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package server
import (
"regexp"
"sync"
)
func init() {
newCmd(varGet, "var", "get")
newCmd(varSet, "var", "set")
newCmd(varDel, "var", "del")
newCmd(varShow, "var", "show")
newCmd(varClear, "var", "clear")
}
type env struct {
m map[string]string
sync.Mutex
}
const varNamePattern = "[a-zA-Z][a-zA-Z0-9]*"
var isValidVarName = regexp.MustCompile("^" + varNamePattern + "$").MatchString
var varTokenRe = regexp.MustCompile("%" + varNamePattern)
func (e *env) get(key string) (string, bool) {
e.Lock()
defer e.Unlock()
v, ok := e.m[key]
return v, ok
}
func (e *env) set(key string, value string) {
e.Lock()
defer e.Unlock()
if e.m == nil {
e.m = make(map[string]string)
}
e.m[key] = value
}
func (e *env) del(key string) bool {
e.Lock()
defer e.Unlock()
if e.m == nil {
return false
}
if _, ok := e.m[key]; !ok {
return false
}
delete(e.m, key)
return true
}
func (e *env) each(f func (string, string) bool) {
e.Lock()
defer e.Unlock()
for k, v := range e.m {
if !f(k, v) {
break
}
}
}
func (e *env) clear() {
e.Lock()
defer e.Unlock()
e.m = nil
}
func varGet(r *request) {
r.expect(1)
if v, ok := r.c.s.env.get(r.args[0]); ok {
r.Print(v)
} else {
r.Fatal("no such variable")
}
}
func varSet(r *request) {
r.expect(2)
if !isValidVarName(r.args[0]) {
r.Fatal("bad variable name")
}
r.c.s.env.set(r.args[0], r.args[1])
}
func varDel(r *request) {
r.expect(1)
if !r.c.s.env.del(r.args[0]) {
r.Fatal("no such variable")
}
}
func varShow(r *request) {
r.c.s.env.each(func (k string, v string) bool {
r.Println(k, v)
return true
})
}
func varClear(r *request) {
r.c.s.env.clear()
}
|
