Use more efficient ReadDir instead of Readdir

[goredo.git] / targets.go

diff --git a/targets.go b/targets.go
index 602fd942abbf16b1741df0c946167f06aa703877..dca27f4e7880626a383b56852942f5435e890997 100644 (file)
--- a/targets.go
+++ b/targets.go
@@ -1,6 +1,6 @@
 /*
 goredo -- djb's redo implementation on pure Go
-Copyright (C) 2020-2021 Sergey Matveev <stargrave@stargrave.org>
+Copyright (C) 2020-2023 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
@@ -25,55 +25,77 @@ import (
        "strings"
 )
 
-func targetsWalker(root string) ([]string, error) {
+func targetsCollect(root string, tgts map[string]struct{}) error {
        root, err := filepath.Abs(root)
        if err != nil {
                panic(err)
        }
        dir, err := os.Open(root)
        if err != nil {
-               return nil, err
+               return err
        }
        defer dir.Close()
-       tgts := make([]string, 0, 1<<10)
        for {
-               fis, err := dir.Readdir(1 << 10)
+               entries, err := dir.ReadDir(1 << 10)
                if err != nil {
                        if err == io.EOF {
                                break
                        }
-                       return tgts, err
+                       return err
                }
-               for _, fi := range fis {
-                       if !fi.IsDir() {
+               for _, entry := range entries {
+                       if !entry.IsDir() {
                                continue
                        }
-                       pth := path.Join(root, fi.Name())
-                       if fi.Name() == RedoDir {
+                       pth := path.Join(root, entry.Name())
+                       if entry.Name() == RedoDir {
                                redoDir, err := os.Open(pth)
                                if err != nil {
-                                       return tgts, err
+                                       return err
                                }
-                               redoFis, err := redoDir.Readdir(0)
+                               redoEntries, err := redoDir.ReadDir(0)
+                               redoDir.Close()
                                if err != nil {
-                                       return tgts, err
+                                       return err
                                }
-                               for _, redoFi := range redoFis {
-                                       name := redoFi.Name()
+                               for _, redoEntry := range redoEntries {
+                                       name := redoEntry.Name()
                                        if strings.HasSuffix(name, DepSuffix) {
                                                name = cwdMustRel(root, name)
-                                               tgts = append(tgts, name[:len(name)-len(DepSuffix)])
+                                               tgts[name[:len(name)-len(DepSuffix)]] = struct{}{}
                                        }
                                }
-                               redoDir.Close()
                        } else {
-                               subTgts, err := targetsWalker(pth)
-                               tgts = append(tgts, subTgts...)
-                               if err != nil {
-                                       return tgts, err
+                               if err = targetsCollect(pth, tgts); err != nil {
+                                       return err
                                }
                        }
                }
        }
-       return tgts, dir.Close()
+       return nil
+}
+
+func targetsWalker(tgts []string) ([]string, error) {
+       tgtsMap := map[string]struct{}{}
+       for _, tgt := range tgts {
+               if err := targetsCollect(tgt, tgtsMap); err != nil {
+                       return nil, err
+               }
+       }
+       tgts = make([]string, 0, len(tgtsMap))
+       for tgt := range tgtsMap {
+               tgts = append(tgts, tgt)
+       }
+       return tgts, nil
+}
+
+func collectWholeDeps(
+       tgts map[string]struct{},
+       deps map[string]map[string]struct{},
+       seen map[string]struct{},
+) {
+       for tgt := range tgts {
+               seen[tgt] = struct{}{}
+               collectWholeDeps(deps[tgt], deps, seen)
+       }
 }