protected int FindSplit(DCompare compare)
{
int x = Root;
int result = 0;
IndexFileRecord r = new IndexFileRecord();
while (x != 0)
{
GetRecord(x, ref r);
int c = compare(ref r);
if (c < 0)
{
x = GetLeft(x);
}
else if (c > 0)
{
result = x;
x = GetRight(x);
}
else // c == 0
{
result = x;
break;
}
}
return(result);
}
int Compare(int x, DCompare seek)
{
IndexFileRecord r = new IndexFileRecord();
GetRecord(x, ref r);
return(seek(ref r));
}
public virtual G.IEnumerable <IndexFileRecord> From(IndexFile ixf, DCompare seek, bool desc)
{
IndexFileRecord v = new IndexFileRecord();
foreach (int x in From(seek, desc))
{
GetRecord(x, ref v);
yield return(v);
}
}
public override G.IEnumerable <IndexFileRecord> From(IndexFile ixf, DCompare seek, bool desc)
{
int x = FindSplit(seek);
long childId = x == 0 ? FirstPage : GetChild(x);
IndexPage cp = ixf.GetPage(childId);
cp.ParentId = PageId;
foreach (IndexFileRecord r in cp.From(ixf, seek, desc))
{
yield return(r);
}
}
G.IEnumerable <int> From(DCompare seek, bool desc)
{
if (desc)
{
foreach (int x in Desc(Root, seek))
{
yield return(x);
}
}
else
{
foreach (int x in Asc(Root, seek))
{
yield return(x);
}
}
}
G.IEnumerable <int> Desc(int x, DCompare cf)
{
if (x == 0)
{
yield break;
}
int c = Compare(x, cf);
if (c > 0)
{
foreach (int a in Desc(GetRight(x), cf))
{
yield return(a);
}
}
if (c >= 0)
{
yield return(x);
}
foreach (int a in Desc(GetLeft(x), cf))
{
yield return(a);
}
}
G.IEnumerable <int> Asc(int x, DCompare cf)
{
if (x == 0)
{
yield break;
}
int c = Compare(x, cf);
if (c < 0)
{
foreach (int a in Asc(GetLeft(x), cf))
{
yield return(a);
}
}
if (c <= 0)
{
yield return(x);
}
foreach (int a in Asc(GetRight(x), cf))
{
yield return(a); // Is this doing extra compares when c <= 0?
}
}
