gecko/mozglue/linker/szip.cpp

563 lines
15 KiB
C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <algorithm>
#include <map>
#include <sys/stat.h>
#include <cstring>
#include <cstdlib>
#include <zlib.h>
#include <fcntl.h>
#include <errno.h>
#include "mozilla/Assertions.h"
#include "mozilla/Scoped.h"
#include "SeekableZStream.h"
#include "Utils.h"
#include "Logging.h"
const char *filterName[] = {
"none",
"thumb",
"arm",
"x86",
"auto"
};
/* Maximum supported size for chunkSize */
static const size_t maxChunkSize =
1 << (8 * std::min(sizeof(((SeekableZStreamHeader *)NULL)->chunkSize),
sizeof(((SeekableZStreamHeader *)NULL)->lastChunkSize)) - 1);
class Buffer: public MappedPtr
{
public:
virtual bool Resize(size_t size)
{
void *buf = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (buf == MAP_FAILED)
return false;
if (*this != MAP_FAILED)
memcpy(buf, *this, std::min(size, GetLength()));
Assign(buf, size);
return true;
}
bool Fill(Buffer &other)
{
size_t size = other.GetLength();
if (!size || !Resize(size))
return false;
memcpy(static_cast<void *>(*this), static_cast<void *>(other), size);
return true;
}
};
class FileBuffer: public Buffer
{
public:
bool Init(const char *name, bool writable_ = false)
{
fd = open(name, writable_ ? O_RDWR | O_CREAT | O_TRUNC : O_RDONLY, 0666);
if (fd == -1)
return false;
writable = writable_;
return true;
}
virtual bool Resize(size_t size)
{
if (writable) {
if (ftruncate(fd, size) == -1)
return false;
}
Assign(mmap(NULL, size, PROT_READ | (writable ? PROT_WRITE : 0),
writable ? MAP_SHARED : MAP_PRIVATE, fd, 0), size);
return this != MAP_FAILED;
}
int getFd()
{
return fd;
}
private:
AutoCloseFD fd;
bool writable;
};
class FilteredBuffer: public Buffer
{
public:
void Filter(Buffer &other, SeekableZStream::FilterId filter, size_t chunkSize)
{
SeekableZStream::ZStreamFilter filterCB =
SeekableZStream::GetFilter(filter);
MOZ_ASSERT(filterCB);
Fill(other);
size_t size = other.GetLength();
Bytef *data = reinterpret_cast<Bytef *>(static_cast<void *>(*this));
size_t avail = 0;
/* Filter needs to be applied in chunks. */
while (size) {
avail = std::min(size, chunkSize);
filterCB(data - static_cast<unsigned char *>(static_cast<void *>(*this)),
SeekableZStream::FILTER, data, avail);
size -= avail;
data += avail;
}
}
};
template <typename T>
class Dictionary: public Buffer
{
typedef T piece;
typedef std::pair<piece, int> stat_pair;
static bool stat_cmp(stat_pair a, stat_pair b)
{
return a.second < b.second;
}
public:
Dictionary(Buffer &inBuf, size_t size)
{
if (!size || !Resize(size))
return;
debug("Creating dictionary");
piece *origBufPieces = reinterpret_cast<piece *>(
static_cast<void *>(inBuf));
std::map<piece, int> stats;
for (int i = 0; i < inBuf.GetLength() / sizeof(piece); i++) {
stats[origBufPieces[i]]++;
}
std::vector<stat_pair> statsVec(stats.begin(), stats.end());
std::sort(statsVec.begin(), statsVec.end(), stat_cmp);
piece *dictPieces = reinterpret_cast<piece *>(
static_cast<void *>(*this));
typename std::vector<stat_pair>::reverse_iterator it = statsVec.rbegin();
