examples

Examples

This directory contains C and C++ examples for pmemkv, the library providing key-value datastore optimized for persistent memory. For more information about library see libpmemkv(3).

Building and execution

Build with sources

To compile examples with current pmemkv sources, follow build steps for your OS (as described in top-level README). Make sure the BUILD_EXAMPLES options is ON. The build directory should now contain examples sub-directory with all binaries, ready to run, e.g.:

cd <build_dir>/examples
./example-pmemkv_basic_c

If an example requires additional parameter it will print its usage, otherwise it will run and print the execution results (if any).

Standalone build

To compile any example as a standalone application (using pmemkv installed in the OS) you have to enter selected example's sub-directory and run e.g.:

cd <repo_dir>/examples/pmemkv_basic_c
mkdir build
cd build
cmake ..
make
./pmemkv_basic_c

Similarly to previous section, if an example requires additional parameter it will print its usage, otherwise it will run and print the execution results (if any).

Descriptions and additional dependencies:

• pmemkv_basic_c/pmemkv_basic.c -- contains basic example workflow of C application

• pmemkv_basic_cpp/pmemkv_basic.cpp -- contains basic example workflow of C++ application

• pmemkv_comparator_c/pmemkv_comparator.c -- example of pmemkv used with custom comparator (C API)

• pmemkv_comparator_c/pmemkv_comparator.cpp -- example of pmemkv used with custom comparator (C++ API)

• pmemkv_config_c/

  • pmemkv_basic_config.c -- example usage for part of the pmemkv config API, which should be preferred

  • pmemkv_config.c -- example usage of the part of the pmemkv config API to set and get data based on their data types.

    It requires to be built:

    • 'rapidjson-devel' package to be installed in the OS and
    • 'BUILD_JSON_CONFIG' pmemkv's CMake variable to be set to ON

• pmemkv_fill_cpp/pmemkv_fill.cpp -- example which calculates how many elements fit into pmemkv. It inserts elements with specified key and value size to the database until OUT_OF_MEMORY status is returned. It then prints number of elements inserted. It may be used to observe the memory overhead of a certain engine with specific key/value sizes.

• pmemkv_iterator_c/pmemkv_iterator.c -- example of pmemkv's iterator (C API)

• pmemkv_iterator_cpp/pmemkv_iterator.cpp -- example of pmemkv's iterators (C++ API). It shows how to use it in single-threaded and concurrent approach.

  It requires to be built:

  • pthread available in the OS

• pmemkv_open_cpp/pmemkv_open_cpp -- contains example of pmemkv usage for already existing pools (and poolsets)

• pmemkv_pmemobj_cpp/pmemkv_pmemobj.cpp -- contains example of pmemkv supporting multiple engines

• pmemkv_transaction_c/pmemkv_transaction.c -- example with pmemkv transactions (C API)

• pmemkv_transaction_cpp/pmemkv_transaction.cpp -- example with pmemkv transactions (C++ API)