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core/mapper.go
2015-02-12 14:50:58 +08:00

255 lines
5.1 KiB
Go

package core
import (
"strings"
"sync"
)
// name translation between struct, fields names and table, column names
type IMapper interface {
Obj2Table(string) string
Table2Obj(string) string
}
type CacheMapper struct {
oriMapper IMapper
obj2tableCache map[string]string
obj2tableMutex sync.RWMutex
table2objCache map[string]string
table2objMutex sync.RWMutex
}
func NewCacheMapper(mapper IMapper) *CacheMapper {
return &CacheMapper{oriMapper: mapper, obj2tableCache: make(map[string]string),
table2objCache: make(map[string]string),
}
}
func (m *CacheMapper) Obj2Table(o string) string {
m.obj2tableMutex.RLock()
t, ok := m.obj2tableCache[o]
m.obj2tableMutex.RUnlock()
if ok {
return t
}
t = m.oriMapper.Obj2Table(o)
m.obj2tableMutex.Lock()
m.obj2tableCache[o] = t
m.obj2tableMutex.Unlock()
return t
}
func (m *CacheMapper) Table2Obj(t string) string {
m.table2objMutex.RLock()
o, ok := m.table2objCache[t]
m.table2objMutex.RUnlock()
if ok {
return o
}
o = m.oriMapper.Table2Obj(t)
m.table2objMutex.Lock()
m.table2objCache[t] = o
m.table2objMutex.Unlock()
return o
}
// SameMapper implements IMapper and provides same name between struct and
// database table
type SameMapper struct {
}
func (m SameMapper) Obj2Table(o string) string {
return o
}
func (m SameMapper) Table2Obj(t string) string {
return t
}
// SnakeMapper implements IMapper and provides name transaltion between
// struct and database table
type SnakeMapper struct {
}
func snakeCasedName(name string) string {
newstr := make([]rune, 0)
for idx, chr := range name {
if isUpper := 'A' <= chr && chr <= 'Z'; isUpper {
if idx > 0 {
newstr = append(newstr, '_')
}
chr -= ('A' - 'a')
}
newstr = append(newstr, chr)
}
return string(newstr)
}
func (mapper SnakeMapper) Obj2Table(name string) string {
return snakeCasedName(name)
}
func titleCasedName(name string) string {
newstr := make([]rune, 0)
upNextChar := true
name = strings.ToLower(name)
for _, chr := range name {
switch {
case upNextChar:
upNextChar = false
if 'a' <= chr && chr <= 'z' {
chr -= ('a' - 'A')
}
case chr == '_':
upNextChar = true
continue
}
newstr = append(newstr, chr)
}
return string(newstr)
}
func (mapper SnakeMapper) Table2Obj(name string) string {
return titleCasedName(name)
}
// GonicMapper implements IMapper. It will consider initialisms when mapping names.
// E.g. id -> ID, user -> User and to table names: UserID -> user_id, MyUID -> my_uid
type GonicMapper map[string]bool
func isASCIIUpper(r rune) bool {
return 'A' <= r && r <= 'Z'
}
func toASCIIUpper(r rune) rune {
if 'a' <= r && r <= 'z' {
r -= ('a' - 'A')
}
return r
}
func gonicCasedName(name string) string {
newstr := make([]rune, 0, len(name)+3)
for idx, chr := range name {
if isASCIIUpper(chr) && idx > 0 {
if !isASCIIUpper(newstr[len(newstr)-1]) {
newstr = append(newstr, '_')
}
}
if !isASCIIUpper(chr) && idx > 1 {
l := len(newstr)
if isASCIIUpper(newstr[l-1]) && isASCIIUpper(newstr[l-2]) {
newstr = append(newstr, newstr[l-1])
newstr[l-1] = '_'
}
}
newstr = append(newstr, chr)
}
return strings.ToLower(string(newstr))
}
func (mapper GonicMapper) Obj2Table(name string) string {
return gonicCasedName(name)
}
func (mapper GonicMapper) Table2Obj(name string) string {
newstr := make([]rune, 0)
name = strings.ToLower(name)
parts := strings.Split(name, "_")
for _, p := range parts {
_, isInitialism := mapper[strings.ToUpper(p)]
for i, r := range p {
if i == 0 || isInitialism {
r = toASCIIUpper(r)
}
newstr = append(newstr, r)
}
}
return string(newstr)
}
// A GonicMapper that contains a list of common initialisms taken from golang/lint
var LintGonicMapper = GonicMapper{
"API": true,
"ASCII": true,
"CPU": true,
"CSS": true,
"DNS": true,
"EOF": true,
"GUID": true,
"HTML": true,
"HTTP": true,
"HTTPS": true,
"ID": true,
"IP": true,
"JSON": true,
"LHS": true,
"QPS": true,
"RAM": true,
"RHS": true,
"RPC": true,
"SLA": true,
"SMTP": true,
"SSH": true,
"TLS": true,
"TTL": true,
"UI": true,
"UID": true,
"UUID": true,
"URI": true,
"URL": true,
"UTF8": true,
"VM": true,
"XML": true,
"XSRF": true,
"XSS": true,
}
// provide prefix table name support
type PrefixMapper struct {
Mapper IMapper
Prefix string
}
func (mapper PrefixMapper) Obj2Table(name string) string {
return mapper.Prefix + mapper.Mapper.Obj2Table(name)
}
func (mapper PrefixMapper) Table2Obj(name string) string {
return mapper.Mapper.Table2Obj(name[len(mapper.Prefix):])
}
func NewPrefixMapper(mapper IMapper, prefix string) PrefixMapper {
return PrefixMapper{mapper, prefix}
}
// provide suffix table name support
type SuffixMapper struct {
Mapper IMapper
Suffix string
}
func (mapper SuffixMapper) Obj2Table(name string) string {
return mapper.Mapper.Obj2Table(name) + mapper.Suffix
}
func (mapper SuffixMapper) Table2Obj(name string) string {
return mapper.Mapper.Table2Obj(name[:len(name)-len(mapper.Suffix)])
}
func NewSuffixMapper(mapper IMapper, suffix string) SuffixMapper {
return SuffixMapper{mapper, suffix}
}