property_map.cpp Source File (kjs Library)

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# property_map.cpp

    00001 // -*- c-basic-offset: 2 -*-
    00002 /*
    00003  *  This file is part of the KDE libraries
    00004  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
    00005  *
    00006  *  This library is free software; you can redistribute it and/or
    00007  *  modify it under the terms of the GNU Lesser General Public
    00008  *  License as published by the Free Software Foundation; either
    00009  *  version 2 of the License, or (at your option) any later version.
    00010  *
    00011  *  This library is distributed in the hope that it will be useful,
    00012  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
    00013  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00014  *  Lesser General Public License for more details.
    00015  *
    00016  *  You should have received a copy of the GNU Lesser General Public License
    00017  *  along with this library; see the file COPYING.LIB.  If not, write to
    00018  *  the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    00019  *  Boston, MA 02111-1307, USA.
    00020  *
    00021  */
    00022
    00023
    00024 #include "property_map.h"
    00025
    00026 #include <string.h>
    00027 #include <assert.h>
    00028 #include <stdio.h>
    00029
    00030 using namespace KJS;
    00031
    00032 // ------------------------------ PropertyMapNode ------------------------------
    00033
    00034 void PropertyMapNode::setLeft(PropertyMapNode *newLeft)
    00035 {
    00036   if (left)
    00037     left->setParent(0);
    00038   left = newLeft;
    00039   if (left)
    00040     left->setParent(this);
    00041 }
    00042
    00043 void PropertyMapNode::setRight(PropertyMapNode *newRight)
    00044 {
    00045   if (right)
    00046     right->setParent(0);
    00047   right = newRight;
    00048   if (right)
    00049     right->setParent(this);
    00050 }
    00051
    00052 void PropertyMapNode::setParent(PropertyMapNode *newParent)
    00053 {
    00054   if (parent) {
    00055     //assert(this == parent->left || this == parent->right);
    00056     if (this == parent->left)
    00057       parent->left = 0;
    00058     else
    00059       parent->right = 0;
    00060   }
    00061   parent = newParent;
    00062 }
    00063
    00064 PropertyMapNode *PropertyMapNode::findMax()
    00065 {
    00066   PropertyMapNode *max = this;
    00067   while (max->right)
    00068     max = max->right;
    00069   return max;
    00070 }
    00071
    00072 PropertyMapNode *PropertyMapNode::findMin()
    00073 {
    00074   PropertyMapNode *min = this;
    00075   while (min->left)
    00076     min = min->left;
    00077   return min;
    00078 }
    00079
    00080 PropertyMapNode *PropertyMapNode::next()
    00081 {
    00082   // find the next node, going from lowest name to highest name
    00083
    00084   // We have a right node. Starting from our right node, keep going left as far as we can
    00085   if (right) {
    00086     PropertyMapNode *n = right;
    00087     while (n->left)
    00088       n = n->left;
    00089     return n;
    00090   }
    00091
    00092   // We have no right node. Keep going up to the left, until we find a node that has a parent
    00093   // to the right. If we find one, go to it. Otherwise, we have reached the end.
    00094   PropertyMapNode *n = this;
    00095   while (n->parent && n->parent->right == n) {
    00096     // parent is to our left
    00097     n = n->parent;
    00098   }
    00099   if (n->parent && n->parent->left == n) {
    00100     // parent is to our right
    00101     return n->parent;
    00102   }
    00103
    00104   return 0;
    00105 }
    00106
    00107 // ------------------------------ PropertyMap ----------------------------------
    00108
    00109 int KJS::uscompare(const UString &s1, const UString &s2)
    00110 {
    00111   int len1 = s1.size();
    00112   int len2 = s2.size();
    00113   if (len1 < len2)
    00114     return -1;
    00115   else if (len1 > len2)
    00116     return 1;
    00117   else
    00118     return memcmp(s1.data(), s2.data(), len1*sizeof(UChar));
    00119 }
    00120
    00121 PropertyMap::PropertyMap()
    00122 {
    00123   root = 0;
    00124 }
    00125
    00126 PropertyMap::~PropertyMap()
    00127 {
    00128   clear();
    00129 }
    00130
