| 1 |
root |
1.1 |
// -*- Mode: C++ -*- |
| 2 |
|
|
|
| 3 |
|
|
// GiSTpath.h |
| 4 |
|
|
// |
| 5 |
|
|
// Copyright (c) 1996, Regents of the University of California |
| 6 |
|
|
// $Header: /usr/local/devel/GiST/libGiST/libGiST/GiSTpath.h,v 1.1.1.1 1996/08/06 23:47:21 jmh Exp $ |
| 7 |
|
|
#ifndef GISTPATH_H |
| 8 |
|
|
#define GISTPATH_H |
| 9 |
|
|
|
| 10 |
|
|
// GiSTpath objects store the path to a node from the root of the tree. |
| 11 |
|
|
// The page number of each node visited is stored. For simplicity, |
| 12 |
|
|
// GiSTpaths are stored as an array with max GIST_MAX_LEVELS elements. |
| 13 |
|
|
// This can be expanded if you want a tree with more than 16 levels |
| 14 |
|
|
// (not likely unless you have big keys, or small pages!) |
| 15 |
|
|
|
| 16 |
|
|
#define GiSTRootPage 1 |
| 17 |
|
|
|
| 18 |
|
|
#define GIST_MAX_LEVELS 16 |
| 19 |
|
|
|
| 20 |
|
|
class GiSTpath : public GiSTobject { |
| 21 |
|
|
GiSTpage pages[GIST_MAX_LEVELS]; |
| 22 |
|
|
int len; |
| 23 |
|
|
public: |
| 24 |
|
|
GiSTpath() { len=0; } |
| 25 |
|
|
GiSTpath(const GiSTpath& path) { |
| 26 |
|
|
len=path.len; |
| 27 |
|
|
for(int i=0; i<path.len; i++) pages[i]=path.pages[i]; |
| 28 |
|
|
} |
| 29 |
|
|
|
| 30 |
|
|
#ifdef PRINTING_OBJECTS |
| 31 |
|
|
void Print(ostream& os) const { |
| 32 |
|
|
os << '['; |
| 33 |
|
|
for(int i=0; i<len; i++) { |
| 34 |
|
|
if(i) os << ' '; |
| 35 |
|
|
os << pages[i]; |
| 36 |
|
|
} |
| 37 |
|
|
os << ']'; |
| 38 |
|
|
} |
| 39 |
|
|
#endif |
| 40 |
|
|
|
| 41 |
|
|
int Level() const { |
| 42 |
|
|
return len-1; |
| 43 |
|
|
} |
| 44 |
|
|
void Clear() { len=0; } |
| 45 |
|
|
void MakeParent() { len--; } |
| 46 |
|
|
void MakeSibling(GiSTpage page) { pages[len-1]=page; } |
| 47 |
|
|
void MakeChild(GiSTpage page) { pages[len++]=page; } |
| 48 |
|
|
void MakeRoot() { |
| 49 |
|
|
len=1; |
| 50 |
|
|
pages[0]=GiSTRootPage; |
| 51 |
|
|
} |
| 52 |
|
|
|
| 53 |
|
|
void SplitRoot(GiSTpage page) { |
| 54 |
|
|
for(int i=len; i>1; i--) pages[i]=pages[i-1]; |
| 55 |
|
|
pages[1]=page; |
| 56 |
|
|
pages[0]=GiSTRootPage; |
| 57 |
|
|
} |
| 58 |
|
|
|
| 59 |
|
|
GiSTpath& operator = (const GiSTpath& path) { |
| 60 |
|
|
len=path.len; |
| 61 |
|
|
for(int i=0; i<path.len; i++) pages[i]=path.pages[i]; |
| 62 |
|
|
return *this; |
| 63 |
|
|
} |
| 64 |
|
|
|
| 65 |
|
|
int operator==(const GiSTpath& p) const { |
| 66 |
|
|
if(len!=p.len) return(0); |
| 67 |
|
|
for(int i=0; i<p.len; i++) if (pages[i]!=p.pages[i]) return(0); |
| 68 |
|
|
return(1); |
| 69 |
|
|
} |
| 70 |
|
|
|
| 71 |
|
|
GiSTpage Page() const { return pages[len-1]; } |
| 72 |
|
|
GiSTpage Parent() const { return len>=2? pages[len-2]: 0; } |
| 73 |
|
|
int IsRoot() const { return len==1; } |
| 74 |
|
|
}; |
| 75 |
|
|
|
| 76 |
|
|
#endif |
