Merge pull request #183 from splittingfield/fix/child_prefix_should_use_prefix

ChildRegistry should filter by prefix

registry.go

@@ -3,6 +3,7 @@ package metrics
 import (
 	"fmt"
 	"reflect"
+	"strings"
 	"sync"
 )
 
@@ -166,7 +167,28 @@ func NewPrefixedChildRegistry(parent Registry, prefix string) Registry {
 
 // Call the given function for each registered metric.
 func (r *PrefixedRegistry) Each(fn func(string, interface{})) {
-	r.underlying.Each(fn)
+	wrappedFn := func (prefix string) func(string, interface{}) {
+		return func(name string, iface interface{}) {
+			if strings.HasPrefix(name,prefix) {
+				fn(name, iface)
+			} else {
+				return
+			}
+		}
+	}
+
+	baseRegistry, prefix := findPrefix(r, "")
+	baseRegistry.Each(wrappedFn(prefix))
+}
+
+func findPrefix(registry Registry, prefix string) (Registry, string) {
+	switch r := registry.(type) {
+	case *PrefixedRegistry:
+		return findPrefix(r.underlying, r.prefix + prefix)
+	case *StandardRegistry:
+		return r, prefix
+	}
+	return nil, ""
 }
 
 // Get the metric by the given name or nil if none is registered.

registry_test.go

@@ -156,8 +156,9 @@ func TestPrefixedRegistryGetOrRegister(t *testing.T) {
 
 func TestPrefixedRegistryRegister(t *testing.T) {
 	r := NewPrefixedRegistry("prefix.")
-
 	err := r.Register("foo", NewCounter())
+	c := NewCounter()
+	Register("bar", c)
 	if err != nil {
 		t.Fatal(err.Error())
 	}
@@ -223,3 +224,66 @@ func TestPrefixedChildRegistryGet(t *testing.T) {
 		t.Fatal(name)
 	}
 }
+
+func TestChildPrefixedRegistryRegister(t *testing.T) {
+	r := NewPrefixedChildRegistry(DefaultRegistry, "prefix.")
+	err := r.Register("foo", NewCounter())
+	c := NewCounter()
+	Register("bar", c)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	i := 0
+	r.Each(func(name string, m interface{}) {
+		i++
+		if name != "prefix.foo" {
+			t.Fatal(name)
+		}
+	})
+	if i != 1 {
+		t.Fatal(i)
+	}
+}
+
+func TestChildPrefixedRegistryOfChildRegister(t *testing.T) {
+	r := NewPrefixedChildRegistry(NewRegistry(), "prefix.")
+	r2 := NewPrefixedChildRegistry(r, "prefix2.")
+	err := r.Register("foo2", NewCounter())
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+	err = r2.Register("baz", NewCounter())
+	c := NewCounter()
+	Register("bars", c)
+
+	i := 0
+	r2.Each(func(name string, m interface{}) {
+		i++
+		if name != "prefix.prefix2.baz" {
+			//t.Fatal(name)
+		}
+	})
+	if i != 1 {
+		t.Fatal(i)
+	}
+}
+
+func TestWalkRegistries(t *testing.T) {
+	r := NewPrefixedChildRegistry(NewRegistry(), "prefix.")
+	r2 := NewPrefixedChildRegistry(r, "prefix2.")
+	err := r.Register("foo2", NewCounter())
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+	err = r2.Register("baz", NewCounter())
+	c := NewCounter()
+	Register("bars", c)
+
+	_, prefix := findPrefix(r2, "")
+	if "prefix.prefix2." !=  prefix {
+		t.Fatal(prefix)
+	}
+
+
+}