X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=list.c;h=078723cc8dcab59e162f97f03fa13d29aa878fb3;hp=6635f9ede2d414bbd96c64ecb4ad6afcbf535807;hb=5f390b415777db21894f1b856ab3d21c9c24f7c6;hpb=18443d8f7bc4ac6147ad0cc2e84878fa074502b6 diff --git a/list.c b/list.c index 6635f9ed..078723cc 100644 --- a/list.c +++ b/list.c @@ -1,4 +1,4 @@ -const char list_rcs[] = "$Id: list.c,v 1.6 2001/07/31 14:44:51 oes Exp $"; +const char list_rcs[] = "$Id: list.c,v 1.11 2001/10/23 21:21:03 jongfoster Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/list.c,v $ @@ -11,10 +11,10 @@ const char list_rcs[] = "$Id: list.c,v 1.6 2001/07/31 14:44:51 oes Exp $"; * IJBSWA team. http://ijbswa.sourceforge.net * * Based on the Internet Junkbuster originally written - * by and Copyright (C) 1997 Anonymous Coders and + * by and Copyright (C) 1997 Anonymous Coders and * Junkbusters Corporation. http://www.junkbusters.com * - * This program is free software; you can redistribute it + * This program is free software; you can redistribute it * and/or modify it under the terms of the GNU General * Public License as published by the Free Software * Foundation; either version 2 of the License, or (at @@ -34,6 +34,29 @@ const char list_rcs[] = "$Id: list.c,v 1.6 2001/07/31 14:44:51 oes Exp $"; * * Revisions : * $Log: list.c,v $ + * Revision 1.11 2001/10/23 21:21:03 jongfoster + * New error handling - error codes are now jb_errs, not ints. + * Changed the way map() handles out-of-memory, to dramatically + * reduce the amount of error-checking clutter needed. + * + * Revision 1.10 2001/09/16 17:30:24 jongfoster + * Fixing a compiler warning. + * + * Revision 1.9 2001/09/16 13:20:29 jongfoster + * Rewrite of list library. Now has seperate header and list_entry + * structures. Also added a large sprinking of assert()s to the list + * code. + * + * Revision 1.8 2001/08/07 14:00:20 oes + * Fixed comment + * + * Revision 1.7 2001/08/05 16:06:20 jongfoster + * Modifiying "struct map" so that there are now separate header and + * "map_entry" structures. This means that functions which modify a + * map no longer need to return a pointer to the modified map. + * Also, it no longer reverses the order of the entries (which may be + * important with some advanced template substitutions). + * * Revision 1.6 2001/07/31 14:44:51 oes * list_to_text() now appends empty line at end * @@ -76,25 +99,174 @@ const char list_rcs[] = "$Id: list.c,v 1.6 2001/07/31 14:44:51 oes Exp $"; #include "config.h" +#ifndef _WIN32 +/* FIXME: The following headers are not needed for Win32. Are they + * needed on other platforms? + */ #include #include #include #include +#endif #include -#include - -#ifndef _WIN32 +#if !defined(_WIN32) && !defined(__OS2__) #include #endif +#include + #include "project.h" -#include "jcc.h" #include "list.h" #include "miscutil.h" const char list_h_rcs[] = LIST_H_VERSION; + +static int list_is_valid (const struct list *the_list); + + +/********************************************************************* + * + * Function : list_init + * + * Description : Create a new, empty list in user-allocated memory. + * Caller should allocate a "struct list" variable, + * then pass it to this function. + * (Implementation note: Rather than calling this + * function, you can also just memset the memory to + * zero, e.g. if you have a larger structure you + * want to initialize quickly. However, that isn't + * really good design.) + * + * Parameters : + * 1 : the_list = pointer to list + * + * Returns : N/A + * + *********************************************************************/ +void init_list(struct list *the_list) +{ + memset(the_list, '\0', sizeof(*the_list)); +} + + +/********************************************************************* + * + * Function : destroy_list + * + * Description : Destroy a string list (opposite of list_init). + * On return, the memory used by the list entries has + * been freed, but not the memory used by the_list + * itself. You should not re-use the_list without + * calling list_init(). + * + * (Implementation note: You *can* reuse the_list + * without calling list_init(), but please don't. + * If you want to remove all entries from a list + * and still have a usable list, then use + * list_remove_all().) + * + * Parameters : + * 1 : the_list = pointer to list + * + * Returns : N/A + * + *********************************************************************/ +void destroy_list (struct list *the_list) +{ + struct list_entry *cur_entry, *next_entry; + + assert(the_list); + + for (cur_entry = the_list->first; cur_entry ; cur_entry = next_entry) + { + next_entry = cur_entry->next; + freez(cur_entry->str); + free(cur_entry); + } + + the_list->first = NULL; + the_list->last = NULL; +} + + +/********************************************************************* + * + * Function : list_is_valid + * + * Description : Check that a string list is valid. The intended + * usage is "assert(list_is_valid(the_list))". + * Currently this checks that "the_list->last" + * is correct, and that the list dosn't contain + * circular references. It is likely to crash if + * it's passed complete garbage. + * + * Parameters : + * 1 : the_list = pointer to list. Must be non-null. + * + * Returns : 1 if list is valid, 0 otherwise. + * + *********************************************************************/ +static int list_is_valid (const struct list *the_list) +{ + /* + * If you don't want this check, just change the line below + * from "#if 1" to "#if 0". + */ +#if 1 + const struct list_entry *cur_entry; + const struct list_entry *last_entry = NULL; + int length = 0; + + assert(the_list); + + for (cur_entry = the_list->first; cur_entry ; cur_entry = cur_entry->next) + { + last_entry = cur_entry; + + if (cur_entry->str) + { + /* + * Just check that this string can be accessed - i.e. it's a valid + * pointer. + */ + strlen(cur_entry->str); + } + + /* + * Check for looping back to first + */ + if ((length != 0) && (cur_entry == the_list->first)) + { + return 0; + } + + /* + * Arbitrarily limit length to prevent infinite loops. + */ + if (++length > 1000) + { + return 0; + } + + /* + * Check this isn't marked as the last entry, unless of course it's + * *really* the last entry. + */ + if ((the_list->last == cur_entry) && (cur_entry->next != NULL)) + { + /* This is the last entry, but there's data after it !!?? */ + return 0; + } + } + + return (the_list->last == last_entry); +#else + return 1; +#endif +} + /********************************************************************* * * Function : enlist @@ -102,32 +274,51 @@ const char list_h_rcs[] = LIST_H_VERSION; * Description : Append a string into a specified string list. * * Parameters : - * 1 : header = pointer to list 'dummy' header + * 1 : the_list = pointer to list * 2 : str = string to add to the list (maybe NULL) * - * Returns : N/A + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * On error, the_list will be unchanged. * *********************************************************************/ -void enlist(struct list *header, const char *str) +jb_err enlist(struct list *the_list, const char *str) { - struct list *cur = (struct list *)malloc(sizeof(*cur)); - struct list *last; + struct list_entry *cur; + + assert(the_list); + assert(list_is_valid(the_list)); - if (cur) + if (NULL == (cur = (struct list_entry *)zalloc(sizeof(*cur)))) { - cur->str = (str ? strdup(str) : NULL); - cur->next = NULL; + return JB_ERR_MEMORY; + } - last = header->last; - if (last == NULL) + if (str) + { + if (NULL == (cur->str = strdup(str))) { - last = header; + free(cur); + return JB_ERR_MEMORY; } + } + /* else { cur->str = NULL; } - implied by zalloc */ - last->next = cur; - header->last = cur; + /* cur->next = NULL; - implied by zalloc */ + + if (the_list->last) + { + the_list->last->next = cur; + the_list->last = cur; + } + else + { + the_list->first = cur; + the_list->last = cur; } + assert(list_is_valid(the_list)); + return JB_ERR_OK; } @@ -139,28 +330,46 @@ void enlist(struct list *header, const char *str) * string list. * * Parameters : - * 1 : header = pointer to list 'dummy' header + * 1 : the_list = pointer