route/vendor/gopkg.in/gorethink/gorethink.v2/encoding/encoder.go

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2017-01-22 17:36:44 +00:00
// This code is based on encoding/json and gorilla/schema
package encoding
import (
"errors"
"reflect"
"runtime"
"sync"
)
type encoderFunc func(v reflect.Value) interface{}
// Encode returns the encoded value of v.
//
// Encode traverses the value v recursively and looks for structs. If a struct
// is found then it is checked for tagged fields and convert to
// map[string]interface{}
func Encode(v interface{}) (ev interface{}, err error) {
defer func() {
if r := recover(); r != nil {
if _, ok := r.(runtime.Error); ok {
panic(r)
}
if v, ok := r.(string); ok {
err = errors.New(v)
} else {
err = r.(error)
}
}
}()
return encode(reflect.ValueOf(v)), nil
}
func encode(v reflect.Value) interface{} {
return valueEncoder(v)(v)
}
var encoderCache struct {
sync.RWMutex
m map[reflect.Type]encoderFunc
}
func valueEncoder(v reflect.Value) encoderFunc {
if !v.IsValid() {
return invalidValueEncoder
}
return typeEncoder(v.Type())
}
func typeEncoder(t reflect.Type) encoderFunc {
encoderCache.RLock()
f := encoderCache.m[t]
encoderCache.RUnlock()
if f != nil {
return f
}
// To deal with recursive types, populate the map with an
// indirect func before we build it. This type waits on the
// real func (f) to
// be ready and then calls it. This indirect
// func is only used for recursive types.
encoderCache.Lock()
var wg sync.WaitGroup
wg.Add(1)
encoderCache.m[t] = func(v reflect.Value) interface{} {
wg.Wait()
return f(v)
}
encoderCache.Unlock()
// Compute fields without lock.
// Might duplicate effort but won't hold other computations back.
f = newTypeEncoder(t, true)
wg.Done()
encoderCache.Lock()
encoderCache.m[t] = f
encoderCache.Unlock()
return f
}
// IgnoreType causes the encoder to ignore a type when encoding
func IgnoreType(t reflect.Type) {
encoderCache.Lock()
encoderCache.m[t] = doNothingEncoder
encoderCache.Unlock()
}