void CombineRanges(const MediaByteRange& pending, const MediaByteRange& preload,
MediaByteRange& request)
{
OP_ASSERT(request.IsEmpty());
// If pending and preload overlap, let request be their union,
// clamped to pending.start.
if (!pending.IsEmpty() && !preload.IsEmpty())
{
request = pending;
request.IntersectWith(preload);
if (!request.IsEmpty())
{
// non-empty intersection => overlap
request = pending;
request.UnionWith(preload);
request.IntersectWith(MediaByteRange(pending.start));
OP_ASSERT(!request.IsEmpty());
}
}
// Otherwise, pick the first non-empty of pending and preload.
if (request.IsEmpty())
{
if (!pending.IsEmpty())
request = pending;
else
request = preload;
}
}
void ReduceRanges(const List<MediaSourceClient>& clients,
MediaByteRange& pending, MediaByteRange& preload)
{
OP_ASSERT(preload.IsEmpty());
MediaSourceClient* client = clients.First();
if (client)
{
for ( ; client; client = client->Suc())
{
// take the first non-empty pending
if (pending.IsEmpty())
pending = client->GetPending();
// preload the union of all ranges
preload.UnionWith(client->GetPreload());
}
}
else
{
// with no clients, preload the whole resource
preload.start = 0;
}
}
