Synopsis

EventVat is an evented in-process key/value store with an API like that of Redis. It's event based, which means that when a method is called that affects the data, corresponding events will be raised. It supports 5 data types, Strings, Numbers, Booleans, Arrays and Hashes.

Motivation

• A datastore for small, volitile working sets
• For processes who do not share data, it reduces unnecessary trips across the process boundary.
• Portability, works in the browser and on the server.
• Write to any storage end-point (such as local browser storage, a filesystem or couchdb).

Installation

$npm install eventvat

Usage

Each new instance of EventVat is a hash. There are lots of convenient methods attached to each new instance.

events

EventVat uses EventEmitter2. Listeners can attached to an EventVat object. An EventVat object can emit and event and a listener will respond. An event has three characteristics, the event name, a listener and an associated data key or wildcard.

  var vat = EventVat();

  vat.on('get foo', function(key, value) {

    console.log('`' + key + '` has the value: `' + value + '`');
  });

  vat.set('foo', 'hello, world');
  vat.get('foo');

API

instance methods

publish()

Synonymous with EventEmitter2.prototype.emit

subscribe()

Synonymous with EventEmitter2.prototype.on

unsubscribe()

Synonymous with EventEmitter2.prototype.removeListener

die(key)

Expire a key

del(key /* ... */)

Delete a key

exists(key)

Determine if a key exists

expire(key, ttl)

Set a key's time to live in seconds

expireat(key, dueDate)

Set the expiration for a key as a UNIX timestamp

keys(regex)

Find all keys matching the given pattern

move(key, db)

Move a key to another database

object(subcommend /* ... */)

Inspect the internals of an object

persist(key)

Remove the expiration from a key

randomkey()

Return a random key from the keyspace

rename(oldKey, newKey)

Rename a key

renamenx(oldKey, newKey)

Rename a key, only if the new key does not exist

sort()

Sort the elements in a list, set or sorted set

type(key)

Determine the type stored at key

ttl(key)

Get the time to live for a key

append(key, value)

Append a value to a key

decr(key)

Decrement the integer value of a key by one

decrby(key, value)

Decrement the integer value of a key by the given number

get(key)

Get the value of a key

getbit(key)

Returns the bit value at offset in the string value stored at key

getrange(key, start, end)

Get a substring of the string stored at a key

getset(key, value)

Set the string value of a key and return its old value

incr(key)

Increment the integer value of a key by one

incrby(key, value)

Increment the integer value of a key by the given number

mget(key /* ... */)

Get the values of all the given keys

mset(keys /* ... /, values / ... */)

Set multiple keys to multiple values

msetnx(keys /* ... /, values / ... */)

Set multiple keys to multiple values, only if none of the keys exist

set(key, value, ttl)

Set the string value of a key

setbit(key, offset, value)

Sets or clears the bit at offset in the string value stored at key

setex(key, seconds, value)

Set the value and expiration of a key

setnx(key, value, ttl)

Set the value of a key, only if the key does not exist

setrange(key, offset, value)

Overwrite part of a string at key starting at the specified offset

strlen(key)

Get the length of the value stored in a key

hdel(key, field /* ... */)

Delete one or more hash fields

hexists(key, field)

Determine if a hash field exists

hget(key, field)

Get the value of a hash field

hgetall(key)

Get all the fields and values in a hash

hincr(key, field)

Increment the integer value of a hash field by one

hincrby(key, field, value)

Increment the integer value of a hash field by the given number

hdecr(key, field)

Decrement the integer value of a hash field by one

hdecrby(key, field, value)

Decrement the integer value of a hash field by the given number

hkeys(key)

Get all the fields in a hash

hlen(key)

Get the number of fields in a hash

hmget(key, field /* ... */)

Get the values of all the given hash fields

hmset(key, fields /* ... /, values / ... */)

Set multiple hash fields to multiple values

hset(key, field, value)

Set the string value of a hash field

hsetnx(key, field, value /* ... */)

Set the value of a hash field, only if the field does not exist

hvals(key)

Get all the values in a hash

dump(stringify)

Dump the current data store into a string

swap(a, b, depth)

Swap two values

findin(key, value)

Search within the value of a key

Tests

$npm test

(The MIT License)

Copyright (c) 2010 hij1nx http://www.twitter.com/hij1nx

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE DBSIZEORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.