stringmap.c File Reference

#include <string.h>
#include <htils/arena.h>
#include <htils/assert.h>
#include <htils/basictypes.h>
#include <htils/stringmap.h>

Macros
#define	DEFAULT_CAPACITY   16

Functions
static u64	hash_key (const string *key)
	Hash a key into an index.
static void	sm_insert_direct (stringmap_t *map, const string *key, void *value, u64 vsize)
	Inserts a key-value pair into the stringmap directly.
static void	sm_grow (stringmap_t *map)
	Grow a stringmap if it's too small.
stringmap_t *	sm_new (arena_t *arena, const u64 capacity)
	Initializes a new stringmap.
stringmap_result_t	__sm_insert (stringmap_t *map, const string *key, const void *value, const u64 vsize)
	Insert key and value into the stringmap.
stringmap_result_t	sm_kill (stringmap_t *map, const string *key)
	Remove the entry at key from the stringmap.
void *	sm_get (stringmap_t *map, const string *key)
	Get a value from the stringmap.

Macro Definition Documentation

DEFAULT_CAPACITY

#define DEFAULT_CAPACITY   16

Function Documentation

__sm_insert()

stringmap_result_t __sm_insert	(	stringmap_t *	map,
		const string *	key,
		const void *	value,
		u64	vsize )

Insert key and value into the stringmap.

Hashes and duplicates the key and sets the value, if the key already exists, it will be updated, if the capacity is too small, it will be automatically grown.

Note

This function is not meant to be run directly, and is called by the sm_insert() macro.

Parameters

map	The stringmap to insert into.
key	The key to insert.
value	The value to associate with the key.
vsize	The size of the value.

Precondition

• map and key must be valid and cannot be null.
• value can't be null, as it would lead to a null dereference.

Returns

The result of the insert (which will be either CREATED or UPDATED in this case).

hash_key()

u64 hash_key ( const string * key )

static

Hash a key into an index.

Hashes a key into an index, using the FNV-1a algorithm.

Parameters

key	The key to hash.

Precondition

key must be valid and cannot be null.

Returns

The hash generated from the key.

sm_get()

void * sm_get	(	stringmap_t *	map,
		const string *	key )

Get a value from the stringmap.

Returns the value stored at key, or null if the key is absent or the entry is dead.

Parameters

map	The stringmap to get from.
key	The key to get.

Precondition

map and key must be valid and cannot be null.

Returns

The value associated with the key, or null if it doesn't exist or is dead.

sm_grow()

void sm_grow ( stringmap_t * map )

static

Grow a stringmap if it's too small.

By doubling the capacity, allocating a new block using arena_alloc(), and copying over all occupied entries.

Parameters

map	The stringmap to grow.

Precondition

map must be valid and cannot be null.

sm_insert_direct()

void sm_insert_direct ( stringmap_t * map, const string * key, void * value, u64 vsize )

static

Inserts a key-value pair into the stringmap directly.

By first hashing the key, then iterating through the entries.

Parameters

map	The stringmap to insert into.
key	The key to insert.
value	The value to insert.
vsize	The size of the value.

Precondition

• map, key, and value must be valid and cannot be null.
• vsize must be greater than 0 and the explicit size of the value, since value is a void * it has to be provided.

sm_kill()

stringmap_result_t sm_kill	(	stringmap_t *	map,
		const string *	key )

Remove the entry at key from the stringmap.

Marks an entry as DEAD, if the key doesn't exist, it will return NOT_FOUND, otherwise it will return KILLED.

Parameters

map	The stringmap to remove from.
key	The key to remove.

Precondition

map and key must be valid and cannot be null.

Returns

The result of the remove (which will be either KILLED or NOT_FOUND in this case).

sm_new()

stringmap_t * sm_new	(	arena_t *	arena,
		const u64	capacity )

Initializes a new stringmap.

Optionally use a nullable type for stringmaps.

With the capacity, and arena, if the given capacity is 0, it will use the built in default capacity, which is 16.

Parameters

arena	The arena to allocate from.
capacity	The capacity of the stringmap.

Precondition

arena must be valid and cannot be null.

Returns

A pointer to the new stringmap.