Revert of Multibuffer reader implementation

media/blink/multibuffer_reader.h

Index: media/blink/multibuffer_reader.h
diff --git a/media/blink/multibuffer_reader.h b/media/blink/multibuffer_reader.h
deleted file mode 100644
index 44f14f996ee3ebd83e74ac2fc7dca0634fb28444..0000000000000000000000000000000000000000
--- a/media/blink/multibuffer_reader.h
+++ /dev/null
@@ -1,158 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef MEDIA_BLINK_MULTIBUFFER_READER_H_
-#define MEDIA_BLINK_MULTIBUFFER_READER_H_
-
-#include <stdint.h>
-
-#include <limits>
-#include <map>
-#include <set>
-
-#include "base/callback.h"
-#include "base/memory/weak_ptr.h"
-#include "media/blink/media_blink_export.h"
-#include "media/blink/multibuffer.h"
-
-namespace media {
-
-// Wrapper for MultiBuffer that offers a simple byte-reading
-// interface with prefetch.
-class MEDIA_BLINK_EXPORT MultiBufferReader
-    : NON_EXPORTED_BASE(public MultiBuffer::Reader) {
- public:
-  // Note that |progress_callback| is guaranteed to be called if
-  // a redirect happens and the url_data is updated. Otherwise
-  // origin checks will become insecure.
-  // Users probably want to call SetMaxBuffer & SetPreload after
-  // creating the a MultiBufferReader.
-  // The progress callback will be called when the "available range"
-  // changes. (The number of bytes available for reading before and
-  // after the current position.) The arguments for the progress
-  // callback is the first byte available (from beginning of file)
-  // and the last byte available + 1. Note that there may be other
-  // regions of available data in the cache as well.
-  // If |end| is not known, use -1.
-  MultiBufferReader(
-      MultiBuffer* multibuffer,
-      int64_t start,
-      int64_t end,
-      const base::Callback<void(int64_t, int64_t)>& progress_callback);
-
-  ~MultiBufferReader() override;
-
-  // Returns number of bytes available for reading. When the rest of the file
-  // is available, the number returned will be greater than the number
-  // or readable bytes. If an error occurs, -1 is returned.
-  int64_t Available() const;
-
-  // Seek to a different position.
-  // If there is a pending Wait(), it will be cancelled.
-  void Seek(int64_t pos);
-
-  // Returns the current position.
-  int64_t Tell() const { return pos_; }
-
-  // Tries to read |len| bytes and advance position.
-  // Returns number of bytes read.
-  // If there is a pending Wait(), it will be cancelled.
-  int64_t TryRead(uint8_t* data, int64_t len);
-
-  // Wait until |len| bytes are available for reading.
-  // Returns net::OK if |len| bytes are already available, otherwise it will
-  // return net::ERR_IO_PENDING and call |cb| at some point later.
-  // |len| must be smaller or equal to max_buffer_forward.
-  int Wait(int64_t len, const base::Closure& cb);
-
-  // Set how much data we try to preload into the cache ahead of our current
-  // location. Normally, we preload until we have preload_high bytes, then
-  // stop until we fall below preload_low bytes. Note that preload can be
-  // set higher than max_buffer_forward, but the result is usually that
-  // some blocks will be freed between the current position and the preload
-  // position.
-  void SetPreload(int64_t preload_high, int64_t preload_low);
-
-  // Change how much data we pin to the cache.
-  // The range [current_position - backward ... current_position + forward)
-  // will be locked in the cache. Calling Wait() or TryRead() with values
-  // larger than |forward| is not supported.
-  void SetMaxBuffer(int64_t backward, int64_t forward);
-
-  // Returns true if we are currently loading data.
-  bool IsLoading() const;
-
-  // Reader implementation.
-  void NotifyAvailableRange(const Interval<MultiBufferBlockId>& range) override;
-
-  // Getters
-  int64_t preload_high() const { return preload_high_; }
-  int64_t preload_low() const { return preload_low_; }
-
- private:
-  // Returns the block for a particular byte position.
-  MultiBufferBlockId block(int64_t byte_pos) const {
-    return byte_pos >> multibuffer_->block_size_shift();
-  }
-
-  // Returns the block for a particular byte position, rounding up.
-  MultiBufferBlockId block_ceil(int64_t byte_pos) const {
-    return block(byte_pos + (1LL << multibuffer_->block_size_shift()) - 1);
-  }
-
-  // Check if wait operation can complete now.
-  void CheckWait();
-
-  // Recalculate preload_pos_ and update our entry in the multibuffer
-  // reader index. Also call CheckWait(). This function is basically
-  // called anything changes, like when we get more data or seek to
-  // a new position.
-  void UpdateInternalState();
-
-  // Indirection function used to call callbacks. When we post a callback
-  // we indirect it through a weak_ptr and this function to make sure we
-  // don't call any callbacks after this object has been destroyed.
-  void Call(const base::Closure& cb) const;
-
-  // The multibuffer we're wrapping, not owned.
-  MultiBuffer* multibuffer_;
-
-  // We're not interested in reading past this position.
-  int64_t end_;
-
-  // Defer reading once we have this much data.
-  int64_t preload_high_;
-  // Stop deferring once we have this much data.
-  int64_t preload_low_;
-
-  // Pin this much data in the cache from the current position.
-  int64_t max_buffer_forward_;
-  int64_t max_buffer_backward_;
-
-  // Current position in bytes.
-  int64_t pos_;
-
-  // [block(pos_)..preload_pos_) are known to be in the cache.
-  // preload_pos_ is only allowed to point to a filled
-  // cache position if it is equal to end_ or pos_+preload_.
-  // This is a pointer to a slot in the cache, so the unit is
-  // blocks.
-  MultiBufferBlockId preload_pos_;
-
-  // True if we've requested data from the cache by calling WaitFor().
-  bool loading_;
-
-  // When Available() > current_wait_size_ we call cb_.
-  int64_t current_wait_size_;
-  base::Closure cb_;
-
-  // Progress callback.
-  base::Callback<void(int64_t, int64_t)> progress_callback_;
-
-  base::WeakPtrFactory<MultiBufferReader> weak_factory_;
-};
-
-}  // namespace media
-
-#endif  // MEDIA_BLINK_MULTIBUFFER_READER_H_