/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=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 "SourceBufferResource.h"

#include "mozilla/Logging.h"
#include "mozilla/TaskQueue.h"
#include "MediaData.h"

mozilla::LogModule* GetSourceBufferResourceLog()
{
  static mozilla::LazyLogModule sLogModule("SourceBufferResource");
  return sLogModule;
}

#define SBR_DEBUG(arg, ...)                                                    \
  MOZ_LOG(                                                                     \
    GetSourceBufferResourceLog(),                                              \
    mozilla::LogLevel::Debug,                                                  \
    ("SourceBufferResource(%p)::%s: " arg, this, __func__, ##__VA_ARGS__))
#define SBR_DEBUGV(arg, ...)                                                   \
  MOZ_LOG(                                                                     \
    GetSourceBufferResourceLog(),                                              \
    mozilla::LogLevel::Verbose,                                                \
    ("SourceBufferResource(%p)::%s: " arg, this, __func__, ##__VA_ARGS__))

namespace mozilla {

nsresult
SourceBufferResource::Close()
{
  MOZ_ASSERT(OnTaskQueue());
  SBR_DEBUG("Close");
  mClosed = true;
  return NS_OK;
}

nsresult
SourceBufferResource::ReadAt(int64_t aOffset,
                             char* aBuffer,
                             uint32_t aCount,
                             uint32_t* aBytes)
{
  SBR_DEBUG("ReadAt(aOffset=%" PRId64 ", aBuffer=%p, aCount=%u, aBytes=%p)",
            aOffset, aBytes, aCount, aBytes);
  return ReadAtInternal(aOffset, aBuffer, aCount, aBytes);
}

nsresult
SourceBufferResource::ReadAtInternal(int64_t aOffset,
                                     char* aBuffer,
                                     uint32_t aCount,
                                     uint32_t* aBytes)
{
  MOZ_ASSERT(OnTaskQueue());

  if (mClosed ||
      aOffset < 0 ||
      uint64_t(aOffset) < mInputBuffer.GetOffset() ||
      aOffset > GetLength()) {
    return NS_ERROR_FAILURE;
  }

  uint32_t available = GetLength() - aOffset;
  uint32_t count = std::min(aCount, available);

  // Keep the position of the last read to have Tell() approximately give us
  // the position we're up to in the stream.
  mOffset = aOffset + count;

  SBR_DEBUGV("offset=%" PRId64 " GetLength()=%" PRId64
             " available=%u count=%u mEnded=%d",
             aOffset,
             GetLength(),
             available,
             count,
             mEnded);
  if (available == 0) {
    SBR_DEBUGV("reached EOF");
    *aBytes = 0;
    return NS_OK;
  }

  mInputBuffer.CopyData(aOffset, count, aBuffer);
  *aBytes = count;

  return NS_OK;
}

nsresult
SourceBufferResource::ReadFromCache(char* aBuffer,
                                    int64_t aOffset,
                                    uint32_t aCount)
{
  SBR_DEBUG("ReadFromCache(aBuffer=%p, aOffset=%" PRId64 ", aCount=%u)",
            aBuffer, aOffset, aCount);
  uint32_t bytesRead;
  nsresult rv = ReadAtInternal(aOffset, aBuffer, aCount, &bytesRead);
  NS_ENSURE_SUCCESS(rv, rv);

  // ReadFromCache return failure if not all the data is cached.
  return bytesRead == aCount ? NS_OK : NS_ERROR_FAILURE;
}

uint32_t
SourceBufferResource::EvictData(uint64_t aPlaybackOffset,
                                int64_t aThreshold,
                                ErrorResult& aRv)
{
  MOZ_ASSERT(OnTaskQueue());
  SBR_DEBUG("EvictData(aPlaybackOffset=%" PRIu64 ","
            "aThreshold=%" PRId64 ")", aPlaybackOffset, aThreshold);
  uint32_t result = mInputBuffer.Evict(aPlaybackOffset, aThreshold, aRv);
  return result;
}

void
SourceBufferResource::EvictBefore(uint64_t aOffset, ErrorResult& aRv)
{
  MOZ_ASSERT(OnTaskQueue());
  SBR_DEBUG("EvictBefore(aOffset=%" PRIu64 ")", aOffset);

  mInputBuffer.EvictBefore(aOffset, aRv);
}

uint32_t
SourceBufferResource::EvictAll()
{
  MOZ_ASSERT(OnTaskQueue());
  SBR_DEBUG("EvictAll()");
  return mInputBuffer.EvictAll();
}

void
SourceBufferResource::AppendData(MediaByteBuffer* aData)
{
  MOZ_ASSERT(OnTaskQueue());
  SBR_DEBUG("AppendData(aData=%p, aLength=%zu)",
            aData->Elements(), aData->Length());
  mInputBuffer.AppendItem(aData);
  mEnded = false;
}

void
SourceBufferResource::Ended()
{
  MOZ_ASSERT(OnTaskQueue());
  SBR_DEBUG("");
  mEnded = true;
}

SourceBufferResource::~SourceBufferResource()
{
  SBR_DEBUG("");
}

SourceBufferResource::SourceBufferResource()
#if defined(DEBUG)
  : mTaskQueue(AbstractThread::GetCurrent()->AsTaskQueue())
  , mOffset(0)
#else
  : mOffset(0)
#endif
  , mClosed(false)
  , mEnded(false)
{
  SBR_DEBUG("");
}

#if defined(DEBUG)
AbstractThread*
SourceBufferResource::GetTaskQueue() const
{
  return mTaskQueue;
}
bool
SourceBufferResource::OnTaskQueue() const
{
  return !GetTaskQueue() || GetTaskQueue()->IsCurrentThreadIn();
}
#endif

#undef SBR_DEBUG
#undef SBR_DEBUGV
} // namespace mozilla
