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// Copyright 2014 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.
#include <map>
#include "base/basictypes.h"
#include "base/time.h"
#include "cobalt/media/base/media_export.h"
#include "starboard/types.h"
namespace cobalt {
namespace media {
// Helper class used by the TextRenderer to filter out text cues that
// have already been passed downstream.
class MEDIA_EXPORT TextRanges {
// Reset the current range pointer, such that we bind to a new range
// (either one that exists already, or one that is freshly-created)
// during the next AddCue().
void Reset();
// Given a cue with starting timestamp |start_time|, add its start
// time to the time ranges. (Note that following a Reset(), cue
// times are assumed to be monotonically increasing.) If this time
// has already been added to the time ranges, then AddCue() returns
// false and clients should not push the cue downstream. Otherwise,
// the time is added to the time ranges and AddCue() returns true,
// meaning that the cue should be pushed downstream.
bool AddCue(base::TimeDelta start_time);
// Returns a count of the number of time ranges, intended for use by
// the unit test module to vet proper time range merge behavior.
size_t RangeCountForTesting() const;
// Describes a range of times for cues that have already been
// pushed downstream.
class Range {
// Initialize last_time count.
void ResetCount(base::TimeDelta start_time);
// Set last_time and associated counts.
void SetLastTime(base::TimeDelta last_time);
// Adjust time range state to mark the cue as having been seen,
// returning true if we have not seen |start_time| already and
// false otherwise.
bool AddCue(base::TimeDelta start_time);
// Returns the value of the last time in the range.
base::TimeDelta last_time() const;
// The last timestamp of this range.
base::TimeDelta last_time_;
// The number of cues we have detected so far, for this range,
// whose timestamp matches last_time.
int max_count_;
// The number of cues we have seen since the most recent Reset(),
// whose timestamp matches last_time.
int count_;
typedef std::map<base::TimeDelta, Range> RangeMap;
// NewRange() is used to create a new time range when AddCue() is
// called immediately following a Reset(), and no existing time
// range contains the indicated |start_time| of the cue.
void NewRange(base::TimeDelta start_time);
// Coalesce curr_range with the range that immediately follows.
void Merge(const RangeMap::iterator& next_range_itr, Range* curr_range);
// The collection of time ranges, each of which is bounded
// (inclusive) by the key and Range::last_time.
RangeMap range_map_;
// The time range to which we bind following a Reset().
RangeMap::iterator curr_range_itr_;
} // namespace media
} // namespace cobalt