prefix search, bucket implemented

weed/filer/arangodb/helpers.go

@@ -0,0 +1,44 @@
+package arangodb
+
+import (
+	"crypto/md5"
+	"encoding/binary"
+	"encoding/hex"
+	"io"
+)
+
+//convert a string into arango-key safe hex bytes hash
+func hashString(dir string) string {
+	h := md5.New()
+	io.WriteString(h, dir)
+	b := h.Sum(nil)
+	return hex.EncodeToString(b)
+}
+
+// convert slice of bytes into slice of uint64
+// the first uint64 indicates the length in bytes
+func bytesToArray(bs []byte) []uint64 {
+	out := make([]uint64, 0, 2+len(bs)/8)
+	out = append(out, uint64(len(bs)))
+	for len(bs)%8 != 0 {
+		bs = append(bs, 0)
+	}
+	for i := 0; i < len(bs); i = i + 8 {
+		out = append(out, binary.BigEndian.Uint64(bs[i:]))
+	}
+	return out
+}
+
+// convert from slice of uint64 back to bytes
+// if input length is 0 or 1, will return nil
+func arrayToBytes(xs []uint64) []byte {
+	if len(xs) < 2 {
+		return nil
+	}
+	first := xs[0]
+	out := make([]byte, len(xs)*8) // i think this can actually be len(xs)*8-8, but i dont think an extra 8 bytes hurts...
+	for i := 1; i < len(xs); i = i + 1 {
+		binary.BigEndian.PutUint64(out[((i-1)*8):], xs[i])
+	}
+	return out[:first]
+}