rohankumardubey / rocksdb-jna-core

Building Library:

1. Compile rocksdb:

We need -fPIC enabled so we can make a static library. Change, rocksdb/MAKEFILE to have the CXXFLAGS include -fPIC

Something like below.

[rocksdb_home]$ git diff
diff --git a/Makefile b/Makefile
index be7758d..fc1aea7 100644
--- a/Makefile
+++ b/Makefile
@@ -33,7 +33,7 @@ endif
 
 WARNING_FLAGS = -Wall -Werror
 CFLAGS += -g $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CCFLAGS) $(OPT)
-CXXFLAGS += -g $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CXXFLAGS) $(OPT) -Woverloaded-virtual
+CXXFLAGS += -fPIC -g $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CXXFLAGS) $(OPT) -Woverloaded-virtual
 
 LDFLAGS += $(PLATFORM_LDFLAGS)

2. Building rocksdb-jna native shared lib:

$ cd cpp; rm rocksdb-jna.*o; 
# Replace with actual path
$ export ROCKSDB_HOME=~/projects/rocksdb; 
$ g++ -c rocksdb-jna.cc -fPIC -I $ROCKSDB_HOME/include -std=c++11; 
$ g++ -shared -fPIC -o rocksdb-jna-ubuntu.so rocksdb-jna.o $ROCKSDB_HOME/librocksdb.a $ROCKSDB_HOME/libmemenv.a -lrt

Then pass the location of this shared library to RocksDB.loadLibrary(..) before you do anything else!!

$ cd rocksdb-jna; ant
$ java -cp dist:dist/rocksdb-jna.jar RocksDBJNAExample `pwd`/cpp/rocksdb-jna-ubuntu.so

3. Get coding : Now time to actually use it in a real application. grab dist/rocksdb-jna.jar.