/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 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. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* * Purpose: Provides a skip list abstract data type. * * (See "Skip Lists: A Probabilistic Alternative to Balanced Trees" * by William Pugh for additional information) * * (This implementation has the optimization for reducing key * key comparisons mentioned in section 3.5 of "A Skip List * Cookbook" by William Pugh) * * (Also, this implementation has a couple of home-grown * optimizations, including setting the "update" vector to the * actual 'forward' pointer to update, instead of the node * containing the forward pointer -QAK) * * (Note: This implementation does not have the information for * implementing the "Linear List Operations" (like insert/delete/ * search by position) in section 3.4 of "A Skip List Cookbook", * but they shouldn't be that hard to add, if necessary) * * (This implementation has an additional backward pointer, which * allows the list to be iterated in reverse) * * (We should also look into "Deterministic Skip Lists" (see * paper by Munro, Papadakis & Sedgewick)) * * (There's also an article on "Alternating Skip Lists", which * are similar to deterministic skip lists, in the August 2000 * issue of Dr. Dobb's Journal) * */ /* Interface initialization */ #define H5_INTERFACE_INIT_FUNC H5SL_init_interface /* Private headers needed */ #include "H5private.h" /* Generic Functions */ #include "H5Eprivate.h" /* Error handling */ #include "H5FLprivate.h" /* Free Lists */ #include "H5MMprivate.h" /* Memory management */ #include "H5SLprivate.h" /* Skip list routines */ /* Local Macros */ /* Define the code template for insertions for the "OP" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_INSERT_FOUND(SLIST,X,UPDATE,I,ITEM) \ HGOTO_ERROR(H5E_SLIST,H5E_CANTINSERT,NULL,"can't insert duplicate key"); /* Define the code template for removals for the "OP" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_REMOVE_FOUND(SLIST,X,UPDATE,I,ITEM) \ void *tmp; \ \ for(I=0; I<=(int)SLIST->curr_level; I++) { \ if(*UPDATE[I]!=X) \ break; \ *UPDATE[I]=X->forward[I]; \ } /* end for */ \ if(SLIST->last==X) \ SLIST->last=X->backward; \ else \ X->forward[0]->backward=X->backward; \ tmp=X->item; \ H5MM_xfree(X); \ while(SLIST->curr_level>0 && SLIST->header->forward[SLIST->curr_level]==NULL) \ SLIST->curr_level--; \ SLIST->nobjs--; \ HGOTO_DONE(tmp); /* Define the code template for searches for the "OP" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_SEARCH_FOUND(SLIST,X,UPDATE,I,ITEM) \ HGOTO_DONE(X->item); /* Define the code template for finds for the "OP" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_FIND_FOUND(SLIST,X,UPDATE,I,ITEM) \ HGOTO_DONE(X); /* Define a code template for updating the "update" vector for the "DOUPDATE" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_YES_UPDATE(X,UPDATE,I) \ UPDATE[I]=&X->forward[I]; /* Define a code template for _NOT_ updating the "update" vector for the "DOUPDATE" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_NO_UPDATE(X,UPDATE,I) /* Define a code template for comparing scalar keys for the "CMP" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_SCALAR_CMP(TYPE,PKEY1,PKEY2) \ (*(TYPE *)PKEY1<*(TYPE *)PKEY2) /* Define a code template for comparing string keys for the "CMP" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_STRING_CMP(TYPE,PKEY1,PKEY2) \ (HDstrcmp(PKEY1,PKEY2)<0) /* Define a code template for comparing scalar keys for the "EQ" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_SCALAR_EQ(TYPE,PKEY1,PKEY2) \ (*(TYPE *)PKEY1==*(TYPE *)PKEY2) /* Define a code template for comparing string keys for the "EQ" in the H5SL_LOCATE macro */ #define H5SL_LOCATE_STRING_EQ(TYPE,PKEY1,PKEY2) \ (HDstrcmp(PKEY1,PKEY2)==0) /* Macro used to find node for operation */ #define H5SL_LOCATE(OP,DOUPDATE,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) \ CHECKED=NULL; \ for(I=(int)SLIST->curr_level; I>=0; I--) { \ if(X->forward[I]!=CHECKED) { \ while(X->forward[I] && H5_GLUE3(H5SL_LOCATE_,CMP,_CMP)(TYPE,X->forward[I]->key,KEY) ) \ X=X->forward[I]; \ CHECKED=X->forward[I]; \ } /* end if */ \ H5_GLUE3(H5SL_LOCATE_,DOUPDATE,_UPDATE)(X,UPDATE,I) \ } /* end for */ \ X=X->forward[0]; \ if(X!