• Stars
    star
    185
  • Rank 208,271 (Top 5 %)
  • Language
    Ruby
  • License
    MIT License
  • Created over 14 years ago
  • Updated about 5 years ago

Reviews

There are no reviews yet. Be the first to send feedback to the community and the maintainers!

Repository Details

Generate nested namespaced keys for key-value databases.

Nest

Object Oriented Keys for Redis.

Description

If you are familiar with databases like Redis and libraries like Ohm you already know how important it is to craft the keys that will hold the data.

>> redis = Redic.new
>> redis.call("HSET", "Event:3", "name", "Redis Meetup")
>> redis.call("HGET", "Event:3", "name")
=> ["Redis Meetup"]

It is a design pattern in key-value databases to use the key to simulate structure, and you can read more about this in the case study for a Twitter clone.

Nest helps you generate those keys by providing chainable namespaces that are already connected to Redis:

>> event = Nest.new("Event")
>> event[3].call("HSET", "name", "Redis Meetup")
>> event[3].call("HGET", "name")
=> ["Redis Meetup"]

Alternatively, you can send the Redis commands as messages to Nest, and if the method definition is missing it will forward the command to Redis:

>> event = Nest.new("Event")
>> event[3].hset("name", "Redis Meetup")
>> event[3].hget("name")
=> ["Redis Meetup"]

Usage

To create a new namespace:

>> ns = Nest.new("foo")
=> "foo"

>> ns["bar"]
=> "foo:bar"

>> ns["bar"]["baz"]["qux"]
=> "foo:bar:baz:qux"

And you can use any object as a key, not only strings:

>> ns[:bar][42]
=> "foo:bar:42"

In a more realistic tone, lets assume you are working with Redis and dealing with events:

>> event = Nest.new("Event")
=> "Event"

>> id = event[:id].incr
=> 1

>> event[id].hset("name", "Redis Meetup")
=> 1

>> meetup = event[id]
=> "Event:1"

>> meetup.hget("name")
=> ["Redis Meetup"]

API

call: Receives a Redis command and its arguments, and returns the reply from the Redis server. If the reply from Redis is an error, an instance of RuntimeError is returned.

call!: Similar to call, but instead of returning an instance of RuntimeError when the command fails, the error is raised.

queue: Receives the same kind of arguments as call, but enqueues the command in a transaction.

commit: Commits the transaction and returns the reply from Redis.

Any call to a missing method will result in Nest converting the method name to a Redis command and applying the arguments in an invocation to call.

For example:

ns = Nest.new("foo")
ns.append("hello,")
ns.append(" world")
ns.get

Is equivalent to:

ns = Nest.new("foo")
ns.call("APPEND", "hello,")
ns.call("APPEND", " world")
ns.call("GET")

Supplying your existing Redis instance

You can supply a Redic instance as a second parameter. If you don't, a default instance is created for you:

>> redis = Redic.new("redis://localhost:6379")
=> #<Redic:0x007fa640845f10 ...>

>> event = Nest.new("Event", redis)
=> "Event"

>> event[:id].call("TYPE")
=> "string"

Nest objects respond to redis and return a Redic instance. It is automatically reused when you create a new namespace, and you can reuse it when creating a new instance of Nest:

>> event = Nest.new("Event", meetup.redis)
=> "Event"

Nest allows you to execute all the Redis commands that expect a key as the first parameter. If you use any other command, the result can be unexpected.

Differences with redis-namespace

redis-namespace wraps Redis and translates the keys back and forth transparently.

Use redis-namespace when you want all your application keys to live in a different scope.

Use Nest when you want to use the keys to represent structure.

Tip: instead of using redis-namespace, it is recommended that you run a different instance of redis-server. Translating keys back and forth is not only delicate, but unnecessary and counterproductive.

Differences with Ohm

Ohm lets you map Ruby objects to Redis with little effort. It not only alleviates you from the pain of generating keys for each object, but also helps you when dealing with references between objects.

Use Ohm when you want to use Redis as your database.

Use Nest when mapping objects with Ohm is not possible or overkill.

Tip: Ohm uses Nest internally to deal with keys. Having a good knowledge of Nest will let you extend Ohm to suit your needs.

