1// Copyright 2011 Google Inc. All rights reserved.
2// Use of this source code is governed by the Apache 2.0
3// license that can be found in the LICENSE file.
4
5package internal
6
7import (
8	"os"
9
10	netcontext "golang.org/x/net/context"
11)
12
13var (
14	// This is set to true in identity_classic.go, which is behind the appengine build tag.
15	// The appengine build tag is set for the first generation runtimes (<= Go 1.9) but not
16	// the second generation runtimes (>= Go 1.11), so this indicates whether we're on a
17	// first-gen runtime. See IsStandard below for the second-gen check.
18	appengineStandard bool
19
20	// This is set to true in identity_flex.go, which is behind the appenginevm build tag.
21	appengineFlex bool
22)
23
24// AppID is the implementation of the wrapper function of the same name in
25// ../identity.go. See that file for commentary.
26func AppID(c netcontext.Context) string {
27	return appID(FullyQualifiedAppID(c))
28}
29
30// IsStandard is the implementation of the wrapper function of the same name in
31// ../appengine.go. See that file for commentary.
32func IsStandard() bool {
33	// appengineStandard will be true for first-gen runtimes (<= Go 1.9) but not
34	// second-gen (>= Go 1.11).
35	return appengineStandard || IsSecondGen()
36}
37
38// IsStandard is the implementation of the wrapper function of the same name in
39// ../appengine.go. See that file for commentary.
40func IsSecondGen() bool {
41	// Second-gen runtimes set $GAE_ENV so we use that to check if we're on a second-gen runtime.
42	return os.Getenv("GAE_ENV") == "standard"
43}
44
45// IsFlex is the implementation of the wrapper function of the same name in
46// ../appengine.go. See that file for commentary.
47func IsFlex() bool {
48	return appengineFlex
49}
50
51// IsAppEngine is the implementation of the wrapper function of the same name in
52// ../appengine.go. See that file for commentary.
53func IsAppEngine() bool {
54	return IsStandard() || IsFlex()
55}
56