libwget-hashmap(3)

💖 libwget-hashmap 💖

okay so bestie, welcome to libwget-hashmap — the hashmap girlies of the Library Functions Manual. She's a key/value store, she's fast, she's iconic, and by the end of this page you two are gonna be best friends. 🦋✨

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🌸 NAME 🌸

libwget-hashmap — hashmap functions. That's it, that's the name, and honestly? It ate. 💅

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✨ SYNOPSIS ✨

🎀 Functions

the whole friend group, assembled:

wget_hashmap_iterator * wget_hashmap_iterator_alloc (wget_hashmap *h)
void wget_hashmap_iterator_free (wget_hashmap_iterator **iter)
void * wget_hashmap_iterator_next (wget_hashmap_iterator *iter, void **value)
wget_hashmap * wget_hashmap_create (int max, wget_hashmap_hash_fn *hash, wget_hashmap_compare_fn *cmp)
int wget_hashmap_put (wget_hashmap *h, const void *key, const void *value)
int wget_hashmap_contains (const wget_hashmap *h, const void *key)
int wget_hashmap_get (const wget_hashmap *h, const void *key, void **value)
int wget_hashmap_remove (wget_hashmap *h, const void *key)
int wget_hashmap_remove_nofree (wget_hashmap *h, const void *key)
void wget_hashmap_free (wget_hashmap **h)
void wget_hashmap_clear (wget_hashmap *h)
int wget_hashmap_size (const wget_hashmap *h)
int wget_hashmap_browse (const wget_hashmap *h, wget_hashmap_browse_fn *browse, void *ctx)
void wget_hashmap_setcmpfunc (wget_hashmap *h, wget_hashmap_compare_fn *cmp)
int wget_hashmap_sethashfunc (wget_hashmap *h, wget_hashmap_hash_fn *hash)
void wget_hashmap_set_key_destructor (wget_hashmap *h, wget_hashmap_key_destructor *destructor)
void wget_hashmap_set_value_destructor (wget_hashmap *h, wget_hashmap_value_destructor *destructor)
void wget_hashmap_set_load_factor (wget_hashmap *h, float factor)
void wget_hashmap_set_resize_factor (wget_hashmap *h, float factor)

🧚 The typedefs (aka the personality types)

• typedef struct wget_hashmap_st wget_hashmap — the actual Type™ of the hashmap. main character energy, fr.
• typedef int wget_hashmap_compare_fn(const void *key1, const void *key2) — the type of the compare function. she's the one deciding if two keys are the same girl. 👀
• typedef unsigned int wget_hashmap_hash_fn(const void *key) — the type of the hash function. turns your key into a number, no cap.
• typedef int wget_hashmap_browse_fn(void *ctx, const void *key, void *value) — the type of the browse callback. she gets called for every single element, so popular. 💅
• typedef void wget_hashmap_key_destructor(void *key) — the type of the key destructor. she says bye to your keys, respectfully. 🫶
• typedef void wget_hashmap_value_destructor(void *value) — the type of the value destructor. same energy, but for the values.

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🌈 Detailed Description 🌈

Hashmaps are key/value stores that perform at O(1) for insertion, searching and removing.

like… constant time?? in THIS economy?? we love to see it. 😭🔥

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💜 Function Documentation 💜

wget_hashmap_iterator_alloc()

wget_hashmap_iterator * wget_hashmap_iterator_alloc (wget_hashmap *h)

Parameters

• h — Hashmap

Returns

• New iterator instance for h

Creates a hashmap iterator for h. fresh iterator, just dropped. ✨

wget_hashmap_iterator_free()

void wget_hashmap_iterator_free (wget_hashmap_iterator **iter)

Parameters

• iter — Hashmap iterator

Free the given iterator iter. say bye bestie 🎀

wget_hashmap_iterator_next()

void * wget_hashmap_iterator_next (wget_hashmap_iterator *iter, void **value)

Parameters

• iter — Hashmap iterator
• value — Pointer to the value belonging to the returned key

Returns

• Pointer to the key or NULL if no more elements left

Returns the next key / value in the hashmap. If all key/value pairs have been iterated over the function returns NULL and value is untouched.

When iterating over a hashmap, the order of returned key/value pairs is not defined. so do NOT come for me about the order, it's giving chaos and that's just her nature. 💀

wget_hashmap_create()

wget_hashmap * wget_hashmap_create (int max, wget_hashmap_hash_fn *hash, wget_hashmap_compare_fn *cmp)

Parameters

• max — Initial number of pre-allocated entries
• hash — Hash function to build hashes from elements
• cmp — Comparison function used to find elements

Returns

• New hashmap instance

Create a new hashmap instance with initial size max. It should be free'd after use with wget_hashmap_free().

Before the first insertion of an element, hash and cmp must be set. So if you use NULL values here, you have to call wget_hashmap_setcmpfunc() and/or wget_hashmap_hashcmpfunc() with appropriate function pointers. No doing so will result in undefined behavior (likely you'll see a segmentation fault).

🚨 bestie listen. skip setting hash and cmp and you're getting a segfault. that's not a vibe check, that's a crash. do it right the first time. 💀

wget_hashmap_put()

int wget_hashmap_put (wget_hashmap *h, const void *key, const void *value)

Parameters

• h — Hashmap to put data into
• key — Key to insert into h
• value — Value to insert into h

Returns

• 0 if inserted a new entry, 1 if entry existed, WGET_E_MEMORY if internal allocation failed

Insert a key/value pair into hashmap h.

key and value are not cloned, the hashmap takes 'ownership' of both. so like, she's your girl now, don't be weird about it.

