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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* 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 "SnappyUtils.h"
#include <stddef.h>
#include "mozilla/Assertions.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/fallible.h"
#include "nsDebug.h"
#include "nsString.h"
#include "snappy/snappy.h"
namespace mozilla::dom {
static_assert(SNAPPY_VERSION == 0x010109);
bool SnappyCompress(const nsACString& aSource, nsACString& aDest) {
MOZ_ASSERT(!aSource.IsVoid());
size_t uncompressedLength = aSource.Length();
if (uncompressedLength <= 16) {
aDest.SetIsVoid(true);
return true;
}
size_t compressedLength = snappy::MaxCompressedLength(uncompressedLength);
if (NS_WARN_IF(!aDest.SetLength(compressedLength, fallible))) {
return false;
}
snappy::RawCompress(aSource.BeginReading(), uncompressedLength,
aDest.BeginWriting(), &compressedLength);
if (compressedLength >= uncompressedLength) {
aDest.SetIsVoid(true);
return true;
}
if (NS_WARN_IF(!aDest.SetLength(compressedLength, fallible))) {
return false;
}
return true;
}
bool SnappyUncompress(const nsACString& aSource, nsACString& aDest) {
MOZ_ASSERT(!aSource.IsVoid());
const char* compressed = aSource.BeginReading();
auto compressedLength = static_cast<size_t>(aSource.Length());
size_t uncompressedLength = 0u;
if (!snappy::GetUncompressedLength(compressed, compressedLength,
&uncompressedLength)) {
return false;
}
CheckedUint32 checkedLength(uncompressedLength);
if (!checkedLength.isValid()) {
return false;
}
aDest.SetLength(checkedLength.value());
if (!snappy::RawUncompress(compressed, compressedLength,
aDest.BeginWriting())) {
return false;
}
return true;
}
} // namespace mozilla::dom
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