#Description This is a stand-alone map/dictionary implementation I've made for the heck of it. All the code is licensed under the public domain and you can use it however you wish. It seems fairly fast, but I havn't ran any comprehensive benchmarks so I couldn't say for certain. Since the code really doesn't have any useful comments, I've tried to make it pretty straight-forward and I've included some documentation below.
###MISC. IMPLEMENTATION INFO NONE of the functions should be assumed to be re-entrant OR thread-safe, because they are not. The functions have collision detection and handle such cases accordingly.
- NOTE: I've discarded the const qualifiers for readibility
- NOTE: All return values are at the end of the README
#Types
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hashfunc -
DECLARATION:
typedef unsigned hashfunc(const char*, unsigned); -
map_t -
The map object.
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mapelem_t -
The map element object used by internal functions, it should not be accessed from the outside.
#Functions
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int map_init(map_t *map, unsigned keys) -
Calls
map_init2()with the built in hash function. The built-in hash function is fairly fast, but requires that the amount of keys be in the form 2^n. -
int map_init2(map_t *map, hashfunc *hash, unsigned keys) -
Initializes map with the specified hash function and keys.
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int map_insert(map_t *map, char *key, char *value) -
Inserts the key/value pair into the specified map. This function is non-destructive. If it encounters that the same key already exists it returns without doing anything.
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int map_reassign(map_t *map, char *key, char *value) -
Like map_insert, it will insert the key/value pair into the map if it doesn't already exist. If it encounters that a key already exists, the current value will be replaced with the value passed to the function.
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int map_exists(map_t *map, char *key) -
Simply returns whether or not the key exists.
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int map_lookup(map_t *map, char *dest, char *key, size_t size) -
If the key exists the value will be written into the pointer specified by dest up to 'size' bytes.
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void map_remove(map_t *map, char *key) -
Removes the specified key from the map if it exists.
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void map_delete(map_t *map) -
Completely deinitializes the map object.
#Function Return Values
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-1 :: There was a memory error
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map_init,map_init2,map_insert,map_reassign -
0 :: The operation was successful
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all functions will return this value on success
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1 :: Differs per function that uses this return value
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map_insert: The key already exists -
map_exists,map_lookup: The key doesn't exist
NOTE: map_remove and map_delete will not return a value, this is because the only reason
for them to 'fail' is if there is nothing for them todo(i.e. the element has either already been
removed or the map has already been deleted).