lbry.go/extras/orderedmap/ordered_map.go
2020-09-01 19:55:06 +02:00

301 lines
7.3 KiB
Go

package orderedmap
// mostly from https://github.com/iancoleman/orderedmap
import (
"encoding/json"
"fmt"
"sort"
"strings"
"sync"
"github.com/lbryio/lbry.go/v2/extras/errors"
)
type keyIndex struct {
Key string
Index int
}
type byIndex []keyIndex
func (a byIndex) Len() int { return len(a) }
func (a byIndex) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a byIndex) Less(i, j int) bool { return a[i].Index < a[j].Index }
type Map struct {
l sync.RWMutex
keys []string
values map[string]interface{}
}
func New() *Map {
o := Map{}
o.l = sync.RWMutex{}
o.keys = []string{}
o.values = map[string]interface{}{}
return &o
}
func (o *Map) Get(key string) (interface{}, bool) {
o.l.RLock()
defer o.l.RUnlock()
val, exists := o.values[key]
return val, exists
}
func (o *Map) Set(key string, value interface{}) {
o.l.Lock()
defer o.l.Unlock()
_, exists := o.values[key]
if !exists {
o.keys = append(o.keys, key)
}
o.values[key] = value
}
const outOfRange = "position value %d is outside of the range %d - %d"
//InsertAt This is a zero based position index: 0,1,2,3..n(from left) OR -1,-2,-3...-n(from right) where -1 is the last place.
func (o *Map) InsertAt(key string, value interface{}, position int) error {
o.l.Lock()
defer o.l.Unlock()
var index = position
if position < 0 {
// support indexing from the back: -1 = last in array.
index += len(o.keys) + 1
if index < 0 || index > len(o.keys) {
return errors.Err(fmt.Sprintf(outOfRange, position, len(o.keys), len(o.keys)-1))
}
} else if index > len(o.keys) {
return errors.Err(fmt.Sprintf(outOfRange, position, len(o.keys), len(o.keys)-1))
}
_, exists := o.values[key]
if !exists {
// left + key + right
o.keys = append(o.keys[0:index], append([]string{key}, o.keys[index:]...)...)
}
o.values[key] = value
return nil
}
func (o *Map) Prepend(key string, value interface{}) {
o.l.Lock()
defer o.l.Unlock()
_, exists := o.values[key]
if !exists {
o.keys = append([]string{key}, o.keys...)
}
o.values[key] = value
}
func (o *Map) Delete(key string) {
o.l.Lock()
defer o.l.Unlock()
// check key is in use
_, ok := o.values[key]
if !ok {
return
}
// remove from keys
for i, k := range o.keys {
if k == key {
o.keys = append(o.keys[:i], o.keys[i+1:]...)
break
}
}
// remove from values
delete(o.values, key)
}
func (o *Map) Keys() []string {
o.l.RLock()
defer o.l.RUnlock()
return o.keys
}
func (o *Map) UnmarshalJSON(b []byte) error {
o.l.Lock()
defer o.l.Unlock()
m := map[string]interface{}{}
if err := json.Unmarshal(b, &m); err != nil {
return errors.Err(err)
}
s := string(b)
mapToOrderedMap(o, s, m)
return nil
}
func mapToOrderedMap(o *Map, s string, m map[string]interface{}) {
// Get the order of the keys
orderedKeys := []keyIndex{}
for k := range m {
kEscaped := strings.Replace(k, `"`, `\"`, -1)
kQuoted := `"` + kEscaped + `"`
// Find how much content exists before this key.
// If all content from this key and after is replaced with a close
// brace, it should still form a valid json string.
