apisix/doc/router-r3.md

libr3

what's libr3?

libr3 is a high-performance path dispatching library. It compiles your route paths into a prefix tree (trie).

APISIX using lua-resty-libr3 as route dispatching library.

How to use libr3 in APISIX?

libr3 supports PCRE(Perl Compatible Regular Expressions), so you can use route flexibly.

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

1. default regular expression

/blog/post/{id}

there is not regular expression included, and [^/]+ will be the default regular expression of id.

So /blog/post/{id} is equivalent to /blog/post/{id:[^/]+}.

2. match all uris

/{:.*}

/ matches root uri, and .* matches any character (except for line terminators).

: means is an anonymous match, for example the uri is /blog/post/1, the libr3 will return [/blog/post/1] if pattern is /{:.*}, and return {"uri":"/blog/post/1"} if pattern is /{uri:.*}.

3. match number

/blog/post/{id:\d+}

for example the uri is /blog/post/1, libr3 will return {"id":"1"}.

4. match characters

/blog/post/{name:\w+}

for example the uri is /blog/post/foo, libr3 will return {"name":"foo"}.

5. match multiple uri segments

/blog/post/{name:\w+}/{id:\d+}

for example the uri is /blog/post/foo/12, libr3 will return {"name":"foo", "id":"12"}.

/blog/post/{:\w+}/{id:\d+}

for example the uri is /blog/post/foo/12, libr3 will return {"1":"foo", "id":"12"}.

How to filter route by Nginx builtin variable

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

$ curl http://127.0.0.1:9080/apisix/admin/routes/1 -X PUT -i -d '
{
    "uri": "/index.html",
    "vars": ["http_k", "header", "cookie_k", "cookie", "arg_k", "uri_arg"],
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "39.97.63.215:80": 1
        }
    }
}'

This route will require the request header k equal "header", request cookie key k equal "cookie" etc.