// Copyright 2015 Google Inc. All rights reserved.
// Use of this source code is governed by the Apache 2.0
// license that can be found in the LICENSE file.
package internal
import (
"errors"
"os"
"github.com/golang/protobuf/proto"
netcontext "golang.org/x/net/context"
)
var errNotAppEngineContext = errors.New("not an App Engine context")
type CallOverrideFunc func(ctx netcontext.Context, service, method string, in, out proto.Message) error
var callOverrideKey = "holds []CallOverrideFunc"
func WithCallOverride(ctx netcontext.Context, f CallOverrideFunc) netcontext.Context {
// We avoid appending to any existing call override
// so we don't risk overwriting a popped stack below.
var cofs []CallOverrideFunc
if uf, ok := ctx.Value(&callOverrideKey).([]CallOverrideFunc); ok {
cofs = append(cofs, uf...)
}
cofs = append(cofs, f)
return netcontext.WithValue(ctx, &callOverrideKey, cofs)
}
func callOverrideFromContext(ctx netcontext.Context) (CallOverrideFunc, netcontext.Context, bool) {
cofs, _ := ctx.Value(&callOverrideKey).([]CallOverrideFunc)
if len(cofs) == 0 {
return nil, nil, false
}
// We found a list of overrides; grab the last, and reconstitute a
// context that will hide it.
f := cofs[len(cofs)-1]
ctx = netcontext.WithValue(ctx, &callOverrideKey, cofs[:len(cofs)-1])
return f, ctx, true
}
type logOverrideFunc func(level int64, format string, args ...interface{})
var logOverrideKey = "holds a logOverrideFunc"
func WithLogOverride(ctx netcontext.Context, f logOverrideFunc) netcontext.Context {
return netcontext.WithValue(ctx, &logOverrideKey, f)
}
var appIDOverrideKey = "holds a string, being the full app ID"
func WithAppIDOverride(ctx netcontext.Context, appID string) netcontext.Context {
return netcontext.WithValue(ctx, &appIDOverrideKey, appID)
}
var namespaceKey = "holds the namespace string"
func withNamespace(ctx netcontext.Context, ns string) netcontext.Context {
return netcontext.WithValue(ctx, &namespaceKey, ns)
}
func NamespaceFromContext(ctx netcontext.Context) string {
// If there's no namespace, return the empty string.
ns, _ := ctx.Value(&namespaceKey).(string)
return ns
}
// FullyQualifiedAppID returns the fully-qualified application ID.
// This may contain a partition prefix (e.g. "s~" for High Replication apps),
// or a domain prefix (e.g. "example.com:").
func FullyQualifiedAppID(ctx netcontext.Context) string {
if id, ok := ctx.Value(&appIDOverrideKey).(string); ok {
return id
}
return fullyQualifiedAppID(ctx)
}
func Logf(ctx netcontext.Context, level int64, format string, args ...interface{}) {
if f, ok := ctx.Value(&logOverrideKey).(logOverrideFunc); ok {
f(level, format, args...)
return
}
c := fromContext(ctx)
if c == nil {
panic(errNotAppEngineContext)
}
logf(c, level, format, args...)
}
// NamespacedContext wraps a Context to support namespaces.
func NamespacedContext(ctx netcontext.Context, namespace string) netcontext.Context {
return withNamespace(ctx, namespace)
}
// SetTestEnv sets the env variables for testing background ticket in Flex.
func SetTestEnv() func() {
var environ = []struct {
key, value string
}{
{"GAE_LONG_APP_ID", "my-app-id"},
{"GAE_MINOR_VERSION", "067924799508853122"},
{"GAE_MODULE_INSTANCE", "0"},
{"GAE_MODULE_NAME", "default"},
{"GAE_MODULE_VERSION", "20150612t184001"},
}
for _, v := range environ {
old := os.Getenv(v.key)
os.Setenv(v.key, v.value)
v.value = old
}
return func() { // Restore old environment after the test completes.
for _, v := range environ {
if v.value == "" {
os.Unsetenv(v.key)
continue
}
os.Setenv(v.key, v.value)
}
}
}