=NULL && H5_GLUE3(H5SL_LOCATE_,CMP,_EQ)(TYPE,X->key,KEY) ) { \ /* What to do when a node is found */ \ H5_GLUE3(H5SL_LOCATE_,OP,_FOUND)(SLIST,X,UPDATE,I,ITEM) \ } /* end if */ /* Macro used to insert node */ #define H5SL_INSERT(CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) \ H5SL_LOCATE(INSERT,YES,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) /* Macro used to remove node */ #define H5SL_REMOVE(CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) \ H5SL_LOCATE(REMOVE,YES,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) /* Macro used to search for node */ #define H5SL_SEARCH(CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) \ H5SL_LOCATE(SEARCH,NO,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) /* Macro used to find a node */ #define H5SL_FIND(CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) \ H5SL_LOCATE(FIND,NO,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) /* Private typedefs & structs */ /* Skip list node data structure */ struct H5SL_node_t { const void *key; /* Pointer to node's key */ void *item; /* Pointer to node's item */ size_t level; /* The level of this node */ struct H5SL_node_t **forward; /* Array of forward pointers from this node */ struct H5SL_node_t *backward; /* Backward pointer from this node */ }; /* Main skip list data structure */ struct H5SL_t { /* Static values for each list */ H5SL_type_t type; /* Type of skip list */ double p; /* Probability of using a higher level [0..1) */ int p1; /* Probability converted into appropriate value for random # generator on this machine */ size_t max_level; /* Maximum number of levels */ /* Dynamic values for each list */ int curr_level; /* Current top level used in list */ size_t nobjs; /* Number of active objects in skip list */ H5SL_node_t *header; /* Header for nodes in skip list */ H5SL_node_t *last; /* Pointer to last node in skip list */ }; /* Static functions */ static size_t H5SL_random_level(int p1, size_t max_level); static H5SL_node_t * H5SL_new_node(size_t lvl, void *item, const void *key); static H5SL_node_t *H5SL_insert_common(H5SL_t *slist, void *item, const void *key); static herr_t H5SL_release_common(H5SL_t *slist, H5SL_operator_t op, void *op_data); static herr_t H5SL_close_common(H5SL_t *slist, H5SL_operator_t op, void *op_data); /* Declare a free list to manage the H5SL_t struct */ H5FL_DEFINE_STATIC(H5SL_t); /*-------------------------------------------------------------------------- NAME H5SL_init_interface PURPOSE Initialize interface-specific information USAGE herr_t H5SL_init_interface() RETURNS Non-negative on success/Negative on failure DESCRIPTION Initializes any interface-specific data or routines. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ static herr_t H5SL_init_interface(void) { time_t curr_time; /* Current time, for seeding random number generator */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_init_interface) /* Create randomized set of numbers */ curr_time=HDtime(NULL); HDsrand((unsigned)curr_time); FUNC_LEAVE_NOAPI(SUCCEED) } /* end H5SL_init_interface() */ /*-------------------------------------------------------------------------- NAME H5SL_random_level PURPOSE Generate a random level USAGE size_t H5SL_random_level(p,max_level) int p1; IN: probability distribution size_t max_level; IN: Maximum level for node height RETURNS Returns non-negative level value DESCRIPTION Count elements in a skip list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS Do we really need a 'random' value, or is a series of nodes with the correct heights "good enough". We could track the state of the nodes allocated for this list and issue node heights appropriately (i.e. 1,2, 1,4,1,2,1,8,...) (or would that be 1,1,2,1,1,2,4,... ?) EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ static size_t H5SL_random_level(int p1, size_t max_level) { size_t lvl; /* Level generated */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_random_level); /* Account for starting at zero offset */ max_level--; lvl=0; while(HDrand()key=key; ret_value->item=item; ret_value->level=lvl; ret_value->forward=(H5SL_node_t **)((unsigned char *)ret_value+sizeof(H5SL_node_t)); done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_new_node() */ /*-------------------------------------------------------------------------- NAME H5SL_insert_common PURPOSE Common code for inserting an object into a skip list USAGE H5SL_node_t *H5SL_insert_common(slist,item,key) H5SL_t *slist; IN/OUT: Pointer to skip list void *item; IN: Item to insert void *key; IN: Key for item to insert RETURNS Returns pointer to new node on success, NULL on failure. DESCRIPTION Common code for inserting an