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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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 "FormatZstd.h"
#include "BaseAlgorithms.h"
#include "mozilla/dom/TransformStreamDefaultController.h"
#include "zstd/zstd.h"
namespace mozilla::dom::compression {
NS_IMPL_CYCLE_COLLECTION_INHERITED(ZstdDecompressionStreamAlgorithms,
TransformerAlgorithmsBase)
NS_IMPL_ADDREF_INHERITED(ZstdDecompressionStreamAlgorithms,
TransformerAlgorithmsBase)
NS_IMPL_RELEASE_INHERITED(ZstdDecompressionStreamAlgorithms,
TransformerAlgorithmsBase)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ZstdDecompressionStreamAlgorithms)
NS_INTERFACE_MAP_END_INHERITING(TransformerAlgorithmsBase)
Result<already_AddRefed<ZstdDecompressionStreamAlgorithms>, nsresult>
ZstdDecompressionStreamAlgorithms::Create() {
RefPtr<ZstdDecompressionStreamAlgorithms> alg =
new ZstdDecompressionStreamAlgorithms();
MOZ_TRY(alg->Init());
return alg.forget();
}
[[nodiscard]] nsresult ZstdDecompressionStreamAlgorithms::Init() {
mDStream = ZSTD_createDStream();
if (!mDStream) {
return NS_ERROR_OUT_OF_MEMORY;
}
// Refuse any frame requiring larger than (1 << WINDOW_LOG_MAX) window size.
// Note: 1 << 23 == 8 * 1024 * 1024
static const uint8_t WINDOW_LOG_MAX = 23;
ZSTD_DCtx_setParameter(mDStream, ZSTD_d_windowLogMax, WINDOW_LOG_MAX);
return NS_OK;
}
// Shared by:
// https://wicg.github.io/compression/#decompress-and-enqueue-a-chunk
// https://wicg.github.io/compression/#decompress-flush-and-enqueue
// All data errors throw TypeError by step 2: If this results in an error,
// then throw a TypeError.
bool ZstdDecompressionStreamAlgorithms::Decompress(
JSContext* aCx, Span<const uint8_t> aInput,
JS::MutableHandleVector<JSObject*> aOutput, Flush aFlush,
ErrorResult& aRv) {
ZSTD_inBuffer inBuffer = {/* src */ const_cast<uint8_t*>(aInput.Elements()),
/* size */ aInput.Length(),
/* pos */ 0};
while (inBuffer.pos < inBuffer.size && !mObservedStreamEnd) {
UniquePtr<uint8_t[], JS::FreePolicy> buffer(
static_cast<uint8_t*>(JS_malloc(aCx, kBufferSize)));
if (!buffer) {
aRv.ThrowTypeError("Out of memory");
return false;
}
ZSTD_outBuffer outBuffer = {/* dst */ buffer.get(),
/* size */ kBufferSize,
/* pos */ 0};
size_t rv = ZSTD_decompressStream(mDStream, &outBuffer, &inBuffer);
if (ZSTD_isError(rv)) {
aRv.ThrowTypeError("zstd decompression error: "_ns +
nsDependentCString(ZSTD_getErrorName(rv)));
return false;
}
if (rv == 0) {
mObservedStreamEnd = true;
}
// Step 3: If buffer is empty, return.
// (We'll implicitly return when the array is empty.)
// Step 4: Split buffer into one or more non-empty pieces and convert them
// into Uint8Arrays.
// (The buffer is 'split' by having a fixed sized buffer above.)
size_t written = outBuffer.pos;
if (written > 0) {
JS::Rooted<JSObject*> view(aCx, nsJSUtils::MoveBufferAsUint8Array(
aCx, written, std::move(buffer)));
if (!view || !aOutput.append(view)) {
JS_ClearPendingException(aCx);
aRv.ThrowTypeError("Out of memory");
return false;
}
}
}
return inBuffer.pos == inBuffer.size;
}
ZstdDecompressionStreamAlgorithms::~ZstdDecompressionStreamAlgorithms() {
if (mDStream) {
ZSTD_freeDStream(mDStream);
mDStream = nullptr;
}
}
} // namespace mozilla::dom::compression
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