diff options
| -rw-r--r-- | go.mod | 5 | ||||
| -rw-r--r-- | go.sum | 2 | ||||
| -rw-r--r-- | main.go | 37 |
3 files changed, 31 insertions, 13 deletions
@@ -2,7 +2,4 @@ module janouch.name/gallery go 1.21.4 -require ( - github.com/mattn/go-sqlite3 v1.14.18 - golang.org/x/sync v0.5.0 -) +require github.com/mattn/go-sqlite3 v1.14.18 @@ -1,4 +1,2 @@ github.com/mattn/go-sqlite3 v1.14.18 h1:JL0eqdCOq6DJVNPSvArO/bIV9/P7fbGrV00LZHc+5aI= github.com/mattn/go-sqlite3 v1.14.18/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg= -golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE= -golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk= @@ -29,7 +29,6 @@ import ( "time" "github.com/mattn/go-sqlite3" - "golang.org/x/sync/semaphore" ) var ( @@ -37,7 +36,7 @@ var ( galleryDirectory string // gallery directory // taskSemaphore limits parallel computations. - taskSemaphore *semaphore.Weighted + taskSemaphore semaphore ) func hammingDistance(a, b int64) int { @@ -89,6 +88,30 @@ func dbCollectStrings(query string) ([]string, error) { return result, nil } +// --- Semaphore --------------------------------------------------------------- + +type semaphore chan struct{} + +func newSemaphore(size int) semaphore { return make(chan struct{}, size) } +func (s semaphore) release() { <-s } + +func (s semaphore) acquire(ctx context.Context) error { + select { + case <-ctx.Done(): + return ctx.Err() + case s <- struct{}{}: + } + + // Give priority to context cancellation. + select { + case <-ctx.Done(): + s.release() + return ctx.Err() + default: + } + return nil +} + // --- Progress bar ------------------------------------------------------------ type progressBar struct { @@ -740,13 +763,13 @@ func cmdImport(args []string) error { ctx, cancel := context.WithCancelCause(context.Background()) wg := sync.WaitGroup{} for _, path := range paths { - if taskSemaphore.Acquire(ctx, 1) != nil { + if taskSemaphore.acquire(ctx) != nil { break } wg.Add(1) go func(path string) { - defer taskSemaphore.Release(1) + defer taskSemaphore.release() defer wg.Done() if err := i.Import(path); err != nil { cancel(err) @@ -1071,13 +1094,13 @@ func cmdThumbnail(args []string) error { ctx, cancel := context.WithCancelCause(context.Background()) wg := sync.WaitGroup{} for _, sha1 := range hexSHA1 { - if taskSemaphore.Acquire(ctx, 1) != nil { + if taskSemaphore.acquire(ctx) != nil { break } wg.Add(1) go func(sha1 string) { - defer taskSemaphore.Release(1) + defer taskSemaphore.release() defer wg.Done() if err := makeThumbnailFor(sha1); err != nil { cancel(err) @@ -1174,7 +1197,7 @@ func main() { log.Fatalln("Unknown command: " + os.Args[1]) } - taskSemaphore = semaphore.NewWeighted(int64(runtime.NumCPU())) + taskSemaphore = newSemaphore(runtime.NumCPU()) err := cmd.handler(os.Args[2:]) // Note that the database object has a closing finalizer, |