dotnet/aspnetcore

Perf: add API to avoid regex matching rewrite rules unless necessary

Open

#5,984 opened on Aug 30, 2016

View on GitHub
 (4 comments) (0 reactions) (0 assignees)C# (10,653 forks)batch import
api-suggestionarea-middlewareenhancementfeature-rewrite-middlewarehelp wanted

Repository metrics

Stars
 (37,933 stars)
PR merge metrics
 (Avg merge 16d 9h) (258 merged PRs in 30d)

Description

Regex is an expensive part of the rewrite middleware a lot in order to do pattern matching. It is common for rewrite patterns to be led by a static prefix.

Example: "blogs/(.*)" => "api/blogs?id=$1"

For this rule, the middleware can avoid unnecessary regex allocations by only running the rule when the path begins with "/blogs/".

Possible API design:

RewriteOptions.AddRewrite(string prefix, string pattern, string urlResult) // prefix is static, doesn't container rules. If uri doesn't start with the prefix, skip this rule
RewriteOptions.Ignore(string prefix); // always skip rule processing for urls beginning with this prefix

Usage

RewriteOptions.AddRewrite(prefix: "/blogs/", pattern: "(.*)", urlResult: "/api/blogs?id=$1")
RewriteOptions.Ignore("/images/")

Contributor guide

Research direction
Implement the AddRewrite and Ignore methods in the RewriteOptions class to allow prefix based skipping of regex matching. The AddRewrite method should store a static prefix and pattern; if the request path does not start with the prefix, skip the rule. The Ignore method should skip all rules for paths beginning with the given prefix. Ensure the existing tests pass and add new tests for prefix matching.
Tech stack
csharp
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C#ASP.NET Core
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60