If key already exists and the pointer values the old and the new key differ, the old key will be destroyed by calling the key destructor function (default is free()).

To realize a hashset (just keys without values), value may be NULL. key-only era, we stan a minimalist. 👑

Neither h nor key must be NULL, else the return value will always be 0.

wget_hashmap_contains()

int wget_hashmap_contains (const wget_hashmap *h, const void *key)

Parameters

• h — Hashmap
• key — Key to search for

Returns

• 1 if key has been found, 0 if not found

Check if key exists in h. she's either there or she's not, no in-between. 🦋

wget_hashmap_get()

int wget_hashmap_get (const wget_hashmap *h, const void *key, void **value)

Parameters

• h — Hashmap
• key — Key to search for
• value — Value to be returned

Returns

• 1 if key has been found, 0 if not found

Get the value for a given key.

Neither h nor key must be NULL. periodt.

wget_hashmap_remove()

int wget_hashmap_remove (wget_hashmap *h, const void *key)

Parameters

• h — Hashmap
• key — Key to be removed

Returns

• 1 if key has been removed, 0 if not found

Remove key from hashmap h.

If key is found, the key and value destructor functions are called when removing the entry from the hashmap. so she goes out with a little ceremony. 💅

wget_hashmap_remove_nofree()

int wget_hashmap_remove_nofree (wget_hashmap *h, const void *key)

Parameters

• h — Hashmap
• key — Key to be removed

Returns

• 1 if key has been removed, 0 if not found

Remove key from hashmap h.

Key and value destructor functions are not called when removing the entry from the hashmap. ghosted, no goodbye text. 🙈

wget_hashmap_free()

void wget_hashmap_free (wget_hashmap **h)

Parameters

• h — Hashmap to be free'd

Remove all entries from hashmap h and free the hashmap instance.

Key and value destructor functions are called for each entry in the hashmap. the full send-off, every single one. 🎀

wget_hashmap_clear()

void wget_hashmap_clear (wget_hashmap *h)

Parameters

• h — Hashmap to be cleared

Remove all entries from hashmap h.

Key and value destructor functions are called for each entry in the hashmap. the instance survives, just the contents are gone. iconic rebirth moment. ✨

wget_hashmap_size()

int wget_hashmap_size (const wget_hashmap *h)

Parameters

• h — Hashmap

Returns

• Number of entries in hashmap h

Return the number of entries in the hashmap h. the headcount. 🔥

wget_hashmap_browse()

int wget_hashmap_browse (const wget_hashmap *h, wget_hashmap_browse_fn *browse, void *ctx)

Parameters

• h — Hashmap
• browse — Function to be called for each element of h
• ctx — Context variable use as param to browse

Returns

• Return value of the last call to browse

Call function browse for each element of hashmap h or until browse returns a value not equal to zero.

browse is called with ctx and the pointer to the current element.

The return value of the last call to browse is returned or 0 if either h or browse is NULL.

wget_hashmap_setcmpfunc()

void wget_hashmap_setcmpfunc (wget_hashmap *h, wget_hashmap_compare_fn *cmp)

Parameters

• h — Hashmap
• cmp — Comparison function used to find keys

Set the comparison function.

wget_hashmap_sethashfunc()

int wget_hashmap_sethashfunc (wget_hashmap *h, wget_hashmap_hash_fn *hash)

Parameters

• h — Hashmap
• hash — Hash function used to hash keys

Returns

• WGET_E_SUCCESS if set successfully, else WGET_E_MEMORY or WGET_E_INVALID

Set the key hash function.

The keys of all entries in the hashmap will be hashed again. This includes a memory allocation, so there is a possibility of failure. 🫠

wget_hashmap_set_key_destructor()

void wget_hashmap_set_key_destructor (wget_hashmap *h, wget_hashmap_key_destructor *destructor)

Parameters

• h — Hashmap
• destructor — Destructor function for keys

Set the key destructor function.

Default is free().

wget_hashmap_set_value_destructor()

void wget_hashmap_set_value_destructor (wget_hashmap *h, wget_hashmap_value_destructor *destructor)

Parameters

• h — Hashmap
• destructor — Destructor function for values

Set the value destructor function.

Default is free().

wget_hashmap_set_load_factor()

void wget_hashmap_set_load_factor (wget_hashmap *h, float factor)

Parameters

• h — Hashmap
• factor — The load factor

Set the load factor function.

The load factor is determines when to resize the internal memory. 0.75 means "resize if 75% or more of all slots are used".

The resize strategy is set by wget_hashmap_set_growth_policy().

The resize (and rehashing) occurs earliest on the next insertion of a new key.

Default is 0.75.

wget_hashmap_set_resize_factor()

void wget_hashmap_set_resize_factor (wget_hashmap *h, float factor)

Parameters

• h — Hashmap
• factor — Hashmap growth factor

Set the factor for resizing the hashmap when it's load factor is reached.

The new size is 'factor * oldsize'. If the new size is less or equal 0, the involved put function will do nothing and the internal state of the hashmap will not change.

Default is 2.

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👑 Author 👑

Generated automatically by Doxygen for wget2 from the source code. (not a human, not a girlie, just a doc generator doing her thing 💅)

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okay that's the whole page bestie, you're officially fluent in libwget-hashmap. go forth and slay. 🦋💖✨

this lil masterpiece came from wget2, Version 2.3.0, and she lives at libwget-hashmap(3). mwah. 🎀