/// <returns>current delta chain depth of this object.</returns>
internal virtual int Depth()
{
return(@object.GetDeltaDepth());
}
/// <exception cref="System.IO.IOException"></exception>
private void Search()
{
// TODO(spearce) If the object is used as a base for other
// objects in this pack we should limit the depth we create
// for ourselves to be the remainder of our longest dependent
// chain and the configured maximum depth. This can happen
// when the dependents are being reused out a pack, but we
// cannot be because we are near the edge of a thin pack.
//
resMaxDepth = maxDepth;
// Loop through the window backwards, considering every entry.
// This lets us look at the bigger objects that came before.
//
for (int srcSlot = Prior(resSlot); srcSlot != resSlot; srcSlot = Prior(srcSlot))
{
DeltaWindowEntry src = window[srcSlot];
if (src.Empty())
{
break;
}
if (Delta(src, srcSlot) == NEXT_RES)
{
bestDelta = null;
return;
}
}
// We couldn't find a suitable delta for this object, but it may
// still be able to act as a base for another one.
//
if (bestDelta == null)
{
KeepInWindow();
return;
}
// Select this best matching delta as the base for the object.
//
ObjectToPack srcObj = window[bestSlot].@object;
ObjectToPack resObj = res.@object;
if (srcObj.IsEdge())
{
// The source (the delta base) is an edge object outside of the
// pack. Its part of the common base set that the peer already
// has on hand, so we don't want to send it. We have to store
// an ObjectId and *NOT* an ObjectToPack for the base to ensure
// the base isn't included in the outgoing pack file.
//
resObj.SetDeltaBase(srcObj.Copy());
}
else
{
// The base is part of the pack we are sending, so it should be
// a direct pointer to the base.
//
resObj.SetDeltaBase(srcObj);
}
resObj.SetDeltaDepth(srcObj.GetDeltaDepth() + 1);
resObj.ClearReuseAsIs();
CacheDelta(srcObj, resObj);
// Discard the cached best result, otherwise it leaks.
//
bestDelta = null;
// If this should be the end of a chain, don't keep
// it in the window. Just move on to the next object.
//
if (resObj.GetDeltaDepth() == maxDepth)
{
return;
}
ShuffleBaseUpInPriority();
KeepInWindow();
}