sTrimmed := s
for len(sTrimmed) > 0 {
lastIndex := strings.LastIndex(sTrimmed, kQuoted)
if lastIndex == -1 {
break
}
sTrimmed = sTrimmed[0:lastIndex]
sTrimmed = strings.TrimSpace(sTrimmed)
if len(sTrimmed) > 0 && sTrimmed[len(sTrimmed)-1] == ',' {
sTrimmed = sTrimmed[0 : len(sTrimmed)-1]
}
maybeValidJson := sTrimmed + "}"
testMap := map[string]interface{}{}
err := json.Unmarshal([]byte(maybeValidJson), &testMap)
if err == nil {
// record the position of this key in s
ki := keyIndex{
Key: k,
Index: len(sTrimmed),
}
orderedKeys = append(orderedKeys, ki)
// shorten the string to get the next key
startOfValueIndex := lastIndex + len(kQuoted)
valueStr := s[startOfValueIndex : len(s)-1]
valueStr = strings.TrimSpace(valueStr)
if len(valueStr) > 0 && valueStr[0] == ':' {
valueStr = valueStr[1:]
}
valueStr = strings.TrimSpace(valueStr)
if valueStr[0] == '{' {
// if the value for this key is a map, convert it to an orderedmap.
// find end of valueStr by removing everything after last }
// until it forms valid json
hasValidJson := false
i := 1
for i < len(valueStr) && !hasValidJson {
if valueStr[i] != '}' {
i = i + 1
continue
}
subTestMap := map[string]interface{}{}
testValue := valueStr[0 : i+1]
err = json.Unmarshal([]byte(testValue), &subTestMap)
if err == nil {
hasValidJson = true
valueStr = testValue
break
}
i = i + 1
}
// convert to orderedmap
if hasValidJson {
mkTyped := m[k].(map[string]interface{})
oo := &Map{}
mapToOrderedMap(oo, valueStr, mkTyped)
m[k] = oo
}
} else if valueStr[0] == '[' {
// if the value for this key is a []interface, convert any map items to an orderedmap.
// find end of valueStr by removing everything after last ]
// until it forms valid json
hasValidJson := false
i := 1
for i < len(valueStr) && !hasValidJson {
if valueStr[i] != ']' {
i = i + 1
continue
}
subTestSlice := []interface{}{}
testValue := valueStr[0 : i+1]
err = json.Unmarshal([]byte(testValue), &subTestSlice)
if err == nil {
hasValidJson = true
valueStr = testValue
break
}
i = i + 1
}
if hasValidJson {
itemsStr := valueStr[1 : len(valueStr)-1]
// get next item in the slice
itemIndex := 0
startItem := 0
endItem := 0
for endItem < len(itemsStr) {
if itemsStr[endItem] != ',' && endItem < len(itemsStr)-1 {
endItem = endItem + 1
continue
}
// if this substring compiles to json, it's the next item
possibleItemStr := strings.TrimSpace(itemsStr[startItem:endItem])
var possibleItem interface{}
err = json.Unmarshal([]byte(possibleItemStr), &possibleItem)
if err != nil {
endItem = endItem + 1
continue
}
// if item is map, convert to orderedmap
if possibleItemStr[0] == '{' {
mkTyped := m[k].([]interface{})
mkiTyped := mkTyped[itemIndex].(map[string]interface{})
oo := &Map{}
mapToOrderedMap(oo, possibleItemStr, mkiTyped)
// replace original map with orderedmap
mkTyped[itemIndex] = oo
m[k] = mkTyped
}
// remove this item from itemsStr
startItem = endItem + 1
endItem = endItem + 1
itemIndex = itemIndex + 1
}
}
}
break
}
}
}
// Sort the keys
sort.Sort(byIndex(orderedKeys))
// Convert sorted keys to string slice
k := []string{}
for _, ki := range orderedKeys {
k = append(k, ki.Key)
}
// Set the Map values
o.values = m
o.keys = k
}
func (o *Map) Copy() *Map {
new := New()
for _, k := range o.keys {
v, _ := o.Get(k)
new.Set(k, v)
}
return new
}
func (o *Map) MarshalJSON() ([]byte, error) {
o.l.RLock()
defer o.l.RUnlock()
s := "{"
for _, k := range o.keys {
// add key
kEscaped := strings.Replace(k, `"`, `\"`, -1)
s = s + `"` + kEscaped + `":`
// add value
v := o.values[k]
vBytes, err := json.Marshal(v)
if err != nil {
return []byte{}, errors.Err(err)
}
s = s + string(vBytes) + ","
}
if len(o.keys) > 0 {
s = s[0 : len(s)-1]
}
s = s + "}"
return []byte(s), nil
}