    00131 void PropertyMap::put(const UString &name, ValueImp *value, int attr)
    00132 {
    00133   // if not root; make the root the new node
    00134   if (!root) {
    00135     root = new PropertyMapNode(name, value, attr, 0);
    00136     return;
    00137   }
    00138
    00139   // try to find the parent node
    00140   PropertyMapNode *parent = root;
    00141   int isLeft = false;
    00142   while (true) {
    00143     int cmp = uscompare(name, parent->name);
    00144     if (cmp < 0) {
    00145       // traverse to left node (if any)
    00146       isLeft = true;
    00147       if (!parent->left)
    00148         break;
    00149       else
    00150         parent = parent->left;
    00151     }
    00152     else if (cmp > 0) {
    00153       // traverse to right node (if any)
    00154       isLeft = false;
    00155       if (!parent->right)
    00156         break;
    00157       else
    00158         parent = parent->right;
    00159     }
    00160     else {
    00161       // a node with this name already exists; just replace the value
    00162       parent->value = value;
    00163       return;
    00164     }
    00165   }
    00166
    00167   // we found the parent
    00168   //assert(parent);
    00169
    00170   if (isLeft) {
    00171     //assert(!parent->left);
    00172     parent->left = new PropertyMapNode(name, value, attr, parent);
    00173   }
    00174   else {
    00175     //assert(!parent->right);
    00176     parent->right = new PropertyMapNode(name, value, attr, parent);
    00177   }
    00178   updateHeight(parent);
    00179
    00180
    00181   PropertyMapNode *node = parent;
    00182   while (node) {
    00183     PropertyMapNode *p = node->parent;
    00184     balance(node); // may change node
    00185     node = p;
    00186   }
    00187 }
    00188
    00189 void PropertyMap::remove(const UString &name)
    00190 {
    00191   PropertyMapNode *node = getNode(name);
    00192   if (!node) // name not in tree
    00193     return;
    00194
    00195   PropertyMapNode *removed = remove(node);
    00196   if (removed)
    00197     delete node;
    00198 }
    00199
    00200 ValueImp *PropertyMap::get(const UString &name) const
    00201 {
    00202   const PropertyMapNode *n = getNode(name);
    00203   return n ? n->value : 0;
    00204 }
    00205
    00206 void PropertyMap::clear(PropertyMapNode *node)
    00207 {
    00208   if (node == 0)
    00209     node = root;
    00210   if (node == 0) // nothing to do
    00211     return;
    00212
    00213   if (node->left)
    00214     clear(node->left);
    00215   if (node->right)
    00216     clear(node->right);
    00217   if (node == root)
    00218     root = 0;
    00219   delete node;
    00220 }
    00221
    00222 void PropertyMap::dump(const PropertyMapNode *node, int indent) const
    00223 {
    00224   if (!node && indent > 0)
    00225     return;
    00226   if (!node)
    00227     node = root;
    00228   if (!node)
    00229     return;
    00230
    00231   assert(!node->right || node->right->parent == node);
    00232   dump(node->right, indent+1);
    00233   for (int i = 0; i < indent; i++) {
    00234     printf("    ");
    00235   }
    00236   printf("[%d] %s\n", node->height, node->name.ascii());
    00237   assert(!node->left || node->left->parent == node);
    00238   dump(node->left, indent+1);
    00239 }
    00240
    00241 void PropertyMap::checkTree(const PropertyMapNode *node) const
    00242 {
    00243   if (!root)
    00244     return;
    00245   if (node == 0)
    00246     node = root;
    00247   if (node == root) {
    00248     assert(!node->parent);
    00249   }
    00250   assert(!node->right || node->right->parent == node);
    00251   assert(!node->left || node->left->parent == node);
    00252   assert(node->left != node);
    00253   assert(node->right != node);
    00254   if (node->left && node->right)
    00255     assert(node->left != node->right);
    00256
    00257   PropertyMapNode *n = node->parent;
    00258   while (n) {
    00259     assert(n != node);
    00260     n = n->parent;
    00261   }
    00262
    00263   if (node->right)
    00264     checkTree(node->right);
    00265   if (node->left)
    00266     checkTree(node->left);
    00267 }
    00268
    00269 PropertyMapNode *PropertyMap::getNode(const UString &name) const
    00270 {
    00271   PropertyMapNode *node = root;
    00272 #if 1 // optimized version of ...
