gopls/internal/filecache/filecache_test.go - tools - Git at Google

 // Copyright 2022 The Go 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 filecache_test

 // This file defines tests of the API of the filecache package.
 //
 // Some properties (e.g. garbage collection) cannot be exercised
 // through the API, so this test does not attempt to do so.

 import (
 	"bytes"
 	cryptorand "crypto/rand"
 	"fmt"
 	"log"
 	mathrand "math/rand"
 	"os"
 	"os/exec"
 	"strconv"
 	"strings"
 	"testing"

 	"golang.org/x/sync/errgroup"
 	"golang.org/x/tools/gopls/internal/filecache"
 	"golang.org/x/tools/internal/testenv"
 )

 func TestBasics(t *testing.T) {
 	const kind = "TestBasics"
 	key := uniqueKey() // never used before
 	value := []byte("hello")

 	// Get of a never-seen key returns not found.
 	if _, err := filecache.Get(kind, key); err != filecache.ErrNotFound {
 		if strings.Contains(err.Error(), "operation not supported") ||
 			strings.Contains(err.Error(), "not implemented") {
 			t.Skipf("skipping: %v", err)
 		}
 		t.Errorf("Get of random key returned err=%q, want not found", err)
 	}

 	// Set of a never-seen key and a small value succeeds.
 	if err := filecache.Set(kind, key, value); err != nil {
 		t.Errorf("Set failed: %v", err)
 	}

 	// Get of the key returns a copy of the value.
 	if got, err := filecache.Get(kind, key); err != nil {
 		t.Errorf("Get after Set failed: %v", err)
 	} else if string(got) != string(value) {
 		t.Errorf("Get after Set returned different value: got %q, want %q", got, value)
 	}

 	// The kind is effectively part of the key.
 	if _, err := filecache.Get("different-kind", key); err != filecache.ErrNotFound {
 		t.Errorf("Get with wrong kind returned err=%q, want not found", err)
 	}
 }

 // TestConcurrency exercises concurrent access to the same entry.
 func TestConcurrency(t *testing.T) {
 	if os.Getenv("GO_BUILDER_NAME") == "plan9-arm" {
 		t.Skip(`skipping on plan9-arm builder due to golang/go#58748: failing with 'mount rpc error'`)
 	}
 	const kind = "TestConcurrency"
 	key := uniqueKey()
 	const N = 100 // concurrency level

 	// Construct N distinct values, each larger
 	// than a typical 4KB OS file buffer page.
 	var values [N][8192]byte
 	for i := range values {
 		if _, err := mathrand.Read(values[i][:]); err != nil {
 			t.Fatalf("rand: %v", err)
 		}
 	}

 	// get calls Get and verifies that the cache entry
 	// matches one of the values passed to Set.
 	get := func(mustBeFound bool) error {
 		got, err := filecache.Get(kind, key)
 		if err != nil {
 			if err == filecache.ErrNotFound && !mustBeFound {
 				return nil // not found
 			}
 			return err
 		}
 		for _, want := range values {
 			if bytes.Equal(want[:], got) {
 				return nil // a match
 			}
 		}
 		return fmt.Errorf("Get returned a value that was never Set")
 	}

 	// Perform N concurrent calls to Set and Get.
 	// All sets must succeed.
 	// All gets must return nothing, or one of the Set values;
 	// there is no third possibility.
 	var group errgroup.Group
 	for i := range values {
 		i := i
 		group.Go(func() error { return filecache.Set(kind, key, values[i][:]) })
 		group.Go(func() error { return get(false) })
 	}
 	if err := group.Wait(); err != nil {
 		if strings.Contains(err.Error(), "operation not supported") ||
 			strings.Contains(err.Error(), "not implemented") {
 			t.Skipf("skipping: %v", err)
 		}
 		t.Fatal(err)
 	}

 	// A final Get must report one of the values that was Set.
 	if err := get(true); err != nil {
 		t.Fatalf("final Get failed: %v", err)
 	}
 }

 const (
 	testIPCKind   = "TestIPC"
 	testIPCValueA = "hello"
 	testIPCValueB = "world"
 )

