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authorUnknwon <u@gogs.io>2017-02-09 19:48:13 -0500
committerUnknwon <u@gogs.io>2017-02-09 19:48:13 -0500
commit2fd69f13d9599a6c58b47225565163fd7d87889f (patch)
treefd19e868e1c2e95a5fb83a268f6e393669d6ee79 /vendor/github.com/go-macaron/inject/inject.go
parenteb66060cd7b9bce996b1d75ae80ce1ef31d5ce62 (diff)
vendor: check in vendors
Bye bye glide...
Diffstat (limited to 'vendor/github.com/go-macaron/inject/inject.go')
-rw-r--r--vendor/github.com/go-macaron/inject/inject.go262
1 files changed, 262 insertions, 0 deletions
diff --git a/vendor/github.com/go-macaron/inject/inject.go b/vendor/github.com/go-macaron/inject/inject.go
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+++ b/vendor/github.com/go-macaron/inject/inject.go
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+// Copyright 2013 Jeremy Saenz
+// Copyright 2015 The Macaron 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 inject provides utilities for mapping and injecting dependencies in various ways.
+package inject
+
+import (
+ "fmt"
+ "reflect"
+)
+
+// Injector represents an interface for mapping and injecting dependencies into structs
+// and function arguments.
+type Injector interface {
+ Applicator
+ Invoker
+ TypeMapper
+ // SetParent sets the parent of the injector. If the injector cannot find a
+ // dependency in its Type map it will check its parent before returning an
+ // error.
+ SetParent(Injector)
+}
+
+// Applicator represents an interface for mapping dependencies to a struct.
+type Applicator interface {
+ // Maps dependencies in the Type map to each field in the struct
+ // that is tagged with 'inject'. Returns an error if the injection
+ // fails.
+ Apply(interface{}) error
+}
+
+// Invoker represents an interface for calling functions via reflection.
+type Invoker interface {
+ // Invoke attempts to call the interface{} provided as a function,
+ // providing dependencies for function arguments based on Type. Returns
+ // a slice of reflect.Value representing the returned values of the function.
+ // Returns an error if the injection fails.
+ Invoke(interface{}) ([]reflect.Value, error)
+}
+
+// FastInvoker represents an interface in order to avoid the calling function via reflection.
+//
+// example:
+// type handlerFuncHandler func(http.ResponseWriter, *http.Request) error
+// func (f handlerFuncHandler)Invoke([]interface{}) ([]reflect.Value, error){
+// ret := f(p[0].(http.ResponseWriter), p[1].(*http.Request))
+// return []reflect.Value{reflect.ValueOf(ret)}, nil
+// }
+//
+// type funcHandler func(int, string)
+// func (f funcHandler)Invoke([]interface{}) ([]reflect.Value, error){
+// f(p[0].(int), p[1].(string))
+// return nil, nil
+// }
+type FastInvoker interface {
+ // Invoke attempts to call the ordinary functions. If f is a function
+ // with the appropriate signature, f.Invoke([]interface{}) is a Call that calls f.
+ // Returns a slice of reflect.Value representing the returned values of the function.
+ // Returns an error if the injection fails.
+ Invoke([]interface{}) ([]reflect.Value, error)
+}
+
+// IsFastInvoker check interface is FastInvoker
+func IsFastInvoker(h interface{}) bool {
+ _, ok := h.(FastInvoker)
+ return ok
+}
+
+// TypeMapper represents an interface for mapping interface{} values based on type.
+type TypeMapper interface {
+ // Maps the interface{} value based on its immediate type from reflect.TypeOf.
+ Map(interface{}) TypeMapper
+ // Maps the interface{} value based on the pointer of an Interface provided.
+ // This is really only useful for mapping a value as an interface, as interfaces
+ // cannot at this time be referenced directly without a pointer.
+ MapTo(interface{}, interface{}) TypeMapper
+ // Provides a possibility to directly insert a mapping based on type and value.
+ // This makes it possible to directly map type arguments not possible to instantiate
+ // with reflect like unidirectional channels.
+ Set(reflect.Type, reflect.Value) TypeMapper
+ // Returns the Value that is mapped to the current type. Returns a zeroed Value if
+ // the Type has not been mapped.
+ GetVal(reflect.Type) reflect.Value
+}
+
+type injector struct {
+ values map[reflect.Type]reflect.Value
+ parent Injector
+}
+
+// InterfaceOf dereferences a pointer to an Interface type.
+// It panics if value is not an pointer to an interface.
