---
phase: 08-rust-directory-archiver
plan: 01
subsystem: archive
tags: [rust, directory-traversal, unix-permissions, binary-format, toc-entry]

# Dependency graph
requires:
  - phase: 07-format-spec-update
    provides: v1.1 FORMAT.md with entry_type, permissions fields, directory entry semantics
provides:
  - v1.1 TocEntry with entry_type and permissions fields (format.rs)
  - Recursive directory traversal in pack with relative paths
  - Directory hierarchy restoration with Unix mode bits in unpack
  - Entry type and permissions display in inspect
  - Directory round-trip integration tests
affects: [09-backward-compat, 10-hardening, 11-polish]

# Tech tracking
tech-stack:
  added: []
  patterns: [collect_entries pattern for recursive directory traversal, DFS preorder for parent-before-child ordering, ProcessedFile entry_type discriminator for file vs directory handling]

key-files:
  created: []
  modified:
    - src/format.rs
    - src/archive.rs
    - src/cli.rs
    - tests/round_trip.rs

key-decisions:
  - "DFS preorder traversal with sorted children for deterministic parent-before-child ordering"
  - "Directory entries use zero-filled crypto fields (no data block) per FORMAT.md v1.1"
  - "Permissions captured via std::os::unix::fs::PermissionsExt::mode() & 0o7777"
  - "Standalone files use filename-only names; directory children use relative paths with / separator"

patterns-established:
  - "collect_entries(): unified entry collection for mixed file/directory inputs"
  - "process_file(): extracted crypto pipeline into reusable function"
  - "make_directory_entry(): factory for zero-length directory ProcessedFile"

requirements-completed: [DIR-01, DIR-02, DIR-03, DIR-04, DIR-05]

# Metrics
duration: 6min
completed: 2026-02-26
---

# Phase 8 Plan 01: Rust Directory Archiver Summary

**v1.1 format implementation with recursive directory traversal, Unix permission preservation, and directory/file type discrimination in pack/unpack/inspect**

## Performance

- **Duration:** 6 min
- **Started:** 2026-02-26T18:42:02Z
- **Completed:** 2026-02-26T18:48:33Z
- **Tasks:** 3
- **Files modified:** 4

## Accomplishments
- Updated format.rs to v1.1 binary layout: VERSION=2, TocEntry with entry_type (u8) and permissions (u16), entry_size=104+name_length
- Implemented recursive directory traversal in pack() with parent-before-child ordering and relative path naming
- unpack() creates full directory hierarchy, restores Unix mode bits on both files and directories
- inspect() displays entry type (dir/file) and octal permissions for each TOC entry
- All 41 tests pass: 25 unit + 7 golden + 9 integration (3 new directory tests)

## Task Commits

Each task was committed atomically:

1. **Task 1: Update format.rs for v1.1 TOC entry layout** - `4e25d19` (feat)
2. **Task 2: Update archive.rs and cli.rs for directory support** - `7820c18` (feat)
3. **Task 3: Add directory round-trip integration test** - `8760981` (test)

## Files Created/Modified
- `src/format.rs` - v1.1 TocEntry with entry_type/permissions, VERSION=2, entry_size=104+N
- `src/archive.rs` - Recursive directory traversal, permission capture/restore, directory-aware pack/unpack/inspect
- `src/cli.rs` - Updated doc comments for directory support
- `tests/round_trip.rs` - 3 new tests: directory round-trip, mixed files+dirs, inspect directory info

## Decisions Made
- Used DFS preorder with sorted children for deterministic parent-before-child ordering (no external walkdir dependency)
- Extracted crypto pipeline into process_file() helper for reuse between single-file and directory-file processing
- Directory entries skip data_offset computation and data block writing (offset=0, no ciphertext)
- Permissions always stored as lower 12 bits of mode_t (0o7777 mask) per FORMAT.md v1.1 spec

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 3 - Blocking] Added entry_type/permissions to archive.rs ProcessedFile during Task 1**
- **Found during:** Task 1 (format.rs update)
- **Issue:** After adding new fields to TocEntry, archive.rs TocEntry constructions failed to compile
- **Fix:** Added entry_type and permissions fields to ProcessedFile struct and its construction in pack()
- **Files modified:** src/archive.rs
- **Verification:** cargo test --lib format:: passed all 13 tests
- **Committed in:** 4e25d19 (Task 1 commit)

---

**Total deviations:** 1 auto-fixed (1 blocking)
**Impact on plan:** Necessary compilation fix from cross-file dependency. No scope creep.

## Issues Encountered
None -- all tasks executed smoothly after the blocking compilation fix.

## User Setup Required
None - no external service configuration required.

## Next Phase Readiness
- v1.1 format fully implemented and tested
- Ready for Phase 9 (backward compatibility) or Phase 10 (hardening) if planned
- All existing v1.0 tests updated to v1.1 format (no backward compat with v1.0 archives per decision)

---
*Phase: 08-rust-directory-archiver*
*Completed: 2026-02-26*