/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Copyright by the Board of Trustees of the University of Illinois. * * All rights reserved. * * * * This file is part of HDF5. The full HDF5 copyright notice, including * * terms governing use, modification, and redistribution, is contained in * * the files COPYING and Copyright.html. COPYING can be found at the root * * of the source code distribution tree; Copyright.html can be found at the * * root level of an installed copy of the electronic HDF5 document set and * * is linked from the top-level documents page. It can also be found at * * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html. If you do not have * * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* WARNING!!! * * The function H5TB_rem() may not delete the node specified in its parameter * list -- if the target node is internal, it may swap data with a leaf node * and delete the leaf instead. * * This implies that any pointer to a node in the supplied tree may be * invalid after this functions returns. Thus any function retaining such * pointers over a call to H5TB_rem() should either discard, or refresh them. * * JRM - 4/9/04 */ /* * Programmer: Quincey Koziol * Saturday, April 22, 2000 * * Purpose: Routines for using threaded, balanced, binary trees. * Extended from (added threads to) Knuth 6.2.3, Algorithm A (AVL trees) * Basic tree structure by Adel'son-Vel'skii and Landis * * These routines are designed to allow use of a general-purpose balanced * tree implimentation. These trees are appropriate for maintaining in * memory one or more lists of items, each list sorted according to key * values (key values must form a "completely ordered set") where no two * items in a single list can have the same key value. The following * operations are supported: * * Create an empty list * Add an item to a list * Look up an item in a list by key value * Look up the Nth item in a list * Delete an item from a list * Find the first/last/next/previous item in a list * Destroy a list * * Each of the above operations requires Order(log(N)) time where N is * the number of items in the list (except for list creation which * requires constant time and list destruction which requires Order(N) * time if the user- supplied free-data-item or free-key-value routines * require constant time). Each of the above operations (except create * and destroy) can be performed on a subtree. * * Each node of a tree has associated with it a generic pointer (void *) * which is set to point to one such "item" and a generic pointer to * point to that item's "key value". The structure of the items and key * values is up to the user to define. The user must specify a method * for comparing key values. This routine takes three arguments, two * pointers to key values and a third integer argument. You can specify * a routine that expects pointers to "data items" rather than key values * in which case the pointer to the key value in each node will be set * equal to the pointer to the data item. * * Since the "data item" pointer is the first field of each tree node, * these routines may be used without this "tbbt.h" file. For example, * assume "ITM" is the structre definition for the data items you want to * store in lists: * * ITM ***H5TB_dmake( int (*cmp)(void *,void *,int), int arg ); * ITM **root= NULL; (* How to create an empty tree w/o H5TB_dmake() *) * ITM **H5TB_dfind( ITM ***tree, void *key, ITM ***pp ); * ITM **H5TB_find( ITM **root, void *key, int (*cmp)(), int arg, ITM ***pp ); * ITM **H5TB_dless( ITM ***tree, void *key, ITM ***pp ); * ITM **H5TB_less( ITM **root, void *key, int (*cmp)(), int arg, ITM ***pp ); * ITM **H5TB_index( ITM **root, long indx ); * ITM **H5TB_dins( ITM ***tree, ITM *item, void *key ); * ITM **H5TB_ins( ITM ***root, ITM *item, void *key, int (*cmp)(), int arg ); * ITM *H5TB_rem( ITM ***root, ITM **node, void **kp ); * ITM ***H5TB_dfree( ITM ***tree, void (*df)(ITM *), void (*kf)(void *) ); * void H5TB_free( ITM ***root, void (*df)(ITM *), void (*kf)(void *) ); */ /* Pablo information */ /* (Put before include files to avoid problems with inline functions) */ #define PABLO_MASK H5TB_mask #include "H5private.h" /*library */ #include "H5Eprivate.h" /*error handling */ #include "H5Fprivate.h" /* File address macros */ #include "H5MMprivate.h" /*Core memory management */ #include "H5FLprivate.h" /*Free Lists */ #include "H5TBprivate.h" /*Threaded, balanced, binary trees */ # define KEYcmp(k1,k2,a) ((NULL!=compar) ? (*compar)( k1, k2, a) \ : HDmemcmp( k1, k2, 0<(a) ? ((size_t)a) : HDstrlen(k1) ) ) /* Return maximum of two scalar values (use arguments w/o side effects): */ #define Max(a,b) ( (a) > (b) ? (a) : (b) ) /* Local Function Prototypes */ static H5TB_NODE *H5TB_ffind(H5TB_NODE * root, const void * key, unsigned fast_compare, H5TB_NODE ** pp); static herr_t H5TB_balance(H5TB_NODE ** root, H5TB_NODE * ptr, int side, int added); static H5TB_NODE *H5TB_swapkid(H5TB_NODE ** root, H5TB_NODE * ptr, int side); #ifdef H5TB_DEBUG static herr_t H5TB_printNode(H5TB_NODE * node, void(*key_dump)(void *,void *)); static herr_t H5TB_dumpNode(H5TB_NODE *node, void (*key_dump)(void *,void *), int method); #endif /* H5TB_DEBUG */ /* Declare a free list to manage the H5TB_NODE struct */ H5FL_DEFINE_STATIC(H5TB_NODE); /* Declare a free list to manage the H5TB_TREE struct */ H5FL_DEFINE_STATIC(H5TB_TREE); /*------------------------------------------------------------------------- * Function: H5TB_strcmp * * Purpose: Key comparison routine for TBBT routines * * Return: same as strcmp() * * Programmer: Quincey Koziol * Wednesday, December 4, 2002 * * Modifications: * *------------------------------------------------------------------------- */ static int H5TB_strcmp(const void *k1, const void *k2, int UNUSED cmparg) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_strcmp); assert(k1); assert(k2); FUNC_LEAVE_NOAPI(HDstrcmp(k1,k2)); } /* end H5TB_strcmp() */ /*------------------------------------------------------------------------- * Function: H5TB_addr_cmp * * Purpose: Key comparison routine for TBBT routines * * Return: same as H5F_addr_cmp() * * Programmer: Quincey Koziol * Friday, December 20, 2002 * * Modifications: * *------------------------------------------------------------------------- */ static int H5TB_addr_cmp(const void *k1, const void *k2, int UNUSED cmparg) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_addr_cmp); assert(k1); assert(k2); FUNC_LEAVE_NOAPI(H5F_addr_cmp(*(const haddr_t *)k1,*(const haddr_t *)k2)); } /* end H5TB_addr_cmp() */ /*------------------------------------------------------------------------- * Function: H5TB_int_cmp * * Purpose: Key comparison routine for TBBT routines * * Return: same as comparing two integers * * Programmer: Quincey Koziol * Friday, December 20, 2002 * * Modifications: * *------------------------------------------------------------------------- */ static int H5TB_int_cmp(const void *k1, const void *k2, int UNUSED cmparg) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_int_cmp); assert(k1); assert(k2); FUNC_LEAVE_NOAPI(*(const int *)k1 - *(const int *)k2); } /* end H5TB_int_cmp() */ /*------------------------------------------------------------------------- * Function: H5TB_hsize_cmp * * Purpose: Key comparison routine for TBBT routines * * Return: same as comparing two hsize_t's * * Programmer: Quincey Koziol * Friday, December 20, 2002 * * Modifications: * *------------------------------------------------------------------------- */ static int H5TB_hsize_cmp(const void *k1, const void *k2, int UNUSED cmparg) { int ret_value; FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_hsize_cmp); assert(k1); assert(k2); if(*(const hsize_t *)k1 < *(const hsize_t *)k2) ret_value=-1; else if(*(const hsize_t *)k1 > *(const hsize_t *)k2) ret_value=1; else ret_value=0; FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_hsize_cmp() */ /*------------------------------------------------------------------------- * Function: H5TB_fast_dmake * * Purpose: Wrapper around H5TB_dmake for callers which want to use * a "fast comparison" key. * * Return: Success: Pointer to a valid H5TB tree * Failure: NULL * * Programmer: Quincey Koziol * Friday, December 20, 2002 * * Modifications: * *------------------------------------------------------------------------- */ H5TB_TREE * H5TB_fast_dmake(unsigned fast_compare) { H5TB_cmp_t compar; /* Key comparison function */ int cmparg; /* Key comparison value */ H5TB_TREE *ret_value; /* Return value */ FUNC_ENTER_NOAPI(H5TB_fast_dmake, NULL); /* Get the corret fast comparison routine */ switch(fast_compare) { case H5TB_FAST_HADDR_COMPARE: compar=H5TB_addr_cmp; cmparg=-1; break; case H5TB_FAST_INTN_COMPARE: compar=H5TB_int_cmp; cmparg=-1; break; case H5TB_FAST_STR_COMPARE: compar=H5TB_strcmp; cmparg=-1; break; case H5TB_FAST_HSIZE_COMPARE: compar=H5TB_hsize_cmp; cmparg=-1; break; default: HGOTO_ERROR (H5E_TBBT, H5E_BADVALUE, NULL, "invalid fast comparison type"); } /* end switch */ /* Set return value */ if((ret_value=H5TB_dmake(compar,cmparg,fast_compare))==NULL) HGOTO_ERROR (H5E_TBBT, H5E_CANTCREATE, NULL, "can't create TBBT"); done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_fast_dmake() */ /*------------------------------------------------------------------------- * Function: H5TB_dmake * * Purpose: Allocates and initializes an empty threaded, balanced, binary tree * and returns a pointer to the control structure for it. You can also create * empty trees without this function as long as you never use H5TB_d* routines * (H5TB_dfind, H5TB_dins, H5TB_dfree) on them. * Examples: * int keycmp(); * H5TB_TREE *tree = H5TB_dmake( keycmp, (int)keysiz , 0); * or * void *tree= H5TB_dmake( strcmp, 0 , 0); * or * void *tree= H5TB_dmake( keycmp, (int)keysiz , H5TB_FAST_HADDR_COMPARE); * or * H5TB_NODE *root= NULL; (* Don't use H5TB_d* routines *) * * `cmp' is the routine to be used to compare two key values [in H5TB_dfind() * and H5TB_dins()]. The arguments to `cmp' are the two keys to compare * and `arg': (*cmp)(k1,k2,arg). `cmp' is expected to return 0 if its first * two arguments point to identical key values, -1 (or any integer less than 0) * if k1 points to a key value lower than that pointed to by k2, and 1 (or any * integer greater than 0) otherwise. If `cmp' is NULL, memcmp is used. If * `cmp' is NULL and `arg' is not greater than 0L, `1+strlen(key1)' is used in * place of `arg' to emulate strcmp(): memcmp( k1, k2, 1+strlen(k1) ). You * can use strcmp() directly (as in the second example above) as long as your C * compiler does not assume strcmp() will always be passed exactly 2 arguments * (only newer, ANSI-influenced C compilers are likely to be able to make this * kind of assumption). You can also use a key comparison routine that expects * pointers to data items rather than key values. * * The "fast compare" option is for keys of simple numeric types * (currently haddr_t and int) and avoids the function call for faster * searches in some cases. The key comparison routine is still required * for some insertion routines which use it. * * Most of the other routines expect a pointer to a root node of a tree, not * a pointer to the tree's control structure (only H5TB_dfind(), H5TB_dins(), * and H5TB_dfree() expect pointers to control structures). However H5TB_TREE * is just defined as "**H5TB_NODE" (unless you have defined H5TB_INTERNALS so * you have access to the internal structure of the nodes) so * H5TB_TREE *tree1= H5TB_dmake( NULL, 0 ); * is equivalent to * H5TB_NODE **tree1= H5TB_dmake( NULL, 0 ); * So could be used as: * node= H5TB_dfind( tree1, key, NULL ); * node= H5TB_find( *tree1, key, compar, arg, NULL ); * node= H5TB_dless( tree1, key, NULL ); * node= H5TB_less( *tree1, key, compar, arg, NULL ); * node= H5TB_dins( tree1, item, key ); * node= H5TB_ins( tree1, item, key, compar, arg ); * item= H5TB_rem( tree1, H5TB_dfind(tree1,key,NULL), NULL ); * item= H5TB_rem( tree1, H5TB_find(*tree1,key,compar,arg,NULL), NULL ); * tree1= H5TB_dfree( tree1, free, NULL ); (* or whatever *) * while * H5TB_NODE *root= NULL; * would be used like: * node= H5TB_find( root, key ); * node= H5TB_ins( &root, item, key ); * node= H5TB_rem( &root, H5TB_find(root,key), NULL ); * H5TB_free( &root, free, NULL ); (* or whatever *) * Never use H5TB_free() on a tree allocated with H5TB_dmake() or on a sub-tree * of ANY tree. Never use H5TB_dfree() except on a H5TB_dmake()d tree. * * Return: Success: Pointer to a valid H5TB tree * Failure: NULL * * Programmer: Quincey Koziol * Saturday, April 22, 2000 * * Modifications: * *------------------------------------------------------------------------- */ H5TB_TREE * H5TB_dmake(H5TB_cmp_t cmp, int arg, unsigned fast_compare) { H5TB_TREE *tree; H5TB_TREE *ret_value; FUNC_ENTER_NOAPI(H5TB_dmake, NULL); if (NULL == (tree = H5FL_MALLOC(H5TB_TREE))) HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed"); tree->root = NULL; tree->count = 0; tree->fast_compare=fast_compare; tree->compar = cmp; tree->cmparg = arg; /* Set return value */ ret_value=tree; done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_dmake() */ /*------------------------------------------------------------------------- * Function: H5TB_dfind * * Purpose: Look up a node in a "described" tree based on a key value * Locate a node based on the key given. A pointer to the node in the tree * with a key value matching `key' is returned. If no such node exists, NULL * is returned. Whether a node is found or not, if `pp' is not NULL, `*pp' * will be set to point to the parent of the node we are looking for (or that * node that would be the parent if the node is not found). H5TB_dfind() is * used on trees created using H5TB_dmake() (so that `cmp' and `arg' don't have * to be passed). [H5TB_find() can be used on the root or any subtree of a tree * create using H5TB_dmake() and is used on any tree (or subtree) created with- * out using H5TB_dmake().] * * Return: Success: Pointer to a valid H5TB node * Failure: NULL * * Programmer: Quincey Koziol * Thursday, May 5, 2000 * * Modifications: * *------------------------------------------------------------------------- */ H5TB_NODE * H5TB_dfind(H5TB_TREE * tree, const void * key, H5TB_NODE ** pp) { H5TB_NODE *ret_value; FUNC_ENTER_NOAPI_NOFUNC(H5TB_dfind); assert(tree); if(tree->root) if(tree->fast_compare!=0) ret_value=H5TB_ffind(tree->root, key, tree->fast_compare, pp); else ret_value=H5TB_find(tree->root, key, tree->compar, tree->cmparg, pp); else { if (NULL != pp) *pp = NULL; ret_value=NULL; } /* end else */ FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_dfind() */ /*------------------------------------------------------------------------- * Function: H5TB_find * * Purpose: Look up a node in a "non-described" tree based on a key value * Locate a node based on the key given. A pointer to the node in the tree * with a key value matching `key' is returned. If no such node exists, NULL * is returned. Whether a node is found or not, if `pp' is not NULL, `*pp' * will be set to point to the parent of the node we are looking for (or that * node that would be the parent if the node is not found). H5TB_dfind() is * used on trees created using H5TB_dmake() (so that `cmp' and `arg' don't have * to be passed). [H5TB_find() can be used on the root or any subtree of a tree * create using H5TB_dmake() and is used on any tree (or subtree) created with- * out using H5TB_dmake().] * * Return: Success: Pointer to a valid H5TB node * Failure: NULL * * Programmer: Quincey Koziol * Thursday, May 5, 2000 * * Modifications: * * Notes: * H5TB_ffind is based on this routine - fix bugs in both places! * *------------------------------------------------------------------------- */ H5TB_NODE * H5TB_find(H5TB_NODE * ptr, const void * key, H5TB_cmp_t compar, int arg, H5TB_NODE ** pp) { H5TB_NODE *parent = NULL; int cmp = 1; FUNC_ENTER_NOAPI_NOFUNC(H5TB_find); if(ptr) { while (0 != (cmp = KEYcmp(key, ptr->key, arg))) { parent = ptr; if(cmp<0) { if(!LeftCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[LEFT]; } /* end if */ else { if(!RightCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[RIGHT]; } /* end else */ } /* end while */ } /* end if */ if (NULL != pp) *pp = parent; FUNC_LEAVE_NOAPI(ptr); } /* end H5TB_find() */ /*------------------------------------------------------------------------- * Function: H5TB_dless * * Purpose: Look up a node in a "described" tree based on a key value. * Locate a node based on the key given. A pointer to the node in the tree * with a key value less than or equal to `key' is returned. If no such node * exists, NULL is returned. Whether a node is found or not, if `pp' is not * NULL, `*pp' will be set to point to the parent of the node we are looking * for (or that node that would be the parent if the node is not found). * H5TB_dless() is used on trees created using H5TB_dmake() (so that `cmp' and * `arg' don't have to be passed). [H5TB_less() can be used on the root or any * subtree of a tree create using H5TB_dmake() and is used on any tree (or * subtree) created with-out using H5TB_dmake().] * * Return: Success: Pointer to a valid H5TB node * Failure: NULL * * Programmer: Quincey Koziol * Thursday, May 5, 2000 * * Modifications: * * Notes: * *------------------------------------------------------------------------- */ H5TB_NODE * H5TB_dless(H5TB_TREE * tree, void * key, H5TB_NODE ** pp) { H5TB_NODE *ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOFUNC(H5TB_dless); assert(tree); /* Set return value */ ret_value= H5TB_less(tree->root, key, tree->compar, tree->cmparg, pp); FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_dless() */ /*------------------------------------------------------------------------- * Function: H5TB_less * * Purpose: Look up a node in a "non-described" tree based on a key value. * Locate a node based on the key given. A pointer to the node in the tree * with a key value less than or equal to `key' is returned. If no such node * exists, NULL is returned. Whether a node is found or not, if `pp' is not * NULL, `*pp' will be set to point to the parent of the node we are looking * for (or that node that would be the parent if the node is not found). * H5TB_dless() is used on trees created using H5TB_dmake() (so that `cmp' and * `arg' don't have to be passed). [H5TB_less() can be used on the root or any * subtree of a tree create using H5TB_dmake() and is used on any tree (or * subtree) created with-out using H5TB_dmake().] * * Return: Success: Pointer to a valid H5TB node * Failure: NULL * * Programmer: Quincey Koziol * Thursday, May 5, 2000 * * Modifications: * Fixed function so it seems to perform as advertized. Two * tests were inverted in the backtrack case. * JRM - 4/13/04 * * Notes: * *------------------------------------------------------------------------- */ H5TB_NODE * H5TB_less(H5TB_NODE * root, void * key, H5TB_cmp_t compar, int arg, H5TB_NODE ** pp) { H5TB_NODE *ptr = root; H5TB_NODE *parent = NULL; int cmp = 1; int side; H5TB_NODE *ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOFUNC(H5TB_less); /* Try to find an exact match */ if (ptr) { while (0 != (cmp = KEYcmp(key, ptr->key, arg))) { parent = ptr; side = (cmp < 0) ? LEFT : RIGHT; if (!HasChild(ptr, side)) break; ptr = ptr->link[side]; } /* end while */ } /* end if */ /* didn't find an exact match, search back up the tree until a node */ /* is found with a key less than the key searched for */ if(cmp!=0) { /* If we haven't already found the least node, then backtrack to * find it */ if(cmp<0) { while((ptr=ptr->Parent)!=NULL) { cmp = KEYcmp(key, ptr->key, arg); if(cmp>0) /* found a node which is less than the search for one */ break; } /* end while */ } /* end if */ if(ptr==NULL) /* didn't find a node in the tree which was less */ cmp=1; else /* reset this for cmp test below */ cmp=0; } /* end if */ if (NULL != pp) *pp = parent; /* Set return value */ ret_value= (0 == cmp) ? ptr : NULL; FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_less */ /*------------------------------------------------------------------------- * Function: H5TB_index * * Purpose: Locate the node that has `indx' nodes with lesser key values. * This is like an array lookup with the first item in the list having index 0. * For large values of `indx', this call is much faster than H5TB_first() * followed by `indx' H5TB_next()s. Thus `H5TB_index(&root,0L)' is equivalent to * (and almost as fast as) `H5TB_first(root)'. * * Return: Success: Pointer to a valid H5TB node * Failure: NULL * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * *------------------------------------------------------------------------- */ H5TB_NODE * H5TB_index(H5TB_NODE * root, unsigned indx) { H5TB_NODE *ptr = root; H5TB_NODE *ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOFUNC(H5TB_index); if (NULL != ptr) { /* Termination condition is if the index equals the number of children on out left plus the current node */ while (ptr != NULL && indx != ((unsigned) LeftCnt(ptr)) ) { if (indx <= (unsigned) LeftCnt(ptr)) { ptr = ptr->Lchild; } /* end if */ else if (HasChild(ptr, RIGHT)) { /* subtract children count from leftchild plus current node when we descend into a right branch */ indx -= (unsigned)(LeftCnt(ptr) + 1); ptr = ptr->Rchild; } /* end if */ else { /* Only `indx' or fewer nodes in tree */ ptr=NULL; break; } /* end else */ } /* end while */ } /* end if */ /* Set return value */ ret_value=ptr; FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_index() */ /*------------------------------------------------------------------------- * Function: H5TB_dins * * Purpose: Insert a new node into a "described" tree, having a key value of * `key' and a data pointer of `item'. If a node already exists in the tree * with key value `key' or if malloc() fails, NULL is returned (no node is * inserted), otherwise a pointer to the inserted node is returned. `cmp' and * `arg' are as for H5TB_find(). * * Return: Success: Pointer to a valid H5TB node * Failure: NULL * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * *------------------------------------------------------------------------- */ H5TB_NODE * H5TB_dins(H5TB_TREE * tree, void * item, void * key) { H5TB_NODE *ret_value; /* the node to return */ FUNC_ENTER_NOAPI_NOFUNC(H5TB_dins); assert(tree); /* Try to insert the node */ ret_value = H5TB_ins(&(tree->root), item, key, tree->fast_compare, tree->compar, tree->cmparg); /* If we successfully inserted the node, increment the node count in the tree */ if (ret_value != NULL) tree->count++; FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_dins() */ /*------------------------------------------------------------------------- * Function: H5TB_ins * * Purpose: Insert a new node into a "non-described" tree, having a key value of * `key' and a data pointer of `item'. If a node already exists in the tree * with key value `key' or if malloc() fails, NULL is returned (no node is * inserted), otherwise a pointer to the inserted node is returned. `cmp' and * `arg' are as for H5TB_find(). * * Return: Success: Pointer to a valid H5TB node * Failure: NULL * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * Assumes that the comparison routine is _NOT_ used for trees with * "fast compare" set. * *------------------------------------------------------------------------- */ H5TB_NODE * H5TB_ins(H5TB_NODE ** root, void * item, void * key, unsigned fast_compare, H5TB_cmp_t compar, int arg) { int cmp; H5TB_NODE *ptr, *parent; H5TB_NODE *ret_value; FUNC_ENTER_NOAPI(H5TB_ins,NULL); assert(root); assert(item); /* Find node in tree, or parent of where node will go */ if(fast_compare!