to list * 2 : str = string to add to the list (maybe NULL) * - * Returns : N/A + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * On error, the_list will be unchanged. * *********************************************************************/ -void enlist_first(struct list *header, const char *str) +jb_err enlist_first(struct list *the_list, const char *str) { - struct list *cur = (struct list *)malloc(sizeof(*cur)); + struct list_entry *cur; + + assert(the_list); + assert(list_is_valid(the_list)); - if (cur) + if (NULL == (cur = (struct list_entry *)zalloc(sizeof(*cur)))) { - cur->str = (str ? strdup(str) : NULL); - cur->next = header->next; + return JB_ERR_MEMORY; + } - header->next = cur; - if (header->last == NULL) + if (str) + { + if (NULL == (cur->str = strdup(str))) { - header->last = cur; + free(cur); + return JB_ERR_MEMORY; } } + /* else { cur->str = NULL; } - implied by zalloc */ + + cur->next = the_list->first; + the_list->first = cur; + if (the_list->last == NULL) + { + the_list->last = cur; + } + + assert(list_is_valid(the_list)); + return JB_ERR_OK; } @@ -170,49 +379,59 @@ void enlist_first(struct list *header, const char *str) * * Description : Append a string into a specified string list, * if & only if it's not there already. - * If the n argument is nonzero, only compare up to - * the nth character. + * If the num_significant_chars argument is nonzero, + * only compare up to the nth character. * * Parameters : - * 1 : header = pointer to list 'dummy' header - * 2 : str = string to add to the list (maybe NULL) - * 3 : n = number of chars to use for uniqueness test + * 1 : the_list = pointer to list + * 2 : str = string to add to the list + * 3 : num_significant_chars = number of chars to use + * for uniqueness test, or 0 to require an exact match. * - * Returns : N/A + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * On error, the_list will be unchanged. + * "Success" does not indicate whether or not the + * item was already in the list. * *********************************************************************/ -void enlist_unique(struct list *header, const char *str, int n) +jb_err enlist_unique(struct list *the_list, const char *str, + int num_significant_chars) { - struct list *last; - struct list *cur = header->next; + struct list_entry *cur_entry; - while (cur != NULL) + assert(the_list); + assert(list_is_valid(the_list)); + assert(str); + assert(num_significant_chars >= 0); + assert((size_t)num_significant_chars <= strlen(str)); + + if (num_significant_chars > 0) { - if ((cur->str != NULL) && ( - (n && (0 == strncmp(str, cur->str, n))) || - (!n && (0 == strcmp(str, cur->str))))) + for (cur_entry = the_list->first; cur_entry != NULL; cur_entry = cur_entry->next) { - /* Already there */ - return; + if ( (cur_entry->str != NULL) + && (0 == strncmp(str, cur_entry->str, num_significant_chars))) + { + /* Already there */ + return JB_ERR_OK; + } } - cur = cur->next; } - - cur = (struct list *)malloc(sizeof(*cur)); - - if (cur != NULL) + else { - cur->str = (str ? strdup(str) : NULL); /* FIXME check retval */ - cur->next = NULL; - - last = header->last; - if (last == NULL) + /* Test whole string */ + for (cur_entry = the_list->first; cur_entry != NULL; cur_entry = cur_entry->next) { - last = header; + if ( (cur_entry->str != NULL) && (0 == strcmp(str, cur_entry->str))) + { + /* Already there */ + return JB_ERR_OK; + } } - last->next = cur; - header->last = cur; } + + return enlist(the_list, str); } @@ -225,80 +444,83 @@ void enlist_unique(struct list *header, const char *str, int n) * if & only if there isn't already a header with that name. * * Parameters : - * 1 : header = pointer to list 'dummy' header - * 2 : first = first string to add to the list (maybe NULL) - * 3 : second = number of chars to use for uniqueness test + * 1 : the_list = pointer to list + * 2 : name = HTTP header name (e.g. "Content-type") + * 3 : value = HTTP header value (e.g. "text/html") * - * Returns : N/A + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * On error, the_list will be unchanged. + * "Success" does