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/********************************************************************* |
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* * |
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* Copyright (c) 1997,1998, 1999 * |
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* Multimedia DB Group and DEIS - CSITE-CNR, * |
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* University of Bologna, Bologna, ITALY. * |
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* * |
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* All Rights Reserved. * |
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* * |
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* Permission to use, copy, and distribute this software and its * |
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* documentation for NON-COMMERCIAL purposes and without fee is * |
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* hereby granted provided that this copyright notice appears in * |
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* all copies. * |
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* * |
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* THE AUTHORS MAKE NO REPRESENTATIONS OR WARRANTIES ABOUT THE * |
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* SUITABILITY OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING * |
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* BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, * |
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* FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THE AUTHOR * |
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* SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A * |
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* RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS * |
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* DERIVATIVES. * |
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* * |
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*********************************************************************/ |
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|
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#ifdef UNIX |
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#include <unistd.h> |
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#endif |
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#include "MT.h" |
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|
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extern double MIN_UTIL; |
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|
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// find the node having the minimum number of children |
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// this is used in the redistributing phase of the BulkLoad algorithm |
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int |
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FindMin(int *children, int max) |
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{ |
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int j, jmin=0; |
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|
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for(j=1; j<max; j++) |
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if(children[j]<children[jmin]) jmin=j; |
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return jmin; |
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} |
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|
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// return root level+1 (the height of the tree) |
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// this is used in the "splitting" phase of the BulkLoad algorithm |
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int |
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MT::MaxLevel() const |
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{ |
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GiSTnode *root; |
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GiSTpath path; |
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int i; |
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|
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path.MakeRoot(); |
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root=ReadNode(path); |
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i=root->Level(); |
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delete root; |
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return i+1; |
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} |
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|
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// split this M-tree into a list of trees having height level |
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// this is used in the "splitting" phase of the BulkLoad algorithm |
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GiSTlist<char *> * |
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MT::SplitTree(int *ncreated, int level, GiSTlist<MTentry *> *children, char *name) |
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// ncreated is the number of created sub-trees, |
