router-radixtree.md

libradixtree

what's libradixtree?

libradixtree, adaptive radix trees implemented in Lua for OpenResty.

APISIX using libradixtree as route dispatching library.

How to use libradixtree in APISIX?

This is Lua-Openresty implementation library base on FFI for rax.

Let's take a look at a few examples and have an intuitive understanding.

1. Full match

/blog/foo

It will only match /blog/foo.

2. Prefix matching

/blog/bar*

It will match the path with the prefix /blog/bar, eg: /blog/bar/a, /blog/bar/b, /blog/bar/c/d/e, /blog/bar etc.

3. Match priority

Full match -> Deep prefix matching.

Here are the rules:

/blog/foo/*
/blog/foo/a/*
/blog/foo/c/*
/blog/foo/bar

path	Match result
/blog/foo/bar	/blog/foo/bar
/blog/foo/a/b/c	/blog/foo/a/*
/blog/foo/c/d	/blog/foo/c/*
/blog/foo/gloo	/blog/foo/*
/blog/bar	not match

How to filter route by Nginx builtin variable

Please take a look at radixtree-new, here is an simple example:

$ curl http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -i -d '
{
    "uri": "/index.html",
    "vars": [
        ["http_host", "iresty.com"],
        ["cookie__device_id", "a66f0cdc4ba2df8c096f74c9110163a9"],
        ["arg_name", "jack"]
    ],
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "39.97.63.215:80": 1
        }
    }
}'

This route will require the request header host equal iresty.com, request cookie key _device_id equal a66f0cdc4ba2df8c096f74c9110163a9 etc.