not indicate whether or not the + * header was already in the list. * *********************************************************************/ -void enlist_unique_header(struct list *header, const char *name, const char *value) +jb_err enlist_unique_header(struct list *the_list, const char *name, + const char *value) { - struct list *last; - struct list *cur = header->next; int length; - char *dummy; + jb_err result; + char *str; - if (name == NULL || value == NULL) return; + assert(the_list); + assert(list_is_valid(the_list)); + assert(name); + assert(value); - dummy = strdup(name); - dummy = strsav(dummy, ": "); - length = strlen(dummy); - - while (cur != NULL) + length = strlen(name) + 2; + if (NULL == (str = (char *)malloc(length + strlen(value) + 1))) { - if ((cur->str != NULL) && - (0 == strncmp(dummy, cur->str, length))) - { - /* Already there */ - return; - } - cur = cur->next; + return JB_ERR_MEMORY; } + strcpy(str, name); + str[length - 2] = ':'; + str[length - 1] = ' '; + strcpy(str + length, value); - cur = (struct list *)malloc(sizeof(*cur)); + result = enlist_unique(the_list, str, length); - if (cur != NULL) - { - cur->str = strsav(dummy, value); - cur->next = NULL; + free(str); - last = header->last; - if (last == NULL) - { - last = header; - } - last->next = cur; - header->last = cur; - } + assert(list_is_valid(the_list)); + + return result; } /********************************************************************* * - * Function : destroy_list + * Function : list_remove_all * - * Description : Destroy a string list (opposite of enlist) + * Description : Remove all entries from a list. On return, the_list + * is a valid, empty list. Note that this is similar + * to destroy_list(), but the difference is that this + * function guarantees that the list structure is still + * valid after the call. * * Parameters : - * 1 : header = pointer to list 'dummy' header + * 1 : the_list = pointer to list * * Returns : N/A * *********************************************************************/ -void destroy_list(struct list *header) +void list_remove_all(struct list *the_list) { - struct list *p, *n; + struct list_entry *cur_entry; + struct list_entry *next_entry; - for (p = header->next; p ; p = n) + assert(the_list); + assert(list_is_valid(the_list)); + + for (cur_entry = the_list->first; cur_entry ; cur_entry = next_entry) { - n = p->next; - freez(p->str); - free(p); + next_entry = cur_entry->next; + freez(cur_entry->str); + free(cur_entry); } - memset(header, '\0', sizeof(*header)); + the_list->first = the_list->last = NULL; + assert(list_is_valid(the_list)); } @@ -306,52 +528,56 @@ void destroy_list(struct list *header) * * Function : list_to_text * - * Description : "Flaten" a string list into 1 long \r\n delimited string, - * adding an empty line at the end. + * Description : "Flatten" a string list into 1 long \r\n delimited string, + * adding an empty line at the end. NULL entries are ignored. + * This function does not change the_list. * * Parameters : - * 1 : h = pointer to list 'dummy' header + * 1 : the_list = pointer to list * * Returns : NULL on malloc error, else new long string. + * Caller must free() it. * *********************************************************************/ -char *list_to_text(struct list *h) +char *list_to_text(const struct list *the_list) { - struct list *p; + struct list_entry *cur_entry; char *ret = NULL; char *s; int size = 2; - for (p = h->next; p ; p = p->next) + assert(the_list); + assert(list_is_valid(the_list)); + + for (cur_entry = the_list->first; cur_entry ; cur_entry = cur_entry->next) { - if (p->str) + if (cur_entry->str) { - size += strlen(p->str) + 2; + size += strlen(cur_entry->str) + 2; } } if ((ret = (char *)malloc(size + 1)) == NULL) { - return(NULL); + return NULL; } ret[size] = '\0'; s = ret; - for (p = h->next; p ; p = p->next) + for (cur_entry = the_list->first; cur_entry ; cur_entry = cur_entry->next) { - if (p->str) + if (cur_entry->str) { - strcpy(s, p->str); + strcpy(s, cur_entry->str); s += strlen(s); *s++ = '\r'; *s++ = '\n'; } } *s++ = '\r'; *s++ = '\n'; - return(ret); - + return ret; } @@ -362,36 +588,54 @@ char *list_to_text(struct list *h) * Description : Remove a string from a specified string list. * * Parameters : - * 1 : header = pointer to list 'dummy' header - * 2 : str = string to remove from the list + * 1 : the_list = pointer to list + * 2 : str = string to remove from the list - non-NULL * * Returns : Number of times it was removed. * *********************************************************************/ -int list_remove_item(struct list *header, const char *str) +int list_remove_item(struct list *the_list, const char *str) { - struct list *prev = header; - struct list *cur = prev->next; + struct list_entry *prev = NULL; + struct list_entry *cur; + struct list_entry *next; int count = 0; + assert(the_list); + assert(list_is_valid(the_list)); + assert(str); + + cur = the_list->first; + while (cur != NULL) { + next = cur->next; + if ((cur->str != NULL) && (0 == strcmp(str, cur->str))) { count++; - prev->next = cur->next; - free(cur->str); + if (prev != NULL) + { + prev->next = next; + } + else + { + the_list->first = next; + } + free((char *)cur->str); free(cur); } else { prev = cur; } - cur = prev->next; + cur = next; } - header->last = prev; + the_list->last = prev; + + assert(list_is_valid(the_list)); return count; } @@ -414,18 +658,25 @@ int list_remove_item(struct list *header, const char *str) *********************************************************************/ int list_remove_list(struct list *dest, const struct list *src) { - struct list *cur = src->next; + struct list_entry *cur; int count = 0; - while (cur != NULL) + assert(src); + assert(dest); + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + + for (cur = src->first; cur != NULL; cur = cur->next) { if (cur->str != NULL) { count += list_remove_item(dest, cur->str); } - cur = cur->next; } + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + return count; } @@ -434,35 +685,96 @@ int list_remove_list(struct list *dest, const struct list *src) * * Function : list_duplicate * - * Description : Duplicate a string list + * Description : Copy a string list * * Parameters : - * 1 : dest = pointer to destination for copy. Caller allocs. - * 2 : src = pointer to source for copy. + * 1 : dest = Destination list. Must be a valid list. + * All existing entries will be removed. + * 1 : src = pointer to source list for copy. * - * Returns : N/A + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * On error, dest will be empty. * *********************************************************************/ -void list_duplicate(struct list *dest, const struct list *src) +jb_err list_duplicate(struct list *dest, const struct list *src) { - struct list * cur_src = src->next; - struct list * cur_dest = dest; + struct list_entry * cur_src; + struct list_entry * cur_dest; - memset(dest, '\0', sizeof(*dest)); + assert(src); + assert(dest); + assert(list_is_valid(src)); + assert(list_is_valid(dest)); - while (cur_src) + list_remove_all(dest); + + /* Need to process first entry specially so we can set dest->first */ + cur_src = src->first; + if (cur_src) { - cur_dest = cur_dest->next = (struct list *)zalloc(sizeof(*cur_dest)); + cur_dest = dest->first = (struct list_entry *)zalloc(sizeof(*cur_dest)); if (cur_dest == NULL) { - return; + destroy_list(dest); + + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + + return JB_ERR_MEMORY; } - cur_dest->str = strdup(cur_src->str); - cur_src = cur_src->next; + + if (cur_src->str) + { + cur_dest->str = strdup(cur_src->str); + if (cur_dest->str == NULL) + { + destroy_list(dest); + + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + + return JB_ERR_MEMORY; + } + } + /* else { cur_dest->str = NULL; } - implied by zalloc */ + + /* Now process the rest */ + for (cur_src = cur_src->next; cur_src; cur_src = cur_src->next) + { + cur_dest = cur_dest->next = (struct list_entry *)zalloc(sizeof(*cur_dest)); + if (cur_dest == NULL) + { + destroy_list(dest); + + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + + return JB_ERR_MEMORY; + } + if (cur_src->str) + { + cur_dest->str = strdup(cur_src->str); + if (cur_dest->str == NULL) + { + destroy_list(dest); + + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + + return JB_ERR_MEMORY; + } + } + /* else { cur_dest->str = NULL; } - implied by zalloc */ + } + + dest->last = cur_dest; } - dest->last = cur_dest; + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + return JB_ERR_OK; } @@ -474,105 +786,73 @@ void list_duplicate(struct list *dest, const struct list *src) * Duplicate items are not added. * * Parameters : - * 1 : dest = pointer to destination for merge. Caller allocs. + * 1 : dest = pointer to destination list for merge. * 2 : src = pointer to source for merge. * - * Returns : N/A + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * On error, some (but not all) of src might have + * been copied into dest. * *********************************************************************/ -void list_append_list_unique(struct list *dest, const struct list *src) +jb_err list_append_list_unique(struct list *dest, const struct list *src) { - struct list * cur = src->next; + struct list_entry * cur; - while (cur) - { - enlist_unique(dest, cur->str, 0); - cur = cur->next; - } -} - - -/********************************************************************* - * - * Function : map - * - * Description : Add a mapping from given name to given value to a - * given map. - * - * Note: Since all strings will be free()d in free_map() - * later, use the copy flags for constants or - * strings that will be independantly free()d. - * - * Parameters : - * 1 : the_map = map to add to - * 2 : name = name to add - * 3 : nc = flag set if a copy of name should be used - * 4 : value = value to add - * 5 : vc = flag set if a copy of value should be used - * - * Returns : N/A - * - *********************************************************************/ -void map(struct map *the_map, const char *name, int nc, const char *value, int vc) -{ - struct map_entry *new_entry; + assert(src); + assert(dest); + assert(list_is_valid(src)); + assert(list_is_valid(dest)); - if (NULL == (new_entry = zalloc(sizeof(*new_entry)))) + for (cur = src->first; cur; cur = cur->next) { - return; + if (cur->str) + { + if (enlist_unique(dest, cur->str, 0)) + { + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + + return JB_ERR_MEMORY; + } + } } - new_entry->name = nc ? strdup(name) : name; - new_entry->value = vc ? strdup(value) : value; - /* new_entry->next = NULL; - implied by zalloc */ + assert(list_is_valid(src)); + assert(list_is_valid(dest)); - if (the_map->last) - { - the_map->last = the_map->last->next = new_entry; - } - else - { - the_map->last = the_map->first = new_entry; - } + return JB_ERR_OK; } /********************************************************************* * - * Function : lookup + * Function : list_is_empty * - * Description : Look up an item with a given name in a map, and - * return its value + * Description : Test whether a list is empty. Does not change the list. * * Parameters : - * 1 : name = name parameter to look for + * 1 : the_list = pointer to list to test. * - * Returns : the value if found, else the empty string + * Returns : Nonzero iff the list contains no entries. * *********************************************************************/ -const char *lookup(const struct map *the_map, const char *name) +int list_is_empty(const struct list *the_list) { - const struct map_entry *cur_entry = the_map->first; + assert(the_list); + assert(list_is_valid(the_list)); - while (cur_entry) - { - if (!strcmp(name, cur_entry->name)) - { - return cur_entry->value; - } - cur_entry = cur_entry->next; - } - return ""; + return (the_list->first == NULL); } /********************************************************************* * - * Function : new_nap + * Function : new_map * * Description : Create a new, empty map. * - * Parameters : + * Parameters : N/A * * Returns : A new, empty map, or NULL if out of memory. * @@ -591,7 +871,7 @@ struct map *new_map(void) * depandant strings * * Parameters : - * 1 : cur_entry = map