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// level is the split level for the tree, |
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// children is the list of the parents of each sub-tree, |
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// name is the root for the sub-trees names |
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// the return value is the list of splitted sub-trees |
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{ |
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GiSTlist<char *> *trees=new GiSTlist<char *>; // this is the results list |
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GiSTlist<MTnode *> *oldList=new GiSTlist<MTnode *>; // this is the nodes list |
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GiSTpath path; |
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MTnode *node=new MTnode; // this is because the first operation on node is a delete |
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char newname[50]; |
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|
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path.MakeRoot(); |
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oldList->Append((MTnode *)ReadNode(path)); |
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do { // build the roots list |
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GiSTlist<MTnode *> *newList=new GiSTlist<MTnode *>; // this is the list of the current level nodes |
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|
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while(!oldList->IsEmpty()) { |
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delete node; // delete the old node created by ReadNode |
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node=oldList->RemoveFront(); // retrieve next node to be examined |
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path=node->Path(); |
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for(int i=0; i<node->NumEntries(); i++) { // append all its children to the new list |
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MTentry *e=(MTentry *)(*node)[i].Ptr(); |
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|
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path.MakeChild(e->Ptr()); |
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newList->Append((MTnode *)ReadNode(path)); |
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path.MakeParent(); |
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} |
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} |
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delete oldList; |
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oldList=newList; |
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} while(node->Level()>level); // stop if we're at the split level |
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delete node; |
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while(!oldList->IsEmpty()) { // now append each sub-tree to its root |
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MT *subtree=new MT; |
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MTnode *newnode; |
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|
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node=oldList->RemoveFront(); |
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sprintf(newname, "%s.%i", name, ++(*ncreated)); |
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unlink(newname); // if this M-tree already exists, delete it |
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subtree->Create(newname); // create a new M-tree |
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path.MakeRoot(); |
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newnode=(MTnode *)subtree->ReadNode(path); // read the root of the tree |
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subtree->Append(newnode, (MTnode *)node->Copy()); // append the sub-tree of current node to the root of this M-tree |
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children->Append(node->Entry()); // insert the root entry into the list |
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trees->Append(strdup(newname)); // insert the new M-tree name into the list |
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delete node; |
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delete newnode; |
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delete subtree; |
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} |
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delete oldList; |
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return trees; |
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} |
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|
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// load this M-tree with n data using the BulkLoad algorithm [CP98] |
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void |
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MT::BulkLoad(MTentry **data, int n, double padFactor, char *name) |
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// data is an array of n entries |
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// padFactor is the maximum node utilization (use 1) |
