Merge pull request #131 from ankgup87/master

[Java] Add multiget JNI bindings
This commit is contained in:
Yueh-Hsuan Chiang 2014-04-29 22:05:55 -07:00
commit 2e11e47c7c
4 changed files with 238 additions and 0 deletions

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@ -4,6 +4,9 @@
// of patent rights can be found in the PATENTS file in the same directory.
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.ArrayList;
import org.rocksdb.*;
import org.rocksdb.util.SizeUnit;
import java.io.IOException;
@ -217,6 +220,25 @@ public class RocksDBSample {
iterator.close();
System.out.println("iterator tests passed.");
iterator = db.newIterator();
List<byte[]> keys = new ArrayList<byte[]>();
for (iterator.seekToLast(); iterator.isValid(); iterator.prev()) {
keys.add(iterator.key());
}
iterator.close();
Map<byte[], byte[]> values = db.multiGet(keys);
assert(values.size() == keys.size());
for(byte[] value1 : values.values()) {
assert(value1 != null);
}
values = db.multiGet(new ReadOptions(), keys);
assert(values.size() == keys.size());
for(byte[] value1 : values.values()) {
assert(value1 != null);
}
} catch (RocksDBException e) {
System.err.println(e);
}

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@ -5,6 +5,9 @@
package org.rocksdb;
import java.util.List;
import java.util.Map;
import java.util.HashMap;
import java.io.Closeable;
import java.io.IOException;
@ -147,6 +150,7 @@ public class RocksDB {
* returned if the specified key is not found.
*
* @param key the key retrieve the value.
* @param opt Read options.
* @return a byte array storing the value associated with the input key if
* any. null if it does not find the specified key.
*
@ -156,6 +160,64 @@ public class RocksDB {
return get(nativeHandle_, opt.nativeHandle_, key, key.length);
}
/**
* Returns a map of keys for which values were found in DB.
*
* @param keys List of keys for which values need to be retrieved.
* @return Map where key of map is the key passed by user and value for map
* entry is the corresponding value in DB.
*
* @see RocksDBException
*/
public Map<byte[], byte[]> multiGet(List<byte[]> keys)
throws RocksDBException {
assert(keys.size() != 0);
List<byte[]> values = multiGet(
nativeHandle_, keys, keys.size());
Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
for(int i = 0; i < values.size(); i++) {
if(values.get(i) == null) {
continue;
}
keyValueMap.put(keys.get(i), values.get(i));
}
return keyValueMap;
}
/**
* Returns a map of keys for which values were found in DB.
*
* @param List of keys for which values need to be retrieved.
* @param opt Read options.
* @return Map where key of map is the key passed by user and value for map
* entry is the corresponding value in DB.
*
* @see RocksDBException
*/
public Map<byte[], byte[]> multiGet(ReadOptions opt, List<byte[]> keys)
throws RocksDBException {
assert(keys.size() != 0);
List<byte[]> values = multiGet(
nativeHandle_, opt.nativeHandle_, keys, keys.size());
Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
for(int i = 0; i < values.size(); i++) {
if(values.get(i) == null) {
continue;
}
keyValueMap.put(keys.get(i), values.get(i));
}
return keyValueMap;
}
/**
* Remove the database entry (if any) for "key". Returns OK on
* success, and a non-OK status on error. It is not an error if "key"
@ -229,6 +291,10 @@ public class RocksDB {
protected native int get(
long handle, long readOptHandle, byte[] key, int keyLen,
byte[] value, int valueLen) throws RocksDBException;
protected native List<byte[]> multiGet(
long dbHandle, List<byte[]> keys, int keysCount);
protected native List<byte[]> multiGet(
long dbHandle, long rOptHandle, List<byte[]> keys, int keysCount);
protected native byte[] get(
long handle, byte[] key, int keyLen) throws RocksDBException;
protected native byte[] get(

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@ -315,5 +315,69 @@ class FilterJni {
reinterpret_cast<jlong>(op));
}
};
class ListJni {
public:
// Get the java class id of java.util.List.
static jclass getListClass(JNIEnv* env) {
static jclass jclazz = env->FindClass("java/util/List");
assert(jclazz != nullptr);
return jclazz;
}
// Get the java class id of java.util.ArrayList.
static jclass getArrayListClass(JNIEnv* env) {
static jclass jclazz = env->FindClass("java/util/ArrayList");
assert(jclazz != nullptr);
return jclazz;
}
// Get the java class id of java.util.Iterator.
static jclass getIteratorClass(JNIEnv* env) {
static jclass jclazz = env->FindClass("java/util/Iterator");
assert(jclazz != nullptr);
return jclazz;
}
// Get the java method id of java.util.List.iterator().
static jmethodID getIteratorMethod(JNIEnv* env) {
static jmethodID mid = env->GetMethodID(
getListClass(env), "iterator", "()Ljava/util/Iterator;");
assert(mid != nullptr);
return mid;
}
// Get the java method id of java.util.Iterator.hasNext().
static jmethodID getHasNextMethod(JNIEnv* env) {
static jmethodID mid = env->GetMethodID(
getIteratorClass(env), "hasNext", "()Z");
assert(mid != nullptr);
return mid;
}
// Get the java method id of java.util.Iterator.next().
static jmethodID getNextMethod(JNIEnv* env) {
static jmethodID mid = env->GetMethodID(
getIteratorClass(env), "next", "()Ljava/lang/Object;");
assert(mid != nullptr);
return mid;
}
// Get the java method id of arrayList constructor.
static jmethodID getArrayListConstructorMethodId(JNIEnv* env, jclass jclazz) {
static jmethodID mid = env->GetMethodID(
jclazz, "<init>", "(I)V");
assert(mid != nullptr);
return mid;
}
// Get the java method id of java.util.List.add().
static jmethodID getListAddMethodId(JNIEnv* env) {
static jmethodID mid = env->GetMethodID(
getListClass(env), "add", "(Ljava/lang/Object;)Z");
assert(mid != nullptr);
return mid;
}
};
} // namespace rocksdb
#endif // JAVA_ROCKSJNI_PORTAL_H_