 // TestIPC exercises interprocess communication through the cache.
 // It calls Set(A) in the parent, { Get(A); Set(B) } in the child
 // process, then Get(B) in the parent.
 func TestIPC(t *testing.T) {
 	testenv.NeedsExec(t)

 	keyA := uniqueKey()
 	keyB := uniqueKey()
 	value := []byte(testIPCValueA)

 	// Set keyA.
 	if err := filecache.Set(testIPCKind, keyA, value); err != nil {
 		if strings.Contains(err.Error(), "operation not supported") {
 			t.Skipf("skipping: %v", err)
 		}
 		t.Fatalf("Set: %v", err)
 	}

 	// Call ipcChild in a child process,
 	// passing it the keys in the environment
 	// (quoted, to avoid NUL termination of C strings).
 	// It will Get(A) then Set(B).
 	cmd := exec.Command(os.Args[0], os.Args[1:]...)
 	cmd.Env = append(os.Environ(),
 		"ENTRYPOINT=ipcChild",
 		fmt.Sprintf("KEYA=%q", keyA),
 		fmt.Sprintf("KEYB=%q", keyB))
 	cmd.Stdout = os.Stderr
 	cmd.Stderr = os.Stderr
 	if err := cmd.Run(); err != nil {
 		t.Fatal(err)
 	}

 	// Verify keyB.
 	got, err := filecache.Get(testIPCKind, keyB)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if string(got) != "world" {
 		t.Fatalf("Get(keyB) = %q, want %q", got, "world")
 	}
 }

 // We define our own main function so that portions of
 // some tests can run in a separate (child) process.
 func TestMain(m *testing.M) {
 	switch os.Getenv("ENTRYPOINT") {
 	case "ipcChild":
 		ipcChild()
 	default:
 		os.Exit(m.Run())
 	}
 }

 // ipcChild is the portion of TestIPC that runs in a child process.
 func ipcChild() {
 	getenv := func(name string) (key [32]byte) {
 		s, _ := strconv.Unquote(os.Getenv(name))
 		copy(key[:], []byte(s))
 		return
 	}

 	// Verify key A.
 	got, err := filecache.Get(testIPCKind, getenv("KEYA"))
 	if err != nil || string(got) != testIPCValueA {
 		log.Fatalf("child: Get(key) = %q, %v; want %q", got, err, testIPCValueA)
 	}

 	// Set key B.
 	if err := filecache.Set(testIPCKind, getenv("KEYB"), []byte(testIPCValueB)); err != nil {
 		log.Fatalf("child: Set(keyB) failed: %v", err)
 	}
 }

 // uniqueKey returns a key that has never been used before.
 func uniqueKey() (key [32]byte) {
 	if _, err := cryptorand.Read(key[:]); err != nil {
 		log.Fatalf("rand: %v", err)
 	}
 	return
 }

 func BenchmarkUncontendedGet(b *testing.B) {
 	const kind = "BenchmarkUncontendedGet"
 	key := uniqueKey()

 	var value [8192]byte
 	if _, err := mathrand.Read(value[:]); err != nil {
 		b.Fatalf("rand: %v", err)
 	}
 	if err := filecache.Set(kind, key, value[:]); err != nil {
 		b.Fatal(err)
 	}
 	b.ResetTimer()
 	b.SetBytes(int64(len(value)))

 	var group errgroup.Group
 	group.SetLimit(50)
 	for i := 0; i < b.N; i++ {
 		group.Go(func() error {
 			_, err := filecache.Get(kind, key)
 			return err
 		})
 	}
 	if err := group.Wait(); err != nil {
 		b.Fatal(err)
 	}
 }

 // These two benchmarks are asymmetric: the one for Get imposes a
 // modest bound on concurrency (50) whereas the one for Set imposes a
 // much higher concurrency (1000) to test the implementation's
 // self-imposed bound.

 func BenchmarkUncontendedSet(b *testing.B) {
 	const kind = "BenchmarkUncontendedSet"
 	key := uniqueKey()
 	var value [8192]byte

 	const P = 1000 // parallelism
 	b.SetBytes(P * int64(len(value)))

 	for i := 0; i < b.N; i++ {
 		// Perform P concurrent calls to Set. All must succeed.
 		var group errgroup.Group
 		for range [P]bool{} {
 			group.Go(func() error {
 				return filecache.Set(kind, key, value[:])
 			})
 		}
 		if err := group.Wait(); err != nil {
 			if strings.Contains(err.Error(), "operation not supported") ||
 				strings.Contains(err.Error(), "not implemented") {
 				b.Skipf("skipping: %v", err)
 			}
 			b.Fatal(err)
 		}
 	}
 }
	// Copyright 2022 The Go 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 filecache_test

