# lv_lru.h (/api/misc/lv_lru_h)



<ApiSummary functions="6" enums="1" structs="1" typedefs="3" />

Functions [#functions]

<ApiTabs items="[&#x22;Setters (1)&#x22;,&#x22;Getters (1)&#x22;,&#x22;Other (4)&#x22;]">
  <ApiTab value="Setters (1)">
    <ApiMember kind="function" name="lv_lru_set" file="misc/lv_lru.h" line="64" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L64">
      lv_lru_set [#lv_lru_set]

      ```c title=" " lineNumbers=1
      lv_lru_res_t lv_lru_set(lv_lru_t *cache, const void *key, size_t key_length, void *value, size_t value_length)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name           | Type                                             |
      | -------------- | ------------------------------------------------ |
      | `cache`        | <ApiLink name="lv_lru_t" display="lv_lru_t *" /> |
      | `key`          | `const void *`                                   |
      | `key_length`   | <ApiLink name="size_t" />                        |
      | `value`        | `void *`                                         |
      | `value_length` | <ApiLink name="size_t" />                        |
    </ApiMember>
  </ApiTab>

  <ApiTab value="Getters (1)">
    <ApiMember kind="function" name="lv_lru_get" file="misc/lv_lru.h" line="66" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L66">
      lv_lru_get [#lv_lru_get]

      ```c title=" " lineNumbers=1
      lv_lru_res_t lv_lru_get(lv_lru_t *cache, const void *key, size_t key_size, void **value)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name       | Type                                             |
      | ---------- | ------------------------------------------------ |
      | `cache`    | <ApiLink name="lv_lru_t" display="lv_lru_t *" /> |
      | `key`      | `const void *`                                   |
      | `key_size` | <ApiLink name="size_t" />                        |
      | `value`    | `void **`                                        |
    </ApiMember>
  </ApiTab>

  <ApiTab value="Other (4)">
    <ApiMember kind="function" name="lv_lru_create" file="misc/lv_lru.h" line="59" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L59">
      lv_lru_create [#lv_lru_create]

      ```c title=" " lineNumbers=1
      lv_lru_t * lv_lru_create(size_t cache_size, size_t average_length, lv_lru_free_cb_t value_free, lv_lru_free_cb_t key_free)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name             | Type                                |
      | ---------------- | ----------------------------------- |
      | `cache_size`     | <ApiLink name="size_t" />           |
      | `average_length` | <ApiLink name="size_t" />           |
      | `value_free`     | <ApiLink name="lv_lru_free_cb_t" /> |
      | `key_free`       | <ApiLink name="lv_lru_free_cb_t" /> |
    </ApiMember>

    <ApiMember kind="function" name="lv_lru_delete" file="misc/lv_lru.h" line="62" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L62">
      lv_lru_delete [#lv_lru_delete]

      ```c title=" " lineNumbers=1
      void lv_lru_delete(lv_lru_t *cache)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name    | Type                                             |
      | ------- | ------------------------------------------------ |
      | `cache` | <ApiLink name="lv_lru_t" display="lv_lru_t *" /> |
    </ApiMember>

    <ApiMember kind="function" name="lv_lru_remove" file="misc/lv_lru.h" line="68" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L68">
      lv_lru_remove [#lv_lru_remove]

      ```c title=" " lineNumbers=1
      lv_lru_res_t lv_lru_remove(lv_lru_t *cache, const void *key, size_t key_size)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name       | Type                                             |
      | ---------- | ------------------------------------------------ |
      | `cache`    | <ApiLink name="lv_lru_t" display="lv_lru_t *" /> |
      | `key`      | `const void *`                                   |
      | `key_size` | <ApiLink name="size_t" />                        |
    </ApiMember>

    <ApiMember kind="function" name="lv_lru_remove_lru_item" file="misc/lv_lru.h" line="75" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L75">
      lv_lru_remove_lru_item [#lv_lru_remove_lru_item]

      remove the least recently used item

      \> &#x2A;*Todo:** we can optimise this by finding the n lru items, where n = required\_space / average\_length