element into a skip list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS Inserting an item with the same key as an existing object fails. EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ static H5SL_node_t * H5SL_insert_common(H5SL_t *slist, void *item, const void *key) { H5SL_node_t **update[H5SL_LEVEL_MAX]; /* 'update' vector */ H5SL_node_t *checked; /* Pointer to last node checked */ H5SL_node_t *x; /* Current node to examine */ size_t lvl; /* Level of new node */ int i; /* Local index value */ H5SL_node_t *ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOINIT(H5SL_insert_common); /* Check args */ assert(slist); assert(key); /* Check internal consistency */ /* (Pre-condition) */ /* Insert item into skip list */ /* Work through the forward pointers for a node, finding the node at each * level that is before the location to insert */ x=slist->header; switch(slist->type) { case H5SL_TYPE_INT: H5SL_INSERT(SCALAR,slist,x,update,i,const int,item,key,checked) break; case H5SL_TYPE_HADDR: H5SL_INSERT(SCALAR,slist,x,update,i,const haddr_t,item,key,checked) break; case H5SL_TYPE_STR: H5SL_INSERT(STRING,slist,x,update,i,char *,item,key,checked) break; case H5SL_TYPE_HSIZE: H5SL_INSERT(SCALAR,slist,x,update,i,const hsize_t,item,key,checked) break; case H5SL_TYPE_UNSIGNED: H5SL_INSERT(SCALAR,slist,x,update,i,const unsigned,item,key,checked) break; } /* end switch */ /* 'key' must not have been found in existing list, if we get here */ /* Generate level for new node */ lvl=H5SL_random_level(slist->p1,slist->max_level); if((int)lvl>slist->curr_level) { /* Cap the increase in the current level to just one greater */ lvl=slist->curr_level+1; /* Set the update pointer correctly */ update[lvl]=&slist->header->forward[lvl]; /* Increase the maximum level of the list */ slist->curr_level=(int)lvl; } /* end if */ /* Create new node of proper level */ if((x=H5SL_new_node(lvl,item,key))==NULL) HGOTO_ERROR(H5E_SLIST,H5E_NOSPACE,NULL,"can't create new skip list node"); /* Update the backward links */ if(*update[0]!=NULL) { x->backward=(*update[0])->backward; (*update[0])->backward=x; } /* end if */ else { HDassert(slist->last); x->backward=slist->last; slist->last=x; } /* end else */ /* Link the new node into the existing forward pointers */ for(i=0; i<=(int)lvl; i++) { x->forward[i]=*update[i]; *update[i]=x; } /* end for */ /* Increment the number of nodes in the skip list */ slist->nobjs++; /* Set return value */ ret_value=x; done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_insert_common() */ /*-------------------------------------------------------------------------- NAME H5SL_release_common PURPOSE Release all nodes from a skip list, optionally calling a 'free' operator USAGE herr_t H5SL_release_common(slist) H5SL_t *slist; IN/OUT: Pointer to skip list to release nodes H5SL_operator_t op; IN: Callback function to free item & key void *op_data; IN/OUT: Pointer to application data for callback RETURNS Returns non-negative on success, negative on failure. DESCRIPTION Release all the nodes in a skip list. The 'op' routine is called for each node in the list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS The return value from the 'op' routine is ignored. The skip list itself is still valid, it just has all its nodes removed. EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ herr_t H5SL_release_common(H5SL_t *slist, H5SL_operator_t op, void *op_data) { H5SL_node_t *node, *next_node; /* Pointers to skip list nodes */ size_t u; /* Local index variable */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_release_common); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ /* Free skip list nodes */ node=slist->header->forward[0]; while(node!=NULL) { next_node=node->forward[0]; /* Call callback, if one is given */ if(op!=NULL) (void)(op)(node->item,(void *)node->key,op_data); H5MM_xfree(node); node=next_node; } /* end while */ /* Reset the header pointers */ for(u=0; umax_level; u++) slist->header->forward[u]=NULL; /* Reset the last pointer */ slist->last=slist->header; /* Reset the dynamic internal fields */ slist->curr_level=-1; slist->nobjs=0; FUNC_LEAVE_NOAPI(SUCCEED); } /* end H5SL_release_common() */ /*-------------------------------------------------------------------------- NAME H5SL_close_common PURPOSE Close a skip list, deallocating it and potentially freeing all its nodes. USAGE herr_t H5SL_close_common(slist,op,opdata) H5SL_t *slist; IN/OUT: Pointer to skip list to close H5SL_operator_t op; IN: Callback function to free item & key void *op_data; IN/OUT: Pointer to application data for callback RETURNS Returns non-negative on success, negative on failure. DESCRIPTION Close a skip list, freeing all internal information. Any objects left in the skip list have the 'op' routine called for each. