first part

2 files changed, 62 insertions, 0 deletions

diff --git a/cmd/bolt/main.go b/cmd/bolt/main.go
index 3397042..659f1c3 100644
--- a/cmd/bolt/main.go
+++ b/cmd/bolt/main.go
@@ -92,6 +92,14 @@ func NewApp() *cli.App {
 			},
 		},
 		{
+			Name:  "stats",
+			Usage: "Retrieve statistics for a bucket (aggregated recursively)",
+			Action: func(c *cli.Context) {
+				path, name := c.Args().Get(0), c.Args().Get(1)
+				Stats(path, name)
+			},
+		},
+		{
 			Name:  "bench",
 			Usage: "Performs a synthetic benchmark",
 			Flags: []cli.Flag{
diff --git a/cmd/bolt/stats.go b/cmd/bolt/stats.go
new file mode 100644
index 0000000..da344d0
--- /dev/null
+++ b/cmd/bolt/stats.go
@@ -0,0 +1,54 @@
+package main
+
+import (
+	"os"
+
+	"github.com/boltdb/bolt"
+)
+
+// Keys retrieves a list of keys for a given bucket.
+func Stats(path, name string) {
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		fatal(err)
+		return
+	}
+
+	db, err := bolt.Open(path, 0600)
+	if err != nil {
+		fatal(err)
+		return
+	}
+	defer db.Close()
+
+	err = db.View(func(tx *bolt.Tx) error {
+		// Find bucket.
+		b := tx.Bucket([]byte(name))
+		if b == nil {
+			fatalf("bucket not found: %s", name)
+			return nil
+		}
+
+		// Iterate over each key.
+		s := b.Stats()
+		println("Page count statistics")
+		printf("\tNumber of logical branch pages: %d\n", s.BranchPageN)
+		printf("\tNumber of physical branch overflow pages: %d\n", s.BranchOverflowN)
+		printf("\tNumber of logical leaf pages: %d\n", s.LeafPageN)
+		printf("\tNumber of physical leaf overflow pages: %d\n", s.LeafOverflowN)
+
+		println("Tree statistics")
+		printf("\tNumber of keys/value pairs: %d\n", s.KeyN)
+		printf("\tNumber of levels in B+tree: %d\n", s.Depth)
+
+		println("Page size utilization")
+		printf("\tBytes allocated for physical branch pages: %d\n", s.BranchAlloc)
+		printf("\tBytes actually used for branch data: %d\n", s.BranchInuse)
+		printf("\tBytes allocated for physical leaf pages: %d\n", s.LeafAlloc)
+		printf("\tBytes actually used for leaf data: %d\n", s.LeafInuse)
+		return nil
+	})
+	if err != nil {
+		fatal(err)
+		return
+	}
+}