	// This file defines tests of the API of the filecache package.
	//
	// Some properties (e.g. garbage collection) cannot be exercised
	// through the API, so this test does not attempt to do so.

	import (
	"bytes"
	cryptorand "crypto/rand"
	"fmt"
	"log"
	mathrand "math/rand"
	"os"
	"os/exec"
	"strconv"
	"strings"
	"testing"

	"golang.org/x/sync/errgroup"
	"golang.org/x/tools/gopls/internal/filecache"
	"golang.org/x/tools/internal/testenv"
	)

	func TestBasics(t *testing.T) {
	const kind = "TestBasics"
	key := uniqueKey() // never used before
	value := []byte("hello")

	// Get of a never-seen key returns not found.
	if _, err := filecache.Get(kind, key); err != filecache.ErrNotFound {
	if strings.Contains(err.Error(), "operation not supported") \|\|
	strings.Contains(err.Error(), "not implemented") {
	t.Skipf("skipping: %v", err)
	}
	t.Errorf("Get of random key returned err=%q, want not found", err)
	}

	// Set of a never-seen key and a small value succeeds.
	if err := filecache.Set(kind, key, value); err != nil {
	t.Errorf("Set failed: %v", err)
	}

	// Get of the key returns a copy of the value.
	if got, err := filecache.Get(kind, key); err != nil {
	t.Errorf("Get after Set failed: %v", err)
	} else if string(got) != string(value) {
	t.Errorf("Get after Set returned different value: got %q, want %q", got, value)
	}

	// The kind is effectively part of the key.
	if _, err := filecache.Get("different-kind", key); err != filecache.ErrNotFound {
	t.Errorf("Get with wrong kind returned err=%q, want not found", err)
	}
	}

	// TestConcurrency exercises concurrent access to the same entry.
	func TestConcurrency(t *testing.T) {
	if os.Getenv("GO_BUILDER_NAME") == "plan9-arm" {
	t.Skip(`skipping on plan9-arm builder due to golang/go#58748: failing with 'mount rpc error'`)
	}
	const kind = "TestConcurrency"
	key := uniqueKey()
	const N = 100 // concurrency level

	// Construct N distinct values, each larger
	// than a typical 4KB OS file buffer page.
	var values [N][8192]byte
	for i := range values {
	if _, err := mathrand.Read(values[i][:]); err != nil {
	t.Fatalf("rand: %v", err)
	}
	}

	// get calls Get and verifies that the cache entry
	// matches one of the values passed to Set.
	get := func(mustBeFound bool) error {
	got, err := filecache.Get(kind, key)
	if err != nil {
	if err == filecache.ErrNotFound && !mustBeFound {
	return nil // not found
	}
	return err
	}
	for _, want := range values {
	if bytes.Equal(want[:], got) {
	return nil // a match
	}
	}
	return fmt.Errorf("Get returned a value that was never Set")
	}

	// Perform N concurrent calls to Set and Get.
	// All sets must succeed.
	// All gets must return nothing, or one of the Set values;
	// there is no third possibility.
	var group errgroup.Group
	for i := range values {
	i := i
	group.Go(func() error { return filecache.Set(kind, key, values[i][:]) })
	group.Go(func() error { return get(false) })
	}
	if err := group.Wait(); err != nil {
	if strings.Contains(err.Error(), "operation not supported") \|\|
	strings.Contains(err.Error(), "not implemented") {
	t.Skipf("skipping: %v", err)
	}
	t.Fatal(err)
	}

	// A final Get must report one of the values that was Set.
	if err := get(true); err != nil {
	t.Fatalf("final Get failed: %v", err)
	}
	}

	const (
	testIPCKind = "TestIPC"
	testIPCValueA = "hello"
	testIPCValueB = "world"
	)

	// TestIPC exercises interprocess communication through the cache.
	// It calls Set(A) in the parent, { Get(A); Set(B) } in the child
	// process, then Get(B) in the parent.
	func TestIPC(t *testing.T) {
	testenv.NeedsExec(t)

	keyA := uniqueKey()
	keyB := uniqueKey()
	value := []byte(testIPCValueA)