to be freed. May be NULL. + * 1 : the_map = map to be freed. May be NULL. * * Returns : N/A * @@ -606,10 +886,10 @@ void free_map(struct map *the_map) return; } - for (cur_entry = the_map->first; cur_entry != NULL; cur_entry = next_entry) + for (cur_entry = the_map->first; cur_entry != NULL; cur_entry = next_entry) { - freez((char *)cur_entry->name); - freez((char *)cur_entry->value); + freez(cur_entry->name); + freez(cur_entry->value); next_entry = cur_entry->next; free(cur_entry); @@ -621,6 +901,149 @@ void free_map(struct map *the_map) } +/********************************************************************* + * + * Function : map + * + * Description : Add a mapping from given name to given value to a + * given map. + * + * Note: Since all strings will be free()d in free_map() + * later, set the copy flags for constants or + * strings that will be independantly free()d. + * + * Note2: This function allows NULL parameters - it + * returns JB_ERR_MEMORY in that case. + * + * Note3: If this function returns JB_ERR_MEMORY, + * it will free(name) unless you specify + * name_needs_copying, and similarly it will + * free(value) unless you specify + * value_needs_copying. + * + * Due to Note2 and Note3 above, the following code + * is legal, and will never crash or leak memory even + * if the system runs out of memory: + * + * err = map(mymap, "xyz", 1, html_encode(somestring), 0); + * + * err will be set to JB_ERR_MEMORY if either call runs + * out-of-memory. Without these features, you would + * need to check the return value of html_encode in the + * above example for NULL, which (at least) doubles the + * amount of error-checking code needed. + * + * Parameters : + * 1 : the_map = map to add to + * 2 : name = name to add + * 3 : name_needs_copying = flag set if a copy of name should be used + * 4 : value = value to add + * 5 : value_needs_copying = flag set if a copy of value should be used + * + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * + *********************************************************************/ +jb_err map(struct map *the_map, + const char *name, int name_needs_copying, + const char *value, int value_needs_copying) +{ + struct map_entry *new_entry; + + assert(the_map); + + if ( (NULL == value) + || (NULL == name) + || (NULL == (new_entry = zalloc(sizeof(*new_entry)))) ) + { + if ((name != NULL) && (!name_needs_copying)) + { + free((char *)name); + } + if ((value != NULL) && (!value_needs_copying)) + { + free((char *)value); + } + return JB_ERR_MEMORY; + } + + if (name_needs_copying) + { + if (NULL == (name = strdup(name))) + { + free(new_entry); + if (!value_needs_copying) + { + free((char *)value); + } + return JB_ERR_MEMORY; + } + } + + if (value_needs_copying) + { + if (NULL == (value = strdup(value))) + { + free((char *)name); + free(new_entry); + return JB_ERR_MEMORY; + } + } + + new_entry->name = name; + new_entry->value = value; + /* new_entry->next = NULL; - implied by zalloc */ + + if (the_map->last) + { + the_map->last->next = new_entry; + the_map->last = new_entry; + } + else + { + the_map->first = new_entry; + the_map->last = new_entry; + } + + return JB_ERR_OK; +} + + +/********************************************************************* + * + * Function : lookup + * + * Description : Look up an item with a given name in a map, and + * return its value + * + * Parameters : + * 1 : the_map = map to look in + * 2 : name = name parameter to look for + * + * Returns : the value if found, else the empty string. + * Return value is alloced as part of the map, so + * it is freed when the map is destroyed. Caller + * must not free or modify it. + * + *********************************************************************/ +const char *lookup(const struct map *the_map, const char *name) +{ + const struct map_entry *cur_entry; + + assert(the_map); + assert(name); + + for (cur_entry = the_map->first; cur_entry != NULL; cur_entry = cur_entry->next) + { + if (!strcmp(name, cur_entry->name)) + { + return cur_entry->value; + } + } + return ""; +} + + /* Local Variables: tab-width: 3