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@ -10,6 +10,7 @@
#include <stdlib.h>
#include <jni.h>
#include <string>
#include <vector>
#include "include/org_rocksdb_RocksDB.h"
#include "rocksjni/portal.h"
@ -244,6 +245,91 @@ jint rocksdb_get_helper(
return cvalue_len;
}
jobject multi_get_helper(JNIEnv* env, jobject jdb, rocksdb::DB* db,
const rocksdb::ReadOptions& rOpt, jobject jkey_list, jint jkeys_count) {
std::vector<rocksdb::Slice> keys;
std::vector<jbyte*> keys_to_free;
// get iterator
jobject iteratorObj = env->CallObjectMethod(
jkey_list, rocksdb::ListJni::getIteratorMethod(env));
// iterate over keys and convert java byte array to slice
while(env->CallBooleanMethod(
iteratorObj, rocksdb::ListJni::getHasNextMethod(env)) == JNI_TRUE) {
jbyteArray jkey = (jbyteArray) env->CallObjectMethod(
iteratorObj, rocksdb::ListJni::getNextMethod(env));
jint key_length = env->GetArrayLength(jkey);
jbyte* key = new jbyte[key_length];
env->GetByteArrayRegion(jkey, 0, key_length, key);
// store allocated jbyte to free it after multiGet call
keys_to_free.push_back(key);
rocksdb::Slice key_slice(
reinterpret_cast<char*>(key), key_length);
keys.push_back(key_slice);
}
std::vector<std::string> values;
std::vector<rocksdb::Status> s = db->MultiGet(rOpt, keys, &values);
// Don't reuse class pointer
jclass jclazz = env->FindClass("java/util/ArrayList");
jmethodID mid = rocksdb::ListJni::getArrayListConstructorMethodId(
env, jclazz);
jobject jvalue_list = env->NewObject(jclazz, mid, jkeys_count);
// insert in java list
for(std::vector<rocksdb::Status>::size_type i = 0; i != s.size(); i++) {
if(s[i].ok()) {
jbyteArray jvalue = env->NewByteArray(values[i].size());
env->SetByteArrayRegion(
jvalue, 0, values[i].size(),
reinterpret_cast<const jbyte*>(values[i].c_str()));
env->CallBooleanMethod(
jvalue_list, rocksdb::ListJni::getListAddMethodId(env), jvalue);
}
else {
env->CallBooleanMethod(
jvalue_list, rocksdb::ListJni::getListAddMethodId(env), nullptr);
}
}
// free up allocated byte arrays
for(std::vector<jbyte*>::size_type i = 0; i != keys_to_free.size(); i++) {
delete[] keys_to_free[i];
}
keys_to_free.clear();
return jvalue_list;
}
/*
* Class: org_rocksdb_RocksDB
* Method: multiGet
* Signature: (JLjava/util/List;I)Ljava/util/List;
*/
jobject Java_org_rocksdb_RocksDB_multiGet__JLjava_util_List_2I(
JNIEnv* env, jobject jdb, jlong jdb_handle,
jobject jkey_list, jint jkeys_count) {
return multi_get_helper(env, jdb, reinterpret_cast<rocksdb::DB*>(jdb_handle),
rocksdb::ReadOptions(), jkey_list, jkeys_count);
}
/*
* Class: org_rocksdb_RocksDB
* Method: multiGet
* Signature: (JJLjava/util/List;I)Ljava/util/List;
*/
jobject Java_org_rocksdb_RocksDB_multiGet__JJLjava_util_List_2I(
JNIEnv* env, jobject jdb, jlong jdb_handle,
jlong jropt_handle, jobject jkey_list, jint jkeys_count) {
return multi_get_helper(env, jdb, reinterpret_cast<rocksdb::DB*>(jdb_handle),
*reinterpret_cast<rocksdb::ReadOptions*>(jropt_handle), jkey_list,
jkeys_count);
}
/*
* Class: org_rocksdb_RocksDB
* Method: get