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Diffstat (limited to 'doc/linkedlists.README')
-rwxr-xr-x | doc/linkedlists.README | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/doc/linkedlists.README b/doc/linkedlists.README new file mode 100755 index 000000000..87e396fbc --- /dev/null +++ b/doc/linkedlists.README @@ -0,0 +1,95 @@ + +2nd version, implemented as macros. + + include <asterisk/linkedlists.h> + +AST_LIST_ENTRY declares pointers inside the object structure : + + struct ast_var_t { + char *name; + char *value; + AST_LIST_ENTRY(ast_var_t) listpointers; + }; + +AST_LIST_HEAD declares a head structure, which is initialized +to AST_LIST_HEAD_NULL : + + AST_LIST_HEAD(head, ast_var_t) head + +Next, we declare a pointer to this structure : + + struct headtype *headp = head; + +AST_LIST_INIT initializes the head pointer to a null value + + AST_LIST_INIT(headp); + +AST_LIST_INSERT_HEAD inserts an element to the head of the list : + + struct ast_var_t *node; + + node=malloc(sizeof(struct ast_var_t)); + (...we fill data in struct....) + data->name=malloc(100); + strcpy(data->name,"lalalalaa"); + etc etc + + (then we insert the node in the head of the list :) + + AST_LIST_INSERT_HEAD(headp,node,listpointers); + +AST_LIST_INSERT_HEAD_AFTER inserts an element after another : + + struct ast_var_t *node1; + ... + AST_LIST_INSERT_AFTER(node,node1,listpointers); + +AST_LIST_REMOVE removes an arbitrary element from the head: + + AST_LIST_REMOVE(headp,node1,ast_var_t,listpointers); + +AST_LIST_REMOVE_HEAD removes the entry at the head of the list: + + AST_LIST_REMOVE(headp,listpointers); + +AST_LIST_FIRST returns a pointer to the first element of the list; + + struct ast_var_t *firstnode; + firstnode=AST_LIST_FIRST(headp); + +AST_LIST_NEXT returns a pointer to the next element : + + struct ast_var_t *nextnode; + nextnode=AST_LIST_NEXT(firstnode,listpointers); + +AST_LIST_TRAVERSE traverses all elements of the list : + + struct ast_var_t *node; + + AST_LIST_TRAVERSE(headp,node,listpointers) { + printf("%s\n",node->name); + } + +AST_LIST_EMPTY evaluates to a true condition if there are no elements on +the list. + +To completely delete a list : + + struct ast_var_t *vardata; + + while (!AST_LIST_EMPTY(headp)) { /* List Deletion. */ + vardata = AST_LIST_FIRST(head); + AST_LIST_REMOVE_HEAD(head, listpointers); + free(vardata->name); + free(vardata->value); + } + +AST_LIST_LOCK returns true if it can lock the list, AST_LIST_UNLOCK unlocks +the list : + +if (AST_LIST_LOCK(headp)) { + ...do all list operations here... + AST_LIST_UNLOCK(headp); +} else { + ast_log(LOG_WARNING,"List locked bla bla bla\n"); +} |