586 lines
14 KiB
Go
586 lines
14 KiB
Go
|
// Copyright 2012 Gary Burd
|
||
|
//
|
||
|
// 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 redis
|
||
|
|
||
|
import (
|
||
|
"errors"
|
||
|
"fmt"
|
||
|
"reflect"
|
||
|
"strconv"
|
||
|
"strings"
|
||
|
"sync"
|
||
|
)
|
||
|
|
||
|
func ensureLen(d reflect.Value, n int) {
|
||
|
if n > d.Cap() {
|
||
|
d.Set(reflect.MakeSlice(d.Type(), n, n))
|
||
|
} else {
|
||
|
d.SetLen(n)
|
||
|
}
|
||
|
}
|
||
|
|
||
|
func cannotConvert(d reflect.Value, s interface{}) error {
|
||
|
var sname string
|
||
|
switch s.(type) {
|
||
|
case string:
|
||
|
sname = "Redis simple string"
|
||
|
case Error:
|
||
|
sname = "Redis error"
|
||
|
case int64:
|
||
|
sname = "Redis integer"
|
||
|
case []byte:
|
||
|
sname = "Redis bulk string"
|
||
|
case []interface{}:
|
||
|
sname = "Redis array"
|
||
|
default:
|
||
|
sname = reflect.TypeOf(s).String()
|
||
|
}
|
||
|
return fmt.Errorf("cannot convert from %s to %s", sname, d.Type())
|
||
|
}
|
||
|
|
||
|
func convertAssignBulkString(d reflect.Value, s []byte) (err error) {
|
||
|
switch d.Type().Kind() {
|
||
|
case reflect.Float32, reflect.Float64:
|
||
|
var x float64
|
||
|
x, err = strconv.ParseFloat(string(s), d.Type().Bits())
|
||
|
d.SetFloat(x)
|
||
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
||
|
var x int64
|
||
|
x, err = strconv.ParseInt(string(s), 10, d.Type().Bits())
|
||
|
d.SetInt(x)
|
||
|
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
|
||
|
var x uint64
|
||
|
x, err = strconv.ParseUint(string(s), 10, d.Type().Bits())
|
||
|
d.SetUint(x)
|
||
|
case reflect.Bool:
|
||
|
var x bool
|
||
|
x, err = strconv.ParseBool(string(s))
|
||
|
d.SetBool(x)
|
||
|
case reflect.String:
|
||
|
d.SetString(string(s))
|
||
|
case reflect.Slice:
|
||
|
if d.Type().Elem().Kind() != reflect.Uint8 {
|
||
|
err = cannotConvert(d, s)
|
||
|
} else {
|
||
|
d.SetBytes(s)
|
||
|
}
|
||
|
default:
|
||
|
err = cannotConvert(d, s)
|
||
|
}
|
||
|
return
|
||
|
}
|
||
|
|
||
|
func convertAssignInt(d reflect.Value, s int64) (err error) {
|
||
|
switch d.Type().Kind() {
|
||
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
||
|
d.SetInt(s)
|
||
|
if d.Int() != s {
|
||
|
err = strconv.ErrRange
|
||
|
d.SetInt(0)
|
||
|
}
|
||
|
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
|
||
|
if s < 0 {
|
||
|
err = strconv.ErrRange
|
||
|
} else {
|
||
|
x := uint64(s)
|
||
|
d.SetUint(x)
|
||
|
if d.Uint() != x {
|
||
|
err = strconv.ErrRange
|
||
|
d.SetUint(0)
|
||
|
}
|
||
|
}
|
||
|
case reflect.Bool:
|
||
|
d.SetBool(s != 0)
|
||
|
default:
|
||
|
err = cannotConvert(d, s)
|
||
|
}
|
||
|
return
|
||
|
}
|
||
|
|
||
|
func convertAssignValue(d reflect.Value, s interface{}) (err error) {
|
||
|
if d.Kind() != reflect.Ptr {
|
||
|
if d.CanAddr() {
|
||
|
d2 := d.Addr()
|
||
|
if d2.CanInterface() {
|
||
|
if scanner, ok := d2.Interface().(Scanner); ok {
|
||
|
return scanner.RedisScan(s)
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
} else if d.CanInterface() {
|
||
|
// Already a reflect.Ptr
|
||
|
if d.IsNil() {
|
||
|
d.Set(reflect.New(d.Type().Elem()))
|
||
|
}
|
||
|
if scanner, ok := d.Interface().(Scanner); ok {
|
||
|
return scanner.RedisScan(s)
|
||
|
}
|
||
|
}
|
||
|
|
||
|
switch s := s.(type) {
|
||
|
case []byte:
|
||
|
err = convertAssignBulkString(d, s)
|
||
|
case int64:
|
||
|
err = convertAssignInt(d, s)
|
||
|
default:
|
||
|
err = cannotConvert(d, s)
|
||
|
}
|
||
|
return err
|
||
|
}
|
||
|
|
||
|
func convertAssignArray(d reflect.Value, s []interface{}) error {
|
||
|
if d.Type().Kind() != reflect.Slice {
|
||
|
return cannotConvert(d, s)
|
||
|
}
|
||
|
ensureLen(d, len(s))
|
||
|
for i := 0; i < len(s); i++ {
|
||
|
if err := convertAssignValue(d.Index(i), s[i]); err != nil {
|
||
|
return err
|
||
|
}
|
||
|
}
|
||
|
return nil
|
||
|
}
|
||
|
|
||
|
func convertAssign(d interface{}, s interface{}) (err error) {
|
||
|
if scanner, ok := d.(Scanner); ok {
|
||
|
return scanner.RedisScan(s)
|
||
|
}
|
||
|
|
||
|
// Handle the most common destination types using type switches and
|
||
|
// fall back to reflection for all other types.