      ```c title=" " lineNumbers=1
      void lv_lru_remove_lru_item(lv_lru_t *cache)
      ```

      <span className="sr-only">
        Parameters
      </span>

      | Name    | Type                                             |
      | ------- | ------------------------------------------------ |
      | `cache` | <ApiLink name="lv_lru_t" display="lv_lru_t *" /> |
    </ApiMember>
  </ApiTab>
</ApiTabs>

Enums [#enums]

<ApiMember kind="enum" name="lv_lru_res_t" file="misc/lv_lru.h" line="29" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L29">
  lv_lru_res_t [#lv_lru_res_t]

  | Name                     | Value |
  | ------------------------ | ----- |
  | `LV_LRU_OK`              | `0`   |
  | `LV_LRU_MISSING_CACHE`   |       |
  | `LV_LRU_MISSING_KEY`     |       |
  | `LV_LRU_MISSING_VALUE`   |       |
  | `LV_LRU_LOCK_ERROR`      |       |
  | `LV_LRU_VALUE_TOO_LARGE` |       |
</ApiMember>

Structs [#structs]

<ApiMember kind="struct" name="_lv_lru_t">
  \_lv_lru_t [#_lv_lru_t]

  | Member                | Type                                                        | Description |
  | --------------------- | ----------------------------------------------------------- | ----------- |
  | `items`               | <ApiLink name="lv_lru_item_t" display="lv_lru_item_t **" /> |             |
  | `access_count`        | <ApiLink name="uint64_t" />                                 |             |
  | `free_memory`         | <ApiLink name="size_t" />                                   |             |
  | `total_memory`        | <ApiLink name="size_t" />                                   |             |
  | `average_item_length` | <ApiLink name="size_t" />                                   |             |
  | `hash_table_size`     | <ApiLink name="size_t" />                                   |             |
  | `seed`                | <ApiLink name="uint32_t" />                                 |             |
  | `value_free`          | <ApiLink name="lv_lru_free_cb_t" />                         |             |
  | `key_free`            | <ApiLink name="lv_lru_free_cb_t" />                         |             |
  | `free_items`          | <ApiLink name="lv_lru_item_t" display="lv_lru_item_t *" />  |             |
</ApiMember>

Typedefs [#typedefs]

<ApiMember kind="typedef" name="lv_lru_free_cb_t" file="misc/lv_lru.h" line="38" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L38">
  lv_lru_free_cb_t [#lv_lru_free_cb_t]

  ```c title=" " lineNumbers=1
  typedef void(* lv_lru_free_cb_t) (void *v)
  ```
</ApiMember>

<TypeUsedBy name="lv_lru_free_cb_t" count="2">
  * `lv_lru_create` — param `value_free`
  * `lv_lru_create` — param `key_free`
</TypeUsedBy>

<ApiMember kind="typedef" name="lv_lru_item_t" file="misc/lv_lru.h" line="40" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L40">
  lv_lru_item_t [#lv_lru_item_t]

  ```c title=" " lineNumbers=1
  typedef struct _lv_lru_item_t lv_lru_item_t
  ```
</ApiMember>

<ApiMember kind="typedef" name="lv_lru_t" file="misc/lv_lru.h" line="53" url="https://github.com/lvgl/lvgl/tree/a7b95c5b0839ce901c09c205610bc2c77cc3345d/src/misc/lv_lru.h#L53">
  lv_lru_t [#lv_lru_t]

  ```c title=" " lineNumbers=1
  typedef struct _lv_lru_t lv_lru_t
  ```
</ApiMember>

<TypeUsedBy name="lv_lru_t" count="5">
  * `lv_lru_delete` — param `cache`
  * `lv_lru_set` — param `cache`
  * `lv_lru_get` — param `cache`
  * `lv_lru_remove` — param `cache`
  * `lv_lru_remove_lru_item` — param `cache`
</TypeUsedBy>

Dependencies [#dependencies]

<FileIncludes includes="[&#x22;lv_conf_internal.h&#x22;, &#x22;lv_types.h&#x22;]" transitiveIncludes="[&#x22;lv_conf_kconfig.h&#x22;]" />