Initial distributor implementation

appengine/cmd/dm/distributor/impl/jobsim/parser/range_slice.go

Index: appengine/cmd/dm/distributor/impl/jobsim/parser/range_slice.go
diff --git a/appengine/cmd/dm/distributor/impl/jobsim/parser/range_slice.go b/appengine/cmd/dm/distributor/impl/jobsim/parser/range_slice.go
new file mode 100644
index 0000000000000000000000000000000000000000..728ec619667349c9a0dc88cd54729a7ac41dcbdb
--- /dev/null
+++ b/appengine/cmd/dm/distributor/impl/jobsim/parser/range_slice.go
@@ -0,0 +1,62 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package parser
+
+import (
+	"bytes"
+	"fmt"
+)
+
+type Range [2]uint64
+
+func (r Range) Low() uint64            { return r[0] }
+func (r Range) Single() (uint64, bool) { return r[0], r[1] == 0 }
+func (r Range) High() uint64 {
+	if r[1] == 0 {
+		return r[0]
+	}
+	return r[1]
+}
+
+func (r Range) Iter(cb func(uint64) error) error {
+	if s, ok := r.Single(); ok {
+		return cb(s)
+	}
+	for i := r.Low(); i < r.High(); i++ {
+		if err := cb(i); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (r Range) String() string {
+	if s, ok := r.Single(); ok {
+		return fmt.Sprintf("%d", s)
+	}
+	return fmt.Sprintf("%d-%d", r.Low(), r.High())
+}
+
+type RangeSlice []Range
+
+func (rs RangeSlice) String() string {
+	b := bytes.Buffer{}
+	for i, r := range rs {
+		if i != 0 {
+			b.WriteRune(',')
+		}
+		b.WriteString(r.String())
+	}
+	return b.String()
+}
+
+func (rs RangeSlice) Iter(cb func(uint64) error) error {
+	for _, rng := range rs {
+		if err := rng.Iter(cb); err != nil {
+			return err
+		}
+	}
+	return nil
+}