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS If the 'op' routine returns non-zero, only the nodes up to that point in the list are released and the list is still valid. EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ herr_t H5SL_close_common(H5SL_t *slist, H5SL_operator_t op, void *op_data) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_close_common); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ /* Free skip list nodes */ (void)H5SL_release_common(slist,op,op_data); /* always succeeds */ /* Release header node */ H5MM_xfree(slist->header); /* Free skip list object */ H5FL_FREE(H5SL_t,slist); FUNC_LEAVE_NOAPI(SUCCEED); } /* end H5SL_close_common() */ /*-------------------------------------------------------------------------- NAME H5SL_create PURPOSE Create a skip list USAGE H5SL_t *H5SL_create(void) RETURNS Returns a pointer to a skip list on success, NULL on failure. DESCRIPTION Create a skip list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ H5SL_t * H5SL_create(H5SL_type_t type, double p, size_t max_level) { H5SL_t *new_slist=NULL; /* Pointer to new skip list object created */ H5SL_node_t *header; /* Pointer to skip list header node */ size_t u; /* Local index variable */ H5SL_t *ret_value; /* Return value */ FUNC_ENTER_NOAPI(H5SL_create,NULL); /* Check args */ HDassert(p>0.0 && p<1.0); HDassert(max_level>0 && max_level<=H5SL_LEVEL_MAX); HDassert(type>=H5SL_TYPE_INT && type<=H5SL_TYPE_UNSIGNED); /* Allocate skip list structure */ if((new_slist=H5FL_MALLOC(H5SL_t))==NULL) HGOTO_ERROR(H5E_SLIST,H5E_NOSPACE,NULL,"memory allocation failed"); /* Set the static internal fields */ new_slist->type=type; new_slist->p=p; new_slist->p1=p*RAND_MAX; new_slist->max_level=max_level; /* Set the dynamic internal fields */ new_slist->curr_level=-1; new_slist->nobjs=0; /* Allocate the header node */ if((header=H5SL_new_node(max_level-1,NULL,NULL))==NULL) HGOTO_ERROR(H5E_SLIST,H5E_NOSPACE,NULL,"memory allocation failed"); /* Initialize header node's forward pointers */ for(u=0; uforward[u]=NULL; /* Initialize header node's backward pointer */ header->backward=NULL; /* Attach the header */ new_slist->header=header; new_slist->last=header; /* Set the return value */ ret_value=new_slist; done: /* Error cleanup */ if(ret_value==NULL) { if(new_slist!=NULL) { H5FL_FREE(H5SL_t,new_slist); } /* end if */ } /* end if */ FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_create() */ /*-------------------------------------------------------------------------- NAME H5SL_count PURPOSE Count the number of objects in a skip list USAGE size_t H5SL_count(slist) H5SL_t *slist; IN: Pointer to skip list to count RETURNS Returns number of objects on success, can't fail DESCRIPTION Count elements in a skip list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ size_t H5SL_count(H5SL_t *slist) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_count); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ FUNC_LEAVE_NOAPI(slist->nobjs); } /* end H5SL_count() */ /*-------------------------------------------------------------------------- NAME H5SL_insert PURPOSE Insert an object into a skip list USAGE herr_t H5SL_insert(slist,item,key) H5SL_t *slist; IN/OUT: Pointer to skip list void *item; IN: Item to insert void *key; IN: Key for item to insert RETURNS Returns non-negative on success, negative on failure. DESCRIPTION Insert element into a skip list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS Inserting an item with the same key as an existing object fails. EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ herr_t H5SL_insert(H5SL_t *slist, void *item, const void *key) { herr_t ret_value=SUCCEED; /* Return value */ FUNC_ENTER_NOAPI_NOINIT(H5SL_insert); /* Check args */ assert(slist); assert(key); /* Check internal consistency */ /* (Pre-condition) */ /* Insert item into skip list */ if(H5SL_insert_common(slist,item,key)==NULL) HGOTO_ERROR(H5E_SLIST,H5E_CANTINSERT,FAIL,"can't create new skip list node") done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_insert() */ /*-------------------------------------------------------------------------- NAME H5SL_add PURPOSE Insert an object into