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jleveldb

A bare bones JNI wrapper for the LevelDB project (http://code.google.com/p/leveldb/)

This project wraps the C-interface to LevelDB with JNI code, exposing it to Java. It is
missing about 3 functions that have callbacks or other weirdness I haven't gotten to yet.

It comes with pre-built LevelDB libraries for OSX 10.6+ and Linux 2.6 (both 64-bit). It
comes with a makefile that should product a JNI library and a jarfile for those platforms.
It also comes with inadequate, but easily expanded, test-coverage.

Note that the libleveldb-linux.a library was built with the -fPIC flag.

It shouldn't be too much work to update the makefile to build for other platforms or
architectures.

The following make targets are useful:
make clean
make
make test

It uses Java longs to represent pointers in native code. This is a hack that seems to work
reasonably well. Be aware that if you pass the wrong kind of structure for a given
parameter, your process will likely crash.

I plan to build a java layer on top of this that more closely mirrors the native LevelDB
API when I get a chance.

This code likely has some bugs yet, as the test coverage is thin. Reproducers and pull
requests welcome.

Here is some sample code:

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NativeInterface ni = new NativeInterface();

long options = ni.leveldb_options_create();
ni.leveldb_options_set_create_if_missing(options, true);
long writeoptions = ni.leveldb_writeoptions_create();
long readoptions = ni.leveldb_readoptions_create();

long db = ni.leveldb_open(options, "testfile.leveldb");
ni.leveldb_put(db, writeoptions, "key".getBytes(), "value".getBytes());
byte[] value = ni.leveldb_get(db, readoptions, "key".getBytes());
assertTrue(Arrays.equals("value".getBytes(), value));
ni.leveldb_close(db);
ni.leveldb_destroy_db(options, "testfile.leveldb");

ni.leveldb_options_destroy(options);
ni.leveldb_readoptions_destroy(readoptions);
ni.leveldb_writeoptions_destroy(writeoptions);

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