hugo scratch 代码
文件路径：/common/maps/scratch.go
/ Copyright 2019 The Hugo Authors. All rights reserved.
/
/ 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 maps
import (
"reflect"
"sort"
"sync"
"github.com/gohugoio/hugo/common/collections"
"github.com/gohugoio/hugo/common/math"
)
/ Scratch is a writable context used for stateful operations in Page/Node rendering.
type Scratch struct {
values map[string]any
mu sync.RWMutex
}
/ Scratcher provides a scratching service.
type Scratcher interface {
Scratch() *Scratch
}
type scratcher struct {
s *Scratch
}
func (s scratcher) Scratch() *Scratch {
return s.s
}
/ NewScratcher creates a new Scratcher.
func NewScratcher() Scratcher {
return scratcher{s: NewScratch()}
}
/ Add will, for single values, add (using the + operator) the addend to the existing addend (if found).
/ Supports numeric values and strings.
/
/ If the first add for a key is an array or slice, then the next value(s) will be appended.
func (c *Scratch) Add(key string, newAddend any) (string, error) {
var newVal any
c.mu.RLock()
existingAddend, found := c.values[key]
c.mu.RUnlock()
if found {
var err error
addendV := reflect.TypeOf(existingAddend)
if addendV.Kind() == reflect.Slice || addendV.Kind() == reflect.Array {
newVal, err = collections.Append(existingAddend, newAddend)
if err != nil {
return "", err
}
} else {
newVal, err = math.DoArithmetic(existingAddend, newAddend, '+')
if err != nil {
return "", err
}
}
} else {
newVal = newAddend
}
c.mu.Lock()
c.values[key] = newVal
c.mu.Unlock()
return "", nil / have to return something to make it work with the Go templates
}
/ Set stores a value with the given key in the Node context.
/ This value can later be retrieved with Get.
func (c *Scratch) Set(key string, value any) string {
c.mu.Lock()
c.values[key] = value
c.mu.Unlock()
return ""
}
/ Delete deletes the given key.
func (c *Scratch) Delete(key string) string {
c.mu.Lock()
delete(c.values, key)
c.mu.Unlock()
return ""
}
/ Get returns a value previously set by Add or Set.
func (c *Scratch) Get(key string) any {
c.mu.RLock()
val := c.values[key]
c.mu.RUnlock()
return val
}
/ Values returns the raw backing map. Note that you should just use
/ this method on the locally scoped Scratch instances you obtain via newScratch, not
/ .Page.Scratch etc., as that will lead to concurrency issues.
func (c *Scratch) Values() map[string]any {
c.mu.RLock()
defer c.mu.RUnlock()
return c.values
}
/ SetInMap stores a value to a map with the given key in the Node context.
/ This map can later be retrieved with GetSortedMapValues.
func (c *Scratch) SetInMap(key string, mapKey string, value any) string {
c.mu.Lock()
_, found := c.values[key]
if !found {
c.values[key] = make(map[string]any)
}
c.values[key].(map[string]any)[mapKey] = value
c.mu.Unlock()
return ""
}
/ DeleteInMap deletes a value to a map with the given key in the Node context.
func (c *Scratch) DeleteInMap(key string, mapKey string) string {
c.mu.Lock()
_, found := c.values[key]
if found {
delete(c.values[key].(map[string]any), mapKey)
}
c.mu.Unlock()
return ""
}
/ GetSortedMapValues returns a sorted map previously filled with SetInMap.
func (c *Scratch) GetSortedMapValues(key string) any {
c.mu.RLock()
if c.values[key] == nil {
c.mu.RUnlock()
return nil
}
unsortedMap := c.values[key].(map[string]any)
c.mu.RUnlock()
var keys []string
for mapKey := range unsortedMap {
keys = append(keys, mapKey)
}
sort.Strings(keys)
sortedArray := make([]any, len(unsortedMap))
for i, mapKey := range keys {
sortedArray[i] = unsortedMap[mapKey]
}
return sortedArray
}
/ NewScratch returns a new instance of Scratch.
func NewScratch() *Scratch {
return &Scratch{values: make(map[string]any)}
}