[re2zero]

Part 6/8 of the reverse tunnel stack (recovery of #802).

This reapplies the reviewed commit on top of the corrected stack because #802 was accidentally merged into its stacked base branch instead of master.

Merge order: #805 → #806 → #807 → #808 → #809 → #810 → #811.
Retargeted to master after #808 merged.

QAbstractSocket buffers incoming bytes in user space without a limit by
default, draining the kernel even when the tunnel credit window is full.
The sender's file server therefore never blocked and reported progress up
to 100% while the receiver was still downloading a large file.

Cap each tunnel stream socket at twice the credit window so TCP
backpressure reaches the writer.

Log: cap tunnel socket read buffers for flow control
PMS: TASK-396845
Influence: large transfers apply TCP backpressure instead of reporting progress the receiver has not received.

Summary by Sourcery

Restore TCP flow control for tunnel streams by limiting socket read buffering.

Bug Fixes:

• Cap tunnel stream socket read buffers so TCP backpressure is applied when the credit window is full, preventing large transfers from reporting progress before data is received.

Tests:

• Add coverage verifying that tunnel sockets on both sides use the configured read-buffer limit.

[sourcery-ai]

Reviewer's Guide

This PR prevents Qt from buffering unlimited incoming tunnel data in user space by setting every stream socket's read buffer to twice the credit window, allowing TCP backpressure to reach the sender; an integration-style test verifies the limit on both sides of a forwarded connection.

Sequence diagram for tunnel socket backpressure

sequenceDiagram
    participant Sender
    participant TCP
    participant ReceiverSocket
    participant TunnelManager
    participant Receiver

    Sender->>TCP: Send stream data
    TCP->>ReceiverSocket: Deliver incoming bytes
    ReceiverSocket->>ReceiverSocket: setReadBufferSize(kReadBufferSize)
    ReceiverSocket->>TunnelManager: readyRead
    TunnelManager->>Receiver: pump
    ReceiverSocket-->>TCP: Buffer capped at 2 * kWindowSize
    TCP-->>Sender: Apply backpressure when buffer is full

Loading

File-Level Changes

Change	Details	Files
Cap incoming tunnel socket buffering to preserve credit-window TCP backpressure.	Define the read-buffer cap as twice the 256 KiB tunnel window. Apply the cap when configuring every stream socket. Add coverage verifying both locally accepted and remotely dialed stream sockets use the configured limit.	src/lib/common/manager/tunnelmanager.h src/lib/common/manager/tunnelmanager.cpp tests/manager/tunnelmanager_test.cpp

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[sourcery-ai]

Hey - I've reviewed your changes and they look great!

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The base branch was changed.

[deepin-ci-robot]

deepin pr auto review

🤖 AI 代码审查报告

总体评分： 100 分 (通过阈值: 70分)

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📊 总体评价

项目	结果
审查结论	代码审查通过
评分详情	本次提交修复了隧道socket读取缓冲区无限制的问题，通过设置QAbstractSocket读取缓冲区上限 来配合信用窗口流控机制。变更仅3个文件，新增61行代码，改动精准且注释完整，包含单元测试 覆盖。语法逻辑正确，代码质量优秀，性能改善明显，无安全漏洞。

|

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🔍 详细分析

1. 语法逻辑 ✅

评价： 语法正确，逻辑清晰 ✅ 通过

潜在问题：
✅ 未发现明显问题

建议： 无

---

2. 代码质量 ✅

评价： 代码结构清晰，注释完整 ✅ 通过

潜在问题：
✅ 未发现明显问题

建议： 无

---

3. 代码性能 ✅

评价： 性能良好，资源使用合理 ✅ 通过

潜在问题：
✅ 未发现明显问题

建议： 无

---

4. 代码安全 🔒

评价： 存在0个安全漏洞 ✅ 通过

🔐 发现 0 个安全漏洞

安全漏洞详情：
✅ 未发现安全漏洞

建议： 无

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💡 改进建议代码示例

// 当前代码已为最佳实践，无需修改。
// tunnelmanager.h
static constexpr int kReadBufferSize = 2 * kWindowSize;  // 512KB，配合信用窗口流控

// tunnelmanager.cpp - setupSocket() 中在连接信号槽前设置
socket->setReadBufferSize(kReadBufferSize);

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本报告由 AI 代码审查工具自动生成

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: lzwind, re2zero

The full list of commands accepted by this bot can be found here.

Details

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• debian/deepin/OWNERS

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