kv-node

#node-kv
An embeded key-value store for node.js, extremely fast.
``
Because rocksdb uses a lot of C++11 features, your compiler should support C++11 to compile it.
I test it on:
Windows + VS2013
CentOS 6.5 + gcc 4.8.1
MacOS

If your compiler doesn't support C++11, you can install 0.2.x (without rocksdb) instead.
`

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Features

- Multiple kv engine support. (LMDB / LevelDB / RocksDB).
- High speed. (> 80% speed of c++ version.)
- Compressed bit-vector support, a good choice for bitmap index. (Coming soon.)
- Embeded, easy to use.

Install

`
npm install node-kv
`

Test & Benchmark

`
git clone https://github.com/talrasha007/node-kv.git
npm install
npm install -g matcha mocha
mocha # Run unit test.
matcha # Run benchmark.
`

Usage

$3

It's a lmdb wrapper, for more information about lmdb, click here & documents
`js
// This example shows how to use lmdb apis.
var path = require('path'),
lmdb = require('node-kv').lmdb;

var env = new lmdb.Env({
dir: path.join(__dirname, 'testdb'),
mapSize: 8 1024 1024, // 128M by default
maxDbs: 64 // 32 by default
});

(function () {
/* Date type can be:
* string
* hex - hex string, will convert to binary data equivalent to Buffer(str, 'hex') for storage.
* int32
* uint32
* int64
* number
* binary - Buffer object
*/
var db = env.openDb({
name: 'test',
keyType: 'int32',
valType: 'int32' // or valveType
});

db.put(1, 1);
console.log(db.get(1));
db.del(1);
console.log(db.get(1));

db.batchPut(6, 6);
console.log(db.get(6));
env.flushBatchOps(); // Data will be flushed automatically after 1ms, if you want to query immediately, do this.
console.log(db.get(6));
})();

(function () {
var db = env.openDb({
name: 'str-test',
keyType: 'string',
valType: 'string' // or valveType
});

var txn = env.beginTxn();
db.put('Hello', 'world', txn);
console.log(db.get('Hello', txn));
txn.abort();
console.log(db.get('Hello'));
})();

(function () {
var db = env.openDb({
name: 'testdup',
keyType: 'int32',
valType: 'int32',
allowDup: true
});

db.put(1, 1);
console.log(db.exists(1, 1));
console.log(db.exists(1, 2));
db.put(1, 2);
console.log(db.exists(1, 1));
console.log(db.exists(1, 2));

// Cursor
var txn = env.beginTxn(true),
cur = db.cursor(txn);

for (var ok = cur.first(); ok; ok = cur.next()) {
console.log("Cursor scan: ", cur.key(), cur.val());
}

console.log(cur.seek(1));
console.log(cur.key(), cur.val());
console.log(cur.gte(0));
console.log(cur.key(), cur.val());

txn.abort();
})();

env.close();
`

$3

`js
// This example shows how to use cache apis.
// Cache is used for caching hot data, it is a wrapper of lmdb, it holds 2 lmdb envs(current & old), when current env is full,
// it will close old env, set current env as old, and then open a new env as current.
var path = require('path'),
cache = require('node-kv').cache;

var cenv = new cache.Env({
dir: path.join(__dirname, 'testdb', 'cache'),
cacheSize: 128 1024 1024, // 256M by default
batchSize: 128 // 64 by default
});

var cdb = cenv.openDb({
name: 'testdb',
keyType: 'int32',
valType: 'int32'
});

cdb.put(1, 2);
cdb.put(2, 3);
cenv.flushBatchOps(); // Data will be flushed automatically after 1ms, if you want to query immediately, do this.
console.log(cdb.get(1));

cdb.put(3, 3);
setTimeout(function () {
console.log(cdb.get(3));
cenv.close();
}, 50);
`

$3

Google leveldb wrapper.
`js
var path = require('path'),
lvldb = require('node-kv').leveldb;

var env = new lvldb.Env({
dir: path.join(__dirname, 'testdb', 'level'),
cacheSize: 256 1024 1024 // 8MB by default.
});

var db = env.openDb({
name: 'test',
keyType: 'int32',
valType: 'int32'
});

db.put(1, 1);
console.log(db.get(1));
db.del(1);
console.log(db.get(1));

db.del(3);
db.batchPut(3, 4);
console.log(db.get(3));
db.flushBatchOps();
console.log(db.get(3));

var cur = db.cursor();
for (var i = cur.first(); i; i = cur.next()) {
console.log([cur.key(), cur.val()]);
}
`

$3

Facebook rocksdb wrapper.
`js
var path = require('path'),
rocksdb = require('node-kv').rocksdb;

var env = new rocksdb.Env({
dir: path.join(__dirname, 'testdb', 'rocks'),
cacheSize: 256 1024 1024 // 4MB by default.
});

var db = env.registerDb({
name: 'test',
keyType: 'int32',
valType: 'int32'
});

env.open();

db.put(1, 1);
console.log(db.get(1));
db.del(1);
console.log(db.get(1));

db.del(3);
db.batchPut(3, 4);
console.log(db.get(3));
db.flushBatchOps();
console.log(db.get(3));

var cur = db.cursor();
for (var i = cur.first(); i; i = cur.next()) {
console.log([cur.key(), cur.val()]);
}
``