a skip list USAGE H5SL_node_t *H5SL_add(slist,item,key) H5SL_t *slist; IN/OUT: Pointer to skip list void *item; IN: Item to insert void *key; IN: Key for item to insert RETURNS Returns pointer to new skip list node on success, NULL on failure. DESCRIPTION Insert element into a skip list and return the skip list node for the new element in the list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS Inserting an item with the same key as an existing object fails. This routine is a useful starting point for next/prev calls EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ H5SL_node_t * H5SL_add(H5SL_t *slist, void *item, const void *key) { H5SL_node_t *ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOINIT(H5SL_add); /* Check args */ assert(slist); assert(key); /* Check internal consistency */ /* (Pre-condition) */ /* Insert item into skip list */ if((ret_value=H5SL_insert_common(slist,item,key))==NULL) HGOTO_ERROR(H5E_SLIST,H5E_CANTINSERT,NULL,"can't create new skip list node") done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_add() */ /*-------------------------------------------------------------------------- NAME H5SL_remove PURPOSE Removes an object from a skip list USAGE void *H5SL_remove(slist,key) H5SL_t *slist; IN/OUT: Pointer to skip list void *key; IN: Key for item to remove RETURNS Returns pointer to item removed on success, NULL on failure. DESCRIPTION Remove element from a skip list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ void * H5SL_remove(H5SL_t *slist, const void *key) { H5SL_node_t **update[H5SL_LEVEL_MAX]; /* 'update' vector */ H5SL_node_t *checked; /* Pointer to last node checked */ H5SL_node_t *x; /* Current node to examine */ int i; /* Local index value */ void *ret_value=NULL; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_remove); /* Check args */ assert(slist); assert(key); /* Check internal consistency */ /* (Pre-condition) */ /* Remove item from skip list */ /* Work through the forward pointers for a node, finding the node at each * level that is before the location to remove */ x=slist->header; switch(slist->type) { case H5SL_TYPE_INT: H5SL_REMOVE(SCALAR,slist,x,update,i,const int,-,key,checked) break; case H5SL_TYPE_HADDR: H5SL_REMOVE(SCALAR,slist,x,update,i,const haddr_t,-,key,checked) break; case H5SL_TYPE_STR: H5SL_REMOVE(STRING,slist,x,update,i,char *,-,key,checked) break; case H5SL_TYPE_HSIZE: H5SL_REMOVE(SCALAR,slist,x,update,i,const hsize_t,-,key,checked) break; case H5SL_TYPE_UNSIGNED: H5SL_REMOVE(SCALAR,slist,x,update,i,const unsigned,-,key,checked) break; } /* end switch */ done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_remove() */ /*-------------------------------------------------------------------------- NAME H5SL_search PURPOSE Search for object in a skip list USAGE void *H5SL_search(slist,key) H5SL_t *slist; IN/OUT: Pointer to skip list void *key; IN: Key for item to search for RETURNS Returns pointer to item on success, NULL on failure DESCRIPTION Search for an object in a skip list, according to it's key GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ void * H5SL_search(H5SL_t *slist, const void *key) { H5SL_node_t *checked; /* Pointer to last node checked */ H5SL_node_t *x; /* Current node to examine */ int i; /* Local index value */ void *ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_search); /* Check args */ assert(slist); assert(key); /* Check internal consistency */ /* (Pre-condition) */ /* Insert item into skip list */ /* Work through the forward pointers for a node, finding the node at each * level that is before the location to insert */ x=slist->header; switch(slist->type) { case H5SL_TYPE_INT: H5SL_SEARCH(SCALAR,slist,x,-,i,const int,-,key,checked) break; case H5SL_TYPE_HADDR: H5SL_SEARCH(SCALAR,slist,x,-,i,const haddr_t,-,key,checked) break; case H5SL_TYPE_STR: H5SL_SEARCH(STRING,slist,x,-,i,char *,-,key,checked) break; case H5SL_TYPE_HSIZE: H5SL_SEARCH(SCALAR,slist,x,-,i,const hsize_t,-,key,checked) break; case H5SL_TYPE_UNSIGNED: H5SL_SEARCH(SCALAR,slist,x,-,i,const unsigned,-,key,checked) break; } /* end switch */ /* 'key' must not have been found in list, if we get here */ ret_value=NULL; done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_search() */ /*-------------------------------------------------------------------------- NAME H5SL_less PURPOSE Search for object in a skip list that is less than or equal to 'key' USAGE void *H5SL_less(slist,key) H5SL_t *slist; IN/OUT: Pointer to