=0) { if(NULL != H5TB_ffind(*root, (key ? key : item), fast_compare, &parent)) HGOTO_ERROR (H5E_TBBT, H5E_EXISTS, NULL, "node already in tree"); } /* end if */ else { if(NULL != H5TB_find(*root, (key ? key : item), compar, arg, &parent)) HGOTO_ERROR (H5E_TBBT, H5E_EXISTS, NULL, "node already in tree"); } /* end else */ if (NULL == (ptr = H5FL_MALLOC(H5TB_NODE))) HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed"); ptr->data = item; ptr->key = key ? key : item; ptr->Parent = parent; ptr->flags = 0L; /* No children on either side */ ptr->lcnt = 0; ptr->rcnt = 0; /* Adding first node to tree: */ if (NULL == parent) { *root = ptr; ptr->Lchild = ptr->Rchild = NULL; } else { cmp = KEYcmp(ptr->key, parent->key, arg); if (cmp < 0) { ptr->Lchild = parent->Lchild; /* Parent's thread now new node's */ ptr->Rchild = parent; /* New nodes right thread is parent */ parent->Lchild = ptr; /* Parent now has a left child */ } else { ptr->Rchild = parent->Rchild; ptr->Lchild = parent; parent->Rchild = ptr; } H5TB_balance(root, parent, (cmp < 0) ? LEFT : RIGHT, 1); } /* end else */ /* Set return value */ ret_value=ptr; done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_ins() */ /*------------------------------------------------------------------------- * Function: H5TB_rem * * Purpose: Remove a node from a tree. You pass in the address of the * pointer to the root node of the tree along, a pointer to the node you wish * to remove, and optionally the address of a pointer to hold the address of * the key value of the deleted node. The second argument is usually the * result from a lookup function call (H5TB_find, H5TB_dfind, or H5TB_index) * so if it is NULL, H5TB_rem returns NULL. Otherwise H5TB_rem removes the * node from the tree and returns a pointer to the data item for that node and, * if the third argument is not NULL, the address of the key value for the * deleted node is placed in the buffer that it points to. * * Examples: * data= H5TB_rem( tree, H5TB_dfind(tree,key), &kp ); free(data); free(kp); * data= H5TB_rem( &root, H5TB_find(root,key,compar,arg), NULL ); * data= H5TB_rem( &tree->root, H5TB_dfind(tree,key), NULL ); * * Return: Success: Pointer to data item deleted * Failure: NULL * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * * WARNING!!! * * H5TB_rem() may not delete the node specified in its parameter * list -- if the target node is internal, it may swap data with a * leaf node and delete the leaf instead. * * This implies that any pointer to a node in the supplied tree may be * invalid after this functions returns. Thus any function retaining * such pointers over a call to H5TB_rem() should either discard, or * refresh them. * * JRM - 4/9/04 * *------------------------------------------------------------------------- */ void * H5TB_rem(H5TB_NODE ** root, H5TB_NODE * node, void * *kp) { H5TB_NODE *leaf; /* Node with one or zero children */ H5TB_NODE *par; /* Parent of `leaf' */ H5TB_NODE *next; /* Next/prev node near `leaf' (`leaf's `side' thread) */ int side; /* `leaf' is `side' child of `par' */ void * data; /* Saved pointer to data item of deleted node */ void *ret_value; /* Return value */ FUNC_ENTER_NOAPI(H5TB_rem, NULL); if (NULL == root || NULL == node) HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, NULL, "bad arguments to delete"); data = node->data; /* Save pointer to data item to be returned at end */ if (NULL != kp) *kp = node->key; /* If the node to be removed is "internal" (children on both sides), we * replace it with it's previous (or next) node in the tree and delete that * previous (next) node (which has one or no children) instead. */ /* Replace with a non-internal node: */ if (Intern(node)) { /* Pick "near-leaf" node from the */ if (Heavy(node, RIGHT)) { side = LEFT; /* heavier of the sub-trees. */ } else if (Heavy(node, LEFT)) { side = RIGHT; } /* If no sub-tree heavier, pick at "random" for "better balance" */ else { side = (0x10 & *(short *) &node) ? LEFT : RIGHT; /* balance" */ } leaf = H5TB_nbr(next = node, Other(side)); par = leaf->Parent; /* Case 2x: `node' had exactly 2 descendants */ if (par == next) { side = Other(side); /* Transform this to Case 2 */ next = leaf->link[side]; } node->data = leaf->data; node->key = leaf->key; } /* end if */ /* Node has one or zero children: */ else { leaf = node; /* Simply remove THIS node */ par = leaf->Parent; /* Case 3: Remove root (of 1- or 2-node tree) */ if (NULL == par) { side = (int) UnBal(node); /* Which side root has a child on */ /* Case 3a: Remove root of 2-node tree: */ if (side) { *root = leaf = node->link[side]; leaf->Parent = leaf->link[Other(side)] = NULL; leaf->flags = 0; /* No left children, balanced, not internal */ } /* Case 3b: Remove last node of tree: */ else { *root = NULL; } /* end else */ H5FL_FREE(H5TB_NODE,node); HGOTO_DONE(data); } side = (par->Rchild == leaf) ? RIGHT : LEFT; next = leaf->link[side]; } /* end else */ /* Now the deletion has been reduced to the following cases (and Case 3 has * been handled completely above and Case 2x has been transformed into * Case 2). `leaf' is a node with one or zero children that we are going * to remove. `next' points where the `side' thread of `leaf' points. * `par' is the parent of `leaf'. The only posibilities (not counting * left/right reversals) are shown below: * [Case 1] [Case 2] [Case 2x] * (next) (next) ^ (next & par) * / ^ \ / ^ \ | / ^ \ * . . . | . . . | | (leaf) / * / | / | \_/ \_/ * (par) | (par) | ^threads^ * \ | \ | * (leaf) / (leaf) / [Case 3a] [Case 3b] * / ^ \_/ (n) * Note that in Cases 1 and 2, `leaf's `side' thread can be NULL making * `next' NULL as well. If you remove a node from a 2-node tree, removing * the root falls into Case 3a while removing the only leaf falls into * Case 2 (with `next' NULL and `par' the root node). */ /* Case 2: `leaf' has no children: */ if (!UnBal(leaf)) { par->link[side] = leaf->link[side]; par->flags &= (H5TB_flag)(~(H5TB_INTERN | H5TB_HEAVY(side))); } /* end if */ /* Case 1: `leaf' has one child: */ else { H5TB_NODE *n; /* two-in-a-row cases */ if (HasChild(leaf, side)) { n = leaf->link[side]; par->link[side] = n; n->Parent = par; if (HasChild(n, Other(side))) while (HasChild(n, Other(side))) n = n->link[Other(side)]; n->link[Other(side)] = par; } /* end if */ /* zig-zag cases */ else { n = leaf->link[Other(side)]; par->link[side] = n; n->Parent = par; if (HasChild(n, side)) while (HasChild(n, side)) n = n->link[side]; n->link[side] = next; } /* end else */ } /* end else */ H5FL_FREE(H5TB_NODE,leaf); H5TB_balance(root, par, side, -1); /* Set return value */ ret_value=data; done: if(ret_value) ((H5TB_TREE *) root)->count--; FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_rem() */ /*------------------------------------------------------------------------- * Function: H5TB_dfree * * Purpose: Frees up an entire tree. `fd' is a pointer to a function that * frees/destroys data items, and `fk' is the same for key values. * void free(); * tree= tbbtdfree( tree, free, free ); * H5TB_free( &root, free, free ); * is a typical usage, where keys and data are individually malloc()d. If `fk' * is NULL, no action is done for the key values (they were allocated on the * stack, as a part of each data item, or together with one malloc() call, for * example) and likewise for `fd'. H5TB_dfree() always returns NULL and * H5TB_free() always sets `root' to be NULL. * * Return: Always returns NULL * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * *------------------------------------------------------------------------- */ H5TB_TREE * H5TB_dfree(H5TB_TREE * tree, void(*fd) (void * /* item */), void(*fk) (void * /* key */)) { H5TB_TREE *ret_value=NULL; /* Return value */ FUNC_ENTER_NOAPI_NOFUNC(H5TB_dfree); if (tree != NULL) { /* Free the actual tree */ H5TB_free(&tree->root, fd, fk); /* Free the tree root */ H5FL_FREE(H5TB_TREE,tree); } /* end if */ FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_dfree() */ /*------------------------------------------------------------------------- * Function: H5TB_free * * Purpose: Frees up an entire tree. `fd' is a pointer to a function that * frees/destroys data items, and `fk' is the same for key values. * void free(); * tree= tbbtdfree( tree, free, free ); * H5TB_free( &root, free, free ); * is a typical usage, where keys and data are individually malloc()d. If `fk' * is NULL, no action is done for the key values (they were allocated on the * stack, as a part of each data item, or together with one malloc() call, for * example) and likewise for `fd'. H5TB_dfree() always returns NULL and * H5TB_free() always sets `root' to be NULL. * * Return: Always returns NULL * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * *------------------------------------------------------------------------- */ void * H5TB_free(H5TB_NODE ** root, void(*fd) (void * /* item */), void(*fk) (void * /* key */)) { H5TB_NODE *par, *node = *root; void *ret_value=NULL; /* Return value */ FUNC_ENTER_NOAPI_NOFUNC(H5TB_free); /* While nodes left to be free()d */ while (NULL != *root) { /* First time at this node (just moved down a new leg of tree) */ if (!HasChild(node, LEFT)) node->Lchild = NULL; if (!HasChild(node, RIGHT)) node->Rchild = NULL; do { par = NULL; /* Assume we aren't ready to move up tree yet */ if (NULL != node->Lchild) node = node->Lchild; /* Move down this leg next */ else if (NULL != node->Rchild) node = node->Rchild; /* Move down this leg next */ /* No children; free node an move up: */ else { par = node->Parent; /* Move up tree (stay in loop) */ if (NULL != fd) (*fd) (node->data); if (NULL != fk) (*fk) (node->key); if (NULL == par) /* Just free()d last node */ *root = NULL; /* NULL=par & NULL=*root gets fully out */ else if (node == par->Lchild) par->Lchild = NULL; /* Now no longer has this child */ else par->Rchild = NULL; /* Ditto */ H5FL_FREE(H5TB_NODE,node); node = par; /* Move up tree; remember which node to do next */ } /* end else */ } while (NULL != par); /* While moving back up tree */ } /* end while */ FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_free() */ /*------------------------------------------------------------------------- * Function: H5TB_count * * Purpose: Returns the number of nodes in a tree * * Return: Success - Number of nodes in the tree * Failure - Negative value * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * *------------------------------------------------------------------------- */ long H5TB_count(H5TB_TREE * tree) { long ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOFUNC(H5TB_count); /* Set return value */ ret_value= (tree==NULL) ? FAIL : (long)tree->count; FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_count() */ #ifdef H5TB_DEBUG /*------------------------------------------------------------------------- * Function: H5TB_dump * * Purpose: Prints out information about an entire tree. * The 'method' variable determines which sort of traversal is used: * -1 : Pre-Order Traversal * 1 : Post-Order Traversal * 0 : In-Order Traversal * * Return: Shouldn't fail * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * *------------------------------------------------------------------------- */ herr_t H5TB_dump(H5TB_TREE *tree, void (*key_dump)(void *,void *), int method) { FUNC_ENTER_NOAPI_NOFUNC(H5TB_dump); printf("H5TB-tree dump %p:\n",tree); printf("capacity = %ld\n\n",(long)tree->count); H5TB_dumpNode(tree->root,key_dump, method); FUNC_LEAVE_NOAPI(SUCCESS); } /* end H5TB_dump() */ /*------------------------------------------------------------------------- * Function: H5TB_printNode * * Purpose: Prints out information about a node in the tree * * Return: Shouldn't fail * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * *------------------------------------------------------------------------- */ static herr_t H5TB_printNode(H5TB_NODE * node, void(*key_dump)(void *,void *)) { herr_t ret_value=SUCCEED; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_printNode); if (node == NULL) { printf("ERROR: null node pointer\n"); HGOTO_DONE(FAIL); } printf("node=%p, key=%p, data=%p, flags=%x\n", node, node->key, node->data, (unsigned) node->flags); printf("Lcnt=%d, Rcnt=%d\n", (int) node->lcnt, (int) node->rcnt); printf("Lchild=%p, Rchild=%p, Parent=%p\n", node->Lchild, node->Rchild, node->Parent); if (key_dump != NULL) (*key_dump)(node->key,node->data); done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_printNode() */ /*------------------------------------------------------------------------- * Function: H5TB_dumpNode * * Purpose: Internal routine to actually dump tree * The 'method' variable determines which sort of traversal is used: * -1 : Pre-Order Traversal * 1 : Post-Order Traversal * 0 : In-Order Traversal * * Return: Shouldn't fail * * Programmer: Quincey Koziol * Friday, May 6, 2000 * * Modifications: * * Notes: * *------------------------------------------------------------------------- */ static herr_t H5TB_dumpNode(H5TB_NODE *node, void (*key_dump)(void *,void *), int method) { herr_t ret_value=SUCCEED; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_dumpNode); if (node == NULL) HGOTO_DONE(FAIL); switch (method) { case -1: /* Pre-Order Traversal */ H5TB_printNode(node, key_dump); if (HasChild(node, LEFT)) H5TB_dumpNode(node->Lchild, key_dump, method); if (HasChild(node, RIGHT)) H5TB_dumpNode(node->Rchild, key_dump, method); break; case 1: /* Post-Order Traversal */ if (HasChild(node, LEFT)) H5TB_dumpNode(node->Lchild, key_dump, method); if (HasChild(node, RIGHT)) H5TB_dumpNode(node->Rchild, key_dump, method); H5TB_printNode(node, key_dump); break; case 0: /* In-Order Traversal */ default: if (HasChild(node, LEFT)) H5TB_dumpNode(node->Lchild, key_dump, method); H5TB_printNode(node, key_dump); if (HasChild(node, RIGHT)) H5TB_dumpNode(node->Rchild, key_dump, method); break; } /* end switch() */ done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_dumpNode() */ #endif /* H5TB_DEBUG */ /*------------------------------------------------------------------------- * Function: H5TB_end * * Purpose: Returns pointer to end-most (to LEFT or RIGHT) node of tree: * * Return: Success: Valid pointer * Failure: NULL * * Programmer: Quincey Koziol * Saturday, April 22, 2000 * * Modifications: * *------------------------------------------------------------------------- */ H5TB_NODE * H5TB_end(H5TB_NODE * root, int side) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_end); assert(side==LEFT || side==RIGHT); if(root) while (HasChild(root, side)) root = root->link[side]; FUNC_LEAVE_NOAPI(root); } /* end H5TB_end() */ /* Returns pointer to neighboring node (to LEFT or RIGHT): */ H5TB_NODE * H5TB_nbr(H5TB_NODE * ptr, int side) { H5TB_NODE *ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_nbr); if (!HasChild(ptr, side)) HGOTO_DONE (ptr->link[side]); ptr = ptr->link[side]; if(ptr==NULL) HGOTO_DONE(NULL); while (HasChild(ptr, Other(side))) ptr = ptr->link[Other(side)]; /* Set return value */ ret_value=ptr; done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5TB_nbr() */ /* H5TB_ffind -- Look up a node in a tree based on a key value */ /* This routine is based on tbbtfind (fix bugs in both places!) */ /* Returns a pointer to the found node (or NULL) */ static H5TB_NODE * H5TB_ffind(H5TB_NODE * ptr, const void * key, unsigned fast_compare, H5TB_NODE ** pp) { H5TB_NODE *parent = NULL; FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_ffind); if(ptr) { switch(fast_compare) { case H5TB_FAST_HADDR_COMPARE: { haddr_t key_val=*(const haddr_t *)key; while (key_val != *(haddr_t *)ptr->key) { parent = ptr; if(key_val < *(haddr_t *)ptr->key) { if(!LeftCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[LEFT]; } /* end if */ else { if(!RightCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[RIGHT]; } /* end else */ } /* end while */ } /* end case */ break; case H5TB_FAST_INTN_COMPARE: { int key_val=*(const int *)key; while (key_val != *(int *)ptr->key) { parent = ptr; if(key_val < *(int *)ptr->key) { if(!LeftCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[LEFT]; } /* end if */ else { if(!RightCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[RIGHT]; } /* end else */ } /* end while */ } /* end case */ break; case H5TB_FAST_STR_COMPARE: { int cmp; while (0 != (cmp = HDstrcmp(key,ptr->key))) { parent = ptr; if(cmp<0) { if(!LeftCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[LEFT]; } /* end if */ else { if(!RightCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[RIGHT]; } /* end else */ } /* end while */ } /* end case */ break; case H5TB_FAST_HSIZE_COMPARE: { hsize_t key_val=*(const hsize_t *)key; while (key_val != *(hsize_t *)ptr->key) { parent = ptr; if(key_val < *(hsize_t *)ptr->key) { if(!LeftCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[LEFT]; } /* end if */ else { if(!RightCnt(ptr)) { ptr=NULL; break; } /* end if */ ptr = ptr->link[RIGHT]; } /* end else */ } /* end while */ } /* end case */ break; default: assert("invalid fast compare type" && 0); break; } /* end switch */ } /* end if */ if (NULL != pp) *pp = parent; FUNC_LEAVE_NOAPI(ptr); } /* H5TB_ffind() */ /* swapkid -- Often refered to as "rotating" nodes. ptr and ptr's `side' * child, kid, are swapped so ptr becomes kid's `Other(side)' child. * Here is how a single swap (rotate) works: * * | --side--> | * (ptr) (kid) * / \ / \ * +-A-+ (kid) (ptr) +-C-+ * | | / \ / \ | | * |...| +-B-+ +-C-+ +-A-+ +-B-+ |...| * | | | | | | | | * |...| |...| |...| |...