DAG Patch Analyzer - Prototype Application
Application Overview
A web application that ingests Git commits and auto-regresses them into DAG-based patch representations, with an interactive interface for exploring the factorization process and resulting operation graph.
Core Functionality
Input
- Git repository URL or path
- Commit ID/hash or range
- Optional: GitHub/GitLab PR URL (extracts commit automatically)
Processing Pipeline
- Clone/Fetch - Retrieve repository and commit data
- State Extraction - Generate before/after tar archives
- Auto-Regression - Factor changes into operation DAG
- Analysis - Compute metrics, detect patterns
- Storage - Persist results for exploration
Output
- Interactive DAG visualization
- Operation-level breakdown
- Compression metrics
- Analysis insights
Architecture
Backend Services
Git Ingestion Service
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Input: repo_url, commit_id
Output: {before_state, after_state, metadata}
- Clone repository (shallow clone for efficiency)
- Checkout commit and parent
- Generate tar archives of both states
- Extract commit metadata (author, message, timestamp, files_changed)
Factorization Engine
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Input: {before_state, after_state}
Output: operation_dag
Algorithm phases:
1. Whitespace isolation
2. Rename/move detection (file and symbol level)
3. Copy detection (code duplication)
4. Regex pattern matching (common replacements)
5. Reorder detection (block movements)
6. Binary delta generation (residual)
7. Dependency graph construction
8. Description length optimization
Analysis Service
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Input: operation_dag
Output: metrics, patterns, insights
Computes:
- Compression ratio (operations vs raw diff size)
- Operation type distribution
- Dependency depth and parallelism potential
- Pattern matching (known refactoring types)
- Semantic coherence scores
- Change impact radius
Storage Layer
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- PostgreSQL for metadata and analysis results
- Object storage (S3/local) for tar archives
- Graph database (Neo4j optional) for DAG queries
- Content-addressed blob store for operations
Frontend Interface
Main Views
1. Commit Input View
- URL/commit input form
- Recent analyses list
- Example commits (curated interesting cases)
2. Processing View
- Real-time progress indicator
- Step-by-step factorization phases
- Live metrics updates
- Logs/debug output (collapsible)
3. Graph Explorer View Primary interface for exploring results:
Left Panel: DAG Visualization
- Interactive force-directed graph
- Nodes: operations (colored by type)
- Edges: dependencies
- Controls: zoom, pan, filter by operation type
- Click node → show details in right panel
- Highlight: critical path, independent subgraphs
- Layout options: topological, hierarchical, force-directed
Right Panel: Operation Details
- Selected operation properties
- Before/after code snippets
- Dependency list (upstream/downstream)
- Metrics: size, compression contribution
- Semantic tags (auto-detected)
Bottom Panel: Global Metrics
- Total operations count by type
- Compression ratio visualization
- Dependency depth histogram
- Parallelism score
- Pattern detection results
4. Comparison View
- Load multiple commits
- Compare DAG structures
- Identify common patterns
- Diff-of-diffs visualization
5. Export View
- Download DAG as JSON/binary format
- Generate patch file
- Export visualizations
- API access details
Technical Stack
Backend
- Language: Python or Rust
- Framework: FastAPI (Python) or Axum (Rust)
- Git Integration: GitPython or git2-rs
- Compression: zlib, zstd
- Regex: re2 for safe pattern matching
- Task Queue: Celery or Rust async runtime
- Database: PostgreSQL + SQLAlchemy/Diesel
Frontend
- Framework: React or Svelte
- Graph Visualization: D3.js or Cytoscape.js
- Code Display: Monaco Editor or CodeMirror
- State Management: Zustand or Svelte stores
- UI Components: Tailwind CSS + headlessui
- Build: Vite
Infrastructure
- Containerization: Docker + docker-compose
- Cache: Redis for job results
- Storage: MinIO (local S3-compatible) or AWS S3
- Monitoring: Prometheus + Grafana (optional)
Key Features
Factorization Visualization
Step-by-step Replay
- Slider to replay factorization process
- Show operations discovered at each step
- Display metrics evolution
- Highlight what changed in each iteration
Alternative Factorizations
- Show multiple valid decompositions
- Compare description lengths
- Let user choose preferred factorization
- Explain trade-offs
Interactive Analysis
Operation Filtering
- Show/hide operation types
- Focus on semantic changes only
- Isolate whitespace/formatting
- Find all operations touching specific files
Dependency Exploration
- Trace forward: “what depends on this?”
- Trace backward: “what does this depend on?”
