102 lines
3.2 KiB
Go
102 lines
3.2 KiB
Go
|
// 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 (
|
||
|
"github.com/golang/protobuf/proto"
|
||
|
netcontext "golang.org/x/net/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
|
||
|
}
|
||
|
logf(fromContext(ctx), level, format, args...)
|
||
|
}
|
||
|
|
||
|
// NamespacedContext wraps a Context to support namespaces.
|
||
|
func NamespacedContext(ctx netcontext.Context, namespace string) netcontext.Context {
|
||
|
n := &namespacedContext{
|
||
|
namespace: namespace,
|
||
|
}
|
||
|
return withNamespace(WithCallOverride(ctx, n.call), namespace)
|
||
|
}
|
||
|
|
||
|
type namespacedContext struct {
|
||
|
namespace string
|
||
|
}
|
||
|
|
||
|
func (n *namespacedContext) call(ctx netcontext.Context, service, method string, in, out proto.Message) error {
|
||
|
// Apply any namespace mods.
|
||
|
if mod, ok := NamespaceMods[service]; ok {
|
||
|
mod(in, n.namespace)
|
||
|
}
|
||
|
return Call(ctx, service, method, in, out)
|
||
|
}
|