refactor: move walk util methods into struct

walk/walk.go

@@ -115,7 +115,7 @@ func Walk(c *config.Config, cexts []config.Configurer, dirs []string, mode Mode,
  }
  }
 
- updateRels := buildUpdateRelMap(c.RepoRoot, dirs)
+ updateRels := NewUpdateFilter(c.RepoRoot, dirs, mode)
 
  var visit func(*config.Config, string, string, bool)
  visit = func(c *config.Config, dir, rel string, updateParent bool) {
@@ -162,32 +162,38 @@ func Walk(c *config.Config, cexts []config.Configurer, dirs []string, mode Mode,
  }
  }
 
- shouldUpdate := shouldUpdate(rel, mode, updateParent, updateRels)
+ shouldUpdate := updateRels.shouldUpdate(rel, updateParent)
  for _, sub := range subdirs {
- if subRel := path.Join(rel, sub); shouldVisit(subRel, mode, shouldUpdate, updateRels) {
+ if subRel := path.Join(rel, sub); updateRels.shouldVisit(subRel, shouldUpdate) {
  visit(c, filepath.Join(dir, sub), subRel, shouldUpdate)
  }
  }
 
  update := !haveError && !wc.ignore && shouldUpdate
- if shouldCall(rel, mode, updateParent, updateRels) {
+ if updateRels.shouldCall(rel, updateParent) {
  genFiles := findGenFiles(wc, f)
  wf(dir, rel, c, update, f, subdirs, regularFiles, genFiles)
  }
  }
  visit(c, c.RepoRoot, "", false)
 }
 
-// buildUpdateRelMap builds a table of prefixes, used to determine which
+// An updateFilter tracks which directories need to be updated
+type updateFilter struct {
+ mode Mode
+
+ // map from slash-separated paths relative to the
+ // root directory ("" for the root itself) to a boolean indicating whether
+ // the directory should be updated.
+ updateRels map[string]bool
+}
+
+// NewUpdateFilter builds a table of prefixes, used to determine which
 // directories to update and visit.
 //
 // root and dirs must be absolute, canonical file paths. Each entry in dirs
 // must be a subdirectory of root. The caller is responsible for checking this.
-//
-// buildUpdateRelMap returns a map from slash-separated paths relative to the
-// root directory ("" for the root itself) to a boolean indicating whether
-// the directory should be updated.
-func buildUpdateRelMap(root string, dirs []string) map[string]bool {
+func NewUpdateFilter(root string, dirs []string, mode Mode) *updateFilter {
  relMap := make(map[string]bool)
  for _, dir := range dirs {
  rel, _ := filepath.Rel(root, dir)
@@ -210,42 +216,42 @@ func buildUpdateRelMap(root string, dirs []string) map[string]bool {
  i = next + 1
  }
  }
- return relMap
+ return &updateFilter{mode, relMap}
 }
 
 // shouldCall returns true if Walk should call the callback in the
 // directory rel.
-func shouldCall(rel string, mode Mode, updateParent bool, updateRels map[string]bool) bool {
- switch mode {
+func (u *updateFilter) shouldCall(rel string, updateParent bool) bool {
+ switch u.mode {
  case VisitAllUpdateSubdirsMode, VisitAllUpdateDirsMode:
  return true
  case UpdateSubdirsMode:
- return updateParent || updateRels[rel]
+ return updateParent || u.updateRels[rel]
  default: // UpdateDirsMode
- return updateRels[rel]
+ return u.updateRels[rel]
  }
 }
 
 // shouldUpdate returns true if Walk should pass true to the callback's update
 // parameter in the directory rel. This indicates the build file should be
 // updated.
-func shouldUpdate(rel string, mode Mode, updateParent bool, updateRels map[string]bool) bool {
- if (mode == VisitAllUpdateSubdirsMode || mode == UpdateSubdirsMode) && updateParent {
+func (u *updateFilter) shouldUpdate(rel string, updateParent bool) bool {
+ if (u.mode == VisitAllUpdateSubdirsMode || u.mode == UpdateSubdirsMode) && updateParent {
  return true
  }
- return updateRels[rel]
+ return u.updateRels[rel]
 }
 
 // shouldVisit returns true if Walk should visit the subdirectory rel.
-func shouldVisit(rel string, mode Mode, updateParent bool, updateRels map[string]bool) bool {
- switch mode {
+func (u *updateFilter) shouldVisit(rel string, updateParent bool) bool {
+ switch u.mode {
  case VisitAllUpdateSubdirsMode, VisitAllUpdateDirsMode:
  return true
  case UpdateSubdirsMode:
- _, ok := updateRels[rel]
+ _, ok := u.updateRels[rel]
  return ok || updateParent
  default: // UpdateDirsMode
- _, ok := updateRels[rel]
+ _, ok := u.updateRels[rel]
  return ok
  }
 }