	// Set keyA.
	if err := filecache.Set(testIPCKind, keyA, value); err != nil {
	if strings.Contains(err.Error(), "operation not supported") {
	t.Skipf("skipping: %v", err)
	}
	t.Fatalf("Set: %v", err)
	}

	// Call ipcChild in a child process,
	// passing it the keys in the environment
	// (quoted, to avoid NUL termination of C strings).
	// It will Get(A) then Set(B).
	cmd := exec.Command(os.Args[0], os.Args[1:]...)
	cmd.Env = append(os.Environ(),
	"ENTRYPOINT=ipcChild",
	fmt.Sprintf("KEYA=%q", keyA),
	fmt.Sprintf("KEYB=%q", keyB))
	cmd.Stdout = os.Stderr
	cmd.Stderr = os.Stderr
	if err := cmd.Run(); err != nil {
	t.Fatal(err)
	}

	// Verify keyB.
	got, err := filecache.Get(testIPCKind, keyB)
	if err != nil {
	t.Fatal(err)
	}
	if string(got) != "world" {
	t.Fatalf("Get(keyB) = %q, want %q", got, "world")
	}
	}

	// We define our own main function so that portions of
	// some tests can run in a separate (child) process.
	func TestMain(m *testing.M) {
	switch os.Getenv("ENTRYPOINT") {
	case "ipcChild":
	ipcChild()
	default:
	os.Exit(m.Run())
	}
	}

	// ipcChild is the portion of TestIPC that runs in a child process.
	func ipcChild() {
	getenv := func(name string) (key [32]byte) {
	s, _ := strconv.Unquote(os.Getenv(name))
	copy(key[:], []byte(s))
	return
	}

	// Verify key A.
	got, err := filecache.Get(testIPCKind, getenv("KEYA"))
	if err != nil \|\| string(got) != testIPCValueA {
	log.Fatalf("child: Get(key) = %q, %v; want %q", got, err, testIPCValueA)
	}

	// Set key B.
	if err := filecache.Set(testIPCKind, getenv("KEYB"), []byte(testIPCValueB)); err != nil {
	log.Fatalf("child: Set(keyB) failed: %v", err)
	}
	}

	// uniqueKey returns a key that has never been used before.
	func uniqueKey() (key [32]byte) {
	if _, err := cryptorand.Read(key[:]); err != nil {
	log.Fatalf("rand: %v", err)
	}
	return
	}

	func BenchmarkUncontendedGet(b *testing.B) {
	const kind = "BenchmarkUncontendedGet"
	key := uniqueKey()

	var value [8192]byte
	if _, err := mathrand.Read(value[:]); err != nil {
	b.Fatalf("rand: %v", err)
	}
	if err := filecache.Set(kind, key, value[:]); err != nil {
	b.Fatal(err)
	}
	b.ResetTimer()
	b.SetBytes(int64(len(value)))

	var group errgroup.Group
	group.SetLimit(50)
	for i := 0; i < b.N; i++ {
	group.Go(func() error {
	_, err := filecache.Get(kind, key)
	return err
	})
	}
	if err := group.Wait(); err != nil {
	b.Fatal(err)
	}
	}

	// These two benchmarks are asymmetric: the one for Get imposes a
	// modest bound on concurrency (50) whereas the one for Set imposes a
	// much higher concurrency (1000) to test the implementation's
	// self-imposed bound.

	func BenchmarkUncontendedSet(b *testing.B) {
	const kind = "BenchmarkUncontendedSet"
	key := uniqueKey()
	var value [8192]byte

	const P = 1000 // parallelism
	b.SetBytes(P * int64(len(value)))

	for i := 0; i < b.N; i++ {
	// Perform P concurrent calls to Set. All must succeed.
	var group errgroup.Group
	for range [P]bool{} {
	group.Go(func() error {
	return filecache.Set(kind, key, value[:])
	})
	}
	if err := group.Wait(); err != nil {
	if strings.Contains(err.Error(), "operation not supported") \|\|
	strings.Contains(err.Error(), "not implemented") {
	b.Skipf("skipping: %v", err)
	}
	b.Fatal(err)
	}
	}
	}