1 files changed, 114 insertions, 0 deletions
diff --git a/pkg/server/env/env.go b/pkg/server/env/env.go
new file mode 100644
index 0000000..ab47ae8
--- /dev/null
+++ b/pkg/server/env/env.go
@@ -0,0 +1,114 @@
+package env
+
+import (
+	"errors"
+	"regexp"
+	"sync"
+)
+
+type env struct {
+	m map[string]string
+	sync.Mutex
+}
+
+type Env struct {
+	*env
+}
+
+const namePattern = "[a-zA-Z][a-zA-Z0-9]*"
+var isNamePattern = regexp.MustCompile("^" + namePattern + "$").MatchString
+var namePatternRe = regexp.MustCompile("@" + namePattern)
+
+var errBadVariable = errors.New("bad variable name")
+
+func New() Env {
+	return Env{new(env)}
+}
+
+func (e *env) Find(key string) (string, bool) {
+	e.Lock()
+	defer e.Unlock()
+
+	v, ok := e.m[key]
+
+	return v, ok
+}
+
+func (e *env) Get(key string) string {
+	v, _ := e.Find(key)
+	return v
+}
+
+func (e *env) Set(key string, value string) error {
+	if !isNamePattern(key) {
+		return errBadVariable
+	}
+
+	e.Lock()
+	defer e.Unlock()
+
+	if e.m == nil {
+		e.m = make(map[string]string)
+	}
+
+	e.m[key] = value
+
+	return nil
+}
+
+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 (e *env) Eval(s string) string {
+	e.Lock()
+	defer e.Unlock()
+
+	repl := func (v string) string {
+		if v, ok := e.m[v[1:]]; ok {
+			return v
+		}
+		return ""
+	}
+
+	for {
+		if t := namePatternRe.ReplaceAllStringFunc(s, repl); t == s {
+			break
+		} else {
+			s = t
+		}
+	}
+
+	return s
+}