/* -*- 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 "ResourceStream.h"

namespace mozilla {

ResourceStream::ResourceStream(mozilla::MediaResource* aResource)
    : mResource(aResource), mPinCount(0) {
  MOZ_ASSERT(aResource);
  DDLINKCHILD("resource", &mResource);
}

ResourceStream::~ResourceStream() { MOZ_ASSERT(mPinCount == 0); }

bool ResourceStream::ReadAt(int64_t aOffset, void* aBuffer, size_t aCount,
                            size_t* aBytesRead) {
  uint32_t sum = 0;
  uint32_t bytesRead = 0;
  do {
    uint64_t offset = aOffset + sum;
    char* buffer = reinterpret_cast<char*>(aBuffer) + sum;
    uint32_t toRead = aCount - sum;
    nsresult rv = mResource.ReadAt(offset, buffer, toRead, &bytesRead);
    if (NS_FAILED(rv)) {
      return false;
    }
    sum += bytesRead;
  } while (sum < aCount && bytesRead > 0);

  *aBytesRead = sum;
  return true;
}

bool ResourceStream::CachedReadAt(int64_t aOffset, void* aBuffer, size_t aCount,
                                  size_t* aBytesRead) {
  nsresult rv = mResource.GetResource()->ReadFromCache(
      reinterpret_cast<char*>(aBuffer), aOffset, aCount);
  if (NS_FAILED(rv)) {
    *aBytesRead = 0;
    return false;
  }
  *aBytesRead = aCount;
  return true;
}

bool ResourceStream::Length(int64_t* aSize) {
  if (mResource.GetLength() < 0) return false;
  *aSize = mResource.GetLength();
  return true;
}

}  // namespace mozilla