skip list void *key; IN: Key for item to search for RETURNS Returns pointer to item who key is less than or equal to 'key' on success, NULL on failure DESCRIPTION Search for an object in a skip list, according to it's key, returning the object itself (for an exact match), or the object with the next highest key that is less than 'key' GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ void * H5SL_less(H5SL_t *slist, const void *key) { H5SL_node_t *checked; /* Pointer to last node checked */ H5SL_node_t *x; /* Current node to examine */ int i; /* Local index value */ void *ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_less); /* Check args */ assert(slist); assert(key); /* Check internal consistency */ /* (Pre-condition) */ /* Insert item into skip list */ /* Work through the forward pointers for a node, finding the node at each * level that is before the location to insert */ x=slist->header; switch(slist->type) { case H5SL_TYPE_INT: H5SL_SEARCH(SCALAR,slist,x,-,i,const int,-,key,checked) break; case H5SL_TYPE_HADDR: H5SL_SEARCH(SCALAR,slist,x,-,i,const haddr_t,-,key,checked) break; case H5SL_TYPE_STR: H5SL_SEARCH(STRING,slist,x,-,i,char *,-,key,checked) break; case H5SL_TYPE_HSIZE: H5SL_SEARCH(SCALAR,slist,x,-,i,const hsize_t,-,key,checked) break; case H5SL_TYPE_UNSIGNED: H5SL_SEARCH(SCALAR,slist,x,-,i,const unsigned,-,key,checked) break; } /* end switch */ /* An exact match for 'key' must not have been found in list, if we get here */ /* Check for a node with a key that is less than the given 'key' */ if(x==NULL) { /* Check for walking off the list */ if(slist->last!=slist->header) ret_value=slist->last->item; else ret_value=NULL; } /* end if */ else { if(x->backward!=slist->header) ret_value=x->backward->item; else ret_value=NULL; } /* end else */ done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_less() */ /*-------------------------------------------------------------------------- NAME H5SL_find PURPOSE Search for _node_ in a skip list USAGE H5SL_node_t *H5SL_node(slist,key) H5SL_t *slist; IN/OUT: Pointer to skip list void *key; IN: Key for item to search for RETURNS Returns pointer to _node_ matching key on success, NULL on failure DESCRIPTION Search for an object in a skip list, according to it's key and returns the node that the object is attached to GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS This routine is a useful starting point for next/prev calls EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ H5SL_node_t * H5SL_find(H5SL_t *slist, const void *key) { H5SL_node_t *checked; /* Pointer to last node checked */ H5SL_node_t *x; /* Current node to examine */ int i; /* Local index value */ H5SL_node_t *ret_value; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_find); /* Check args */ assert(slist); assert(key); /* Check internal consistency */ /* (Pre-condition) */ /* Insert item into skip list */ /* Work through the forward pointers for a node, finding the node at each * level that is before the location to insert */ x=slist->header; switch(slist->type) { case H5SL_TYPE_INT: H5SL_FIND(SCALAR,slist,x,-,i,const int,-,key,checked) break; case H5SL_TYPE_HADDR: H5SL_FIND(SCALAR,slist,x,-,i,const haddr_t,-,key,checked) break; case H5SL_TYPE_STR: H5SL_FIND(STRING,slist,x,-,i,char *,-,key,checked) break; case H5SL_TYPE_HSIZE: H5SL_FIND(SCALAR,slist,x,-,i,const hsize_t,-,key,checked) break; case H5SL_TYPE_UNSIGNED: H5SL_FIND(SCALAR,slist,x,-,i,const unsigned,-,key,checked) break; } /* end switch */ /* 'key' must not have been found in list, if we get here */ ret_value=NULL; done: FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_find() */ /*-------------------------------------------------------------------------- NAME H5SL_first PURPOSE Gets a pointer to the first node in a skip list USAGE H5SL_node_t *H5SL_first(slist) H5SL_t *slist; IN: Pointer to skip list RETURNS Returns pointer to first node in skip list on success, NULL on failure. DESCRIPTION Retrieves a pointer to the first node in a skip list, for iterating over the list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ H5SL_node_t * H5SL_first(H5SL_t *slist) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_first); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ FUNC_LEAVE_NOAPI(slist->header->forward[0]); } /* end H5SL_first() */ /*-------------------------------------------------------------------------- NAME H5SL_next PURPOSE Gets a pointer to the next node in a skip list USAGE H5SL_node_t *H5SL_next(slist_node) H5SL_node_t *slist_node; IN: Pointer to skip list node RETURNS Returns pointer to node after slist_node in skip list on success, NULL on failure. DESCRIPTION Retrieves a pointer to the next node in a skip list, for iterating over the list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ H5SL_node_t * H5SL_next(H5SL_node_t *slist_node) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_next); /* Check args */ assert(slist_node); /* Check internal consistency */ /* (Pre-condition) */ FUNC_LEAVE_NOAPI(slist_node->forward[0]); } /* end H5SL_next() */ /*-------------------------------------------------------------------------- NAME H5SL_prev PURPOSE Gets a pointer to the previos node in a skip list USAGE H5SL_node_t *H5SL_prev(slist_node) H5SL_node_t *slist_node; IN: Pointer to skip list node RETURNS Returns pointer to node before slist_node in skip list on success, NULL on failure. DESCRIPTION Retrieves a pointer to the previous node in a skip list, for iterating over the list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ H5SL_node_t * H5SL_prev(H5SL_node_t *slist_node) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_prev); /* Check args */ assert(slist_node); /* Check internal consistency */ /* (Pre-condition) */ /* Walk backward, detecting the header node (which has it's key set to NULL) */ FUNC_LEAVE_NOAPI(slist_node->backward->key==NULL ? NULL : slist_node->backward); } /* end H5SL_prev() */ /*-------------------------------------------------------------------------- NAME H5SL_last PURPOSE Gets a pointer to the lsat node in a skip list USAGE H5SL_node_t *H5SL_last(slist) H5SL_t *slist; IN: Pointer to skip list RETURNS Returns pointer to last node in skip list on success, NULL on failure. DESCRIPTION Retrieves a pointer to the last node in a skip list, for iterating over the list. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ H5SL_node_t * H5SL_last(H5SL_t *slist) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_last); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ /* Find last node, avoiding the header node */ FUNC_LEAVE_NOAPI(slist->last==slist->header ? NULL : slist->last); } /* end H5SL_last() */ /*-------------------------------------------------------------------------- NAME H5SL_item PURPOSE Gets pointer to the 'item' for a skip list node USAGE void *H5SL_item(slist_node) H5SL_node_t *slist_node; IN: Pointer to skip list node RETURNS Returns pointer to node 'item' on success, NULL on failure. DESCRIPTION Retrieves a node's 'item' GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ void * H5SL_item(H5SL_node_t *slist_node) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_item); /* Check args */ assert(slist_node); /* Check internal consistency */ /* (Pre-condition) */ FUNC_LEAVE_NOAPI(slist_node->item); } /* end H5SL_item() */ /*-------------------------------------------------------------------------- NAME H5SL_iterate PURPOSE Iterate over all nodes in a skip list USAGE herr_t H5SL_iterate(slist, op, op_data) H5SL_t *slist; IN/OUT: Pointer to skip list to iterate over H5SL_operator_t op; IN: Callback function for iteration void *op_data; IN/OUT: Pointer to application data for callback RETURNS Returns a negative value if something is wrong, the return value of the last operator if it was non-zero, or zero if all nodes were processed. DESCRIPTION Iterate over all the nodes in a skip list, calling an application callback with the item, key and any operator data. The operator callback receives a pointer to the item and key for the list being iterated over ('mesg'), and the pointer to the operator data passed in to H5SL_iterate ('op_data'). The return values from an operator are: A. Zero causes the iterator to continue, returning zero when all nodes of that type have been processed. B. Positive causes the iterator to immediately return that positive value, indicating short-circuit success. C. Negative causes the iterator to immediately return that value, indicating failure. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ herr_t H5SL_iterate(H5SL_t *slist, H5SL_operator_t op, void *op_data) { H5SL_node_t *node; /* Pointers to skip list nodes */ herr_t ret_value=0; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_iterate); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ /* Free skip list nodes */ node=slist->header->forward[0]; while(node!=NULL) { /* Call the iterator callback */ /* Casting away const OK -QAK */ if((ret_value=(op)(node->item,(void *)node->key,op_data))!