Skip to content
Low Level Persistence Library
Java C++ C Makefile
Branch: master
Clone or download
Latest commit 2e79ef7 Oct 15, 2019
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
src Fixed bug in PersistentHeap open method May 7, 2019
.gitignore Initial commit May 29, 2018
CONTRIBUTING.md Update CONTRIBUTING.md Jun 14, 2019
LICENSE - Refactored API and implementation to accomodate better usage patterns Jan 10, 2019
Makefile fixed path in jar target in Makefile Jan 11, 2019
README.md Update README.md Oct 14, 2019

README.md

Low Level Persistence Library

OVERVIEW

The Low Level Persistence Library offers access to persistent memory using MemoryBlocks allocated from a persistent Heap.

This Java library uses the libpmemobj library from the Persistent Memory Development Kit (PMDK). For more information on PMDK, please visit http://pmem.io and https://github.com/pmem/pmdk.

HOW TO BUILD & RUN

PREREQUISITES TO BUILD

The following are the prerequisites for building this Java library:

  1. Linux operating system (tested on CentOS 7.2)
  2. Persistent Memory Development Kit (PMDK)
  3. Java 8 or above
  4. Build tools - g++ compiler and make

PREREQUISITES TO RUN

This library assumes the availability of hardware persistent memory or emulated persistent memory. Instructions for creating emulated persistent memory are shown below.

EMULATING PERSISTENT MEMORY

The preferred way is to create an in-memory DAX file system. This requires Linux kernel 4.2 or greater. Please follow the steps at:

http://pmem.io/2016/02/22/pm-emulation.html

Alternatively, for use with older kernels, create a tmpfs partition as follows (as root):

$ mount -t tmpfs -o size=8G tmpfs /mnt/mem  # creates a 8GB tmpfs partition
$ chmod -R a+rw /mnt/mem                    # enables read/write permissions to all users

STEPS TO BUILD AND RUN TESTS

Once all the prerequisites have been satisfied:

$ git clone https://github.com/pmem/llpl.git
$ cd llpl
$ make && make tests

Available Makefile targets include:

  • sources - builds only sources
  • examples - builds the sources and examples
  • tests - builds and runs tests
  • docs - builds javadocs
  • jar - builds jar file into target directory

USING THIS LIBRARY IN EXISTING JAVA APPLICATIONS

To import this library into an existing Java application, include the project's target/classes directory in your Java classpath and the project's target/cppbuild directory in your java.library.path. For example:

$ javac -cp .:<path>/llpl/target/classes <source>
$ java -cp .:<path>/llpl/target/classes -Djava.library.path=<path>/llpl/target/cppbuild <class>

CONTRIBUTING

Thanks for your interest! Right now, architectural changes are still happening in the project. This makes it difficult to contribute code and difficult to effectively process pull requests. We expect these changes to settle out around March of this year and we look forward to code contributions once this happens. We will update this README then.

In the meantime, we would love to hear your comments and suggestions via https://github.com/pmem/llpl/issues.

Contacts

For more information on this library, contact Olasoji Denloye (olasoji.denloye@intel.com) or Steve Dohrmann (steve.dohrmann@intel.com).

You can’t perform that action at this time.