|
||
|
switch s := s.(type) {
|
||
|
case nil:
|
||
|
// ignore
|
||
|
case []byte:
|
||
|
switch d := d.(type) {
|
||
|
case *string:
|
||
|
*d = string(s)
|
||
|
case *int:
|
||
|
*d, err = strconv.Atoi(string(s))
|
||
|
case *bool:
|
||
|
*d, err = strconv.ParseBool(string(s))
|
||
|
case *[]byte:
|
||
|
*d = s
|
||
|
case *interface{}:
|
||
|
*d = s
|
||
|
case nil:
|
||
|
// skip value
|
||
|
default:
|
||
|
if d := reflect.ValueOf(d); d.Type().Kind() != reflect.Ptr {
|
||
|
err = cannotConvert(d, s)
|
||
|
} else {
|
||
|
err = convertAssignBulkString(d.Elem(), s)
|
||
|
}
|
||
|
}
|
||
|
case int64:
|
||
|
switch d := d.(type) {
|
||
|
case *int:
|
||
|
x := int(s)
|
||
|
if int64(x) != s {
|
||
|
err = strconv.ErrRange
|
||
|
x = 0
|
||
|
}
|
||
|
*d = x
|
||
|
case *bool:
|
||
|
*d = s != 0
|
||
|
case *interface{}:
|
||
|
*d = s
|
||
|
case nil:
|
||
|
// skip value
|
||
|
default:
|
||
|
if d := reflect.ValueOf(d); d.Type().Kind() != reflect.Ptr {
|
||
|
err = cannotConvert(d, s)
|
||
|
} else {
|
||
|
err = convertAssignInt(d.Elem(), s)
|
||
|
}
|
||
|
}
|
||
|
case string:
|
||
|
switch d := d.(type) {
|
||
|
case *string:
|
||
|
*d = s
|
||
|
case *interface{}:
|
||
|
*d = s
|
||
|
case nil:
|
||
|
// skip value
|
||
|
default:
|
||
|
err = cannotConvert(reflect.ValueOf(d), s)
|
||
|
}
|
||
|
case []interface{}:
|
||
|
switch d := d.(type) {
|
||
|
case *[]interface{}:
|
||
|
*d = s
|
||
|
case *interface{}:
|
||
|
*d = s
|
||
|
case nil:
|
||
|
// skip value
|
||
|
default:
|
||
|
if d := reflect.ValueOf(d); d.Type().Kind() != reflect.Ptr {
|
||
|
err = cannotConvert(d, s)
|
||
|
} else {
|
||
|
err = convertAssignArray(d.Elem(), s)
|
||
|
}
|
||
|
}
|
||
|
case Error:
|
||
|
err = s
|
||
|
default:
|
||
|
err = cannotConvert(reflect.ValueOf(d), s)
|
||
|
}
|
||
|
return
|
||
|
}
|
||
|
|
||
|
// Scan copies from src to the values pointed at by dest.
|
||
|
//
|
||
|
// Scan uses RedisScan if available otherwise:
|
||
|
//
|
||
|
// The values pointed at by dest must be an integer, float, boolean, string,
|
||
|
// []byte, interface{} or slices of these types. Scan uses the standard strconv
|
||
|
// package to convert bulk strings to numeric and boolean types.
|
||
|
//
|
||
|
// If a dest value is nil, then the corresponding src value is skipped.