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// name is the name of the tree |
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{ |
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int i, Size=0, totSize, addEntrySize=(sizeofEntry()? sizeof(GiSTpage): sizeof(GiSTlte)+sizeof(GiSTpage)), minSize=(int)(Store()->PageSize()*MIN_UTIL), NumEntries; // this is the total size of entries |
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|
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if(sizeofEntry()) Size=n*(sizeof(GiSTpage)+sizeofEntry()); // (only valid if we've fixed size entries) |
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else for(i=0; i<n; i++) Size+=sizeof(GiSTlte)+sizeof(GiSTpage)+data[i]->CompressedLength(); |
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totSize=Size+GIST_PAGE_HEADER_SIZE+sizeof(GiSTlte); |
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NumEntries=(int)(Store()->PageSize()*padFactor*n)/totSize; |
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// cout << "exp. size=" << totSize << endl; |
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if(totSize>Store()->PageSize()) { // we need to split the entries into several sub-trees |
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GiSTlist<char *> nameslist, othernameslist; // list of the sub-trees names |
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GiSTlist<MTentry *> plist, parentslist; // lists of the root entries of each sub-tree |
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GiSTlist<int> *lists=NULL; // list of entries for each sub-tree |
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GiSTlist<double> *dists=NULL; // list of distances for each sub-tree |
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char **trees; // array of the sub-trees names |
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GiSTlist<MTnode *> *oldList=new GiSTlist<MTnode *>; |
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GiSTpath path; |
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MTentry ***arrays; // array of the entries for each sub-tree |
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MTentry **parents; // array of the root entries for each sub-tree |
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MTnode *node=NULL; |
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GiSTlist<double *> *distm; // distance matrix |
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int s=(int)MAX(MIN(NumEntries, ceil(((float)n)/NumEntries)), NumEntries*MIN_UTIL); // initial number of samples |
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int j, nsamples, *samples=new int[s], *sizes=NULL, *ns=NULL, ncreated=0, minLevel=MAXINT, nInit, l, iters=0, MAXITER=s*s; |
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char newname[50]; |
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BOOL *sampled=new BOOL[n]; // is this entry in the samples set? |
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|
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// cout << "NE*pF=" << NumEntries*padFactor << ", n/NE*pF=" << n/floor(NumEntries*padFactor) << ", s=" << s << endl; |
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distm=(GiSTlist<double *> *)calloc(s,sizeof(GiSTlist<double *>)); |
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do { // sampling phase |
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iters++; |
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if(iters>1) { // this is a new sampling phase |
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// cout << "Re-sampling: " << iters << "/" << MAXITER << endl; |
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while(!lists[0].IsEmpty()) { |
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lists[0].RemoveFront(); |
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dists[0].RemoveFront(); |
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} |
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delete []lists; |
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delete []dists; |
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delete []sizes; |
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delete []ns; |
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while(!distm[0].IsEmpty()) delete []distm[0].RemoveFront(); // empty the distance list |
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for(i=1; i<s; i++) distm[i].front=distm[i].rear=NULL; |
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} |
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// if(iters>=MAXITER) minSize=0; |
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if(iters>=MAXITER) { |
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cout << "Too many loops in BulkLoad!\nPlease select a lower minimum node utilization or a bigger node size.\n"; |
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exit(1); |
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} |
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nsamples=0; |
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for(i=0; i<n; i++) sampled[i]=FALSE; |
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// pick samples to create parents |
