Multi-Repository Support¶

The rninja daemon efficiently handles builds across multiple repositories.

How It Works¶

A single daemon can serve builds from different repositories:

graph TB
    subgraph "Daemon"
        D[rninja-daemon]
        C1[(Cache: Repo A)]
        C2[(Cache: Repo B)]
        C3[(Cache: Repo C)]
    end

    A[Repo A] -->|build| D
    B[Repo B] -->|build| D
    C[Repo C] -->|build| D

    D --> C1
    D --> C2
    D --> C3

Namespace Isolation¶

Each repository gets isolated state:

Build manifest: Parsed separately per directory
File cache: Isolated per working directory
Build cache: Shared (content-addressed)

# Build in repo A
cd ~/projects/repo-a
rninja

# Build in repo B (same daemon, isolated state)
cd ~/projects/repo-b
rninja

Benefits¶

Shared Resources¶

Single daemon process for all repos
Shared memory pool
Coordinated disk access

Content Deduplication¶

If repos share similar code:

Repo A: libcommon.a (hash: abc123)
Repo B: libcommon.a (hash: abc123)  # Same content

Cache: stores once, both repos get hits

Fast Context Switching¶

Switch between repos without restart penalty:

cd repo-a && rninja  # Fast
cd repo-b && rninja  # Also fast
cd repo-a && rninja  # Still fast (cached)

Concurrent Builds¶

Build multiple repos simultaneously:

# Terminal 1
cd ~/projects/repo-a
rninja

# Terminal 2 (same time)
cd ~/projects/repo-b
rninja

The daemon coordinates:

Independent build sessions
Shared cache access
Resource management

Configuration¶

Per-Repo Settings¶

Settings are resolved per working directory:

# repo-a/.rninjarc
[build]
jobs = 4

# repo-b/.rninjarc
[build]
jobs = 8

Shared Daemon Socket¶

Default: All repos use same daemon socket

# Both repos use same daemon
cd ~/repo-a && rninja
cd ~/repo-b && rninja

Separate Daemons (Advanced)¶

If needed, run separate daemons:

# Repo A with dedicated daemon
rninja --daemon-socket /tmp/repo-a-daemon.sock

# Repo B with different daemon
rninja --daemon-socket /tmp/repo-b-daemon.sock

Monorepo Considerations¶

For monorepos with multiple build directories:

monorepo/
├── build.ninja           # Root
├── frontend/
│   └── build.ninja       # Frontend
└── backend/
    └── build.ninja       # Backend

# All use same daemon
rninja -C frontend
rninja -C backend
rninja  # Root build

Resource Management¶

Memory Usage¶

Daemon caches manifest data per repo:

Memory ≈ Base + (Repos × Manifest Size)

Example:
- Base: 50 MB
- 5 repos × 10 MB each = 50 MB
- Total: ~100 MB

Limiting Cached Repos¶

# Start daemon with limit
rninja-daemon --max-cached 10

Older repos evicted when limit reached.

Best Practices¶

Use Single Daemon¶

For most users, one daemon is sufficient:

# Let auto-spawn handle it
rninja

Project-Specific When Needed¶

For isolation (e.g., different toolchains):

# Project needing specific environment
RNINJA_DAEMON_SOCKET=/tmp/special-project.sock rninja

CI Runners¶

Each runner can have its own daemon:

# Runner 1
RNINJA_DAEMON_SOCKET: /tmp/runner-1.sock

# Runner 2
RNINJA_DAEMON_SOCKET: /tmp/runner-2.sock

Troubleshooting¶

Wrong Repo State¶

If builds seem to use wrong state:

# Verify working directory
pwd

# Force daemon to reload
pkill -f rninja-daemon
rninja

Cache Confusion¶

If cache seems shared incorrectly:

# Check cache stats per repo
cd repo-a && rninja -t cache-stats
cd repo-b && rninja -t cache-stats

Resource Contention¶

If many repos cause slowdown:

# Limit concurrent builds
rninja-daemon --max-builds 2