Merge pull request #55 from dims/move-pkg-util-strings-from-kubernete…

…s-kubernetes

Move pkg util strings/keymutex from kubernetes kubernetes

keymutex/BUILD

@@ -0,0 +1,36 @@
+package(default_visibility = ["//visibility:public"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_library",
+    "go_test",
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "hashed.go",
+        "keymutex.go",
+    ],
+    importpath = "k8s.io/kubernetes/pkg/util/keymutex",
+    deps = ["//vendor/github.com/golang/glog:go_default_library"],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["keymutex_test.go"],
+    embed = [":go_default_library"],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+)

keymutex/hashed.go

@@ -0,0 +1,64 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package keymutex
+
+import (
+	"hash/fnv"
+	"runtime"
+	"sync"
+
+	"github.com/golang/glog"
+)
+
+// NewHashed returns a new instance of KeyMutex which hashes arbitrary keys to
+// a fixed set of locks. `n` specifies number of locks, if n <= 0, we use
+// number of cpus.
+// Note that because it uses fixed set of locks, different keys may share same
+// lock, so it's possible to wait on same lock.
+func NewHashed(n int) KeyMutex {
+	if n <= 0 {
+		n = runtime.NumCPU()
+	}
+	return &hashedKeyMutex{
+		mutexes: make([]sync.Mutex, n),
+	}
+}
+
+type hashedKeyMutex struct {
+	mutexes []sync.Mutex
+}
+
+// Acquires a lock associated with the specified ID.
+func (km *hashedKeyMutex) LockKey(id string) {
+	glog.V(5).Infof("hashedKeyMutex.LockKey(...) called for id %q\r\n", id)
+	km.mutexes[km.hash(id)%len(km.mutexes)].Lock()
+	glog.V(5).Infof("hashedKeyMutex.LockKey(...) for id %q completed.\r\n", id)
+}
+
+// Releases the lock associated with the specified ID.
+func (km *hashedKeyMutex) UnlockKey(id string) error {
+	glog.V(5).Infof("hashedKeyMutex.UnlockKey(...) called for id %q\r\n", id)
+	km.mutexes[km.hash(id)%len(km.mutexes)].Unlock()
+	glog.V(5).Infof("hashedKeyMutex.UnlockKey(...) for id %q completed.\r\n", id)
+	return nil
+}
+
+func (km *hashedKeyMutex) hash(id string) int {
+	h := fnv.New32a()
+	h.Write([]byte(id))
+	return int(h.Sum32())
+}

keymutex/keymutex.go

@@ -0,0 +1,27 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package keymutex
+
+// KeyMutex is a thread-safe interface for acquiring locks on arbitrary strings.
+type KeyMutex interface {
+	// Acquires a lock associated with the specified ID, creates the lock if one doesn't already exist.
+	LockKey(id string)
+
+	// Releases the lock associated with the specified ID.
+	// Returns an error if the specified ID doesn't exist.
+	UnlockKey(id string) error
+}

