faster loading boltdb or leveldb needle map metrics by bloomfilter

avoid btree

weed/storage/needle_map_metric_test.go

@@ -0,0 +1,29 @@
+package storage
+
+import (
+	"testing"
+	"io/ioutil"
+	"math/rand"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+func TestFastLoadingNeedleMapMetrics(t *testing.T) {
+
+	idxFile, _ := ioutil.TempFile("", "tmp.idx")
+	nm := NewBtreeNeedleMap(idxFile)
+
+	for i := 0; i < 10000; i++ {
+		nm.Put(uint64(i+1), uint32(0), uint32(1))
+		if rand.Float32() < 0.2 {
+			nm.Delete(uint64(rand.Int63n(int64(i))+1), uint32(0))
+		}
+	}
+
+	mm, _ := newNeedleMapMetricFromIndexFile(idxFile)
+
+	glog.V(0).Infof("FileCount expected %d actual %d", nm.FileCount(), mm.FileCount())
+	glog.V(0).Infof("DeletedSize expected %d actual %d", nm.DeletedSize(), mm.DeletedSize())
+	glog.V(0).Infof("ContentSize expected %d actual %d", nm.ContentSize(), mm.ContentSize())
+	glog.V(0).Infof("DeletedCount expected %d actual %d", nm.DeletedCount(), mm.DeletedCount())
+	glog.V(0).Infof("MaxFileKey expected %d actual %d", nm.MaxFileKey(), mm.MaxFileKey())
+}