/// <summary>
/// Finds the range that contains "val", or an appropriate place in the list to
/// insert a new range.
/// </summary>
/// <param name="val">Value to find.</param>
/// <returns>The index of the matching element, or a negative value indicating
/// the index to insert at. 2C doesn't support negative 0, so the insertion
/// index will be incremented before negation.</returns>
private int FindValue(int val)
{
int low = 0;
int high = mRangeList.Count - 1;
while (low <= high)
{
int mid = (low + high) / 2;
TypedRange midRange = mRangeList[mid];
if (midRange.Contains(val))
{
// found it
return(mid);
}
else if (val < midRange.Low)
{
// too big, move the high end in
high = mid - 1;
}
else if (val > midRange.High)
{
// too small, move the low end in
low = mid + 1;
}
else
{
// WTF... list not sorted?
throw new Exception("Bad binary search");
}
}
// Not found, insert before "low".
return(-(low + 1));
}
/// <summary>
/// Finds a range that contains searchVal, or identifies the one that immediately
/// follows. The caller can determine which by checking to see if range.Low is
/// greater than searchVal.
/// </summary>
/// <param name="searchVal">Value to find.</param>
/// <param name="range">Result.</param>
/// <returns>True if a valid range was returned.</returns>
public bool GetContainingOrSubsequentRange(int searchVal, out TypedRange range)
{
int index = FindValue(searchVal);
if (index >= 0)
{
// found a range that contains val
range = mRangeList[index];
return(true);
}
// No matching range, so the index of the insertion point was returned. The
// indexed range will have a "low" value that is greater than searchVal. If
// we've reached the end of the list, the index will be past the end.
index = -index - 1;
if (index >= mRangeList.Count)
{
// reached the end of the list
range = new TypedRange(-128, -128, -128);
return(false);
}
range = mRangeList[index];
return(true);
}
public void DebugDump(string name)
{
Debug.WriteLine(name + " has " + RangeCount + " ranges");
IEnumerator <TypedRange> iter = RangeListIterator;
while (iter.MoveNext())
{
TypedRange rng = iter.Current;
Debug.WriteLine("[+{0:x6},+{1:x6}] ({2:x2})", rng.Low, rng.High, rng.Type);
}
}
/// <summary>
/// Puts the next range in the list in mCurrentRange.
/// </summary>
/// <returns>True on success, false if we reached the end of the list.</returns>
private bool GetNextRange()
{
mListIndex++; // increments to 0 on first invocation
if (mListIndex == mSet.mRangeList.Count)
{
// no more ranges
return(false);
}
mCurrentRange = mSet.mRangeList[mListIndex];
mCurrentVal = mCurrentRange.Low;
return(true);
}
/// <summary>
/// Removes a value from the set. If the value is not present, nothing changes.
/// </summary>
/// <param name="val">Value to remove.</param>
public void Remove(int val)
{
int listIndex = FindValue(val);
if (listIndex < 0)
{
// not found
return;
}
Count--;
TypedRange rng = mRangeList[listIndex];
if (rng.Low == val && rng.High == val)
{
// Single-value range. Remove.
mRangeList.RemoveAt(listIndex);
}
else if (rng.Low == val)
{
// We're at the low end, reduce range.
rng.Low = val + 1;
mRangeList[listIndex] = rng;
}
else if (rng.High == val)
{
// We're at the high end, reduce range.
rng.High = val - 1;
mRangeList[listIndex] = rng;
}
else
{
// We're in the middle, split the range.
TypedRange next = new TypedRange(val + 1, rng.High, rng.Type);
rng.High = val - 1;
mRangeList[listIndex] = rng;
mRangeList.Insert(listIndex + 1, next);
}
}
/// <summary>
/// Adds or changes a value to the set. If the value is already present and has
/// a matching type, nothing changes.
/// </summary>
/// <param name="val">Value to add.</param>
/// <param name="type">Value's type.</param>
public void Add(int val, int type)
{
int listIndex = FindValue(val);
if (listIndex >= 0)
{
// Value is present in set, check type.
if (mRangeList[listIndex].Type == type)
{
// It's a match, do nothing.
return;
}
// Wrong type. Remove previous entry, then fall through to add new.
Remove(val);
listIndex = FindValue(val); // get insertion point
}
Count++;
if (mRangeList.Count == 0)
{
// Empty list, skip the gymnastics.
mRangeList.Add(new TypedRange(val, val, type));
return;
}
// Negate and decrement to get insertion index. This value may == Count if
// the value is higher than all current members.
listIndex = -listIndex - 1;
if (listIndex > 0 && mRangeList[listIndex - 1].High == val - 1 &&
mRangeList[listIndex - 1].Type == type)
{
// Expand prior range. Check to see if it blends into next as well.
if (listIndex < mRangeList.Count && mRangeList[listIndex].Low == val + 1 &&
mRangeList[listIndex].Type == type)
{
// Combine ranges.
TypedRange prior = mRangeList[listIndex - 1];
TypedRange next = mRangeList[listIndex];
Debug.Assert(prior.High + 2 == next.Low);
prior.High = next.High;
mRangeList[listIndex - 1] = prior;
mRangeList.RemoveAt(listIndex);
}
else
{
// Nope, just expand the prior range.
TypedRange prior = mRangeList[listIndex - 1];
Debug.Assert(prior.High == val - 1);
prior.High = val;
mRangeList[listIndex - 1] = prior;
}
}
else if (listIndex < mRangeList.Count && mRangeList[listIndex].Low == val + 1 &&
mRangeList[listIndex].Type == type)
{
// Expand next range.
TypedRange next = mRangeList[listIndex];
Debug.Assert(next.Low == val + 1);
next.Low = val;
mRangeList[listIndex] = next;
}
else
{
// Nothing adjacent, add a new single-entry element.
mRangeList.Insert(listIndex, new TypedRange(val, val, type));
}
}
public TypedRangeEnumerator(TypedRange owner)
{
this.owner = owner;
Reset();
}