X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fstrmap%2Fstrmap.h;fp=ccan%2Fstrmap%2Fstrmap.h;h=77197507c742707a5c8ff3e3e41d36ad27d635c5;hb=20f3b260313fb4d5566aeb0d0c5439574e914e2d;hp=0000000000000000000000000000000000000000;hpb=3dda2c8bfc6430ea97cbb3bc1040df2b793dab91;p=ccan diff --git a/ccan/strmap/strmap.h b/ccan/strmap/strmap.h new file mode 100644 index 00000000..77197507 --- /dev/null +++ b/ccan/strmap/strmap.h @@ -0,0 +1,224 @@ +#ifndef CCAN_STRMAP_H +#define CCAN_STRMAP_H +#include "config.h" +#include +#include +#include +#include + +/** + * struct strmap - representation of a string map + * + * It's exposed here to allow you to embed it and so we can inline the + * trivial functions. + */ +struct strmap { + union { + struct node *n; + const char *s; + } u; + void *v; +}; + +/** + * STRMAP_MEMBERS - declare members for a type-specific strmap. + * @type: type for this map's values, or void * for any pointer. + * + * You use this to create your own typed strmap for a particular type. + * You can use an integer type, *but* remember you can't use "0" as a + * value! + * + * Example: + * struct strmap_intp { + * STRMAP_MEMBERS(int *); + * }; + */ +#define STRMAP_MEMBERS(type) \ + struct strmap raw; \ + TCON(type canary) + + +/** + * strmap_init - initialize a string map (empty) + * @map: the typed strmap to initialize. + * + * For completeness; if you've arranged for it to be NULL already you don't + * need this. + * + * Example: + * struct strmap_intp map; + * + * strmap_init(&map); + */ +#define strmap_init(map) strmap_init_(&(map)->raw) + +static inline void strmap_init_(struct strmap *map) +{ + map->u.n = NULL; +} + +/** + * strmap_empty - is this string map empty? + * @map: the typed strmap to check. + * + * Example: + * if (!strmap_empty(&map)) + * abort(); + */ +#define strmap_empty(map) strmap_empty_(&(map)->raw) + +static inline bool strmap_empty_(const struct strmap *map) +{ + return map->u.n == NULL; +} + +/** + * strmap_get - get a value from a string map + * @map: the typed strmap to search. + * @member: the string to search for. + * + * Returns the value, or NULL if it isn't in the map. + * + * Example: + * int *val = strmap_get(&map, "hello"); + * if (val) + * printf("hello => %i\n", *val); + */ +#define strmap_get(map, member) \ + tcon_cast((map), canary, strmap_get_(&(map)->raw, (member))) +void *strmap_get_(const struct strmap *map, const char *member); + +/** + * strmap_add - place a member in the string map. + * @map: the typed strmap to add to. + * @member: the string to place in the map. + * @v: the (non-NULL) value. + * + * This returns false if we run out of memory, or (more normally) if that + * string already appears in the map. + * + * Note that the pointer is placed in the map, the string is not copied. If + * you want a copy in the map, use strdup(). Similarly for the value. + * + * Example: + * val = malloc(sizeof *val); + * *val = 17; + * if (!strmap_add(&map, "goodbye", val)) + * printf("goodbye was already in the map\n"); + */ +#define strmap_add(map, member, value) \ + strmap_add_(&tcon_check((map), canary, (value))->raw, \ + (member), (void *)(value)) + +bool strmap_add_(struct strmap *map, const char *member, const void *value); + +/** + * strmap_del - remove a member from the string map. + * @map: the typed strmap to delete from. + * @member: the string to remove from the map. + * @valuep: the value (if non-NULL) + * + * This returns the string which was passed to strmap_map(), or NULL. + * This means that if you allocated a string (eg. using strdup()), you + * can free it here. Similarly, the value is returned in @valuep if + * @valuep is not NULL. + * + * Example: + * if (!strmap_del(&map, "goodbye", NULL)) + * printf("goodbye was not in the map?\n"); + */ +#define strmap_del(map, member, valuep) \ + strmap_del_(&tcon_check_ptr((map), canary, valuep)->raw, \ + (member), (void **)valuep) +char *strmap_del_(struct strmap *map, const char *member, void **valuep); + +/** + * strmap_clear - remove every member from the map. + * @map: the typed strmap to clear. + * + * The map will be empty after this. + * + * Example: + * strmap_clear(&map); + */ +#define strmap_clear(map) strmap_clear_(&(map)->raw) + +void strmap_clear_(struct strmap *map); + +/** + * strmap_iterate - ordered iteration over a map + * @map: the typed strmap to iterate through. + * @handle: the function to call. + * @arg: the argument for the function (types should match). + * + * @handle's prototype should be: + * bool @handle(const char *member, type value, typeof(arg) arg) + * + * If @handle returns true, the iteration will stop. + * You should not alter the map within the @handle function! + * + * Example: + * struct strmap_intp { + * STRMAP_MEMBERS(int *); + * }; + * static bool dump_some(const char *member, int *value, int *num) + * { + * // Only dump out num nodes. + * if (*(num--) == 0) + * return true; + * printf("%s=>%i\n", member, *value); + * return false; + * } + * + * static void dump_map(const struct strmap_intp *map) + * { + * int max = 100; + * strmap_iterate(map, dump_some, &max); + * if (max < 0) + * printf("... (truncated to 100 entries)\n"); + * } + */ +#define strmap_iterate(map, handle, arg) \ + strmap_iterate_(&(map)->raw, \ + typesafe_cb_cast(bool (*)(const char *, \ + void *, void *), \ + bool (*)(const char *, \ + tcon_type((map), canary), \ + __typeof__(arg)), (handle)), \ + (arg)) +void strmap_iterate_(const struct strmap *map, + bool (*handle)(const char *, void *, void *), void *data); + + +/** + * strmap_prefix - return a submap matching a prefix + * @map: the map. + * @prefix: the prefix. + * + * This returns a pointer into @map, so don't alter @map while using + * the return value. You can use strmap_iterate(), strmap_get() or + * strmap_empty() on the returned pointer. + * + * Example: + * static void dump_prefix(const struct strmap_intp *map, + * const char *prefix) + * { + * int max = 100; + * printf("Nodes with prefix %s:\n", prefix); + * strmap_iterate(strmap_prefix(map, prefix), dump_some, &max); + * if (max < 0) + * printf("... (truncated to 100 entries)\n"); + * } + */ +#if HAVE_TYPEOF +#define strmap_prefix(map, prefix) \ + ((const __typeof__(map))strmap_prefix_(&(map)->raw, (prefix))) +#else +#define strmap_prefix(map, prefix) \ + ((const void *)strmap_prefix_(&(map)->raw, (prefix))) +#endif + +const struct strmap *strmap_prefix_(const struct strmap *map, + const char *prefix); + +#endif /* CCAN_STRMAP_H */