feat!: Use a radix trie for route matching

[ElijahAhianyo]

Description

The current router implementation uses a Vec to store routers, which has some real limitations. For example, using a vec meant route conflict detection was cumbersome and hacky to get right. Using a Radix trie is the right data structure for this problem. This PR delegates the core Trie logic to the matchit crate. We still keep our business logic in a light wrapper over the Matchit Router.

Breaking Changes

1. Registering a route with a duplicate parameter at the same segment will now fail

Router::with_urls([
    Route::with_handler_and_name("/foo/{bar}", index, "index"),
        Route::with_handler_and_name("/foo/{baz}", add_example_form, "add"),
])

2. When a handler and router are registered for the same route, the handler will take precedence at lookup time

let nested_router = Router::with_urls([Route::with_handler_and_name(
        "/inner/{id}",
        nested,
       "nested",
)]);

Router::with_urls([
    Route::with_handler_and_name("/foo", index, "index"),
    Route::with_router("/foo", nested_router),
])

3. A route is treated as different from its trailing-slash counterpart:

Router::with_urls([
    Route::with_handler_and_name("/foo", index, "index"),
    Route::with_handler_and_name("/foo/", another_handler, "another" ),
])

4. Routers with the same mount point or path will be merged into one

Router::with_urls([
    Route::with_router("/foo", nested_router_a),
    Route::with_router("/foo/", nested_router_b ),
])

Type of change

• Bug fix
• New feature
• Documentation
• Refactor / cleanup
• Performance improvement
• Other (describe above)

[github-actions]

Bencher Report

Project	cot
Branch	elijah/router-trie
Testbed	github-ubuntu-latest

Click to view all benchmark results

Benchmark	Latency	Benchmark Result milliseconds (ms) (Result Δ%)	Upper Boundary milliseconds (ms) (Limit %)
empty_router/empty_router	📈 view plot 🚷 view threshold	13.42 ms (+19.16%) Baseline: 11.26 ms	18.78 ms (71.46%)
json_api/json_api	📈 view plot 🚷 view threshold	1.14 ms (+12.57%) Baseline: 1.01 ms	1.34 ms (84.44%)
nested_routers/nested_routers	📈 view plot 🚷 view threshold	1.10 ms (+15.19%) Baseline: 0.95 ms	1.25 ms (87.58%)
single_root_route/single_root_route	📈 view plot 🚷 view threshold	1.02 ms (+10.97%) Baseline: 0.91 ms	1.21 ms (83.72%)
single_root_route_burst/single_root_route_burst	📈 view plot 🚷 view threshold	18.98 ms (+12.97%) Baseline: 16.80 ms	22.17 ms (85.60%)

🐰 View full continuous benchmarking report in Bencher

[ElijahAhianyo]

Should be rebased on and merged after #586

[m4tx]

Do we have any way of registering multiple routers at the same URL? This is an important feature - people might want to merge different routers at the same base URL.

If matchit doesn't let us do that because it detects a conflict, we should merge the routers. I'm not sure if we should have separate methods to do that explicitly, or keep the implicit behavior - I'll let you decide.

[ElijahAhianyo]

Ended up going towards the implicit route. When two routers share the same path, we implicitly merge them into one right before we build the route lookup table and trie

[m4tx]

Why not just use expect here?

[codecov]

Codecov Report

❌ Patch coverage is 97.80764% with 31 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
cot/src/router/tree.rs	93.58%	6 Missing and 11 partials ⚠️
cot/src/router.rs	99.37%	3 Missing and 3 partials ⚠️
cot/src/error_page.rs	92.45%	3 Missing and 1 partial ⚠️
cot/src/router/path.rs	96.92%	3 Missing and 1 partial ⚠️

Flag	Coverage Δ
rust	90.58% <97.80%> (+0.34%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
cot-cli/src/project/cache.rs	87.73% <100.00%> (+0.47%)	⬆️
cot/src/form/fields.rs	87.85% <100.00%> (ø)
cot/src/openapi.rs	95.60% <ø> (ø)
cot/src/error_page.rs	92.10% <92.45%> (+0.63%)	⬆️
cot/src/router/path.rs	98.53% <96.92%> (-0.89%)	⬇️
cot/src/router.rs	97.08% <99.37%> (+4.86%)	⬆️
cot/src/router/tree.rs	93.58% <93.58%> (ø)

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[m4tx]

LGTM, feel free to merge after you fix the last few minor comments.

Also, if this is a breaking change as indicated by "feat**!**", please update the Upgrade Guide in the docs/.