|
||
|
//
|
||
|
// If a src element is nil, then the corresponding dest value is not modified.
|
||
|
//
|
||
|
// To enable easy use of Scan in a loop, Scan returns the slice of src
|
||
|
// following the copied values.
|
||
|
func Scan(src []interface{}, dest ...interface{}) ([]interface{}, error) {
|
||
|
if len(src) < len(dest) {
|
||
|
return nil, errors.New("redigo.Scan: array short")
|
||
|
}
|
||
|
var err error
|
||
|
for i, d := range dest {
|
||
|
err = convertAssign(d, src[i])
|
||
|
if err != nil {
|
||
|
err = fmt.Errorf("redigo.Scan: cannot assign to dest %d: %v", i, err)
|
||
|
break
|
||
|
}
|
||
|
}
|
||
|
return src[len(dest):], err
|
||
|
}
|
||
|
|
||
|
type fieldSpec struct {
|
||
|
name string
|
||
|
index []int
|
||
|
omitEmpty bool
|
||
|
}
|
||
|
|
||
|
type structSpec struct {
|
||
|
m map[string]*fieldSpec
|
||
|
l []*fieldSpec
|
||
|
}
|
||
|
|
||
|
func (ss *structSpec) fieldSpec(name []byte) *fieldSpec {
|
||
|
return ss.m[string(name)]
|
||
|
}
|
||
|
|
||
|
func compileStructSpec(t reflect.Type, depth map[string]int, index []int, ss *structSpec) {
|
||
|
for i := 0; i < t.NumField(); i++ {
|
||
|
f := t.Field(i)
|
||
|
switch {
|
||
|
case f.PkgPath != "" && !f.Anonymous:
|
||
|
// Ignore unexported fields.
|
||
|
case f.Anonymous:
|
||
|
// TODO: Handle pointers. Requires change to decoder and
|
||
|
// protection against infinite recursion.
|
||
|
if f.Type.Kind() == reflect.Struct {
|
||
|
compileStructSpec(f.Type, depth, append(index, i), ss)
|
||
|
}
|
||
|
default:
|
||
|
fs := &fieldSpec{name: f.Name}
|
||
|
tag := f.Tag.Get("redis")
|
||
|
p := strings.Split(tag, ",")
|
||
|
if len(p) > 0 {
|
||
|
if p[0] == "-" {
|
||
|
continue
|
||
|
}
|
||
|
if len(p[0]) > 0 {
|
||
|
fs.name = p[0]
|
||
|
}
|
||
|
for _, s := range p[1:] {
|
||
|
switch s {
|
||
|
case "omitempty":
|
||
|
fs.omitEmpty = true
|
||
|
default:
|
||
|
panic(fmt.Errorf("redigo: unknown field tag %s for type %s", s, t.Name()))
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
d, found := depth[fs.name]
|
||
|
if !found {
|
||
|
d = 1 << 30
|
||
|
}
|
||
|
switch {
|
||
|
case len(index) == d:
|
||
|
// At same depth, remove from result.
|
||
|
delete(ss.m, fs.name)
|
||
|
j := 0
|
||
|
for i := 0; i < len(ss.l); i++ {
|
||
|
if fs.name != ss.l[i].name {
|
||
|
ss.l[j] = ss.l[i]
|
||
|
j += 1
|
||
|
}
|
||
|
}
|
||
|
ss.l = ss.l[:j]
|
||
|
case len(index) < d:
|
||
|
fs.index = make([]int, len(index)+1)
|
||
|
copy(fs.index, index)
|
||
|
fs.index[len(index)] = i
|
||
|
depth[fs.name] = len(index)
|
||
|
ss.m[fs.name] = fs
|
||
|
ss.l = append(ss.l, fs)
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
var (
|
||
|
structSpecMutex sync.RWMutex
|
||
|
structSpecCache = make(map[reflect.Type]*structSpec)
|
||
|
defaultFieldSpec = &fieldSpec{}
|
||
|
)
|
||
|
|
||
|
func structSpecForType(t reflect.Type) *structSpec {
|
||
|
|
||
|
structSpecMutex.RLock()
|
||
|
ss, found := structSpecCache[t]
|
||
|
structSpecMutex.RUnlock()
|
||
|
if found {
|
||
|
return ss
|
||
|
}
|
||
|
|
||
|
structSpecMutex.Lock()
|
||
|
defer structSpecMutex.Unlock()
|
||
|
ss, found = structSpecCache[t]
|
||
|
if found {
|
||
|
return ss
|
||
|
}
|
||
|
|
||
|
ss = &structSpec{m: make(map[string]*fieldSpec)}
|
||
|
compileStructSpec(t, make(map[string]int), nil, ss)
|
||
|
structSpecCache[t] = ss
|
||
|
return ss
|
||
|
}
|
||
|
|
||
|
var errScanStructValue = errors.New("redigo.ScanStruct: value must be non-nil pointer to a struct")
|
||
|
|
||
|
// ScanStruct scans alternating names and values from src to a struct. The
|
||
|
// HGETALL and CONFIG GET commands return replies in this format.