keymutex/keymutex_test.go

@@ -0,0 +1,105 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package keymutex
+
+import (
+	"testing"
+	"time"
+)
+
+const (
+	callbackTimeout = 1 * time.Second
+)
+
+func newKeyMutexes() []KeyMutex {
+	return []KeyMutex{
+		NewHashed(0),
+		NewHashed(1),
+		NewHashed(2),
+		NewHashed(4),
+	}
+}
+
+func Test_SingleLock_NoUnlock(t *testing.T) {
+	for _, km := range newKeyMutexes() {
+		// Arrange
+		key := "fakeid"
+		callbackCh := make(chan interface{})
+
+		// Act
+		go lockAndCallback(km, key, callbackCh)
+
+		// Assert
+		verifyCallbackHappens(t, callbackCh)
+	}
+}
+
+func Test_SingleLock_SingleUnlock(t *testing.T) {
+	for _, km := range newKeyMutexes() {
+		// Arrange
+		key := "fakeid"
+		callbackCh := make(chan interface{})
+
+		// Act & Assert
+		go lockAndCallback(km, key, callbackCh)
+		verifyCallbackHappens(t, callbackCh)
+		km.UnlockKey(key)
+	}
+}
+
+func Test_DoubleLock_DoubleUnlock(t *testing.T) {
+	for _, km := range newKeyMutexes() {
+		// Arrange
+		key := "fakeid"
+		callbackCh1stLock := make(chan interface{})
+		callbackCh2ndLock := make(chan interface{})
+
+		// Act & Assert
+		go lockAndCallback(km, key, callbackCh1stLock)
+		verifyCallbackHappens(t, callbackCh1stLock)
+		go lockAndCallback(km, key, callbackCh2ndLock)
+		verifyCallbackDoesntHappens(t, callbackCh2ndLock)
+		km.UnlockKey(key)
+		verifyCallbackHappens(t, callbackCh2ndLock)
+		km.UnlockKey(key)
+	}
+}
+
+func lockAndCallback(km KeyMutex, id string, callbackCh chan<- interface{}) {
+	km.LockKey(id)
+	callbackCh <- true
+}
+
+func verifyCallbackHappens(t *testing.T, callbackCh <-chan interface{}) bool {
+	select {
+	case <-callbackCh:
+		return true
+	case <-time.After(callbackTimeout):
+		t.Fatalf("Timed out waiting for callback.")
+		return false
+	}
+}
+
+func verifyCallbackDoesntHappens(t *testing.T, callbackCh <-chan interface{}) bool {
+	select {
+	case <-callbackCh:
+		t.Fatalf("Unexpected callback.")
+		return false
+	case <-time.After(callbackTimeout):
+		return true
+	}
+}

strings/BUILD

@@ -0,0 +1,40 @@
+package(default_visibility = ["//visibility:public"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_library",
+    "go_test",
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "escape.go",
+        "line_delimiter.go",
+        "strings.go",
+    ],
+    importpath = "k8s.io/kubernetes/pkg/util/strings",
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "escape_test.go",
+        "line_delimiter_test.go",
+        "strings_test.go",
+    ],
+    embed = [":go_default_library"],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+)

strings/escape.go

@@ -0,0 +1,36 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package strings
+
+import (
+	"strings"
+)
+
+// EscapeQualifiedName converts a plugin name, which might contain a / into a
+// string that is safe to use on-disk.  This assumes that the input has already
+// been validates as a qualified name.  we use "~" rather than ":" here in case
+// we ever use a filesystem that doesn't allow ":".
+func EscapeQualifiedName(in string) string {
+	return strings.Replace(in, "/", "~", -1)
+}
+
+// UnescapeQualifiedName converts an escaped plugin name (as per EscapeQualifiedName)
+// back to its normal form.  This assumes that the input has already been
+// validates as a qualified name.
+func UnescapeQualifiedName(in string) string {
+	return strings.Replace(in, "~", "/", -1)
+}

strings/escape_test.go

@@ -0,0 +1,42 @@
+/*
+Copyright 2016 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package strings
+
+import (
+	"testing"
+)
+
+func TestEscapeQualifiedNameForDisk(t *testing.T) {
+	testCases := []struct {
+		input  string
+		output string
+	}{
+		{"kubernetes.io/blah", "kubernetes.io~blah"},
+		{"blah/blerg/borg", "blah~blerg~borg"},
+		{"kubernetes.io", "kubernetes.io"},
+	}
+	for i, tc := range testCases {
+		escapee := EscapeQualifiedName(tc.input)
+		if escapee != tc.output {
+			t.Errorf("case[%d]: expected (%q), got (%q)", i, tc.output, escapee)
+		}
+		original := UnescapeQualifiedName(escapee)
+		if original != tc.input {
+			t.Errorf("case[%d]: expected (%q), got (%q)", i, tc.input, original)
+		}
+	}
+}