for (int i = size / sizeof(piece); i > 0 && it < statsVec.rend();
i--, ++it) {
dictPieces[i - 1] = it->first;
}
}
};
class SzipAction
{
public:
virtual int run(const char *name, Buffer &origBuf,
const char *outName, Buffer &outBuf) = 0;
virtual ~SzipAction() {}
};
class SzipDecompress: public SzipAction
{
public:
int run(const char *name, Buffer &origBuf,
const char *outName, Buffer &outBuf);
};
class SzipCompress: public SzipAction
{
public:
int run(const char *name, Buffer &origBuf,
const char *outName, Buffer &outBuf);
SzipCompress(size_t aChunkSize, SeekableZStream::FilterId aFilter,
size_t aDictSize)
: chunkSize(aChunkSize ? aChunkSize : 16384)
, filter(aFilter)
, dictSize(aDictSize)
{}
const static signed char winSizeLog = 15;
const static size_t winSize = 1 << winSizeLog;
const static SeekableZStream::FilterId DEFAULT_FILTER =
#if defined(TARGET_THUMB)
SeekableZStream::BCJ_THUMB;
#elif defined(TARGET_ARM)
SeekableZStream::BCJ_ARM;
#elif defined(TARGET_X86)
SeekableZStream::BCJ_X86;
#else
SeekableZStream::NONE;
#endif
private:
int do_compress(Buffer &origBuf, Buffer &outBuf, const unsigned char *aDict,
size_t aDictSize, SeekableZStream::FilterId aFilter);
size_t chunkSize;
SeekableZStream::FilterId filter;
size_t dictSize;
};
/* Decompress a seekable compressed stream */
int SzipDecompress::run(const char *name, Buffer &origBuf,
const char *outName, Buffer &outBuf)
{
size_t origSize = origBuf.GetLength();
if (origSize < sizeof(SeekableZStreamHeader)) {
log("%s is not a seekable zstream", name);
return 1;
}
SeekableZStream zstream;
if (!zstream.Init(origBuf, origSize))
return 1;
size_t size = zstream.GetUncompressedSize();
/* Give enough room for the uncompressed data */
if (!outBuf.Resize(size)) {
log("Error resizing %s: %s", outName, strerror(errno));
return 1;
}
if (!zstream.Decompress(outBuf, 0, size))
return 1;
return 0;
}
/* Generate a seekable compressed stream. */
int SzipCompress::run(const char *name, Buffer &origBuf,
const char *outName, Buffer &outBuf)
{
size_t origSize = origBuf.GetLength();
if (origSize == 0) {
log("Won't compress %s: it's empty", name);
return 1;
}
bool compressed = false;
log("Size = %" PRIuSize, origSize);
/* Allocate a buffer the size of the uncompressed data: we don't want
* a compressed file larger than that anyways. */
if (!outBuf.Resize(origSize)) {
log("Couldn't allocate output buffer: %s", strerror(errno));
return 1;
}
/* Find the most appropriate filter */
SeekableZStream::FilterId firstFilter, lastFilter;
bool scanFilters;
if (filter == SeekableZStream::FILTER_MAX) {
firstFilter = SeekableZStream::NONE;
lastFilter = SeekableZStream::FILTER_MAX;
scanFilters = true;
} else {
firstFilter = lastFilter = filter;
++lastFilter;
scanFilters = false;
}
mozilla::ScopedDeletePtr<Buffer> filteredBuf;
Buffer *origData;
for (SeekableZStream::FilterId f = firstFilter; f < lastFilter; ++f) {
FilteredBuffer *filteredTmp = NULL;
Buffer tmpBuf;
if (f != SeekableZStream::NONE) {
debug("Applying filter \"%s\"", filterName[f]);
filteredTmp = new FilteredBuffer();
filteredTmp->Filter(origBuf, f, chunkSize);
origData = filteredTmp;