|
||
|
//
|
||
|
// ScanStruct uses exported field names to match values in the response. Use
|
||
|
// 'redis' field tag to override the name:
|
||
|
//
|
||
|
// Field int `redis:"myName"`
|
||
|
//
|
||
|
// Fields with the tag redis:"-" are ignored.
|
||
|
//
|
||
|
// Each field uses RedisScan if available otherwise:
|
||
|
// Integer, float, boolean, string and []byte fields are supported. Scan uses the
|
||
|
// standard strconv package to convert bulk string values to numeric and
|
||
|
// boolean types.
|
||
|
//
|
||
|
// If a src element is nil, then the corresponding field is not modified.
|
||
|
func ScanStruct(src []interface{}, dest interface{}) error {
|
||
|
d := reflect.ValueOf(dest)
|
||
|
if d.Kind() != reflect.Ptr || d.IsNil() {
|
||
|
return errScanStructValue
|
||
|
}
|
||
|
d = d.Elem()
|
||
|
if d.Kind() != reflect.Struct {
|
||
|
return errScanStructValue
|
||
|
}
|
||
|
ss := structSpecForType(d.Type())
|
||
|
|
||
|
if len(src)%2 != 0 {
|
||
|
return errors.New("redigo.ScanStruct: number of values not a multiple of 2")
|
||
|
}
|
||
|
|
||
|
for i := 0; i < len(src); i += 2 {
|
||
|
s := src[i+1]
|
||
|
if s == nil {
|
||
|
continue
|
||
|
}
|
||
|
name, ok := src[i].([]byte)
|
||
|
if !ok {
|
||
|
return fmt.Errorf("redigo.ScanStruct: key %d not a bulk string value", i)
|
||
|
}
|
||
|
fs := ss.fieldSpec(name)
|
||
|
if fs == nil {
|
||
|
continue
|
||
|
}
|
||
|
if err := convertAssignValue(d.FieldByIndex(fs.index), s); err != nil {
|
||
|
return fmt.Errorf("redigo.ScanStruct: cannot assign field %s: %v", fs.name, err)
|
||
|
}
|
||
|
}
|
||
|
return nil
|
||
|
}
|
||
|
|
||
|
var (
|
||
|
errScanSliceValue = errors.New("redigo.ScanSlice: dest must be non-nil pointer to a struct")
|
||
|
)
|
||
|
|
||
|
// ScanSlice scans src to the slice pointed to by dest. The elements the dest
|
||
|
// slice must be integer, float, boolean, string, struct or pointer to struct
|
||
|
// values.
|
||
|
//
|
||
|
// Struct fields must be integer, float, boolean or string values. All struct
|
||
|
// fields are used unless a subset is specified using fieldNames.
|
||
|
func ScanSlice(src []interface{}, dest interface{}, fieldNames ...string) error {
|
||
|
d := reflect.ValueOf(dest)
|
||
|
if d.Kind() != reflect.Ptr || d.IsNil() {
|
||
|
return errScanSliceValue
|
||
|
}
|
||
|
d = d.Elem()
|
||
|
if d.Kind() != reflect.Slice {
|
||
|
return errScanSliceValue
|
||
|
}
|
||
|
|
||
|
isPtr := false
|
||
|
t := d.Type().Elem()
|
||
|
if t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct {
|
||
|
isPtr = true
|
||
|
t = t.Elem()
|
||
|
}
|
||
|
|
||
|
if t.Kind() != reflect.Struct {
|
||
|
ensureLen(d, len(src))
|
||
|
for i, s := range src {
|
||
|
if s == nil {
|
||
|
continue
|
||
|
}
|
||
|
if err := convertAssignValue(d.Index(i), s); err != nil {
|
||
|
return fmt.Errorf("redigo.ScanSlice: cannot assign element %d: %v", i, err)
|
||
|
}
|
||
|
}
|
||
|
return nil
|
||
|
}
|
||
|
|
||
|
ss := structSpecForType(t)
|
||
|
fss := ss.l
|
||
|
if len(fieldNames) > 0 {
|
||
|
fss = make([]*fieldSpec, len(fieldNames))
|
||
|
for i, name := range fieldNames {
|
||
|
fss[i] = ss.m[name]
|
||
|
if fss[i] == nil {
|
||
|
return fmt.Errorf("redigo.ScanSlice: ScanSlice bad field name %s", name)
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if len(fss) == 0 {
|
||
|