- Find critical path (longest dependency chain)
- Identify parallelizable subgraphs
- Collapse/expand operation groups
Code Context
- Inline diff view for each operation
- Syntax highlighting
- Jump to file locations
- Show surrounding context
Pattern Recognition
Auto-Detection
- Rename refactoring (class, function, variable)
- Extract method/interface
- Move class/function
- Add error handling pattern
- Update import statements
- Configuration changes
Pattern Library
- Save interesting patterns
- Search past commits for similar patterns
- Suggest operations based on partial changes
Metrics Dashboard
Compression Analysis
- Description length breakdown by operation type
- Savings vs traditional diff
- Compression ratio over time (for multiple commits)
Complexity Metrics
- Operation count by type
- Dependency graph complexity
- Cyclomatic complexity of changes
- Change coupling (files changed together)
Semantic Analysis
- Functional vs non-functional changes ratio
- Impact radius (files/functions affected)
- Refactoring safety score
- Breaking change detection
User Workflows
Workflow 1: Analyze Single Commit
- Enter repo URL + commit hash
- Wait for processing (show progress)
- Explore DAG in graph view
- Click operations to see details
- Export results or save analysis
Workflow 2: Compare Commits
- Load multiple commits
- View side-by-side DAGs
- Identify common operation patterns
- See metric comparisons
- Export pattern library
Workflow 3: Debug Factorization
- Load commit with unexpected results
- Step through factorization phases
- View alternative decompositions
- Adjust algorithm parameters (advanced mode)
- Re-run with new settings
Workflow 4: Pattern Mining
- Analyze repository history (bulk mode)
- Build pattern library automatically
- Browse discovered patterns
- Search for pattern occurrences
- Export reusable transform templates
API Endpoints
REST API
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POST /api/analyze
body: {repo_url, commit_id, options}
returns: {job_id}
GET /api/jobs/{job_id}
returns: {status, progress, result_id}
GET /api/results/{result_id}
returns: {dag, metrics, metadata}
GET /api/results/{result_id}/graph
returns: graph data in various formats
POST /api/compare
body: {result_ids: [...]}
returns: comparison analysis
GET /api/patterns
returns: saved pattern library
POST /api/patterns
body: {pattern_data}
saves pattern for reuse
WebSocket
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WS /api/analyze/stream
- Real-time factorization progress
- Live metrics updates
- Step-by-step operation discovery
MVP Scope (Phase 1)
Core Functionality
- Git commit ingestion (single commit)
- Basic factorization (whitespace, move, delete, binary delta)
- Simple DAG construction
- Graph visualization (D3.js force-directed)
- Operation details panel
- Basic metrics (compression ratio, operation count)
Deferred Features (Phase 2+)
- Regex-based string replace
- Advanced pattern recognition
- Multi-commit comparison
- Alternative factorizations
- Pattern library
- Bulk analysis mode
- API for external tools
- Export to production patch format
Implementation Phases
Phase 1: Proof of Concept (2-3 weeks)
- Backend: Git ingestion + basic factorization
- Frontend: Simple graph view + metrics
- Single-commit analysis only
- Local storage only
Phase 2: Enhanced Factorization (2-3 weeks)
- All operation types implemented
- Dependency analysis refined
- Description length optimization
- Step-by-step replay
Phase 3: Polish & Features (2-3 weeks)
- Multi-commit comparison
- Pattern recognition
- Improved UI/UX
- Export functionality
- Performance optimization
Phase 4: Production Ready (ongoing)
- API development
- Scalability improvements
- Pattern library
- Integration examples
- Documentation
Success Metrics
Technical
- Factorization completes in <30s for typical commits
- Compression ratio >2x vs traditional diff
- 90%+ operation accuracy vs manual review
User Experience
- Clear visualization of complex commits
- Intuitive operation exploration
- Useful insights for code review
- Adoption by development teams
Example Use Cases
Large Refactoring Analysis
- Developer submits 5000-line refactoring commit
- Tool factors into 20 semantic operations
- Reviewer explores operation-by-operation
- Identifies one operation needs discussion
- Rest auto-approved
Pattern Learning
- Team analyzes 100 recent commits
- Tool discovers common “add logging” pattern
- Pattern saved to library
- Future commits auto-tagged with pattern
- Enables pattern-based code search
Merge Conflict Prevention
- Two PRs analyzed before merge
- DAG comparison shows independent changes
- No true conflicts detected
- Safe to merge in either order
Open Questions
- Factorization algorithm convergence criteria?
- How to handle merge commits?
- Binary file handling strategy?
- Performance on monorepos?
- User authentication for private repos?
- Cost model for hosted version?
