Download link for 2.6.2 release

[goredo.git] / tgt.go

diff --git a/tgt.go b/tgt.go
index 8e454f2c94a884dc85a826e47ba570eaf705c362..a8525ed426aa2aa374959b18a8ca3a1e507f2753 100644 (file)
--- a/tgt.go
+++ b/tgt.go
@@ -1,11 +1,30 @@
+// goredo -- djb's redo implementation on pure Go
+// Copyright (C) 2020-2024 Sergey Matveev <stargrave@stargrave.org>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, version 3 of the License.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 package main
 
 import (
        "path"
        "path/filepath"
+       "sync"
 )
 
-var TgtCache = make(map[string]*Tgt)
+var (
+       TgtCache  = make(map[string]*Tgt)
+       TgtCacheM sync.RWMutex
+)
 
 func mustAbs(pth string) string {
        pth, err := filepath.Abs(pth)
@@ -27,45 +46,44 @@ func cwdMustRel(paths ...string) string {
        return mustRel(Cwd, path.Join(paths...))
 }
 
+func pathSplit(a string) (h, t string) {
+       h, t = path.Split(a)
+       if len(h) > 1 {
+               h = h[:len(h)-1]
+       }
+       return
+}
+
 type Tgt struct {
-       // a/h/t resemble zsh'es :a, :h, :t modifiers
        a   string // absolute path
-       h   string // head of the path, directory
-       t   string // tail of the path, only name
        rel string // relative to Cwd
        dep string // path to dependency file
 }
 
 func NewTgt(tgt string) *Tgt {
        a := mustAbs(tgt)
-       if TgtCache != nil {
-               if t := TgtCache[a]; t != nil {
-                       return t
-               }
+       TgtCacheM.RLock()
+       cached := TgtCache[a]
+       TgtCacheM.RUnlock()
+       if cached != nil {
+               return cached
        }
-       t := Tgt{a: a}
-       t.h, t.t = path.Split(t.a)
-       if len(t.h) > 1 {
-               t.h = t.h[:len(t.h)-1]
+       h, t := pathSplit(a)
+       res := Tgt{
+               a:   a,
+               rel: mustRel(Cwd, a),
+               dep: path.Join(h, RedoDir, t+DepSuffix),
        }
-       t.rel = mustRel(Cwd, t.a)
-       if TgtCache != nil {
-               TgtCache[a] = &t
-       }
-       return &t
+       TgtCacheM.Lock()
+       TgtCache[a] = &res
+       TgtCacheM.Unlock()
+       return &res
 }
 
 func (tgt *Tgt) String() string {
        return tgt.rel
 }
 
-func (tgt *Tgt) Dep() string {
-       if tgt.dep == "" {
-               tgt.dep = path.Join(tgt.h, RedoDir, tgt.t+DepSuffix)
-       }
-       return tgt.dep
-}
-
 func (tgt *Tgt) RelTo(cwd string) string {
        return mustRel(cwd, tgt.a)
 }