=0) break; node=node->forward[0]; } /* end while */ FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_iterate() */ /*-------------------------------------------------------------------------- NAME H5SL_release PURPOSE Release all nodes from a skip list USAGE herr_t H5SL_release(slist) H5SL_t *slist; IN/OUT: Pointer to skip list to release nodes RETURNS Returns non-negative on success, negative on failure. DESCRIPTION Release all the nodes in a skip list. Any objects left in the skip list nodes are not deallocated. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS The skip list itself is still valid, it just has all its nodes removed. EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ herr_t H5SL_release(H5SL_t *slist) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_release); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ /* Free skip list nodes */ H5SL_release_common(slist,NULL,NULL); /* always succeeds */ FUNC_LEAVE_NOAPI(SUCCEED); } /* end H5SL_release() */ /*-------------------------------------------------------------------------- NAME H5SL_free PURPOSE Release all nodes from a skip list, freeing all nodes USAGE herr_t H5SL_free(slist,op,op_data) H5SL_t *slist; IN/OUT: Pointer to skip list to release nodes H5SL_operator_t op; IN: Callback function to free item & key void *op_data; IN/OUT: Pointer to application data for callback RETURNS Returns non-negative on success, negative on failure. DESCRIPTION Release all the nodes in a skip list. Any objects left in the skip list have the 'op' routine called for each. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS The skip list itself is still valid, it just has all its nodes removed. The return value from the 'op' routine is ignored. This routine is essentially a combination of iterating over all the nodes (where the iterator callback is supposed to free the items and/or keys) followed by a call to H5SL_release(). EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ herr_t H5SL_free(H5SL_t *slist, H5SL_operator_t op, void *op_data) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_free); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ /* Free skip list nodes */ H5SL_release_common(slist,op,op_data); /* always succeeds */ FUNC_LEAVE_NOAPI(SUCCEED); } /* end H5SL_free() */ /*-------------------------------------------------------------------------- NAME H5SL_destroy PURPOSE Close a skip list, deallocating it and freeing all its nodes. USAGE herr_t H5SL_destroy(slist,op,opdata) H5SL_t *slist; IN/OUT: Pointer to skip list to close H5SL_operator_t op; IN: Callback function to free item & key void *op_data; IN/OUT: Pointer to application data for callback RETURNS Returns non-negative on success, negative on failure. DESCRIPTION Close a skip list, freeing all internal information. Any objects left in the skip list have the 'op' routine called for each. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS The return value from the 'op' routine is ignored. This routine is essentially a combination of iterating over all the nodes (where the iterator callback is supposed to free the items and/or keys) followed by a call to H5SL_close(). EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ herr_t H5SL_destroy(H5SL_t *slist, H5SL_operator_t op, void *op_data) { herr_t ret_value=SUCCEED; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_destroy); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ /* Close skip list */ (void)H5SL_close_common(slist,op,op_data); /* always succeeds */ FUNC_LEAVE_NOAPI(ret_value); } /* end H5SL_destroy() */ /*-------------------------------------------------------------------------- NAME H5SL_close PURPOSE Close a skip list, deallocating it. USAGE herr_t H5SL_close(slist) H5SL_t *slist; IN/OUT: Pointer to skip list to close RETURNS Returns non-negative on success, negative on failure. DESCRIPTION Close a skip list, freeing all internal information. Any objects left in the skip list are not deallocated. GLOBAL VARIABLES COMMENTS, BUGS, ASSUMPTIONS EXAMPLES REVISION LOG --------------------------------------------------------------------------*/ herr_t H5SL_close(H5SL_t *slist) { FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_close); /* Check args */ assert(slist); /* Check internal consistency */ /* (Pre-condition) */ /* Close skip list */ (void)H5SL_close_common(slist,NULL,NULL); /* always succeeds */ FUNC_LEAVE_NOAPI(SUCCEED); } /* end H5SL_close() */