} else {
origData = &origBuf;
}
if (dictSize && !scanFilters) {
filteredBuf = filteredTmp;
break;
}
debug("Compressing with no dictionary");
if (do_compress(*origData, tmpBuf, NULL, 0, f) == 0) {
if (tmpBuf.GetLength() < outBuf.GetLength()) {
outBuf.Fill(tmpBuf);
compressed = true;
filter = f;
filteredBuf = filteredTmp;
continue;
}
}
delete filteredTmp;
}
origData = filteredBuf ? filteredBuf : &origBuf;
if (dictSize) {
Dictionary<uint64_t> dict(*origData, dictSize ? SzipCompress::winSize : 0);
/* Find the most appropriate dictionary size */
size_t firstDictSize, lastDictSize;
if (dictSize == (size_t) -1) {
/* If we scanned for filters, we effectively already tried dictSize=0 */
firstDictSize = scanFilters ? 4096 : 0;
lastDictSize = SzipCompress::winSize;
} else {
firstDictSize = lastDictSize = dictSize;
}
Buffer tmpBuf;
for (size_t d = firstDictSize; d <= lastDictSize; d += 4096) {
debug("Compressing with dictionary of size %" PRIuSize, d);
if (do_compress(*origData, tmpBuf, static_cast<unsigned char *>(dict)
+ SzipCompress::winSize - d, d, filter))
continue;
if (!compressed || tmpBuf.GetLength() < outBuf.GetLength()) {
outBuf.Fill(tmpBuf);
compressed = true;
dictSize = d;
}
}
}
if (!compressed) {
outBuf.Fill(origBuf);
log("Not compressed");
return 0;
}
if (dictSize == (size_t) -1)
dictSize = 0;
debug("Used filter \"%s\" and dictionary size of %" PRIuSize,
filterName[filter], dictSize);
log("Compressed size is %" PRIuSize, outBuf.GetLength());
/* Sanity check */
Buffer tmpBuf;
SzipDecompress decompress;
if (decompress.run("buffer", outBuf, "buffer", tmpBuf))
return 1;
size_t size = tmpBuf.GetLength();
if (size != origSize) {
log("Compression error: %" PRIuSize " != %" PRIuSize, size, origSize);
return 1;
}
if (memcmp(static_cast<void *>(origBuf), static_cast<void *>(tmpBuf), size)) {
log("Compression error: content mismatch");
return 1;
}
return 0;
}
int SzipCompress::do_compress(Buffer &origBuf, Buffer &outBuf,
const unsigned char *aDict, size_t aDictSize,
SeekableZStream::FilterId aFilter)
{
size_t origSize = origBuf.GetLength();
MOZ_ASSERT(origSize != 0);
/* Expected total number of chunks */
size_t nChunks = ((origSize + chunkSize - 1) / chunkSize);
/* The first chunk is going to be stored after the header, the dictionary
* and the offset table */
size_t offset = sizeof(SeekableZStreamHeader) + aDictSize
+ nChunks * sizeof(uint32_t);
if (offset >= origSize)
return 1;
/* Allocate a buffer the size of the uncompressed data: we don't want
* a compressed file larger than that anyways. */
if (!outBuf.Resize(origSize)) {
log("Couldn't allocate output buffer: %s", strerror(errno));
return 1;
}
SeekableZStreamHeader *header = new (outBuf) SeekableZStreamHeader;
unsigned char *dictionary = static_cast<unsigned char *>(
outBuf + sizeof(SeekableZStreamHeader));
le_uint32 *entry =
reinterpret_cast<le_uint32 *>(dictionary + aDictSize);
/* Initialize header */
header->chunkSize = chunkSize;
header->dictSize = aDictSize;
header->totalSize = offset;
header->windowBits = -SzipCompress::winSizeLog; // Raw stream,
// window size of 32k.
