## Name and Contact Information - Full Name: Zheng Yuting - Email Address: 05ZYT30@xxxxxxxxx - Time Zone: UTC +8:00 --- ## Abstract The current Git reference management functionality is fragmented across multiple independent commands (git-show-ref, git-for-each-ref, git-update-ref, git-pack-refs, git-check-ref-format, and git-symbolic-ref), leading to code redundancy and increased maintenance costs. Based on Patrick Steinhardt’s integration vision[1], this project aims to introduce 8 new subcommands (list, exists, show, resolve, pack, update, delete, check-format) under the existing git-refs command to achieve the following objectives: - Feature Integration: Consolidate existing reference management commands under git-refs, while maintaining backward compatibility. - Feature Enhancement: Introduce recursion depth control for git-refs resolve. - Testing & Documentation: Add test cases ensuring consistency and update relevant documentation. --- ## Implementation Plan ### Command Integration Strategy #### Design Goals The project will unify scattered reference management functionalities under the git-refs subcommand framework, ensuring: 1. Complete Feature Coverage: Each subcommand fully replaces its corresponding legacy command. 2. Parameter Compatibility: Preserve the semantics and output behavior of legacy command options. 3. Code Reusability: Minimize redundancy by sharing underlying modules (e.g., refs/files-backend.c). #### Subcommand Mapping - git-refs list Replaces git-show-ref and git-for-each-ref, merging reference listing functionalities with support for formatting (--format), filtering (--heads, --tags), and sorting (--sort). - git-refs exists Replaces git-show-ref --exists, providing reference existence checks with positive (<ref>) and exclusion-based (--exclude-existing) verification. - git-refs show Replaces git-show-ref --verify, validating reference correctness with a strict mode (--strict). - git-refs resolve Replaces git-symbolic-ref, resolving symbolic references with added recursion depth control (--max-depth), while retaining deletion (-d) and quiet mode (-q) options. - git-refs pack Replaces git-pack-refs, packing loose references with support for filtering (--include, --exclude) and automatic cleanup (--prune). - git-refs update Replaces git-update-ref, providing transactional reference updates with batch processing (--stdin) and atomic guarantees. - git-refs delete Separates the delete functionality from git-update-ref, ensuring explicit handling of reference removals with safety checks and batch operations (--stdin). - git-refs check-format Replaces git-check-ref-format, validating reference format with support for normalized output (--normalize). #### Implementation Strategy 1. Option Parsing: Each subcommand will reuse the argument parsing logic from legacy commands (e.g., git-pack-refs --prune). 2. Shared Backend Logic: Calls to common functions in refs/ (e.g., reference traversal, locking mechanisms). 3. Error Consistency: Maintain the same error codes and message formats as legacy commands. --- ### Example: Implementing git-refs pack #### Functional Implementation 1. Modify builtin/refs.c: - Add cmd_refs_pack function implementing git-pack-refs logic. - Update cmd_refs to include pack with OPT_SUBCOMMAND("pack", &fn, cmd_refs_pack). - Define REFS_PACK_USAGE: git refs pack [--all] [--no-prune] [--auto] [--include <pattern>] [--exclude <pattern>]. 2. Register New Subcommand in git.c: - Add { "refs-pack", cmd_refs_pack }, to the command array. 3. Reuse refs/files-backend.c Logic: - Ensure cmd_refs_pack calls pack_refs correctly, adjusting as necessary for new options. #### Testing Plan - Test Cases: Add t/txxx-refs-pack.sh, leveraging t/t0601-reffiles-pack-refs.sh scenarios to verify: - --prune removes obsolete references correctly. - --include and --exclude apply filtering as expected. - Packed references match legacy command outputs (diff .git/packed-refs). - Performance Benchmarking (if needed): Add performance tests in t/perf to ensure no significant regression in execution time or memory usage. #### Documentation Updates - User Manual: Add a pack section to Documentation/git-refs.txt, mapping options to legacy command equivalents. - Developer Notes: Comment code to highlight functional parity between git-refs pack and git-pack-refs. --- ### Timeline - May 8 - May 11 (4 days): Initial Testing & Subcommand Framework Setup - May 12 - May 28 (17 days): pack Subcommand Implementation - May 29 - June 14 (17 days): check-format Subcommand Development - June 15 - July 5 (21 days): update and delete Subcommands Development - July 6 - July 26 (21 days): show and exists Subcommands Development - July 27 - August 16 (21 days): resolve Subcommand Implementation - August 17 - September 6 (21 days): list Subcommand Implementation - September 7 - September 16 (10 days): Mid-term Review - September 17 - September 23 (7 days): Mentor Review & Final Adjustments --- ## Background & Experience I graduated in June 2024 from Wenzhou University with a degree in Network Engineering. My experience includes C programming and command-line tool development, along with proficiency in Shell scripting. I am currently in a transitional phase and expect to finalize my schedule by late April, and then update my weekly schedule for GSoC, estimating 25-30 hours per week for this project currently. ### Project Experience - One Student One Chip Project[2] Extending the open-source NEMU simulator by implementing CPU cycle functionalities in C. - Web Development Developed a Django-based campus website, including user chat, news publishing, and teacher management modules. - Custom Communication Protocols Built a UDP-based chatroom with peer-to-peer and group messaging. - Stock Monitoring Tool Implemented real-time monitoring and historical data analysis, with email alerting and planned AI-driven strategy optimization. I have also obtained CCNA certification and gained hands-on experience as a network engineer. Additionally, I contributed a patch optimizing send-email functionality in Git[3], giving me insights into the Git codebase. ## Appendix [1] https://gitlab.com/gitlab-org/git/-/issues/330 [2] https://ysyx.oscc.cc/en/project/intro.html [3]https://lore.kernel.org/git/20250312064639.668875-1-05ZYT30@xxxxxxxxx/