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while(nsamples<s) { |
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do i=PickRandom(0, n); |
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while(sampled[i]); |
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sampled[i]=TRUE; |
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samples[nsamples++]=i; |
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} |
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// cout << "Samples:\n"; |
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// for(i=0; i<s; i++) cout << "\t" << i << ":\t" << data[samples[i]]; |
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lists=new GiSTlist<int>[s]; |
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dists=new GiSTlist<double>[s]; |
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sizes=new int[s]; |
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ns=new int[s]; |
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for(i=0; i<s; i++) { |
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sizes[i]=GIST_PAGE_HEADER_SIZE+sizeof(GiSTlte); |
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ns[i]=1; |
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} |
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for(i=0; i<s; i++) distm[i].Prepend(new double[s]); |
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for(i=0; i<s; i++) { // compute the relative distances between samples |
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for(j=0; j<i; j++) |
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distm[j].front->entry[i]=(distm[i].front->entry[j]=data[samples[j]]->object().distance(data[samples[i]]->object())); |
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distm[i].front->entry[i]=0; |
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} |
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for(i=0; i<n; i++) { // assign each entry to its nearest parent |
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// cout << "Now assigning " << data[i]; |
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if(sampled[i]) { |
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for(j=0; samples[j]!=i; j++); |
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lists[j].Prepend(i); // insert the entry in the right list |
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dists[j].Prepend(0); |
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sizes[j]+=addEntrySize+data[i]->CompressedLength(); |
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// cout << "\tAssigned (0) to " << j << ", " << data[samples[j]]; |
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} |
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else { // here we optimize the distance computations (like we do in the insert algorithm) |
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double *dist=new double[s]; |
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int minindex=0; |
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|
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dist[0]=data[samples[0]]->object().distance(data[i]->object()); |
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for(j=1; j<s; j++) { |
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BOOL cont=TRUE; |
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|
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dist[j]=-1; |
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if(fabs(data[samples[j]]->Key()->distance-data[i]->Key()->distance)>dist[minindex]) continue; // pruning for reference point (parent) |
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for(int k=0; (k<j)&&cont; k++) // pruning for reference points (other samples) |
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if(dist[k]<0) continue; |
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else cont=(fabs(dist[k]-distm[j].front->entry[k])<dist[minindex]); |
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if(!cont) continue; |
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dist[j]=data[samples[j]]->object().distance(data[i]->object()); // we have to compute this distance |
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if(dist[j]<dist[minindex]) minindex=j; |
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} |
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// cout << "\tAssigned (" << dist[minindex] << ") to " << minindex << ", " << data[samples[minindex]]; |
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lists[minindex].Append(i); |
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dists[minindex].Append(dist[minindex]); |
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sizes[minindex]+=addEntrySize+data[i]->CompressedLength(); |
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ns[minindex]++; |
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if(sizes[minindex]>=minSize) delete []dist; |
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else distm[minindex].Append(dist); |
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} |
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} |
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// redistribute underfilled parents |