    00273   int len1 = name.size();
    00274   int ulen = len1 * sizeof(UChar);
    00275   const UChar* const data1 = name.data();
    00276   while (node) {
    00277     int diff = len1 - node->name.size();
    00278     if (diff == 0 && (diff = memcmp(data1, node->name.data(), ulen)) == 0)
    00279         return node;
    00280     node = diff < 0 ? node->left : node->right;
    00281   }
    00282 #else // this one
    00283     while (node) {
    00284       int cmp = uscompare(name, node->name);
    00285       if (cmp == 0)
    00286         return node;
    00287       node = cmp < 0 ? node->left : node->right;
    00288     }
    00289 #endif
    00290   return 0;
    00291 }
    00292
    00293 PropertyMapNode *PropertyMap::first() const
    00294 {
    00295   if (!root)
    00296     return 0;
    00297
    00298   PropertyMapNode *node = root;
    00299   while (node->left)
    00300     node = node->left;
    00301   return node;
    00302 }
    00303
    00304 PropertyMapNode * PropertyMap::remove(PropertyMapNode *node)
    00305 {
    00306   PropertyMapNode *parent = node->parent;
    00307   //assert(!parent || (node == parent->left || node == parent->right));
    00308   bool isLeft = (parent && node == parent->left);
    00309
    00310   PropertyMapNode *replace = 0;
    00311   if (node->left && node->right) {
    00312     PropertyMapNode *maxLeft = node->left->findMax();
    00313     if (maxLeft == node->left) {
    00314       maxLeft->setRight(node->right);
    00315       replace = maxLeft;
    00316     }
    00317     else {
    00318       remove(maxLeft);
    00319
    00320       maxLeft->setLeft(node->left);
    00321       maxLeft->setRight(node->right);
    00322       replace = maxLeft;
    00323     }
    00324     // removing maxLeft could have re-balanced the tree, so recalculate
    00325     // parent again
    00326     parent = node->parent;
    00327     //assert(!parent || (node == parent->left || node == parent->right));
    00328     isLeft = (parent && node == parent->left);
    00329   }
    00330   else if (node->left) {
    00331     replace = node->left;
    00332   }
    00333   else if (node->right) {
    00334     replace = node->right;
    00335   }
    00336   else {
    00337     replace = 0;
    00338   }
    00339
    00340   if (parent) {
    00341     if (isLeft)
    00342       parent->setLeft(replace);
    00343     else
    00344       parent->setRight(replace);
    00345   }
    00346   else {
    00347     root = replace;
    00348     if (replace)
    00349       replace->parent = 0;
    00350   }
    00351
    00352   if (replace)
    00353     updateHeight(replace); // will also update parent's height
    00354   else if (parent)
    00355     updateHeight(parent);
    00356   else if (root)
    00357     updateHeight(root);
    00358
    00359
    00360   // balance the tree
    00361   PropertyMapNode *bal = parent;
    00362   while (bal) {
    00363     PropertyMapNode *p = bal->parent;
    00364     balance(bal); // may change bal
    00365     bal = p;
    00366   }
    00367
    00368   return node;
    00369 }
    00370
    00371 void PropertyMap::balance(PropertyMapNode* node)
    00372 {
    00373   int lheight = node->left ? node->left->height : 0;
    00374   int rheight = node->right ? node->right->height : 0;
    00375
    00376   int bal = rheight-lheight;
    00377
    00378   if (bal < -1) {
    00379     //assert(node->left);
    00380     int llheight = node->left->left ? node->left->left->height : 0;
    00381     int lrheight = node->left->right ? node->left->right->height : 0;
    00382     int lbal = lrheight - llheight;
    00383
    00384     if (lbal < 0) {
    00385       rotateLL(node); // LL rotation
    00386     }
    00387     else {
    00388       // lbal >= 0
    00389       rotateLR(node);
    00390     }
    00391   }
    00392   else if (bal > 1) {
    00393     int rlheight = node->right->left ? node->right->left->height : 0;
    00394     int rrheight = node->right->right ? node->right->right->height : 0;
    00395     int rbal = rrheight - rlheight;
    00396     if (rbal < 0) {
    00397       rotateRL(node);
    00398     }
    00399     else {
    00400       // rbal >= 0
    00401       rotateRR(node); // RR rotateion
    00402     }
    00403   }
    00404 }
    00405
    00406 void PropertyMap::updateHeight(PropertyMapNode* &node)
    00407 {
    00408   int lheight = node->left ? node->left->height : 0;
    00409   int rheight = node->right ? node->right->height : 0;
    00410   if (lheight > rheight)
    00411     node->height = lheight+1;
    00412   else
    00413     node->height = rheight+1;
    00414   //assert(node->parent != node);
    00415   if (node->parent)
    00416     updateHeight(node->parent);
    00417 }
    00418
    00419 void PropertyMap::rotateRR(PropertyMapNode* &node)
