1 files changed, 100 insertions, 0 deletions
diff --git a/core/load/load.go b/core/load/load.go
new file mode 100644
index 0000000..c568517
--- /dev/null
+++ b/core/load/load.go
@@ -0,0 +1,100 @@
+package load
+
+import (
+	log "github.com/sirupsen/logrus"
+
+	"context"
+	"errors"
+	"runtime"
+	"sync"
+
+	"github.com/isacikgoz/gitbatch/core/git"
+	"golang.org/x/sync/semaphore"
+)
+
+// AsyncAdd is interface to caller
+type AsyncAdd func(r *git.Repository)
+
+// SyncLoad initializes the go-git's repository obejcts with given
+// slice of paths. since this job is done parallel, the order of the directories
+// is not kept
+func SyncLoad(directories []string) (entities []*git.Repository, err error) {
+	entities = make([]*git.Repository, 0)
+
+	var wg sync.WaitGroup
+	var mu sync.Mutex
+
+	for _, dir := range directories {
+		// increment wait counter by one because we run a single goroutine
+		// below
+		wg.Add(1)
+		go func(d string) {
+			// decrement the wait counter by one, we call it in a defer so it's
+			// called at the end of this goroutine
+			defer wg.Done()
+			entity, err := git.InitializeRepo(d)
+			if err != nil {
+				log.WithFields(log.Fields{
+					"directory": d,
+				}).Trace("Cannot load git repository.")
+				return
+			}
+			// lock so we don't get a race if multiple go routines try to add
+			// to the same entities
+			mu.Lock()
+			entities = append(entities, entity)
+			mu.Unlock()
+		}(dir)
+	}
+	// wait until the wait counter is zero, this happens if all goroutines have
+	// finished
+	wg.Wait()
+	if len(entities) == 0 {
+		return entities, errors.New("There are no git repositories at given path(s)")
+	}
+	return entities, nil
+}
+
+// AsyncLoad asynchronously adds to AsyncAdd function
+func AsyncLoad(directories []string, add AsyncAdd, d chan bool) error {
+	ctx := context.TODO()
+
+	var (
+		maxWorkers = runtime.GOMAXPROCS(0)
+		sem        = semaphore.NewWeighted(int64(maxWorkers))
+	)
+
+	var mx sync.Mutex
+
+	// Compute the output using up to maxWorkers goroutines at a time.
+	for _, dir := range directories {
+		if err := sem.Acquire(ctx, 1); err != nil {
+			log.Errorf("Failed to acquire semaphore: %v", err)
+			break
+		}
+
+		go func(d string) {
+
+			defer sem.Release(1)
+			entity, err := git.InitializeRepo(d)
+			if err != nil {
+				log.WithFields(log.Fields{
+					"directory": d,
+				}).Trace("Cannot load git repository.")
+				return
+			}
+			// lock so we don't get a race if multiple go routines try to add
+			// to the same entities
+			mx.Lock()
+			add(entity)
+			mx.Unlock()
+		}(dir)
+	}
+	// Acquire all of the tokens to wait for any remaining workers to finish.
+	if err := sem.Acquire(ctx, int64(maxWorkers)); err != nil {
+		return err
+	}
+	d <- true
+	sem = nil
+	return nil
+}