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/* -*- 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/. */
#ifndef MOZILLA_RESOURCEQUEUE_H_
#define MOZILLA_RESOURCEQUEUE_H_
#include "nsDeque.h"
#include "MediaSpan.h"
namespace mozilla {
class ErrorResult;
// A SourceBufferResource has a queue containing the data that is appended
// to it. The queue holds instances of ResourceItem which is an array of the
// bytes. Appending data to the SourceBufferResource pushes this onto the
// queue.
// Data is evicted once it reaches a size threshold. This pops the items off
// the front of the queue and deletes it. If an eviction happens then the
// MediaSource is notified (done in SourceBuffer::AppendData) which then
// requests all SourceBuffers to evict data up to approximately the same
// timepoint.
struct ResourceItem {
ResourceItem(const MediaSpan& aData, uint64_t aOffset);
size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
MediaSpan mData;
uint64_t mOffset;
};
class ResourceQueue : private nsDeque<ResourceItem> {
public:
ResourceQueue();
// Returns the logical byte offset of the start of the data.
uint64_t GetOffset();
// Returns the length of all items in the queue plus the offset.
// This is the logical length of the resource.
uint64_t GetLength();
// Copies aCount bytes from aOffset in the queue into aDest.
void CopyData(uint64_t aOffset, uint32_t aCount, char* aDest);
void AppendItem(const MediaSpan& aData);
// Tries to evict at least aSizeToEvict from the queue up until
// aOffset. Returns amount evicted.
uint32_t Evict(uint64_t aOffset, uint32_t aSizeToEvict);
uint32_t EvictBefore(uint64_t aOffset);
uint32_t EvictAll();
size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const;
#if defined(DEBUG)
void Dump(const char* aPath);
#endif
const uint8_t* GetContiguousAccess(int64_t aOffset, size_t aSize);
private:
ResourceItem* ResourceAt(uint32_t aIndex) const;
// Returns the index of the resource that contains the given
// logical offset. aResourceOffset will contain the offset into
// the resource at the given index returned if it is not null. If
// no such resource exists, returns GetSize() and aOffset is
// untouched.
uint32_t GetAtOffset(uint64_t aOffset, uint32_t* aResourceOffset) const;
ResourceItem* PopFront();
// Logical length of the resource.
uint64_t mLogicalLength;
// Logical offset into the resource of the first element in the queue.
uint64_t mOffset;
};
} // namespace mozilla
#endif /* MOZILLA_RESOURCEQUEUE_H_ */