Quelle ArrayBufferInputStream.cpp Sprache: C

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 <algorithm>
#include "ArrayBufferInputStream.h"
#include "nsStreamUtils.h"
#include "js/ArrayBuffer.h"  // JS::{GetArrayBuffer{ByteLength,Data},IsArrayBufferObject}
#include "js/RootingAPI.h"  // JS::{Handle,Rooted}
#include "js/Value.h"       // JS::Value
#include "mozilla/Span.h"
#include "mozilla/UniquePtrExtensions.h"
#include "mozilla/dom/ScriptSettings.h"

using mozilla::dom::RootingCx;

NS_IMPL_ISUPPORTS(ArrayBufferInputStream, nsIArrayBufferInputStream,
                  nsIInputStream);

NS_IMETHODIMP
ArrayBufferInputStream::SetDataFromJS(JS::Handle<JS::Value> aBuffer,
                                      uint64_t aByteOffset, uint64_t aLength) {
  NS_ASSERT_OWNINGTHREAD(ArrayBufferInputStream);

  if (!aBuffer.isObject()) {
    return NS_ERROR_FAILURE;
  }
  JS::Rooted<JSObject*> arrayBuffer(RootingCx(), &aBuffer.toObject());
  if (!JS::IsArrayBufferObject(arrayBuffer)) {
    return NS_ERROR_FAILURE;
  }

  uint64_t buflen = JS::GetArrayBufferByteLength(arrayBuffer);
  uint64_t offset = std::min(buflen, aByteOffset);
  uint64_t bufferLength = std::min(buflen - offset, aLength);

  // Prevent truncation.
  if (bufferLength > UINT32_MAX) {
    return NS_ERROR_INVALID_ARG;
  }

  mArrayBuffer = mozilla::MakeUniqueFallible<uint8_t[]>(bufferLength);
  if (!mArrayBuffer) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  mBufferLength = bufferLength;

  JS::AutoCheckCannotGC nogc;
  bool isShared;
  uint8_t* src = JS::GetArrayBufferData(arrayBuffer, &isShared, nogc) + offset;
  memcpy(&mArrayBuffer[0], src, mBufferLength);
  return NS_OK;
}

nsresult ArrayBufferInputStream::SetData(mozilla::UniquePtr<uint8_t[]> aBytes,
                                         uint64_t aByteLen) {
  mArrayBuffer = std::move(aBytes);
  mBufferLength = aByteLen;
  return NS_OK;
}

NS_IMETHODIMP
ArrayBufferInputStream::Close() {
  mClosed = true;
  return NS_OK;
}

NS_IMETHODIMP
ArrayBufferInputStream::Available(uint64_t* aCount) {
  if (mClosed) {
    return NS_BASE_STREAM_CLOSED;
  }
  if (mArrayBuffer) {
    *aCount = mBufferLength ? mBufferLength - mPos : 0;
  } else {
    *aCount = 0;
  }
  return NS_OK;
}

NS_IMETHODIMP
ArrayBufferInputStream::StreamStatus() {
  return mClosed ? NS_BASE_STREAM_CLOSED : NS_OK;
}

NS_IMETHODIMP
ArrayBufferInputStream::Read(char* aBuf, uint32_t aCount,
                             uint32_t* aReadCount) {
  return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, aReadCount);
}

NS_IMETHODIMP
ArrayBufferInputStream::ReadSegments(nsWriteSegmentFun writer, void* closure,
                                     uint32_t aCount, uint32_t* result) {
  NS_ASSERTION(result, "null ptr");
  NS_ASSERTION(mBufferLength >= mPos, "bad stream state");

  if (mClosed) {
    return NS_BASE_STREAM_CLOSED;
  }

  MOZ_ASSERT(mArrayBuffer || (mPos == mBufferLength),
             "stream inited incorrectly");

  *result = 0;
  while (mPos < mBufferLength) {
    uint32_t remaining = mBufferLength - mPos;
    MOZ_ASSERT(mArrayBuffer);

    uint32_t count = std::min(aCount, remaining);
    if (count == 0) {
      break;
    }

    uint32_t written;
    nsresult rv = writer(this, closure, (char*)&mArrayBuffer[0] + mPos, *result,
                         count, &written);
    if (NS_FAILED(rv)) {
      // InputStreams do not propagate errors to caller.
      return NS_OK;
    }

    NS_ASSERTION(written <= count,
                 "writer should not write more than we asked it to write");
    mPos += written;
    *result += written;
    aCount -= written;
  }

  return NS_OK;
}

NS_IMETHODIMP
ArrayBufferInputStream::IsNonBlocking(bool* aNonBlocking) {
  *aNonBlocking = true;
  return NS_OK;
}

quality95%

¤ Dauer der Verarbeitung: 0.0 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.