[j2rong4cn]

Description / 描述

🛠️ 主要改动

• 引入 LinearMemory 与 HybridCache，用于改进内存管理和缓存机制。
• 替换 mmap 实现为 LinearMemory。
• 新增 GuardedMemory，并增加 min_free_memory 配置项。
• 重构 FileStream 与 StreamSectionReader 接口，统一使用 HybridCache。
• HybridCache 支持内存优先，失败时回退到文件缓存

⚙️ 配置

• 新增配置项：

  • cache_threshold 单位MB
    • 默认值：4
    • 大于该阈值的数据流将使用HybridCache，可主动释放内存。 否则使用Go的内存分配，直到GC回收
  • min_free_memory 单位MB
    • 默认值：小于16为自动大小，总内存的10%，最大1024
    • 最小空闲内存，当内存不足时，HybridCache会回退到文件缓存。
    • 如果小于0，HybridCache仅使用文件缓存，不占用内存。
  • max_block_limit 单位BM
    • 默认值：小于4为自动大小，总内存的3%，最大64
    • 限制HybridCache手动管理内存单次的扩容大小，超过该阈值将分多次扩容。 min_free_memory大于0时，也限制多线程下载的分片大小

• 废弃配置项：

  • max_buffer_limitMB
  • mmap_thresholdMB

Motivation and Context / 背景

Close #2395

How Has This Been Tested? / 测试

• go test -run '^(TestRangeRead|TestPreHash|TestStreamSectionReader)$' ./internal/stream
• go test -run '^(TestDownloadOrder|TestHighConcurrency|TestDownloadSingle)$' ./internal/net
• go test -run '^TestMultiFileCache$' ./internal/cache

Checklist / 检查清单

• I have read the CONTRIBUTING document.
  我已阅读 CONTRIBUTING 文档。
• I have formatted my code with go fmt or prettier.
  我已使用 go fmt 或 prettier 格式化提交的代码。
• I have added appropriate labels to this PR (or mentioned needed labels in the description if lacking permissions).
  我已为此 PR 添加了适当的标签（如无权限或需要的标签不存在，请在描述中说明，管理员将后续处理）。
• I have requested review from relevant code authors using the "Request review" feature when applicable.
  我已在适当情况下使用"Request review"功能请求相关代码作者进行审查。
• I have updated the repository accordingly (If it’s needed).
  我已相应更新了相关仓库（若适用）。
  • OpenList-Frontend #XXXX
  • OpenList-Docs #XXXX

[Copilot]

Pull request overview

This PR refactors stream buffering/caching to use a new HybridCache abstraction (memory-first with file fallback) and removes the prior mmap-based buffering path, while also introducing guarded memory allocation tied to a configurable minimum free-memory threshold.

Changes:

• Added internal/mem (LinearMemory, GuardedMemory, HybridCache) and wired it into stream caching + downloader buffering.
• Introduced pkg/buffer section/stream abstractions (Section, StreamBuffer) and updated stream readers to use them.
• Added min_free_memoryMB configuration and updated bootstrap logic to derive memory/buffer limits from system memory.

Reviewed changes

Copilot reviewed 20 out of 20 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
pkg/pool/pool.go	Simplifies generic pool and adds Close() for closer-based lifecycle management.
pkg/buffer/utils.go	Adds helpers to obtain reader/writer views for Section implementations.
pkg/buffer/type.go	Introduces SectionReader/SectionWriter interfaces.
pkg/buffer/stream.go	Adds a concurrent 1-reader/1-writer streaming buffer over a Section.
pkg/buffer/bytes.go	Adds Close() to Reader and introduces byteSection (Section) backed by a byte slice.
internal/stream/util.go	Refactors StreamSectionReader to use pooled sections and HybridCache instead of mmap/temp-file logic.
internal/stream/stream.go	Refactors FileStream caching/peek behavior to use HybridCache for large streams.
internal/stream/stream_test.go	Updates tests to exercise the new caching thresholds and behavior.
internal/net/request.go	Refactors downloader chunk buffering to use buffer.StreamBuffer + optional HybridCache.
internal/net/request_test.go	Removes unused test helpers after downloader refactor.
internal/mem/utils.go	Adds memory growth checks and guarded allocation wrappers.
internal/mem/type.go	Defines LinearMemory and GrowCheck primitives.
internal/mem/mem_windows.go	Implements LinearMemory via Windows VirtualAlloc.
internal/mem/mem_unix.go	Implements LinearMemory via mmap/mprotect on unix.
internal/mem/mem_other.go	Fallback LinearMemory implementation using Go slices on other platforms.
internal/mem/cache.go	Implements HybridCache (memory-first, file fallback) and a reader over cached sections.
internal/conf/var.go	Adds MinFreeMemory global var.
internal/conf/config.go	Adds min_free_memoryMB config field.
internal/bootstrap/config.go	Computes and logs MinFreeMemory, MaxBufferLimit, and MmapThreshold from system memory/config.
drivers/teldrive/types.go	Updates interface type name to the new StreamSectionReader.

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[Copilot]

Pull request overview

Copilot reviewed 21 out of 21 changed files in this pull request and generated 11 comments.

[Copilot]

Pull request overview

Copilot reviewed 23 out of 23 changed files in this pull request and generated 10 comments.

[Copilot]

Pull request overview

Copilot reviewed 23 out of 23 changed files in this pull request and generated 6 comments.

[Copilot]

Pull request overview

Copilot reviewed 24 out of 24 changed files in this pull request and generated 4 comments.