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// cout << "Underfilled parents redistribution...\n"; |
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while(sizes[i=FindMin(sizes, nsamples)]<minSize) { |
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GiSTlist<int> list=lists[i]; |
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GiSTlist<double *> dlist=distm[i]; |
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|
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while(!dists[i].IsEmpty()) dists[i].RemoveFront(); |
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// cout << "Redistributing " << i << "' set (" << sizes[i] << "/" << minSize << ")...\n"; |
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for(j=0; j<nsamples; j++) |
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for(GiSTlistnode<double *> *lnode=distm[j].front; lnode; lnode=lnode->next) lnode->entry[i]=lnode->entry[nsamples-1]; |
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// substitute this set with last set |
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distm[i]=distm[nsamples-1]; |
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lists[i]=lists[nsamples-1]; |
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dists[i]=dists[nsamples-1]; |
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samples[i]=samples[nsamples-1]; |
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sizes[i]=sizes[nsamples-1]; |
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ns[i]=ns[nsamples-1]; |
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nsamples--; |
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while(!list.IsEmpty()) { // assign each entry to its nearest parent |
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double *d=dlist.RemoveFront(); |
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int k=list.RemoveFront(), index, minindex=-1; |
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// cout << "Now assigning " << data[k]; |
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|
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for(index=0; (index<nsamples)&&(minindex<0); index++) // search for a computed distance |
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if(d[index]>0) minindex=index; |
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if(minindex<0) { // no distance was computed (i.e. all distances were pruned) |
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d[0]=data[samples[0]]->object().distance(data[k]->object()); |
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minindex=0; |
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} |
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for(index=0; index<nsamples; index++) { |
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BOOL cont=TRUE; |
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|
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if(index==minindex) continue; |
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if(d[index]<0) { // distance wasn't computed |
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if(fabs(data[samples[index]]->Key()->distance-data[k]->Key()->distance)>d[minindex]) continue; // pruning for reference point (parent) |
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for(l=0; (l<index)&&cont; l++) // pruning for reference points (other samples) |
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if(d[l]<0) continue; |
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else cont=(fabs(d[l]-distm[index].front->entry[l])<d[minindex]); |
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if(!cont) continue; |
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d[index]=data[samples[index]]->object().distance(data[k]->object()); // we have to compute this distance |
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} |
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if(d[index]<d[minindex]) minindex=index; |
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} |
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// cout << "\tAssigned (" << d[minindex] << ") to " << minindex << ", " << data[samples[minindex]]; |
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lists[minindex].Append(k); |
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dists[minindex].Append(d[minindex]); |
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sizes[minindex]+=addEntrySize+data[k]->CompressedLength(); |
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ns[minindex]++; |
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if(sizes[minindex]>=minSize) delete []d; |
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else distm[minindex].Append(d); |
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} |
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assert(dlist.IsEmpty()); |
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} |
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} while(nsamples==1); // if there's only one child, repeat the sampling phase |
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// cout << "Samples:\n"; |
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// for(i=0; i<nsamples; i++) cout << "\t" << i << ": " << data[samples[i]]; |
