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/* 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 INTERVAL_H_
#define INTERVAL_H_
#include "nsTArray.h"
#include <algorithm>
namespace mp4_demuxer
{
template <typename T>
struct Interval
{
Interval() : start(0), end(0) {}
Interval(T aStart, T aEnd) : start(aStart), end(aEnd)
{
MOZ_ASSERT(aStart <= aEnd);
}
T Length() { return end - start; }
Interval Intersection(const Interval& aOther) const
{
T s = start > aOther.start ? start : aOther.start;
T e = end < aOther.end ? end : aOther.end;
if (s > e) {
return Interval();
}
return Interval(s, e);
}
bool Contains(const Interval& aOther) const
{
return aOther.start >= start && aOther.end <= end;
}
bool operator==(const Interval& aOther) const
{
return start == aOther.start && end == aOther.end;
}
bool operator!=(const Interval& aOther) const { return !(*this == aOther); }
bool IsNull() const
{
return end == start;
}
Interval Extents(const Interval& aOther) const
{
if (IsNull()) {
return aOther;
}
return Interval(std::min(start, aOther.start),
std::max(end, aOther.end));
}
T start;
T end;
static void SemiNormalAppend(nsTArray<Interval<T>>& aIntervals,
Interval<T> aInterval)
{
if (!aIntervals.IsEmpty() &&
aIntervals.LastElement().end == aInterval.start) {
aIntervals.LastElement().end = aInterval.end;
} else {
aIntervals.AppendElement(aInterval);
}
}
static void Normalize(const nsTArray<Interval<T>>& aIntervals,
nsTArray<Interval<T>>* aNormalized)
{
if (!aNormalized || !aIntervals.Length()) {
MOZ_ASSERT(aNormalized);
return;
}
MOZ_ASSERT(aNormalized->IsEmpty());
nsTArray<Interval<T>> sorted;
sorted = aIntervals;
sorted.Sort(Compare());
Interval<T> current = sorted[0];
for (size_t i = 1; i < sorted.Length(); i++) {
MOZ_ASSERT(sorted[i].start <= sorted[i].end);
if (current.Contains(sorted[i])) {
continue;
}
if (current.end >= sorted[i].start) {
current.end = sorted[i].end;
} else {
aNormalized->AppendElement(current);
current = sorted[i];
}
}
aNormalized->AppendElement(current);
}
static void Intersection(const nsTArray<Interval<T>>& a0,
const nsTArray<Interval<T>>& a1,
nsTArray<Interval<T>>* aIntersection)
{
MOZ_ASSERT(IsNormalized(a0));
MOZ_ASSERT(IsNormalized(a1));
size_t i0 = 0;
size_t i1 = 0;
while (i0 < a0.Length() && i1 < a1.Length()) {
Interval i = a0[i0].Intersection(a1[i1]);
if (i.Length()) {
aIntersection->AppendElement(i);
}
if (a0[i0].end < a1[i1].end) {
i0++;
// Assert that the array is sorted
MOZ_ASSERT(i0 == a0.Length() || a0[i0 - 1].start < a0[i0].start);
} else {
i1++;
// Assert that the array is sorted
MOZ_ASSERT(i1 == a1.Length() || a1[i1 - 1].start < a1[i1].start);
}
}
}
static bool IsNormalized(const nsTArray<Interval<T>>& aIntervals)
{
for (size_t i = 1; i < aIntervals.Length(); i++) {
if (aIntervals[i - 1].end >= aIntervals[i].start) {
return false;
}
}
return true;
}
struct Compare
{
bool Equals(const Interval<T>& a0, const Interval<T>& a1) const
{
return a0.start == a1.start && a0.end == a1.end;
}
bool LessThan(const Interval<T>& a0, const Interval<T>& a1) const
{
return a0.start < a1.start;
}
};
};
}
#endif
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