytef *dest, uLongf *destLen,
|
|
const Bytef *source, uLong sourceLen) {
|
|
int err;
|
|
if ( (err=UncompressChunkOrAll(dest, destLen, source, sourceLen,
|
|
Z_FINISH)) != Z_OK ) {
|
|
Reset(); // let us try to compress again
|
|
return err;
|
|
}
|
|
if ( !UncompressChunkDone() ) // calls Reset()
|
|
return Z_DATA_ERROR;
|
|
return Z_OK; // stream_end is ok
|
|
}
|
|
|
|
#endif // HAVE_LIBZ
|
|
|
|
} // namespace snappy
|