107 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			107 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C++
		
	
	
	
//===--- Compression.cpp - Compression implementation ---------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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//  This file implements compression functions.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Support/Compression.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/Config/config.h"
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#include "llvm/Support/Compiler.h"
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#include "llvm/Support/Error.h"
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#include "llvm/Support/ErrorHandling.h"
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#if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H
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#include <zlib.h>
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#endif
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using namespace llvm;
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#if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ
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static Error createError(StringRef Err) {
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  return make_error<StringError>(Err, inconvertibleErrorCode());
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}
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static StringRef convertZlibCodeToString(int Code) {
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  switch (Code) {
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  case Z_MEM_ERROR:
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    return "zlib error: Z_MEM_ERROR";
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  case Z_BUF_ERROR:
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    return "zlib error: Z_BUF_ERROR";
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  case Z_STREAM_ERROR:
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    return "zlib error: Z_STREAM_ERROR";
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  case Z_DATA_ERROR:
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    return "zlib error: Z_DATA_ERROR";
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  case Z_OK:
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  default:
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    llvm_unreachable("unknown or unexpected zlib status code");
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  }
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}
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bool zlib::isAvailable() { return true; }
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Error zlib::compress(StringRef InputBuffer,
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                     SmallVectorImpl<char> &CompressedBuffer, int Level) {
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  unsigned long CompressedSize = ::compressBound(InputBuffer.size());
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  CompressedBuffer.reserve(CompressedSize);
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  int Res =
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      ::compress2((Bytef *)CompressedBuffer.data(), &CompressedSize,
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                  (const Bytef *)InputBuffer.data(), InputBuffer.size(), Level);
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  // Tell MemorySanitizer that zlib output buffer is fully initialized.
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  // This avoids a false report when running LLVM with uninstrumented ZLib.
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  __msan_unpoison(CompressedBuffer.data(), CompressedSize);
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  CompressedBuffer.set_size(CompressedSize);
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  return Res ? createError(convertZlibCodeToString(Res)) : Error::success();
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}
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Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
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                       size_t &UncompressedSize) {
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  int Res =
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      ::uncompress((Bytef *)UncompressedBuffer, (uLongf *)&UncompressedSize,
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                   (const Bytef *)InputBuffer.data(), InputBuffer.size());
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  // Tell MemorySanitizer that zlib output buffer is fully initialized.
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  // This avoids a false report when running LLVM with uninstrumented ZLib.
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  __msan_unpoison(UncompressedBuffer, UncompressedSize);
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  return Res ? createError(convertZlibCodeToString(Res)) : Error::success();
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}
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Error zlib::uncompress(StringRef InputBuffer,
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                       SmallVectorImpl<char> &UncompressedBuffer,
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                       size_t UncompressedSize) {
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  UncompressedBuffer.resize(UncompressedSize);
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  Error E =
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      uncompress(InputBuffer, UncompressedBuffer.data(), UncompressedSize);
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  UncompressedBuffer.resize(UncompressedSize);
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  return E;
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}
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uint32_t zlib::crc32(StringRef Buffer) {
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  return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size());
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}
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#else
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bool zlib::isAvailable() { return false; }
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Error zlib::compress(StringRef InputBuffer,
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                     SmallVectorImpl<char> &CompressedBuffer, int Level) {
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  llvm_unreachable("zlib::compress is unavailable");
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}
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Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
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                       size_t &UncompressedSize) {
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  llvm_unreachable("zlib::uncompress is unavailable");
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}
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Error zlib::uncompress(StringRef InputBuffer,
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                       SmallVectorImpl<char> &UncompressedBuffer,
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                       size_t UncompressedSize) {
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  llvm_unreachable("zlib::uncompress is unavailable");
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}
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uint32_t zlib::crc32(StringRef Buffer) {
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  llvm_unreachable("zlib::crc32 is unavailable");
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}
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#endif
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