header->filter = aFilter;
if (aDictSize)
memcpy(dictionary, aDict, aDictSize);
/* Initialize zlib structure */
z_stream zStream;
memset(&zStream, 0, sizeof(zStream));
zStream.avail_out = origSize - offset;
zStream.next_out = static_cast<Bytef*>(outBuf) + offset;
size_t avail = 0;
size_t size = origSize;
unsigned char *data = reinterpret_cast<unsigned char *>(
static_cast<void *>(origBuf));
while (size) {
avail = std::min(size, chunkSize);
/* Compress chunk */
int ret = deflateInit2(&zStream, 9, Z_DEFLATED, header->windowBits,
MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
if (aDictSize)
deflateSetDictionary(&zStream, dictionary, aDictSize);
MOZ_ASSERT(ret == Z_OK);
zStream.avail_in = avail;
zStream.next_in = data;
ret = deflate(&zStream, Z_FINISH);
MOZ_ASSERT(ret == Z_STREAM_END);
ret = deflateEnd(&zStream);
MOZ_ASSERT(ret == Z_OK);
if (zStream.avail_out <= 0)
return 1;
size_t len = origSize - offset - zStream.avail_out;
/* Adjust headers */
header->totalSize += len;
*entry++ = offset;
header->nChunks++;
/* Prepare for next iteration */
size -= avail;
data += avail;
offset += len;
}
header->lastChunkSize = avail;
MOZ_ASSERT(header->totalSize == offset);
if (!outBuf.Resize(offset)) {
log("Error truncating output: %s", strerror(errno));
return 1;
}
MOZ_ASSERT(header->nChunks == nChunks);
return 0;
}
bool GetSize(const char *str, size_t *out)
{
char *end;
MOZ_ASSERT(out);
errno = 0;
*out = strtol(str, &end, 10);
return (!errno && !*end);
}
int main(int argc, char* argv[])
{
mozilla::ScopedDeletePtr<SzipAction> action;
char **firstArg;
bool compress = true;
size_t chunkSize = 0;
SeekableZStream::FilterId filter = SzipCompress::DEFAULT_FILTER;
size_t dictSize = (size_t) 0;
for (firstArg = &argv[1]; argc > 3; argc--, firstArg++) {
if (!firstArg[0] || firstArg[0][0] != '-')
break;
if (strcmp(firstArg[0], "-d") == 0) {
compress = false;
} else if (strcmp(firstArg[0], "-c") == 0) {
firstArg++;
argc--;
if (!firstArg[0])
break;
if (!GetSize(firstArg[0], &chunkSize) || !chunkSize ||
(chunkSize % 4096) || (chunkSize > maxChunkSize)) {
log("Invalid chunk size");
return 1;
}
} else if (strcmp(firstArg[0], "-f") == 0) {
firstArg++;
argc--;
if (!firstArg[0])
break;
bool matched = false;
for (int i = 0; i < sizeof(filterName) / sizeof(char *); ++i) {
if (strcmp(firstArg[0], filterName[i]) == 0) {
filter = static_cast<SeekableZStream::FilterId>(i);
matched = true;
break;
}
}
if (!matched) {
log("Invalid filter");
return 1;
}
} else if (strcmp(firstArg[0], "-D") == 0) {
firstArg++;
argc--;
if (!firstArg[0])
break;
if (strcmp(firstArg[0], "auto") == 0) {
dictSize = -1;
} else if (!GetSize(firstArg[0], &dictSize) || (dictSize >= 1 << 16)) {
log("Invalid dictionary size");
return 1;
}
}
}
if (argc != 3 || !firstArg[0] || !firstArg[1] ||
(strcmp(firstArg[0], firstArg[1]) == 0)) {
log("usage: %s [-d] [-c CHUNKSIZE] [-f FILTER] [-D DICTSIZE] "
"in_file out_file", argv[0]);
return 1;
}
if (compress) {
action = new SzipCompress(chunkSize, filter, dictSize);
} else {
if (chunkSize) {
log("-c is incompatible with -d");
return 1;
}
if (dictSize != (size_t) -1) {
log("-D is incompatible with -d");
return 1;
}
action = new SzipDecompress();
}
FileBuffer origBuf;
if (!origBuf.Init(firstArg[0])) {
log("Couldn't open %s: %s", firstArg[0], strerror(errno));
return 1;
}
struct stat st;
int ret = fstat(origBuf.getFd(), &st);
if (ret == -1) {
log("Couldn't stat %s: %s", firstArg[0], strerror(errno));
return 1;
}
size_t origSize = st.st_size;
/* Mmap the original file */
if (!origBuf.Resize(origSize)) {
log("Couldn't mmap %s: %s", firstArg[0], strerror(errno));
return 1;
}
/* Create the compressed file */
FileBuffer outBuf;
if (!outBuf.Init(firstArg[1], true)) {
log("Couldn't open %s: %s", firstArg[1], strerror(errno));
return 1;
}
ret = action->run(firstArg[0], origBuf, firstArg[1], outBuf);
return ret;
}