return errors.New("redigo.ScanSlice: no struct fields")
|
||
|
}
|
||
|
|
||
|
n := len(src) / len(fss)
|
||
|
if n*len(fss) != len(src) {
|
||
|
return errors.New("redigo.ScanSlice: length not a multiple of struct field count")
|
||
|
}
|
||
|
|
||
|
ensureLen(d, n)
|
||
|
for i := 0; i < n; i++ {
|
||
|
d := d.Index(i)
|
||
|
if isPtr {
|
||
|
if d.IsNil() {
|
||
|
d.Set(reflect.New(t))
|
||
|
}
|
||
|
d = d.Elem()
|
||
|
}
|
||
|
for j, fs := range fss {
|
||
|
s := src[i*len(fss)+j]
|
||
|
if s == nil {
|
||
|
continue
|
||
|
}
|
||
|
if err := convertAssignValue(d.FieldByIndex(fs.index), s); err != nil {
|
||
|
return fmt.Errorf("redigo.ScanSlice: cannot assign element %d to field %s: %v", i*len(fss)+j, fs.name, err)
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
return nil
|
||
|
}
|
||
|
|
||
|
// Args is a helper for constructing command arguments from structured values.
|
||
|
type Args []interface{}
|
||
|
|
||
|
// Add returns the result of appending value to args.
|
||
|
func (args Args) Add(value ...interface{}) Args {
|
||
|
return append(args, value...)
|
||
|
}
|
||
|
|
||
|
// AddFlat returns the result of appending the flattened value of v to args.
|
||
|
//
|
||
|
// Maps are flattened by appending the alternating keys and map values to args.
|
||
|
//
|
||
|
// Slices are flattened by appending the slice elements to args.
|
||
|
//
|
||
|
// Structs are flattened by appending the alternating names and values of
|
||
|
// exported fields to args. If v is a nil struct pointer, then nothing is
|
||
|
// appended. The 'redis' field tag overrides struct field names. See ScanStruct
|
||
|
// for more information on the use of the 'redis' field tag.
|
||
|
//
|
||
|
// Other types are appended to args as is.
|
||
|
func (args Args) AddFlat(v interface{}) Args {
|
||
|
rv := reflect.ValueOf(v)
|
||
|
switch rv.Kind() {
|
||
|
case reflect.Struct:
|
||
|
args = flattenStruct(args, rv)
|
||
|
case reflect.Slice:
|
||
|
for i := 0; i < rv.Len(); i++ {
|
||
|
args = append(args, rv.Index(i).Interface())
|
||
|
}
|
||
|
case reflect.Map:
|
||
|
for _, k := range rv.MapKeys() {
|
||
|
args = append(args, k.Interface(), rv.MapIndex(k).Interface())
|
||
|
}
|
||
|
case reflect.Ptr:
|
||
|
if rv.Type().Elem().Kind() == reflect.Struct {
|
||
|
if !rv.IsNil() {
|
||
|
args = flattenStruct(args, rv.Elem())
|
||
|
}
|
||
|
} else {
|
||
|
args = append(args, v)
|
||
|
}
|
||
|
default:
|
||
|
args = append(args, v)
|
||
|
}
|
||
|
return args
|
||
|
}
|
||
|
|
||
|
func flattenStruct(args Args, v reflect.Value) Args {
|
||
|
ss := structSpecForType(v.Type())
|
||
|
for _, fs := range ss.l {
|
||
|
fv := v.FieldByIndex(fs.index)
|
||
|
if fs.omitEmpty {
|
||
|
var empty = false
|
||
|
switch fv.Kind() {
|
||
|
case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
|
||
|
empty = fv.Len() == 0
|
||
|
case reflect.Bool:
|
||
|
empty = !fv.Bool()
|
||
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
||
|
empty = fv.Int() == 0
|
||
|
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
|
||
|
empty = fv.Uint() == 0
|
||
|
case reflect.Float32, reflect.Float64:
|
||
|
empty = fv.Float() == 0
|
||
|
case reflect.Interface, reflect.Ptr:
|
||
|
empty = fv.IsNil()
|
||
|
}
|
||
|
if empty {
|
||
|
continue
|
||
|
}
|
||
|
}
|
||
|
args = append(args, fs.name, fv.Interface())
|
||
|
}
|
||
|
return args
|
||
|
}
|