c58f935fdc
The example (and related documentation at redis.io) was not updated for 5 years. Redis had no sorted sets and hashes when the original code was written (!). An update was really needed. We also use a modern PHP client now: Predis. A copy is shipped within this repository to make life easier to newcomers trying Redis for the first time via this example.
68 lines
2.2 KiB
Markdown
68 lines
2.2 KiB
Markdown
Retwis is the Redis Hello World. A minimal Twitter-style social network clone
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written using Redis and PHP. The source code is designed to be very simple and
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at the same time to show different Redis data structures.
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You can find a tutorial explaining step by step how the example was created
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in the [Twitter clone tutorial of the Redis documentation](http://redis.io/topics/twitter-clone).
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This code was written back in 2009 when Redis was initially published, in order
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to expose interested developers to the Redis concepts and data types.
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Later, in May 2014, it was reworked in order to update it to *modern Redis*,
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since when the example was introduced Redis lacked sorted sets, hashes,
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and many other features.
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The following is a description of the data layout.
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Users
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---
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User IDs are generated sequencially via increments:
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INCR next_user_id => 1000
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(We'll use the example user ID 1000 in the next examples)
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Users are stored into Redis hashes, the key name of the hash representing a
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given user is `user:1000`. Every hash has the following fields:
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username (the username of the user)
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password (password of course)
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auth 9458sd893448dfd
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There are additional keys for following, followers, and posts:
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following:1000 (sorted set of user ids)
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followers:1000 (sorted set of user ids)
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posts:1000 (list of posts ids)
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In order to reverse lookup the user ID from the authentication toke or
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username we have the following two additional keys:
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The key `auths` is an hash mapping auth tokens to user IDs.
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Example of field and value: 9458sd893448dfd => 1000
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The key `users` is an hash mapping usernames to user IDs.
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Example of field and value: antirez => 1000
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Additionally we take a sorted set with usernames indexed by registration
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time (the score is the unix time the user joined), so that we can populate
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our "latest users" view. The key is called `users_by_time`.
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Posts
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---
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Posts also have sequencial IDs, generated by incrementing the following key:
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INCR next_post_id => 134
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Every post is stored into an hash named `post:134` with the following
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fields:
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user_id
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time
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body
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Timeline
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---
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Just a list of post IDs in the `timeline` key.
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