/* 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>
#include <nsString.h>
namespace mozilla {
template <
typename T>
struct MP4Interval {
MP4Interval() : start{}, end{} {}
MP4Interval(T aStart, T aEnd) : start(aStart), end(aEnd) {
MOZ_ASSERT(aStart <= aEnd);
}
T Length() {
return end - start; }
MP4Interval Intersection(
const MP4Interval& aOther)
const {
T s = start > aOther.start ? start : aOther.start;
T e = end < aOther.end ? end : aOther.end;
if (s > e) {
return MP4Interval();
}
return MP4Interval(s, e);
}
bool Contains(
const MP4Interval& aOther)
const {
return aOther.start >= start && aOther.end <= end;
}
bool operator==(
const MP4Interval& aOther)
const {
return start == aOther.start && end == aOther.end;
}
bool operator!=(
const MP4Interval& aOther)
const {
return !(*
this == aOther);
}
bool IsNull()
const {
return end == start; }
MP4Interval Extents(
const MP4Interval& aOther)
const {
if (IsNull()) {
return aOther;
}
return MP4Interval(std::min(start, aOther.start),
std::max(end, aOther.end));
}
T start;
T end;
nsCString ToString() {
return nsPrintfCString(
"[%s, %s]", start.ToString().get(),
end.ToString().get());
}
static void SemiNormalAppend(nsTArray<MP4Interval<T>>& aIntervals,
MP4Interval<T> aMP4Interval) {
if (!aIntervals.IsEmpty() &&
aIntervals.LastElement().end == aMP4Interval.start) {
aIntervals.LastElement().end = aMP4Interval.end;
}
else {
aIntervals.AppendElement(aMP4Interval);
}
}
static void Normalize(
const nsTArray<MP4Interval<T>>& aIntervals,
nsTArray<MP4Interval<T>>* aNormalized) {
if (!aNormalized || !aIntervals.Length()) {
MOZ_ASSERT(aNormalized);
return;
}
MOZ_ASSERT(aNormalized->IsEmpty());
nsTArray<MP4Interval<T>> sorted = aIntervals.Clone();
sorted.Sort(Compare());
MP4Interval<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<MP4Interval<T>>& a0,
const nsTArray<MP4Interval<T>>& a1,
nsTArray<MP4Interval<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()) {
MP4Interval 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<MP4Interval<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 MP4Interval<T>& a0,
const MP4Interval<T>& a1)
const {
return a0.start == a1.start && a0.end == a1.end;
}
bool LessThan(
const MP4Interval<T>& a0,
const MP4Interval<T>& a1)
const {
return a0.start < a1.start;
}
};
};
}
// namespace mozilla
#endif
