Incremental Build

IGraph implements incremental builds based on SHA-256 diff, dramatically reducing rebuild times.

How It Works

On each build, IGraph records the SHA-256 hash of every file. On subsequent build runs, only changed files are processed:

# First build (full)
igraph build
# ✓ Parsed 142 files, generated 856 symbol nodes

# After modifying 3 files (incremental)
igraph build
# ✓ Detected 3 changed files, incrementally updated 18 nodes

Cascading Updates

Incremental builds don't just update the changed files — they cascade updates to affected dependencies:

1. File changed → Re-parse the file's symbols
2. Symbol changed → Update the symbol's call relationship edges
3. Relationship changed → Re-generate summaries for affected symbols
4. Summary changed → Re-vectorize affected nodes

This ensures the graph stays consistent with source code.

Forcing a Full Rebuild

If you need to rebuild from scratch (e.g., after switching LLM models or modifying parser config), use rebuild:

igraph rebuild            # Clear database and rebuild from scratch
igraph rebuild --no-llm   # Full rebuild with heuristic fallback
igraph rebuild --dry-run  # Preview only, no execution

Build Options

Command	Behavior
igraph build	Auto-incremental (full on first run)
igraph build --incremental	Explicit incremental mode
igraph build --dry-run	Preview parse stats without writing to DB
igraph build --no-llm	Skip LLM summaries and vectorization
igraph rebuild	Clear and full rebuild
igraph rebuild --full	Same as rebuild (default behavior)