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arrays=new MTentry **[nsamples]; |
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for(i=0; i<nsamples; i++) { // convert the lists into arrays |
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arrays[i]=new MTentry *[ns[i]]; |
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for(j=0; j<ns[i]; j++) { |
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int k=lists[i].RemoveFront(); |
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|
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arrays[i][j]=(MTentry *)data[k]->Copy(); |
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arrays[i][j]->Key()->distance=dists[i].RemoveFront(); |
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} |
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assert(lists[i].IsEmpty()); |
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assert(dists[i].IsEmpty()); |
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} |
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delete []dists; |
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delete []lists; |
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for(i=0; i<nsamples; i++) |
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while(!distm[i].IsEmpty()) |
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delete [](distm[i].RemoveFront()); |
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free(distm); |
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// build an M-tree under each parent |
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nInit=nsamples; |
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// cout << "Now building " << nsamples << " sub-trees...\n"; |
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MT *tree=new MT; |
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|
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// for(i=0; i<nsamples; i++) cout << i+1 << "' set: " << ns[i] << endl; |
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for(i=0; i<nInit; i++) { |
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MTnode *root; |
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GiSTpath path; |
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|
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sprintf(newname, "%s.%i", name, ++ncreated); |
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unlink(newname); |
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tree->Create(newname); // create the new sub-tree |
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// cout << "Now building sub-tree " << newname << " on " << ns[i] << " data (exp. size=" << sizes[i] << ")...\n"; |
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tree->BulkLoad(arrays[i], ns[i], padFactor, newname); // insert the data into the sub-tree |
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// cout << "Tree level=" << tree->MaxLevel() << endl; |
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// if the root node is underfilled, we have to split the tree |
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path.MakeRoot(); |
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root=(MTnode *)tree->ReadNode(path); |
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if(root->IsUnderFull(*Store())) { |
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GiSTlist<MTentry *> *roots=new GiSTlist<MTentry *>; |
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GiSTlist<char *> *list=tree->SplitTree(&ncreated, tree->MaxLevel()-1, roots, name); // split the tree |
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|
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nsamples--; |
| 328 |
while(!list->IsEmpty()) { // insert all the new trees in the sub-trees list |
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MTentry *e=roots->RemoveFront(); |
| 330 |
|
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othernameslist.Append(list->RemoveFront()); |
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for(j=0; j<n; j++) if(data[j]->object()==e->object()) { // append also the root entry to the parents list |
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// cout << "parent=" << data[j]; |
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plist.Append(data[j]); |
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j=n; |
| 336 |
} |
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delete e; |
| 338 |
nsamples++; |
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} |
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delete list; |
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delete roots; |
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minLevel=MIN(minLevel, tree->MaxLevel()-1); |
| 343 |
} |
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else { |
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char *tmp=new char[50]; |
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|
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strcpy(tmp, newname); |
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othernameslist.Append(tmp); |
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plist.Append(data[samples[i]]); |