    00420 {
    00421   /*
    00422     Perform a RR ("single left") rotation, e.g.
    00423
    00424       a                b
    00425      / \              / \
    00426     X   b     -->    a   Z
    00427        / \          / \
    00428       Y   Z        X   Y
    00429   */
    00430
    00431   // Here, node is initially a, will be replaced with b
    00432
    00433   PropertyMapNode *a = node;
    00434   PropertyMapNode *b = node->right;
    00435
    00436   PropertyMapNode *parent = a->parent;
    00437   //assert(!parent || (a == parent->left || a == parent->right));
    00438   bool isLeft = (parent && a == parent->left);
    00439
    00440   // do the rotation
    00441   a->setRight(b->left);
    00442   b->setLeft(a);
    00443
    00444   // now node is b
    00445   node = b;
    00446   if (parent) {
    00447     if (isLeft)
    00448       parent->setLeft(b);
    00449     else
    00450       parent->setRight(b);
    00451   }
    00452   else {
    00453     // a was the root node
    00454     root = b;
    00455   }
    00456
    00457   updateHeight(a);
    00458   updateHeight(b);
    00459 }
    00460
    00461
    00462 void PropertyMap::rotateLL(PropertyMapNode* &node)
    00463 {
    00464   /*
    00465     Perform a LL ("single right") rotation, e.g.
    00466
    00467
    00468         a              b
    00469        / \            / \
    00470       b   Z   -->    X   a
    00471      / \                / \
    00472     X   Y              Y   Z
    00473   */
    00474
    00475   // Here, node is initially a, will be replaced with b
    00476
    00477   PropertyMapNode *a = node;
    00478   PropertyMapNode *b = node->left;
    00479
    00480   PropertyMapNode *parent = a->parent;
    00481   //assert(!parent || (a == parent->left || a == parent->right));
    00482   bool isLeft = (parent && a == parent->left);
    00483
    00484   // do the rotation
    00485   a->setLeft(b->right);
    00486   b->setRight(a);
    00487
    00488   // now node is b
    00489   node = b;
    00490   if (parent) {
    00491     if (isLeft)
    00492       parent->setLeft(b);
    00493     else
    00494       parent->setRight(b);
    00495   }
    00496   else {
    00497     // a was the root node
    00498     root = b;
    00499   }
    00500
    00501   updateHeight(a);
    00502   updateHeight(b);
    00503 }
    00504
    00505 void PropertyMap::rotateRL(PropertyMapNode* &node)
    00506 {
    00507   /*
    00508     Perform a RL ("double left") rotation, e.g.
    00509
    00510         a                   a                          b
    00511       /   \      LL on c  /   \          RR on b     /   \
    00512      W      c      -->   W      b          -->     a       c
    00513            / \                 / \                / \     / \
    00514           b   Z               X   c              W   X   Y   Z
    00515          / \                     / \
    00516         X   Y                   Y   Z
    00517
    00518   */
    00519
    00520   PropertyMapNode *a = node;
    00521   PropertyMapNode *c = node->right;
    00522   PropertyMapNode *b = node->right->left;
    00523
    00524   rotateLL(c);
    00525   rotateRR(b);
    00526
    00527   updateHeight(a);
    00528   updateHeight(c);
    00529   updateHeight(b);
    00530 }
    00531
    00532 void PropertyMap::rotateLR(PropertyMapNode* &node)
    00533 {
    00534   /*
    00535     Perform a LR ("double right") rotation, e.g.
    00536
    00537           a                         a                      b
    00538         /   \    RR on c          /   \     LL on a      /   \
    00539       c       Z    -->          b       Z     -->      c       a
    00540      / \                       / \                    / \     / \
    00541     W   b                     c   Y                  W   X   Y   Z
    00542        / \                   / \
    00543       X   Y                 W   X
    00544   */
    00545
    00546   PropertyMapNode *a = node;
    00547   PropertyMapNode *c = node->left;
    00548   PropertyMapNode *b = node->left->right;
    00549
    00550   rotateRR(c);
    00551   rotateLL(a);
    00552
    00553   updateHeight(c);
    00554   updateHeight(a);
    00555   updateHeight(b);
    00556 }

This file is part of the documentation for kdelibs Version 3.1.5.
Documentation copyright © 1996-2002 the KDE developers.
Generated on Wed Jan 28 13:08:34 2004 by doxygen 1.3.4 written by Dimitri van Heesch, © 1997-2001