X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=list.c;h=b9963af1965e2af8f9ccd8e3f05ac4599a11b181;hp=a44c0e9dd3837fb76cf877d129dbbd2fceb76ce3;hb=32ba28b1225c54c850c48814b018e7afcffbd0a5;hpb=31a3c127af9bc2bdea9d0b00526bdb5d03553fb7 diff --git a/list.c b/list.c index a44c0e9d..b9963af1 100644 --- a/list.c +++ b/list.c @@ -1,20 +1,17 @@ -const char list_rcs[] = "$Id: list.c,v NOT CHECKED IN $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/list.c,v $ * * Purpose : Declares functions to handle lists. - * Functions declared include: - * `destroy_list', `enlist' and `list_to_text' * - * Copyright : Written by and Copyright (C) 2001 the SourceForge - * IJBSWA team. http://ijbswa.sourceforge.net + * Copyright : Written by and Copyright (C) 2001-2007 members of the + * Privoxy team. https://www.privoxy.org/ * * 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 @@ -32,30 +29,180 @@ const char list_rcs[] = "$Id: list.c,v NOT CHECKED IN $"; * or write to the Free Software Foundation, Inc., 59 * Temple Place - Suite 330, Boston, MA 02111-1307, USA. * - * Revisions : - * $Log: list.c,v $ - * *********************************************************************/ - + #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 -#ifndef _WIN32 +#if !defined(_WIN32) #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 : init_list + * + * 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 doesn'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 entry = 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. + */ + (void)strlen(cur_entry->str); + } + + /* + * Check for looping back to first + */ + if ((entry++ != 0) && (cur_entry == the_list->first)) + { + return 0; + } + + /* + * Arbitrarily limit list length to prevent infinite loops. + * Note that the 1000 limit was hit by a real user in tracker 911950; + * removing it for now. Real circular references should eventually + * be caught by the check above, anyway. + */ + /* + if (entry > 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 +} /********************************************************************* * @@ -64,107 +211,268 @@ 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; - if (cur) + assert(the_list); + assert(list_is_valid(the_list)); + + 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 */ + + /* cur->next = NULL; - implied by zalloc */ - last->next = cur; - header->last = cur; + 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; } /********************************************************************* * - * Function : enlist_unique + * Function : enlist_first * - * Description : Append a string into a specified string list, - * if & only if it's not there already. + * Description : Append a string as first element 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_unique(struct list *header, const char *str) +jb_err enlist_first(struct list *the_list, const char *str) { - struct list *last; - struct list *cur = header->next; + struct list_entry *cur; - while (cur != NULL) + assert(the_list); + assert(list_is_valid(the_list)); + + if (NULL == (cur = (struct list_entry *)zalloc(sizeof(*cur)))) { - if ((cur->str != NULL) && (0 == strcmp(str, cur->str))) + return JB_ERR_MEMORY; + } + + if (str) + { + if (NULL == (cur->str = strdup(str))) { - /* Already there */ - return; + free(cur); + return JB_ERR_MEMORY; } - cur = cur->next; } + /* else { cur->str = NULL; } - implied by zalloc */ - cur = (struct list *)malloc(sizeof(*cur)); + cur->next = the_list->first; - if (cur != NULL) + the_list->first = cur; + if (the_list->last == NULL) { - cur->str = (str ? strdup(str) : NULL); /* FIXME check retval */ - cur->next = NULL; + the_list->last = cur; + } + + assert(list_is_valid(the_list)); + return JB_ERR_OK; +} + + +/********************************************************************* + * + * Function : enlist_unique + * + * Description : Append a string into a specified string list, + * if & only if it's not there already. + * If the num_significant_chars argument is nonzero, + * only compare up to the nth character. + * + * Parameters : + * 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 : 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. + * + *********************************************************************/ +jb_err enlist_unique(struct list *the_list, const char *str, + size_t num_significant_chars) +{ + struct list_entry *cur_entry; + + assert(the_list); + assert(list_is_valid(the_list)); + assert(str); + assert(num_significant_chars >= 0); + assert(num_significant_chars <= strlen(str)); - last = header->last; - if (last == NULL) + if (num_significant_chars > 0) + { + for (cur_entry = the_list->first; cur_entry != NULL; cur_entry = cur_entry->next) + { + if ((cur_entry->str != NULL) + && (0 == strncmp(str, cur_entry->str, num_significant_chars))) + { + /* Already there */ + return JB_ERR_OK; + } + } + } + else + { + /* 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); } /********************************************************************* * - * Function : destroy_list + * Function : enlist_unique_header * - * Description : Destroy a string list (opposite of enlist) + * Description : Make a HTTP header from the two strings name and value, + * and append the result into a specified string list, + * if & only if there isn't already a header with that name. * * Parameters : - * 1 : header = pointer to list 'dummy' header + * 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 : 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. + * + *********************************************************************/ +jb_err enlist_unique_header(struct list *the_list, const char *name, + const char *value) +{ + jb_err result = JB_ERR_MEMORY; + char *header; + size_t header_size; + + assert(the_list); + assert(list_is_valid(the_list)); + assert(name); + assert(value); + + /* + 2 for the ': ', + 1 for the \0 */ + header_size = strlen(name) + 2 + strlen(value) + 1; + header = (char *)malloc(header_size); + + if (NULL != header) + { + const size_t bytes_to_compare = strlen(name) + 2; + char *p = header; + + snprintf(header, header_size, "%s: %s", name, value); + /* + * The trailing "\r\n" is added by list_to_text(), + * if the caller passed them anyway, cut the header + * at the first one or dump core if this is a debug + * build. + */ + do + { + if ((*p == '\r') || (*p == '\n')) + { + assert(*p != '\r'); + assert(*p != '\n'); + *p = '\0'; + } + } while (*p++); + result = enlist_unique(the_list, header, bytes_to_compare); + free(header); + assert(list_is_valid(the_list)); + } + + return result; + +} + + +/********************************************************************* + * + * Function : list_remove_all + * + * 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 : 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; + + assert(the_list); + assert(list_is_valid(the_list)); - for (p = header->next; p ; p = n) + 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)); } @@ -172,52 +480,79 @@ void destroy_list(struct list *header) * * Function : list_to_text * - * Description : "Flaten" a string list into 1 long \r\n delimited string. + * 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. + * + * XXX: Should probably be renamed as it's only + * useful (and used) to flatten header lists. * * 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; - char *ret = NULL; - char *s; - int size; - - size = 0; - - for (p = h->next; p ; p = p->next) + struct list_entry *cur_entry; + char *text; + size_t text_length; + char *cursor; + size_t bytes_left; + + assert(the_list); + assert(list_is_valid(the_list)); + + /* + * Calculate the length of the final text. + * '2' because of the '\r\n' at the end of + * each string and at the end of the text. + */ + text_length = 2; + 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; + text_length += strlen(cur_entry->str) + 2; } } - if ((ret = (char *)malloc(size + 1)) == NULL) + bytes_left = text_length + 1; + + text = (char *)malloc(bytes_left); + if (NULL == text) { - return(NULL); + return NULL; } - ret[size] = '\0'; + cursor = text; - 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); - s += strlen(s); - *s++ = '\r'; *s++ = '\n'; + const int written = snprintf(cursor, bytes_left, "%s\r\n", cur_entry->str); + + assert(written > 0); + assert(written < bytes_left); + + bytes_left -= (size_t)written; + cursor += (size_t)written; } } - return(ret); + assert(bytes_left == 3); + + *cursor++ = '\r'; + *cursor++ = '\n'; + *cursor = '\0'; + assert(text_length == cursor - text); + assert(text[text_length] == '\0'); + + return text; } @@ -228,36 +563,54 @@ 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; } @@ -280,18 +633,25 @@ 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; } @@ -300,35 +660,96 @@ 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; + + assert(src); + assert(dest); + assert(list_is_valid(src)); + assert(list_is_valid(dest)); - memset(dest, '\0', sizeof(*dest)); + list_remove_all(dest); - while (cur_src) + /* 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; + } + + 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 */ } - cur_dest->str = strdup(cur_src->str); - cur_src = cur_src->next; + + dest->last = cur_dest; } - dest->last = cur_dest; + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + return JB_ERR_OK; } @@ -336,268 +757,394 @@ void list_duplicate(struct list *dest, const struct list *src) * * Function : list_append_list_unique * - * Description : Append a string list to another list + * Description : Append a string list to another list. + * 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) + assert(src); + assert(dest); + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + + for (cur = src->first; cur; cur = cur->next) { - enlist_unique(dest, cur->str); - cur = cur->next; + if (cur->str) + { + if (enlist_unique(dest, cur->str, 0)) + { + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + + return JB_ERR_MEMORY; + } + } } + + assert(list_is_valid(src)); + assert(list_is_valid(dest)); + + return JB_ERR_OK; } /********************************************************************* * - * Function : destroy_list_share + * Function : list_is_empty * - * Description : Destroy a string list (opposite of enlist) + * Description : Test whether a list is empty. Does not change the list. * * Parameters : - * 1 : h = pointer to list 'dummy' header + * 1 : the_list = pointer to list to test. * - * Returns : N/A + * Returns : Nonzero if the list contains no entries. * *********************************************************************/ -void destroy_list_share(struct list_share *h) +int list_is_empty(const struct list *the_list) { - struct list_share *p, *n; - - for (p = h->next; p ; p = n) - { - n = p->next; - free(p); - } - - memset(h, '\0', sizeof(*h)); + assert(the_list); + assert(list_is_valid(the_list)); + return (the_list->first == NULL); } /********************************************************************* * - * Function : enlist_share + * Function : list_contains_item * - * Description : Append a string into a specified string list. + * Description : Tests whether a list item is already set. + * Does not change the list. * * Parameters : - * 1 : header = pointer to list 'dummy' header - * 2 : str = string to add to the list (maybe NULL) + * 1 : the_list = list to search in + * 2 : str = string to search for * - * Returns : N/A + * Returns : TRUE if the item was found, + * FALSE otherwise. * *********************************************************************/ -void enlist_share(struct list_share *header, const char *str) +int list_contains_item(const struct list *the_list, const char *str) { - struct list_share *cur = (struct list_share *)malloc(sizeof(*cur)); - struct list_share *last; + struct list_entry *entry; - if (cur) - { - cur->str = (str ? strdup(str) : NULL); - cur->next = NULL; + assert(the_list); + assert(list_is_valid(the_list)); + assert(str); - last = header->last; - if (last == NULL) + for (entry = the_list->first; entry != NULL; entry = entry->next) + { + if (entry->str == NULL) { - last = header; + /* + * NULL pointers are allowed in some lists. + * For example for csp->headers in case a + * header was removed. + */ + continue; } - last->next = cur; - header->last = cur; + if (0 == strcmp(str, entry->str)) + { + /* Item found */ + return TRUE; + } } + return FALSE; } /********************************************************************* * - * Function : enlist_unique_share + * Function : new_map * - * Description : Append a string into a specified string list, - * if & only if it's not there already. + * Description : Create a new, empty map. + * Causes program exit if the memory allocation fails. * - * Parameters : - * 1 : header = pointer to list 'dummy' header - * 2 : str = string to add to the list (maybe NULL) + * Parameters : N/A * - * Returns : N/A + * Returns : A new, empty map * *********************************************************************/ -void enlist_unique_share(struct list_share *header, const char *str) +struct map *new_map(void) { - struct list_share *last; - struct list_share *cur = header->next; + struct map *empty_map = zalloc(sizeof(struct map)); - while (cur != NULL) + if (NULL == empty_map) { - if ((cur->str != NULL) && (0 == strcmp(str, cur->str))) - { - /* Already there */ - return; - } - cur = cur->next; + exit(1); } - cur = (struct list_share *)malloc(sizeof(*cur)); + return empty_map; - if (cur != NULL) - { - cur->str = str; - cur->next = NULL; - - last = header->last; - if (last == NULL) - { - last = header; - } - last->next = cur; - header->last = cur; - } } /********************************************************************* * - * Function : list_append_list_unique_share + * Function : free_map * - * Description : Append a string list to another list + * Description : Free the memory occupied by a map and its + * dependent strings * * Parameters : - * 1 : dest = pointer to destination for merge. Caller allocs. - * 2 : src = pointer to source for merge. + * 1 : the_map = map to be freed. May be NULL. * * Returns : N/A * *********************************************************************/ -void list_append_list_unique_share(struct list_share *dest, const struct list *src) +void free_map(struct map *the_map) { - struct list * cur = src->next; + struct map_entry *cur_entry; + struct map_entry *next_entry; + + if (the_map == NULL) + { + return; + } - while (cur) + for (cur_entry = the_map->first; cur_entry != NULL; cur_entry = next_entry) { - enlist_unique_share(dest, cur->str); - cur = cur->next; + freez(cur_entry->name); + freez(cur_entry->value); + + next_entry = cur_entry->next; + free(cur_entry); } + + the_map->first = the_map->last = NULL; + + free(the_map); } /********************************************************************* * - * Function : list_remove_item_share + * Function : map * - * Description : Remove a string from a specified string list. + * 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 independently 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 : header = pointer to list 'dummy' header - * 2 : str = string to remove from the list + * 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 : Number of times it was removed. + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -int list_remove_item_share(struct list_share *header, const char *str) +jb_err map(struct map *the_map, + const char *name, int name_needs_copying, + const char *value, int value_needs_copying) { - struct list_share *prev = header; - struct list_share *cur = prev->next; - int count = 0; + struct map_entry *new_entry; - while (cur != NULL) + assert(the_map); + + if ( (NULL == value) + || (NULL == name) + || (NULL == (new_entry = zalloc(sizeof(*new_entry))))) { - if ((cur->str != NULL) && (0 == strcmp(str, cur->str))) + if ((name != NULL) && (!name_needs_copying)) { - count++; + free((char *)name); + } + if ((value != NULL) && (!value_needs_copying)) + { + free((char *)value); + } + return JB_ERR_MEMORY; + } - prev->next = cur->next; - free(cur); + if (name_needs_copying) + { + if (NULL == (name = strdup(name))) + { + free(new_entry); + if (!value_needs_copying) + { + free((char *)value); + } + return JB_ERR_MEMORY; } - else + } + + if (value_needs_copying) + { + if (NULL == (value = strdup(value))) { - prev = cur; + free((char *)name); + free(new_entry); + return JB_ERR_MEMORY; } - cur = prev->next; } - header->last = prev; + new_entry->name = name; + new_entry->value = value; + /* new_entry->next = NULL; - implied by zalloc */ - return count; + 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 : list_remove_list_share + * Function : unmap * - * Description : Remove all strings in one list from another list. - * This is currently a brute-force algorithm - * (it compares every pair of strings). + * Description : Remove all map_entry structs with a given name from + * a given map. * * Parameters : - * 1 : dest = list to change - * 2 : src = list of strings to remove + * 1 : the_map = map to look in + * 2 : name = name to unmap * - * Returns : Total number of strings removed. + * Returns : JB_ERR_OK * *********************************************************************/ -int list_remove_list_share(struct list_share *dest, const struct list *src) +jb_err unmap(struct map *the_map, const char *name) { - struct list *cur = src->next; - int count = 0; + struct map_entry *cur_entry, *last_entry; - while (cur != NULL) + assert(the_map); + assert(name); + + last_entry = NULL; + + for (cur_entry = the_map->first; cur_entry != NULL; cur_entry = cur_entry->next) { - if (cur->str != NULL) + if (!strcmp(name, cur_entry->name)) + { + /* + * Update the incoming pointer + */ + if (cur_entry == the_map->first) + { + the_map->first = cur_entry->next; + } + else + { + last_entry->next = cur_entry->next; + } + + /* + * Update the map's last pointer + */ + if (cur_entry == the_map->last) + { + the_map->last = last_entry; + } + + /* + * Free the map_entry + */ + freez(cur_entry->name); + freez(cur_entry->value); + freez(cur_entry); + if (last_entry == NULL) + { + /* The map only had a single entry which has just been removed. */ + break; + } + cur_entry = last_entry; + } + else { - count += list_remove_item_share(dest, cur->str); + last_entry = cur_entry; } - cur = cur->next; } - - return count; + return JB_ERR_OK; } /********************************************************************* * - * Function : list_duplicate_share + * Function : lookup * - * Description : Duplicate a string list + * Description : Look up an item with a given name in a map, and + * return its value * * Parameters : - * 1 : dest = pointer to destination for copy. Caller allocs. - * 2 : src = pointer to source for copy. + * 1 : the_map = map to look in + * 2 : name = name parameter to look for * - * Returns : N/A + * Returns : the value if found, else the empty string. + * Return value is allocated as part of the map, so + * it is freed when the map is destroyed. Caller + * must not free or modify it. * *********************************************************************/ -void list_duplicate_share(struct list_share *dest, const struct list *src) +const char *lookup(const struct map *the_map, const char *name) { - struct list * cur_src = src->next; - struct list_share * cur_dest = dest; + const struct map_entry *cur_entry; - memset(dest, '\0', sizeof(*dest)); + assert(the_map); + assert(name); - while (cur_src) + for (cur_entry = the_map->first; cur_entry != NULL; cur_entry = cur_entry->next) { - cur_dest = cur_dest->next = (struct list_share *)zalloc(sizeof(*cur_dest)); - if (cur_dest == NULL) + if (!strcmp(name, cur_entry->name)) { - return; + return cur_entry->value; } - cur_dest->str = cur_src->str; - cur_src = cur_src->next; } - - dest->last = cur_dest; - + return ""; } + +/* + Local Variables: + tab-width: 3 + end: +*/