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minLevel=MIN(minLevel, tree->MaxLevel()); |
| 351 |
} |
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delete root; |
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tree->Close(); |
| 354 |
delete tree->Store(); // it was created in tree->Create() |
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} |
| 356 |
for(i=0; i<nInit; i++) { |
| 357 |
for(j=0; j<ns[i]; j++) delete arrays[i][j]; |
| 358 |
delete []arrays[i]; |
| 359 |
} |
| 360 |
delete []arrays; |
| 361 |
while(!plist.IsEmpty()) { // insert the trees in the list (splitting if necessary) |
| 362 |
MTentry *parent=plist.RemoveFront(); |
| 363 |
char *tmp=othernameslist.RemoveFront(); |
| 364 |
|
| 365 |
strcpy(newname, tmp); |
| 366 |
delete []tmp; |
| 367 |
tree->Open(newname); |
| 368 |
// cout << ": Tree level=" << tree->MaxLevel() << " (" << minLevel << ")\n"; |
| 369 |
if(tree->MaxLevel()>minLevel) { // we have to split the tree to reduce its height |
| 370 |
// cout << "level too high!!! (min=" << minLevel << ") Splitting the tree...\n"; |
| 371 |
GiSTlist<MTentry *> *roots=new GiSTlist<MTentry *>; |
| 372 |
GiSTlist<char *> *list=tree->SplitTree(&ncreated, minLevel, roots, name); // split the tree |
| 373 |
|
| 374 |
nsamples--; |
| 375 |
while(!list->IsEmpty()) { // insert all the new trees in the sub-trees list |
| 376 |
MTentry *e=roots->RemoveFront(); |
| 377 |
|
| 378 |
nameslist.Append(list->RemoveFront()); |
| 379 |
for(j=0; j<n; j++) if(data[j]->object()==e->object()) { // append also the root entry to the parents list |
| 380 |
// cout << "parent=" << data[j]; |
| 381 |
parentslist.Append(data[j]); |
| 382 |
j=n; |
| 383 |
} |
| 384 |
delete e; |
| 385 |
nsamples++; |
| 386 |
} |
| 387 |
delete list; |
| 388 |
delete roots; |
| 389 |
} |
| 390 |
else { // simply insert the tree and its root to the lists |
| 391 |
char *tmp=new char[50]; |
| 392 |
|
| 393 |
strcpy(tmp, newname); |
| 394 |
nameslist.Append(tmp); |
| 395 |
// cout << "parent=" << data[samples[i]]; |
| 396 |
parentslist.Append(parent); |
| 397 |
} |
| 398 |
tree->Close(); |
| 399 |
delete tree->Store(); // it was created in tree->Open() |
| 400 |
} |
| 401 |
parents=new MTentry *[nsamples]; |
| 402 |
trees=new char *[nsamples]; |
| 403 |
for(i=0; i<nsamples; i++) { // convert the lists into arrays |
| 404 |
trees[i]=nameslist.RemoveFront(); |
| 405 |
parents[i]=parentslist.RemoveFront(); |
| 406 |
} |
| 407 |
// build the super-tree upon the parents |
| 408 |
sprintf(newname, "%s.0", name); |
| 409 |
// cout << "Now building super-tree " << newname << " on " << nsamples << " data...\n"; |
| 410 |
BulkLoad(parents, nsamples, padFactor, newname); |
| 411 |
// attach each sub-tree to the leaves of the super-tree |
| 412 |
path.MakeRoot(); |
| 413 |
node=(MTnode *)ReadNode(path); |
| 414 |
oldList->Append(node); |
| 415 |
// cout << "super-tree built!\n"; |
| 416 |
l=node->Level(); |
| 417 |
while(l>0) { // build the leaves list for super-tree |
| 418 |
GiSTlist<MTnode *> *newList=new GiSTlist<MTnode *>; |
| 419 |
|
| 420 |
while(!oldList->IsEmpty()) { |
| 421 |
node=oldList->RemoveFront(); |
| 422 |
path=node->Path(); |
| 423 |
node->SetLevel(node->Level()+minLevel); // update level of the upper nodes of the super-tree |
| 424 |
WriteNode(node); |
| 425 |
for(i=0; i<node->NumEntries(); i++) { |
| 426 |
MTentry *e=(MTentry *)(*node)[i].Ptr(); |
| 427 |
|
| 428 |
path.MakeChild(e->Ptr()); |
| 429 |
newList->Append((MTnode *)ReadNode(path)); |
| 430 |
path.MakeParent(); |
| 431 |
} |
| 432 |
delete node; |
| 433 |
} |
| 434 |
delete oldList; |
| 435 |
oldList=newList; |
| 436 |
l--; |
| 437 |
} |
| 438 |
// cout << "Finished " << newname << endl; |
| 439 |
while(!oldList->IsEmpty()) { // attach each sub-tree to its leaf |
| 440 |
GiSTpath rootpath; |
| 441 |
|
| 442 |
rootpath.MakeRoot(); |
| 443 |
node=oldList->RemoveFront(); // retrieve next leaf (root of sub tree) |
| 444 |
node->SetLevel(minLevel); // update level of the root of the sub-tree |
| 445 |
path=node->Path(); |
| 446 |
for(i=0; i<node->NumEntries(); i++) { |
| 447 |
MTnode *newnode=(MTnode *)CreateNode(); |
| 448 |
MTentry *e=(MTentry *)(*node)[i].Ptr(); |
| 449 |
GiSTpath newpath; |
| 450 |
|
| 451 |
path.MakeChild(Store()->Allocate()); |
| 452 |
newnode->Path()=path; |
| 453 |
e->SetPtr(path.Page()); |
| 454 |
path.MakeParent(); |
| 455 |
for(j=0; e->object()!=parents[j]->object(); j++); // search the tree to append |
| 456 |
tree->Open(trees[j]); |
| 457 |
// cout << "Now appending sub-tree " << trees[j] << endl; |
| 458 |
Append(newnode, (MTnode *)tree->ReadNode(rootpath)); // append this sub-tree to the super-tree |
| 459 |
tree->Close(); |
| 460 |
delete tree->Store(); // it was created in tree->Open() |
| 461 |
newpath=newnode->Path(); |
| 462 |
delete newnode; |
| 463 |
} |
| 464 |
WriteNode(node); |
| 465 |
delete node; |
| 466 |
} |
| 467 |
tree->Open(trees[0]); // in order to destroy the object tree |
| 468 |
delete tree; |
| 469 |
for(i=0; i<nsamples; i++) delete []trees[i]; |
| 470 |
delete []trees; |
| 471 |
// update radii of the upper nodes of the result M-tree |
| 472 |
path.MakeRoot(); |
| 473 |
node=(MTnode *)ReadNode(path); |
| 474 |
oldList->Append(node); |