Installation

$ gem install nest

More Repositories

1

cuba

Rum based microframework for web development.
Ruby
1,438
star
2

ohm

Object-Hash Mapping for Redis
Ruby
1,390
star
3

micromachine

Minimal Finite State Machine
Ruby
522
star
4

clac

Command-line, stack-based calculator with postfix notation
C
350
star
5

map

Map lines from stdin to commands
C
221
star
6

mote

Minimum Operational Template
Ruby
217
star
7

ost

Redis based queues and workers.
Ruby
166
star
8

toro

Tree oriented routing
Crystal
144
star
9

syro

Simple router for web applications
Ruby
135
star
10

cargo

Require libraries without cluttering your namespace.
Ruby
127
star
11

scrivener

Validation frontend for models.
Ruby
124
star
12

clap

Command line argument parsing
Ruby
90
star
13

ohm-crystal

Ohm for Crystal
Crystal
71
star
14

disque-rb

Disque client for Ruby
Ruby
68
star
15

gs

Gemset management
Ruby
67
star
16

totp

Time-based One-Time Passwords
Ruby
44
star
17

mailcat

Fake SMTP server that prints emails to stdout
C
38
star
18

chen

Change directory entries with your text editor
C
37
star
19

spawn

A ridiculously simple fixtures replacement for your web framework of choice.
Ruby
36
star
20

finist

Redis based Finite State Machine
Ruby
36
star
21

redisurl

Connect to Redis using a REDIS_URL and the redigo client.
Go
33
star
22

hart

Hash router
Ruby
24
star
23

stal-ruby

Set algebra solver for Redis
Ruby
22
star
24

redisent

Sentinels aware Redis client.
Ruby
22
star
25

relay

Relay commands over SSH
Ruby
21
star
26

resp

Lightweight RESP client for Lua
Lua
21
star
27

lomo

Apply a lomo filter to your pictures from the command line using ImageMagick.
Ruby
19
star
28

terco

Obstinate DNS
Ruby
16
star
29

override

The as-simple-as-possible-but-not-simpler stubbing library.
Ruby
16
star
30

ox

Skeleton for a Cuba-based JSON API.
Ruby
16
star
31

nido

Structured keys helper
Ruby
14
star
32

syro-demo

Demo application with Syro
Ruby
14
star
33

resp-crystal

Lightweight RESP client
Crystal
14
star
34

mt

Mail tester daemon.
Ruby
13
star
35

stringent

Generate a string with a target entropy
Ruby
12
star
36

rediscan

Scanner for Redis keyspace
Ruby
12
star
37

hypertext

Hypertext authoring with Ruby
Ruby
11
star
38

filmo

A single page presentation tool.
11
star
39

cuba-book

Cuba Book
11
star
40

sc

List of HTTP status codes.
Ruby
11
star
41

finist.lua

Redis based Finite State Machine
Lua
10
star
42

drawer

Ultra slim file-based cache
Ruby
10
star
43

nest-crystal

Object Oriented Keys for Redis
Crystal
9
star
44

basica

Basic authentication library.
Ruby
8
star
45

rino

Remove a file by its inode number
C
7
star
46

seg.rb

Segment matcher for paths
Ruby
7
star
47

seg

Segment matcher for paths
Crystal
7
star
48

trim

Read from stdin and remove a prefix from each line
C
7
star
49

tas

Trees as strings
Ruby
6
star
50

stal

Set algebra solver for Redis
Lua
6
star
51

pac

Package management for Lua libraries.
Shell
6
star
52

prep

Read from stdin and prepend a string to each line while preserving identation.
C
6
star
53

m4s2

Static Site Generator
HTML
5
star
54

contract

Contract helper
Ruby
5
star
55

stal-crystal

Set algebra solver for Redis
Crystal
5
star
56

loco

Lines of code counter
C
4
star
57

ook

Object Oriented Keys for Redis
Ruby
4
star
58

walk

Walk a directory tree and print the name of every regular file
C
4
star
59

rel

Ruby client for the Bandicoot database.
Ruby
4
star
60

textorama

Text slides for the terminal
Shell
4
star
61

homebrew-tools

Formulae for Homebrew
Ruby
4
star
62

rediscan.lua

Scanner for Redis keyspace in Lua
Lua
3
star
63

seg.go

Segment matcher for paths
Go
3
star
64

look

Add a vendor directory to your load path.
Ruby
3
star
65

app

Cuba application template for gn, the file generator.
Ruby
2
star
66

packer

Require different versions of the same Cargo-compatible gem
Ruby
2
star
67

tele.sh

2
star
68

ers

AWK script easy replacements in templates
Awk
2
star
69

soveran.github.io

2
star
70

filter

Workflow template for gn.
Ruby
1
star
71

remoto

Ruby
1
star
72

gem

Gem template for gn, the file generator.
Ruby
1
star
73

ohm-scripts

Lua scripts for Ohm compatible libraries
Lua
1
star
74

ostgo

Ost client.
Go
1
star
75

miga

Breadcrumb name of the working directory
C
1
star