зеркало из https://github.com/mozilla/gecko-dev.git
79 строки
2.0 KiB
C++
79 строки
2.0 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this file,
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* You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "SnappyUtils.h"
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#include <stddef.h>
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#include "mozilla/Assertions.h"
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#include "mozilla/CheckedInt.h"
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#include "mozilla/fallible.h"
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#include "nsDebug.h"
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#include "nsString.h"
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#include "snappy/snappy.h"
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namespace mozilla::dom {
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bool SnappyCompress(const nsACString& aSource, nsACString& aDest) {
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MOZ_ASSERT(!aSource.IsVoid());
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size_t uncompressedLength = aSource.Length();
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if (uncompressedLength <= 16) {
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aDest.SetIsVoid(true);
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return true;
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}
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size_t compressedLength = snappy::MaxCompressedLength(uncompressedLength);
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if (NS_WARN_IF(!aDest.SetLength(compressedLength, fallible))) {
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return false;
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}
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snappy::RawCompress(aSource.BeginReading(), uncompressedLength,
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aDest.BeginWriting(), &compressedLength);
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if (compressedLength >= uncompressedLength) {
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aDest.SetIsVoid(true);
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return true;
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}
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if (NS_WARN_IF(!aDest.SetLength(compressedLength, fallible))) {
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return false;
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}
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return true;
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}
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bool SnappyUncompress(const nsACString& aSource, nsACString& aDest) {
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MOZ_ASSERT(!aSource.IsVoid());
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const char* compressed = aSource.BeginReading();
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auto compressedLength = static_cast<size_t>(aSource.Length());
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size_t uncompressedLength = 0u;
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if (!snappy::GetUncompressedLength(compressed, compressedLength,
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&uncompressedLength)) {
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return false;
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}
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CheckedUint32 checkedLength(uncompressedLength);
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if (!checkedLength.isValid()) {
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return false;
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}
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aDest.SetLength(checkedLength.value());
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if (!snappy::RawUncompress(compressed, compressedLength,
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aDest.BeginWriting())) {
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return false;
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}
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return true;
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}
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} // namespace mozilla::dom
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