| 475 |
l=node->Level(); |
| 476 |
while(l>=minLevel) { // build the list of the nodes which radii should be recomputed |
| 477 |
GiSTlist<MTnode *> *newList=new GiSTlist<MTnode *>; |
| 478 |
|
| 479 |
while(!oldList->IsEmpty()) { |
| 480 |
|
| 481 |
node=oldList->RemoveFront(); |
| 482 |
path=node->Path(); |
| 483 |
for(i=0; i<node->NumEntries(); i++) { |
| 484 |
MTentry *e=(MTentry *)(*node)[i].Ptr(); |
| 485 |
|
| 486 |
path.MakeChild(e->Ptr()); |
| 487 |
newList->Append((MTnode *)ReadNode(path)); |
| 488 |
path.MakeParent(); |
| 489 |
} |
| 490 |
delete node; |
| 491 |
} |
| 492 |
delete oldList; |
| 493 |
oldList=newList; |
| 494 |
l--; |
| 495 |
} |
| 496 |
while(!oldList->IsEmpty()) { // adjust the radii of the nodes |
| 497 |
MTnode *node=oldList->RemoveFront(); |
| 498 |
|
| 499 |
AdjKeys(node); |
| 500 |
delete node; |
| 501 |
} |
| 502 |
// be tidy... |
| 503 |
delete oldList; |
| 504 |
delete []parents; |
| 505 |
delete []sizes; |
| 506 |
delete []ns; |
| 507 |
delete []sampled; |
| 508 |
delete []samples; |
| 509 |
for(i=0; i<=ncreated; i++) { // delete all temporary sub-trees |
| 510 |
sprintf(newname, "%s.%i", name, i); |
| 511 |
unlink(newname); |
| 512 |
} |
| 513 |
} |
| 514 |
else { // we can insert all the entries in a single node |
| 515 |
GiSTpath path; |
| 516 |
GiSTnode *node; |
| 517 |
|
| 518 |
path.MakeRoot(); |
| 519 |
node=ReadNode(path); |
| 520 |
for(i=0; i<n; i++) |
| 521 |
node->Insert(*(data[i])); |
| 522 |
assert(!node->IsOverFull(*Store())); |
| 523 |
// cout << "real size=" << node->Size() << endl; |
| 524 |
WriteNode(node); |
| 525 |
delete node; |
| 526 |
} |
| 527 |
} |
| 528 |
|
| 529 |
// append the sub-tree rooted at from to the node to |
| 530 |
// this is used in the "append" phase of the BulkLoad algorithm |
| 531 |
void |
| 532 |
MT::Append(MTnode *to, MTnode *from) |
| 533 |
{ |
| 534 |
GiSTlist<MTnode *> *oldList=new GiSTlist<MTnode *>; // list of the nodes to append |
| 535 |
GiSTlist<GiSTpath> pathList; |
| 536 |
MT *fromtree=(MT *)from->Tree(); |
| 537 |
MTnode *node=new MTnode, *newnode; |
| 538 |
|
| 539 |
// cout << "Appending " << from; |
| 540 |
oldList->Append(from); |
| 541 |
pathList.Append(to->Path()); |
| 542 |
do { |
| 543 |
GiSTlist<MTnode *> *newList=new GiSTlist<MTnode *>; |
| 544 |
|
| 545 |
while(!oldList->IsEmpty()) { |
| 546 |
GiSTpath newpath=pathList.RemoveFront(); |
| 547 |
|
| 548 |
delete node; |
| 549 |
node=oldList->RemoveFront(); |
| 550 |
newnode=(MTnode *)ReadNode(newpath); |
| 551 |
// cout << "Inserting " << node->NumEntries() << " entries:\n"; |
| 552 |
for(int i=0; i<node->NumEntries(); i++) { |
| 553 |
MTentry *e=(MTentry *)(*node)[i].Ptr()->Copy(); |
| 554 |
|
| 555 |
if(node->Level()>0) { // if node isn't a leaf, we've to allocate its children |
| 556 |
GiSTpath nodepath=node->Path(); |
| 557 |
MTnode *childnode=(MTnode *)CreateNode(), *fromnode; |
| 558 |
|
| 559 |
nodepath.MakeChild(e->Ptr()); |
| 560 |
fromnode=(MTnode *)fromtree->ReadNode(nodepath); |
| 561 |
newList->Append(fromnode); |
| 562 |
e->SetPtr(Store()->Allocate()); |
| 563 |
newpath.MakeChild(e->Ptr()); |
| 564 |
childnode->Path()=newpath; |
| 565 |
childnode->SetTree(this); |
| 566 |
WriteNode(childnode); // write the empty node |
| 567 |
pathList.Append(newpath); |
| 568 |
newpath.MakeParent(); |
| 569 |
nodepath.MakeParent(); |
| 570 |
delete childnode; |
| 571 |
} |
| 572 |
newnode->Insert(*e); |
| 573 |
// cout << "\tInserted " << e; |
| 574 |
delete e; |
| 575 |
} |
| 576 |
newnode->SetLevel(node->Level()); |
| 577 |
WriteNode(newnode); // write the node |
| 578 |
// cout << "Created " << newnode; |
| 579 |
delete newnode; |
| 580 |
} |
| 581 |
delete oldList; |
| 582 |
oldList=newList; |
| 583 |
} while(node->Level()>0); // until we reach the leaves' level |
| 584 |
// cout << node; |
| 585 |
delete node; |
| 586 |
delete oldList; |
| 587 |
} |
| 588 |
|
| 589 |
// adjust the keys of node |
| 590 |
// this is used during the final phase of the BulkLoad algorithm |
| 591 |
void |
| 592 |
MT::AdjKeys(GiSTnode *node) |
| 593 |
{ |
| 594 |
GiSTnode *P; |
| 595 |
GiSTpath parent_path=node->Path(); |
| 596 |
GiSTentry *entry, *actual; |
| 597 |
|
| 598 |
if(node->Path().IsRoot()) return; |
| 599 |
parent_path.MakeParent(); |
| 600 |
P=ReadNode(parent_path); |
| 601 |
entry=P->SearchPtr(node->Path().Page()); |
| 602 |
assert(entry!=NULL); |
| 603 |
actual=node->Union(); |
| 604 |
actual->SetPtr(node->Path().Page()); |
| 605 |
((MTkey *)actual->Key())->distance=((MTkey *)entry->Key())->distance; // necessary to keep track of the distance from the parent |
| 606 |
if(!entry->IsEqual(*actual)) { // replace this entry |
| 607 |
int pos=entry->Position(); |
| 608 |
|
| 609 |
P->DeleteEntry(pos); |
| 610 |
P->Insert(*actual); |
| 611 |
/* if(P->IsOverFull(*Store())) { // this code should be unnecessary (if we have fixed length entries) |
| 612 |
GiSTpage page=node->Path().Page(); |
| 613 |
|
| 614 |
Split(&P, *actual); |
| 615 |
node->Path()=P->Path(); |
| 616 |
node->Path().MakeChild(page); |
| 617 |
} |
| 618 |
else { |
| 619 |
WriteNode(P); |
| 620 |
AdjKeys(P); |
| 621 |
} */ |
| 622 |
WriteNode(P); |
| 623 |
AdjKeys(P); |
| 624 |
} |
| 625 |
delete P; |
| 626 |
delete actual; |
| 627 |
delete entry; |
| 628 |
} |
