background "class" works

1 files changed, 66 insertions, 0 deletions

diff --git a/internal/server/background/background.go b/internal/server/background/background.go
new file mode 100644
index 0000000..d31c1f2
--- /dev/null
+++ b/internal/server/background/background.go
@@ -0,0 +1,66 @@
+package background
+
+import (
+	"context"
+	"sync"
+
+	"github.com/mimecast/dtail/internal/io/logger"
+)
+
+type job struct {
+	cancel context.CancelFunc
+	done   <-chan struct{}
+}
+
+type Background struct {
+	mutex sync.Mutex
+	jobs  map[string]job
+}
+
+func NewBackground() *Background {
+	return &Background{
+		jobs: make(map[string]job),
+	}
+}
+
+func (b Background) Add(name string, cancel context.CancelFunc, done <-chan struct{}) {
+	b.mutex.Lock()
+	defer b.mutex.Unlock()
+
+	logger.Debug("background", name, "adding job")
+	b.jobs[name] = job{cancel, done}
+}
+
+func (b Background) get(name string) (job, bool) {
+	b.mutex.Lock()
+	defer b.mutex.Unlock()
+
+	job, ok := b.jobs[name]
+	return job, ok
+}
+
+func (b Background) delete(name string) {
+	b.mutex.Lock()
+	defer b.mutex.Unlock()
+
+	delete(b.jobs, name)
+}
+
+func (b Background) Stop(name string) {
+	logger.Debug("background", name, "stopping job")
+	job, ok := b.get(name)
+
+	if !ok {
+		logger.Debug("background", name, "no such job")
+		return
+	}
+
+	logger.Debug("background", name, "canceling job")
+	job.cancel()
+
+	logger.Debug("background", name, "waiting for job to complete")
+	<-job.done
+
+	logger.Debug("background", name, "deleting job")
+	b.delete(name)
+}