.. zephyr:code-sample:: system_hashmap
   :name: System hashmap
   :relevant-api: hashmap_apis

   Insert, replace, and remove entries in a hashmap.

Overview

This is a simple example that repeatedly:

• inserts up to CONFIG_TEST_LIB_HASH_MAP_MAX_ENTRIES
• replaces up to the same number that were previously inserted
• removes all previously inserted keys

Building

This application can be built on :ref:`native_sim <native_sim>` as follows:

.. zephyr-app-commands::
   :zephyr-app: samples/basic/hash_map
   :host-os: unix
   :board: native_sim
   :goals: build
   :compact:

To build for another board, change "native_sim" above to that board's name.

Additionally, it is possible to use one of the other Hashmap implementations by specifying

• CONFIG_SYS_HASH_MAP_CHOICE_SC=y (Separate Chaining)
• CONFIG_SYS_HASH_MAP_CHOICE_OA_LP=y (Open Addressing / Linear Probe)
• CONFIG_SYS_HASH_MAP_CHOICE_CXX=y (C Wrapper around the C++ std::unordered_map)

To stress the Hashmap implementation, adjust CONFIG_TEST_LIB_HASH_MAP_MAX_ENTRIES.

Running

Run build/zephyr/zephyr.exe

Sample Output

System Hashmap sample

[00:00:11.000,000] <inf> hashmap_sample: n_insert: 118200 n_remove: 295500 n_replace: 329061 n_miss: 0 n_error: 0 max_size: 118200
[00:00:11.010,000] <inf> hashmap_sample: success