wails/v3/internal/libpath/cache_linux.go
Lea Anthony f1a4ffe72d
feat(linux): add libpath package for finding native library paths (#4847)
* feat(linux): add libpath package for finding native library paths

Add a new internal/libpath package that locates shared libraries (.so files)
on Linux systems. Supports multiple distributions and package managers.

Features:
- Multi-tier search: pkg-config -> ldconfig -> filesystem scanning
- Parallel search using goroutines for faster lookups
- Cached dynamic path discovery for Flatpak, Snap, and Nix
- Support for Debian/Ubuntu, Fedora/RHEL, Arch, openSUSE, NixOS
- Context-aware cancellation for graceful shutdown

Performance:
- Library found: ~1.4ms (parallel search)
- Library not found: ~46ms (was 84ms sequential)
- Cached path discovery: 14ns (was 15ms uncached)

* feat(libpath): add multi-library parallel search functions

Add functions to search for multiple library candidates in parallel:

- FindFirstLibrary: Search multiple libs in parallel, return first found
- FindFirstLibraryOrdered: Search in order of preference (for version priority)
- FindAllLibraries: Find all available libraries from a list

Useful when the exact library version is unknown, e.g.:
  match, _ := FindFirstLibrary("webkit2gtk-4.1", "webkit2gtk-4.0", "webkit2gtk-6.0")

Also adds findLibraryPathCtx for context-aware searching used by the
multi-library functions.

* refactor(libpath): split into separate files and fix race condition

Split libpath_linux.go into smaller, focused files:
- cache_linux.go: Path cache with thread-safe init/invalidate
- flatpak_linux.go: Flatpak runtime path discovery
- snap_linux.go: Snap package path discovery
- nix_linux.go: Nix/NixOS path discovery
- libpath_linux.go: Core search functions

Fixes:
- Fix data race between init() and invalidate() by holding mutex
  during cache writes inside sync.Once.Do (CodeRabbit review)
- Fix FindLibraryPathWithOptions not searching dynamic paths
  (Flatpak/Snap/Nix) - now uses GetAllLibPaths() (CodeRabbit review)
2026-01-04 11:59:22 +11:00

79 lines
1.7 KiB
Go

//go:build linux
package libpath
import "sync"
// pathCache holds cached dynamic library paths to avoid repeated
// expensive filesystem and subprocess operations.
type pathCache struct {
mu sync.RWMutex
flatpak []string
snap []string
nix []string
initOnce sync.Once
inited bool
}
var cache pathCache
// init populates the cache with dynamic paths from package managers.
// This is called lazily on first access.
func (c *pathCache) init() {
c.initOnce.Do(func() {
// Discover paths without holding the lock
flatpak := discoverFlatpakLibPaths()
snap := discoverSnapLibPaths()
nix := discoverNixLibPaths()
// Hold lock only while updating the cache
c.mu.Lock()
c.flatpak = flatpak
c.snap = snap
c.nix = nix
c.inited = true
c.mu.Unlock()
})
}
// getFlatpak returns cached Flatpak library paths.
func (c *pathCache) getFlatpak() []string {
c.init()
c.mu.RLock()
defer c.mu.RUnlock()
return c.flatpak
}
// getSnap returns cached Snap library paths.
func (c *pathCache) getSnap() []string {
c.init()
c.mu.RLock()
defer c.mu.RUnlock()
return c.snap
}
// getNix returns cached Nix library paths.
func (c *pathCache) getNix() []string {
c.init()
c.mu.RLock()
defer c.mu.RUnlock()
return c.nix
}
// invalidate clears the cache and forces re-discovery on next access.
func (c *pathCache) invalidate() {
c.mu.Lock()
defer c.mu.Unlock()
c.flatpak = nil
c.snap = nil
c.nix = nil
c.initOnce = sync.Once{} // Reset so init() runs again
c.inited = false
}
// InvalidateCache clears the cached dynamic library paths.
// Call this if packages are installed or removed during runtime
// and you need to re-discover library paths.
func InvalidateCache() {
cache.invalidate()
}