Refactor: Cache Proxy HTTP Clients with Reset on Channel Updates

[RedwindA]

PR 类型

• Bug 修复
• 新功能
• 文档更新
• 其他

PR 是否包含破坏性更新？

• 是
• 否

PR 描述

close #1863

• 引入 proxyClients 缓存，按代理 URL 存储已初始化的 *http.Client，避免重复创建客户端和连接池。
• 命中缓存时直接复用客户端；添加 ResetProxyClientCache，在渠道增改后清空缓存并关闭空闲连接，确保配置更新即时生效。

动机

• 频繁为同一代理 URL 构造新的 http.Client 会重复握手、建立连接池，带来额外延迟与代理端负载。
• 渠道配置变化后，立即刷新关联的代理客户端，防止继续使用过期的代理设置。

涉及改动

• service/http_client.go: 新增缓存 map 与互斥锁，支持缓存命中与主动刷新；在 HTTP/HTTPS 与 SOCKS5 初始化逻辑中写入缓存；提供
  ResetProxyClientCache 用于清理缓存和关闭空闲连接。
• controller/channel.go: 在渠道新增、更新流程成功后调用 ResetProxyClientCache，触发代理客户端重建。

Summary by CodeRabbit

• New Features

  • None.

• Bug Fixes

  • Proxy updates now take effect immediately after adding or updating channels, reducing stale connections.

• Refactor

  • Improved reuse of proxy clients to reduce overhead and speed repeated requests.

• Chores

  • Enhanced internal proxy cache management to improve stability and reduce unnecessary reconnections.

[coderabbitai]

Walkthrough

Adds a mutex-guarded cache of proxy *http.Client instances and a ResetProxyClientCache() function in the service. Controller now calls service.ResetProxyClientCache() after channel Add and Update operations. Reset closes idle connections for cached clients and reinitializes the cache.

Changes

Cohort / File(s)	Summary of edits
Controller: cache reset on channel mutations controller/channel.go	Added import for service and calls to service.ResetProxyClientCache() after AddChannel and after UpdateChannel (post-update and cache reinit).
Service: proxy HTTP client cache and reset service/http_client.go	Added mutex-guarded map caching proxyURL → *http.Client; implemented GetHTTPClient(proxyURL) to return http.DefaultClient for empty proxy, reuse cached clients on hits, or create & cache clients for http/https and socks5 schemes. Added ResetProxyClientCache() to call CloseIdleConnections() on cached transports and clear/reinit the cache.

Sequence Diagram(s)

sequenceDiagram
  autonumber
  actor Caller
  participant Controller
  participant Service as Service (HTTP Client Cache)
  note over Service: Map[proxyURL]*http.Client + Mutex

  Caller->>Controller: AddChannel/UpdateChannel(...)
  Controller->>Controller: Persist changes and refresh channel cache
  Controller->>Service: ResetProxyClientCache()
  activate Service
  Service->>Service: For each cached client: CloseIdleConnections()
  Service->>Service: Clear and reinit cache map
  deactivate Service
  Controller-->>Caller: Success

Loading

sequenceDiagram
  autonumber
  participant Code as Caller
  participant Service as Service (HTTP Client Cache)

  Code->>Service: GetHTTPClient(proxyURL)
  alt proxyURL == ""
    Service-->>Code: http.DefaultClient
  else proxyURL in cache
    Service-->>Code: Cached *http.Client
  else (cache miss)
    Service->>Service: Create *http.Client (http/https or socks5 transport + Timeout)
    Service->>Service: Store in cache
    Service-->>Code: New *http.Client
  end

  rect rgba(235,248,255,0.6)
  note right of Service: On channel add/update -> ResetProxyClientCache() closes idle conns and clears cache
  end

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

A rabbit hops, a cache refreshed,
Closing old holes where leaks once crept.
New clients snug in tidy rows,
Idle tunnels swept and kept.
I twitch my nose — connections rest. 🐇✨

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The pull request title succinctly describes the central change of introducing a cache for proxy HTTP clients and resetting it on channel updates, which accurately reflects the modifications in service/http_client.go and controller/channel.go without extraneous detail.
Linked Issues Check	✅ Passed	The pull request implements a thread-safe cache for proxy HTTP clients and adds a ResetProxyClientCache function that closes idle connections and clears the cache, as well as invokes this reset after channel create and update, directly addressing the connection leak described in issue #1863 and ensuring proper connection release under load.
Out of Scope Changes Check	✅ Passed	All modifications are focused on introducing and integrating proxy client caching and reset behavior in service/http_client.go and controller/channel.go to address the connection leak issue, and there are no unrelated or extraneous changes outside this scope.

✨ Finishing touches

• 📝 Generate Docstrings

🧪 Generate unit tests

• Create PR with unit tests
• Post copyable unit tests in a comment

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[coderabbitai]

Actionable comments posted: 1

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 74122e4 and 486c828.

📒 Files selected for processing (2)

• controller/channel.go (3 hunks)
• service/http_client.go (3 hunks)

🧰 Additional context used

🧬 Code graph analysis (1)

controller/channel.go (1)

service/http_client.go (1)

• ResetProxyClientCache (37-46)

[coderabbitai]

Actionable comments posted: 1

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 486c828 and 466d19c.

📒 Files selected for processing (1)

• service/http_client.go (3 hunks)

🧰 Additional context used

🧬 Code graph analysis (1)

service/http_client.go (1)

common/constants.go (1)

• RelayTimeout (121-121)