+func InterfaceOf(value interface{}) reflect.Type {
+ t := reflect.TypeOf(value)
+
+ for t.Kind() == reflect.Ptr {
+ t = t.Elem()
+ }
+
+ if t.Kind() != reflect.Interface {
+ panic("Called inject.InterfaceOf with a value that is not a pointer to an interface. (*MyInterface)(nil)")
+ }
+
+ return t
+}
+
+// New returns a new Injector.
+func New() Injector {
+ return &injector{
+ values: make(map[reflect.Type]reflect.Value),
+ }
+}
+
+// Invoke attempts to call the interface{} provided as a function,
+// providing dependencies for function arguments based on Type.
+// Returns a slice of reflect.Value representing the returned values of the function.
+// Returns an error if the injection fails.
+// It panics if f is not a function
+func (inj *injector) Invoke(f interface{}) ([]reflect.Value, error) {
+ t := reflect.TypeOf(f)
+ switch v := f.(type) {
+ case FastInvoker:
+ return inj.fastInvoke(v, t, t.NumIn())
+ default:
+ return inj.callInvoke(f, t, t.NumIn())
+ }
+}
+
+func (inj *injector) fastInvoke(f FastInvoker, t reflect.Type, numIn int) ([]reflect.Value, error) {
+ var in []interface{}
+ if numIn > 0 {
+ in = make([]interface{}, numIn) // Panic if t is not kind of Func
+ var argType reflect.Type
+ var val reflect.Value
+ for i := 0; i < numIn; i++ {
+ argType = t.In(i)
+ val = inj.GetVal(argType)
+ if !val.IsValid() {
+ return nil, fmt.Errorf("Value not found for type %v", argType)
+ }
+
+ in[i] = val.Interface()
+ }
+ }
+ return f.Invoke(in)
+}
+
+// callInvoke reflect.Value.Call
+func (inj *injector) callInvoke(f interface{}, t reflect.Type, numIn int) ([]reflect.Value, error) {
+ var in []reflect.Value
+ if numIn > 0 {
+ in = make([]reflect.Value, numIn)
+ var argType reflect.Type
+ var val reflect.Value
+ for i := 0; i < numIn; i++ {
+ argType = t.In(i)
+ val = inj.GetVal(argType)
+ if !val.IsValid() {
+ return nil, fmt.Errorf("Value not found for type %v", argType)
+ }
+
+ in[i] = val
+ }
+ }
+ return reflect.ValueOf(f).Call(in), nil
+}
+
+// Maps dependencies in the Type map to each field in the struct
+// that is tagged with 'inject'.
+// Returns an error if the injection fails.
+func (inj *injector) Apply(val interface{}) error {
+ v := reflect.ValueOf(val)
+
+ for v.Kind() == reflect.Ptr {
+ v = v.Elem()
+ }
+
+ if v.Kind() != reflect.Struct {
+ return nil // Should not panic here ?
+ }
+
+ t := v.Type()
+
+ for i := 0; i < v.NumField(); i++ {
+ f := v.Field(i)
+ structField := t.Field(i)
+ if f.CanSet() && (structField.Tag == "inject" || structField.Tag.Get("inject") != "") {
+ ft := f.Type()
+ v := inj.GetVal(ft)
+ if !v.IsValid() {
+ return fmt.Errorf("Value not found for type %v", ft)
+ }
+
+ f.Set(v)
+ }
+
+ }
+
+ return nil
+}
+
+// Maps the concrete value of val to its dynamic type using reflect.TypeOf,
+// It returns the TypeMapper registered in.
+func (i *injector) Map(val interface{}) TypeMapper {
+ i.values[reflect.TypeOf(val)] = reflect.ValueOf(val)
+ return i
+}
+
+func (i *injector) MapTo(val interface{}, ifacePtr interface{}) TypeMapper {
+ i.values[InterfaceOf(ifacePtr)] = reflect.ValueOf(val)
+ return i
+}
+
+// Maps the given reflect.Type to the given reflect.Value and returns
+// the Typemapper the mapping has been registered in.
+func (i *injector) Set(typ reflect.Type, val reflect.Value) TypeMapper {
+ i.values[typ] = val
+ return i
+}
+
+func (i *injector) GetVal(t reflect.Type) reflect.Value {
+ val := i.values[t]
+
+ if val.IsValid() {
+ return val
+ }
+
+ // no concrete types found, try to find implementors
+ // if t is an interface
+ if t.Kind() == reflect.Interface {
+ for k, v := range i.values {
+ if k.Implements(t) {
+ val = v
+ break
+ }
+ }
+ }
+
+ // Still no type found, try to look it up on the parent
+ if !val.IsValid() && i.parent != nil {
+ val = i.parent.GetVal(t)
+ }
+
+ return val
+
+}
+
+func (i *injector) SetParent(parent Injector) {
+ i.parent = parent
+}