| * `deep' contains the relative depths of the subtrees so, since we set * `deep[1]' (the relative depth of subtree [B]) to 0, `deep[2]' is the depth * of [C] minus the depth of [B] (-1, 0, or 1 since `kid' is never too out of * balance) and `deep[0]' is the depth of [A] minus the depth of [B]. These * values are used to compute the balance levels after the rotation. Note that * [A], [B], or [C] can have depth 0 so `link[]' contains threads rather than * pointers to children. */ static H5TB_NODE * H5TB_swapkid(H5TB_NODE ** root, H5TB_NODE * ptr, int side) { H5TB_NODE *kid = ptr->link[side]; /* Sibling to be swapped with parent */ int deep[3]; /* Relative depths of three sub-trees involved. */ /* 0:ptr->link[Other(side)], 1:kid->link[Other(side)], 2:kid->link[side] */ H5TB_flag ptrflg; /* New value for ptr->flags (ptr->flags used after set) */ H5TB_leaf plcnt, prcnt, /* current values of the ptr's and kid's leaf count */ klcnt, krcnt; FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_swapkid); deep[2] = (deep[1] = 0) + Delta(kid, side); deep[0] = Max(0, deep[2]) + 1 - Delta(ptr, side); kid->Parent = ptr->Parent; ptrflg = (H5TB_flag)SetFlags(ptr, side, deep[0], HasChild(ptr, Other(side)) && HasChild(kid, Other(side))); plcnt = LeftCnt(ptr); prcnt = RightCnt(ptr); klcnt = LeftCnt(kid); krcnt = RightCnt(kid); if (HasChild(kid, Other(side))) { ptr->link[side] = kid->link[Other(side)]; /* Real child */ ptr->link[side]->Parent = ptr; } else { ptr->link[side] = kid; /* Thread */ } /* Update grand parent's pointer: */ if (NULL == ptr->Parent) { *root = kid; } else if (ptr /*->Lchild*/ == ptr->Parent->Lchild) { ptr->Parent->Lchild = kid; } else { ptr->Parent->Rchild = kid; } ptr->Parent = kid; kid->link[Other(side)] = ptr; kid->flags = (H5TB_flag)SetFlags(kid, Other(side), deep[2] - 1 - Max(deep[0], 0), HasChild(kid, side)); /* update leaf counts */ if (side == LEFT) { /* kid's left count doesn't change, nor ptr's r-count */ kid->rcnt = prcnt + krcnt + 1; /* kid's leafs+former parent's leafs+parent */ ptr->lcnt = krcnt; } /* end if */ else { /* kid's right count doesn't change, nor ptr's l-count */ kid->lcnt = plcnt + klcnt + 1; /* kid's leafs+former parent's leafs+parent */ ptr->rcnt = klcnt; } /* end if */ ptr->flags = ptrflg; FUNC_LEAVE_NOAPI(kid); } /* end H5TB_swapkid() */ /* balance -- Move up tree, incrimenting number of left children when needed * and looking for unbalanced ancestors. Adjust all balance factors and re- * balance through "rotation"s when needed. */ /* Here is how rotatation rebalances a tree: * Either the deletion of a node shortened the sub-tree [A] (to length `h') * while [B] or [C] or both are length `h+1' or the addition of a node * lengthened [B] or [C] to length `h+1' while the other and [A] are both * length `h'. Each case changes `ptr' from being "right heavy" to being * overly unbalanced. * This | Becomes: | * sub-tree: (ptr) (kid) * / \ --side--> / \ * +-A-+ (kid) (ptr) +-C-+ * | | / \ / \ | | * | h | +-B-+ +-C-+ +-A-+ +-B-+ | h | * | | | | | | | | | | | | * +---+ | h | | h | | h | | h | +---+ * : - : | | | | | | | | : 1 : * `- -' +---+ +---+ +---+ +---+ + - + * : 1 : : 1 : : 1 : * + - + + - + + - + * * However, if [B] is long (h+1) while [C] is short (h), a double rotate is * required to rebalance. In this case, [A] was shortened or [X] or [Y] was * lengthened so [A] is length `h' and one of [X] and [Y] is length `h' while * the other is length `h-1'. Swap `kid' with `babe' then `ptr' with `babe'. * This | Becomes: | * sub-tree: (ptr) (babe) * / \ --side--> / \ * +-A-+ (kid) (ptr) (kid) * | | / \ / \ / \ * | h | (babe) +-C-+ +-A-+ +-X-+ +-Y-+ +-C-+ * | | / \ | | | | |h-1| |h-1| | | * +---+ +-X-+ +-Y-+ | h | | h | +---+ +---+ | h | * : - : |h-1| |h-1| | | | | : 1 : : 1 : | | * `- -' +---+ +---+ +---+ +---+ + - + + - + +---+ * : 1 : : 1 : * + - + + - + * * Note that in the node insertion cases total sub-tree length always increases * by one then decreases again so after the rotation(s) no more rebalancing is * required. In the node removal cases, the single rotation reduces total sub- * tree length unless [B] is length `h+1' (`ptr' ends of "right heavy") while * the double rotation ALWAYS reduces total sub-tree length. Thus removing a * single node can require log(N) rotations for rebalancing. On average, only * are usually required. */ static herr_t H5TB_balance(H5TB_NODE ** root, H5TB_NODE * ptr, int side, int added) { int deeper = added; /* 1 if sub-tree got longer; -1 if got shorter */ int odelta; int obal; FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5TB_balance); while (NULL != ptr) { odelta = Delta(ptr, side); /* delta before the node was added */ obal = UnBal(ptr); if (LEFT == side) /* One more/fewer left child: */ if (0 < added) ptr->lcnt++; /* LeftCnt(ptr)++ */ else ptr->lcnt--; /* LeftCnt(ptr)-- */ else if (0 < added) ptr->rcnt++; /* RightCnt(ptr)++ */ else ptr->rcnt--; /* RightCnt(ptr)-- */ if (0 != deeper) { /* One leg got longer or shorter: */ if ((deeper < 0 && odelta < 0) || (deeper > 0 && odelta > 0)) { /* Became too unbalanced: */ H5TB_NODE *kid; ptr->flags |= H5TB_DOUBLE; /* Mark node too unbalanced */ if (deeper < 0) /* Just removed a node: */ side = Other(side); /* Swap with child from other side. */ else /* Just inserted a node: */ if (ptr->Parent && UnBal(ptr->Parent)) { deeper = 0; /* Fix will re-shorten sub-tree. */ } kid = ptr->link[side]; if (Heavy(kid, Other(side))) { /* Double rotate needed: */ kid = H5TB_swapkid(root, kid, Other(side)); ptr = H5TB_swapkid(root, ptr, side); } else { /* Just rotate parent and kid: */ if (HasChild(kid, side)) /* In this case, sub-tree gets */ if (ptr->Parent && UnBal(ptr->Parent)) { deeper = 0; /* re-lengthened after a node removed. */ } ptr = H5TB_swapkid(root, ptr, side); } } else if (obal) { /* Just became balanced: */ ptr->flags &= ~H5TB_UNBAL; if (0 < deeper) { /* Shorter of legs lengthened */ ptr->flags |= H5TB_INTERN; /* Mark as internal node now */ deeper = 0; /* so max length unchanged */ } /* end if */ } else if (deeper < 0) { /* Just became unbalanced: */ if (ptr->link[Other(side)] != NULL && ptr->link[Other(side)]->Parent == ptr) { ptr->flags |= (H5TB_flag)H5TB_HEAVY(Other(side)); /* Other side longer */ if (ptr->Parent) { if (ptr->Parent->Rchild == ptr) { /* we're the right child */ if (Heavy(ptr->Parent, RIGHT) && LeftCnt(ptr->Parent) == 1) { deeper = 0; } else { /* we're the left child */ if (Heavy(ptr->Parent, LEFT)) { if (ptr->Parent->Rchild && !UnBal(ptr->Parent->Rchild)) { deeper = 0; } } } } } } } else { /* Just became unbalanced: */ ptr->flags |= (H5TB_flag)H5TB_HEAVY(side); /* 0Parent) { if (ptr == (ptr->Parent->Rchild)) side = RIGHT; else side = LEFT; } /* end if */ ptr = ptr->Parent; /* Move up the tree */ } /* total tree depth += deeper; */ FUNC_LEAVE_NOAPI(SUCCEED); } /* end H5TB_balance() */