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// Copyright 2016 The Bazel Authors. All rights reserved.
//
// 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.
#include <stdlib.h>
#include <algorithm>
#include <cstdio>
#include "third_party/ijar/common.h"
#include "third_party/ijar/zlib_client.h"
#include <zlib.h>
namespace devtools_ijar {
u4 ComputeCrcChecksum(u1 *buf, size_t length) {
return crc32(0, buf, length);
}
size_t TryDeflate(u1 *buf, size_t length) {
u1 *outbuf = reinterpret_cast<u1 *>(malloc(length));
z_stream stream;
// Initialize the z_stream strcut for reading from buf and wrinting in outbuf.
stream.zalloc = Z_NULL;
stream.zfree = Z_NULL;
stream.opaque = Z_NULL;
stream.total_in = length;
stream.avail_in = length;
stream.total_out = length;
stream.avail_out = length;
stream.next_in = buf;
stream.next_out = outbuf;
// deflateInit2 negative windows size prevent the zlib wrapper to be used.
if (deflateInit2(&stream, Z_DEFAULT_COMPRESSION, Z_DEFLATED, -MAX_WBITS, 8,
Z_DEFAULT_STRATEGY) != Z_OK) {
// Failure to compress => return the buffer uncompressed
free(outbuf);
return length;
}
if (deflate(&stream, Z_FINISH) == Z_STREAM_END) {
// Compression successful and fits in outbuf, let's copy the result in buf.
length = stream.total_out;
memcpy(buf, outbuf, length);
}
deflateEnd(&stream);
free(outbuf);
// Return the length of the resulting buffer
return length;
}
Decompressor::Decompressor() {
uncompressed_data_allocated_ = INITIAL_BUFFER_SIZE;
uncompressed_data_ =
reinterpret_cast<u1 *>(malloc(uncompressed_data_allocated_));
}
Decompressor::~Decompressor() { free(uncompressed_data_); }
DecompressedFile *Decompressor::UncompressFile(const u1 *buffer,
size_t bytes_avail) {
z_stream stream;
stream.zalloc = Z_NULL;
stream.zfree = Z_NULL;
stream.opaque = Z_NULL;
stream.avail_in = bytes_avail;
stream.next_in = const_cast<Bytef*>(reinterpret_cast<const Bytef*>(buffer));
int ret = inflateInit2(&stream, -MAX_WBITS);
if (ret != Z_OK) {
error("inflateInit: %d\n", ret);
return NULL;
}
int uncompressed_until_now = 0;
while (true) {
stream.avail_out = uncompressed_data_allocated_ - uncompressed_until_now;
stream.next_out = uncompressed_data_ + uncompressed_until_now;
int old_avail_out = stream.avail_out;
ret = inflate(&stream, Z_SYNC_FLUSH);
int uncompressed_now = old_avail_out - stream.avail_out;
uncompressed_until_now += uncompressed_now;
switch (ret) {
case Z_STREAM_END: {
struct DecompressedFile *decompressedFile =
reinterpret_cast<DecompressedFile *>(
malloc(sizeof(DecompressedFile)));
// zlib said that there is no more data to decompress.
u1 *new_p = reinterpret_cast<u1 *>(stream.next_in);
decompressedFile->compressed_size = new_p - buffer;
decompressedFile->uncompressed_size = uncompressed_until_now;
decompressedFile->uncompressed_data = uncompressed_data_;
inflateEnd(&stream);
return decompressedFile;
}
case Z_OK: {
// zlib said that there is no more room in the buffer allocated for
// the decompressed data. Enlarge that buffer and try again.
if (uncompressed_data_allocated_ == MAX_BUFFER_SIZE) {
error(
"ijar does not support decompressing files "
"larger than %dMB.\n",
static_cast<int>((MAX_BUFFER_SIZE / (1024 * 1024))));
return NULL;
}
uncompressed_data_allocated_ *= 2;
if (uncompressed_data_allocated_ > MAX_BUFFER_SIZE) {
uncompressed_data_allocated_ = MAX_BUFFER_SIZE;
}
uncompressed_data_ = reinterpret_cast<u1 *>(
realloc(uncompressed_data_, uncompressed_data_allocated_));
break;
}
case Z_DATA_ERROR:
case Z_BUF_ERROR:
case Z_STREAM_ERROR:
case Z_NEED_DICT:
default: {
error("zlib returned error code %d during inflate.\n", ret);
return NULL;
}
}
}
}
char *Decompressor::GetError() {
if (errmsg[0] == 0) {
return NULL;
}
return errmsg;
}
int Decompressor::error(const char *fmt, ...) {
va_list ap;
va_start(ap, fmt);
vsnprintf(errmsg, 4 * PATH_MAX, fmt, ap);
va_end(ap);
return -1;
}
} // namespace devtools_ijar