From 8d59f7cc685e7b83a3634a329f7f8eabe583653a Mon Sep 17 00:00:00 2001 From: jongfoster Date: Tue, 23 Oct 2001 21:21:03 +0000 Subject: [PATCH] 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. --- list.c | 155 ++++++++++++++++++++++++++++++++++++--------------------- list.h | 25 ++++++---- 2 files changed, 112 insertions(+), 68 deletions(-) diff --git a/list.c b/list.c index 0625e660..752948f0 100644 --- a/list.c +++ b/list.c @@ -1,4 +1,4 @@ -const char list_rcs[] = "$Id: list.c,v 1.9 2001/09/16 13:20:29 jongfoster Exp $"; +const char list_rcs[] = "$Id: list.c,v 1.10 2001/09/16 17:30:24 jongfoster Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/list.c,v $ @@ -34,6 +34,9 @@ const char list_rcs[] = "$Id: list.c,v 1.9 2001/09/16 13:20:29 jongfoster Exp $" * * Revisions : * $Log: list.c,v $ + * 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 @@ -269,11 +272,12 @@ static int list_is_valid (const struct list *the_list) * 1 : the_list = pointer to list * 2 : str = string to add to the list (maybe NULL) * - * Returns : 0 on success, nonzero on out-of-memory error. On - * error, the_list will be unchanged. + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * On error, the_list will be unchanged. * *********************************************************************/ -int enlist(struct list *the_list, const char *str) +jb_err enlist(struct list *the_list, const char *str) { struct list_entry *cur; @@ -282,7 +286,7 @@ int enlist(struct list *the_list, const char *str) if (NULL == (cur = (struct list_entry *)zalloc(sizeof(*cur)))) { - return 1; + return JB_ERR_MEMORY; } if (str) @@ -290,7 +294,7 @@ int enlist(struct list *the_list, const char *str) if (NULL == (cur->str = strdup(str))) { free(cur); - return 1; + return JB_ERR_MEMORY; } } /* else { cur->str = NULL; } - implied by zalloc */ @@ -309,7 +313,7 @@ int enlist(struct list *the_list, const char *str) } assert(list_is_valid(the_list)); - return 0; + return JB_ERR_OK; } @@ -324,11 +328,12 @@ int enlist(struct list *the_list, const char *str) * 1 : the_list = pointer to list * 2 : str = string to add to the list (maybe NULL) * - * Returns : 0 on success, nonzero on out-of-memory error. On - * error, the_list will be unchanged. + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * On error, the_list will be unchanged. * *********************************************************************/ -int enlist_first(struct list *the_list, const char *str) +jb_err enlist_first(struct list *the_list, const char *str) { struct list_entry *cur; @@ -337,7 +342,7 @@ int enlist_first(struct list *the_list, const char *str) if (NULL == (cur = (struct list_entry *)zalloc(sizeof(*cur)))) { - return 1; + return JB_ERR_MEMORY; } if (str) @@ -345,7 +350,7 @@ int enlist_first(struct list *the_list, const char *str) if (NULL == (cur->str = strdup(str))) { free(cur); - return 1; + return JB_ERR_MEMORY; } } /* else { cur->str = NULL; } - implied by zalloc */ @@ -359,7 +364,7 @@ int enlist_first(struct list *the_list, const char *str) } assert(list_is_valid(the_list)); - return 0; + return JB_ERR_OK; } @@ -378,14 +383,15 @@ int enlist_first(struct list *the_list, const char *str) * 3 : num_significant_chars = number of chars to use * for uniqueness test, or 0 to require an exact match. * - * Returns : 0 on success, nonzero 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. + * 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. * *********************************************************************/ -int enlist_unique(struct list *the_list, const char *str, - int num_significant_chars) +jb_err enlist_unique(struct list *the_list, const char *str, + int num_significant_chars) { struct list_entry *cur_entry; @@ -403,7 +409,7 @@ int enlist_unique(struct list *the_list, const char *str, && (0 == strncmp(str, cur_entry->str, num_significant_chars))) { /* Already there */ - return 0; + return JB_ERR_OK; } } } @@ -415,7 +421,7 @@ int enlist_unique(struct list *the_list, const char *str, if ( (cur_entry->str != NULL) && (0 == strcmp(str, cur_entry->str))) { /* Already there */ - return 0; + return JB_ERR_OK; } } } @@ -437,16 +443,18 @@ int enlist_unique(struct list *the_list, const char *str, * 2 : name = HTTP header name (e.g. "Content-type") * 3 : value = HTTP header value (e.g. "text/html") * - * Returns : 0 on success, nonzero 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. + * 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. * *********************************************************************/ -int enlist_unique_header(struct list *the_list, const char *name, const char *value) +jb_err enlist_unique_header(struct list *the_list, const char *name, + const char *value) { int length; - int result; + jb_err result; char *str; assert(the_list); @@ -457,7 +465,7 @@ int enlist_unique_header(struct list *the_list, const char *name, const char *va length = strlen(name) + 2; if (NULL == (str = (char *)malloc(length + strlen(value) + 1))) { - return 1; + return JB_ERR_MEMORY; } strcpy(str, name); str[length - 2] = ':'; @@ -546,7 +554,7 @@ char *list_to_text(const struct list *the_list) if ((ret = (char *)malloc(size + 1)) == NULL) { - return(NULL); + return NULL; } ret[size] = '\0'; @@ -564,7 +572,7 @@ char *list_to_text(const struct list *the_list) } *s++ = '\r'; *s++ = '\n'; - return(ret); + return ret; } @@ -679,11 +687,12 @@ int list_remove_list(struct list *dest, const struct list *src) * All existing entries will be removed. * 1 : src = pointer to source list for copy. * - * Returns : 0 on success, nonzero on error. On error, dest - * will be empty. + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. + * On error, dest will be empty. * *********************************************************************/ -int list_duplicate(struct list *dest, const struct list *src) +jb_err list_duplicate(struct list *dest, const struct list *src) { struct list_entry * cur_src; struct list_entry * cur_dest; @@ -707,7 +716,7 @@ int list_duplicate(struct list *dest, const struct list *src) assert(list_is_valid(src)); assert(list_is_valid(dest)); - return 1; + return JB_ERR_MEMORY; } if (cur_src->str) @@ -720,7 +729,7 @@ int list_duplicate(struct list *dest, const struct list *src) assert(list_is_valid(src)); assert(list_is_valid(dest)); - return 1; + return JB_ERR_MEMORY; } } /* else { cur_dest->str = NULL; } - implied by zalloc */ @@ -736,7 +745,7 @@ int list_duplicate(struct list *dest, const struct list *src) assert(list_is_valid(src)); assert(list_is_valid(dest)); - return 1; + return JB_ERR_MEMORY; } if (cur_src->str) { @@ -748,7 +757,7 @@ int list_duplicate(struct list *dest, const struct list *src) assert(list_is_valid(src)); assert(list_is_valid(dest)); - return 1; + return JB_ERR_MEMORY; } } /* else { cur_dest->str = NULL; } - implied by zalloc */ @@ -760,7 +769,7 @@ int list_duplicate(struct list *dest, const struct list *src) assert(list_is_valid(src)); assert(list_is_valid(dest)); - return 0; + return JB_ERR_OK; } @@ -775,12 +784,13 @@ int list_duplicate(struct list *dest, const struct list *src) * 1 : dest = pointer to destination list for merge. * 2 : src = pointer to source for merge. * - * Returns : 0 on success, nonzero on out-of-memory error. + * 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. * *********************************************************************/ -int 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_entry * cur; @@ -798,7 +808,7 @@ int list_append_list_unique(struct list *dest, const struct list *src) assert(list_is_valid(src)); assert(list_is_valid(dest)); - return 1; + return JB_ERR_MEMORY; } } } @@ -806,7 +816,7 @@ int list_append_list_unique(struct list *dest, const struct list *src) assert(list_is_valid(src)); assert(list_is_valid(dest)); - return 0; + return JB_ERR_OK; } @@ -897,6 +907,27 @@ void free_map(struct map *the_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 @@ -904,22 +935,31 @@ void free_map(struct map *the_map) * 4 : value = value to add * 5 : value_needs_copying = flag set if a copy of value should be used * - * Returns : 0 on success, nonzero on out-of-memory error. + * Returns : JB_ERR_OK on success + * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ -int map(struct map *the_map, - const char *name, int name_needs_copying, - const char *value, int value_needs_copying) +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); - assert(name); - assert(value); - if (NULL == (new_entry = zalloc(sizeof(*new_entry)))) + if ( (NULL == value) + || (NULL == name) + || (NULL == (new_entry = zalloc(sizeof(*new_entry)))) ) { - return 1; + 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) @@ -927,7 +967,11 @@ int map(struct map *the_map, if (NULL == (name = strdup(name))) { free(new_entry); - return 1; + if (!value_needs_copying) + { + free((char *)value); + } + return JB_ERR_MEMORY; } } @@ -935,12 +979,9 @@ int map(struct map *the_map, { if (NULL == (value = strdup(value))) { - if (name_needs_copying) - { - free((char *)name); - } + free((char *)name); free(new_entry); - return 1; + return JB_ERR_MEMORY; } } @@ -959,7 +1000,7 @@ int map(struct map *the_map, the_map->last = new_entry; } - return 0; + return JB_ERR_OK; } diff --git a/list.h b/list.h index edb4ded4..11e46ff2 100644 --- a/list.h +++ b/list.h @@ -1,6 +1,6 @@ #ifndef LIST_H_INCLUDED #define LIST_H_INCLUDED -#define LIST_H_VERSION "$Id: list.h,v 1.7 2001/09/16 13:20:29 jongfoster Exp $" +#define LIST_H_VERSION "$Id: list.h,v 1.8 2001/09/16 17:30:24 jongfoster Exp $" /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/list.h,v $ @@ -36,6 +36,9 @@ * * Revisions : * $Log: list.h,v $ + * Revision 1.8 2001/09/16 17:30:24 jongfoster + * Fixing a compiler warning. + * * Revision 1.7 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 @@ -99,18 +102,18 @@ extern "C" { extern void init_list (struct list *the_list); extern void destroy_list (struct list *the_list); -extern int enlist (struct list *the_list, const char *str); -extern int enlist_unique (struct list *the_list, const char *str, int num_significant_chars); -extern int enlist_unique_header (struct list *the_list, const char *name, const char *value); -extern int enlist_first (struct list *the_list, const char *str); -extern int list_append_list_unique(struct list *dest, const struct list *src); -extern int list_duplicate (struct list *dest, const struct list *src); +extern jb_err enlist (struct list *the_list, const char *str); +extern jb_err enlist_unique (struct list *the_list, const char *str, int num_significant_chars); +extern jb_err enlist_unique_header (struct list *the_list, const char *name, const char *value); +extern jb_err enlist_first (struct list *the_list, const char *str); +extern jb_err list_append_list_unique(struct list *dest, const struct list *src); +extern jb_err list_duplicate (struct list *dest, const struct list *src); -extern int list_remove_item(struct list *the_list, const char *str); -extern int list_remove_list(struct list *dest, const struct list *src); -extern void list_remove_all (struct list *the_list); +extern int list_remove_item(struct list *the_list, const char *str); +extern int list_remove_list(struct list *dest, const struct list *src); +extern void list_remove_all (struct list *the_list); -extern int list_is_empty(const struct list *the_list); +extern int list_is_empty(const struct list *the_list); extern char * list_to_text(const struct list *the_list); -- 2.39.2