Allow overlapping catch-all and param segment

[tigerwill90]

Earlier this year, the RFC: Route Overlapping was introduced to enhance the routing flexibility of the router by allowing overlapping of wildcard segments with static segments. The current rules, as outlined in the RFC, are as follows:

Rules

1. Prioritize the more specific route:
   • If a catch-all or named route overlaps with a static route segment, the static segment should be prioritized.
2. Allow only one named or catch-all route to overlap with a static route segment.
3. Overlapping named parameters and catch-all parameters in the same segment is not allowed.
4. Each HTTP method has its own tree, so overlapping routes with different methods are allowed.

For example, the following route configurations are allowed:

/*{filepath}
/static

/content/{id}
/content/articles/{id}
/content/news/{id}
/content/events/{id}

Proposition

While supporting overlapping named parameters, such as /users/{id}/book and /users/{name}, presents challenges, this new RFC aims to introduce the capability to overlap catch-all and named parameter segments (overlapping named parameters within the same segment remains prohibited at this stage).

As a result, the following route configurations would be allowed:

/*{filepath}
/{chain}/track

/users/uuid:{id}
/users/uuid:*{any}

New Rules

• Static segments are always evaluated first.
• A named parameter can only overlap with a catch-all parameter or static segments.
• A catch-all parameter can only overlap with a named parameter or static segments.
• When a named parameter overlaps with a catch-all parameter, the named parameter is evaluated first.
• Each HTTP method has its own tree, so overlapping routes with different methods are allowed.

Priority example

Pattern /users/123/email

Route	Matching order
/users/{id}/email	1
/users/{id}/{action}	2
/users/*{any}	3

Pattern /users/123/revoke

Route	Matching order
/users/{id}/email	no match
/users/{id}/{action}	1
/users/*{any}	2

Pattern /users/123/orders/5

Route	Matching order
/users/{id}/email	no match
/users/{id}/{action}	no match
/users/*{any}	1

Performance comparaison

goos: linux
goarch: amd64
pkg: github.com/tigerwill90/fox
cpu: Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz
                    │   old.txt    │               new.txt                │
                    │    sec/op    │    sec/op      vs base               │
StaticAll-16          11.01µ ±  2%    11.13µ ±  0%  +1.08% (p=0.019 n=10)
GithubParamsAll-16    86.16n ±  3%    92.61n ±  2%  +7.49% (p=0.000 n=10)
OverlappingRoute-16   98.58n ±  0%   103.15n ±  1%  +4.64% (p=0.000 n=10)
StaticParallel-16     10.04n ±  8%    10.48n ± 12%  +4.46% (p=0.015 n=10)
CatchAll-16           32.15n ±  1%    32.63n ±  2%       ~ (p=0.086 n=10)
CatchAllParallel-16   5.927n ± 20%    6.111n ± 14%       ~ (p=0.190 n=10)
MultiWriter-16        106.8n ±  1%    103.5n ±  2%  -3.14% (p=0.000 n=10)
geomean               346.1n          350.7n        +1.33%

The impact on performance is expected to be null for static route and minimal for wildcard route.

[codecov]

Codecov Report

Merging #24 (a43a499) into master (ed06170) will increase coverage by 0.20%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #24      +/-   ##
==========================================
+ Coverage   86.42%   86.62%   +0.20%     
==========================================
  Files          12       12              
  Lines        1790     1787       -3     
==========================================
+ Hits         1547     1548       +1     
+ Misses        210      205       -5     
- Partials       33       34       +1     

Flag	Coverage Δ
coverage.txt	86.62% <100.00%> (+0.20%)	⬆️

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

Impacted Files	Coverage Δ
context.go	89.57% <ø> (ø)
error.go	54.54% <ø> (ø)
node.go	74.04% <ø> (ø)
helpers.go	100.00% <100.00%> (ø)
tree.go	92.48% <100.00%> (-0.04%)	⬇️

... and 2 files with indirect coverage changes

[pawndev]

@tigerwill90 sorry, I didn't take time to review this one 🙈