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Commit 9edabbe0 authored by Robert Griesemer's avatar Robert Griesemer
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go/token: replaced Files() with Iterate() 

- Use a faster closure-based iterator rather than a channel-based one.
- Otherwise: better code organization, but no other API changes.

R=r, r
CC=golang-dev
https://golang.org/cl/5557051
parent 6b346282
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Inline Side-by-side
Showing with 145 additions and 139 deletions
src/pkg/exp/types/check_test.go
View file @ 9edabbe0
......@@ -47,17 +47,17 @@ var tests = []struct {
var fset = token.NewFileSet()
// TODO(gri) This functionality should be in token.Fileset.
func getFile(filename string) *token.File {
for f := range fset.Files() {
func getFile(filename string) (file *token.File) {
fset.Iterate(func(f *token.File) bool {
if f.Name() == filename {
return f
file = f
return false // end iteration
}
}
return nil
return true
})
return file
}
// TODO(gri) This functionality should be in token.Fileset.
func getPos(filename string, offset int) token.Pos {
if f := getFile(filename); f != nil {
return f.Pos(offset)
......@@ -65,8 +65,6 @@ func getPos(filename string, offset int) token.Pos {
return token.NoPos
}
// TODO(gri) Need to revisit parser interface. We should be able to use parser.ParseFiles
// or a similar function instead.
func parseFiles(t *testing.T, testname string, filenames []string) (map[string]*ast.File, error) {
files := make(map[string]*ast.File)
var errors scanner.ErrorList
......@@ -145,8 +143,6 @@ func eliminate(t *testing.T, expected map[token.Pos]string, errors error) {
for _, error := range errors.(scanner.ErrorList) {
// error.Pos is a token.Position, but we want
// a token.Pos so we can do a map lookup
// TODO(gri) Need to move scanner.Errors over
// to use token.Pos and file set info.
pos := getPos(error.Pos.Filename, error.Pos.Offset)
if msg, found := expected[pos]; found {
// we expect a message at pos; check if it matches
......
src/pkg/go/token/position.go
View file @ 9edabbe0
......@@ -12,6 +12,9 @@ import (
"sync"
)
// -----------------------------------------------------------------------------
// Positions
// Position describes an arbitrary source position
// including the file, line, and column location.
// A Position is valid if the line number is > 0.
......@@ -81,84 +84,8 @@ func (p Pos) IsValid() bool {
return p != NoPos
}
func searchFiles(a []*File, x int) int {
return sort.Search(len(a), func(i int) bool { return a[i].base > x }) - 1
}
func (s *FileSet) file(p Pos) *File {
// common case: p is in last file touched
if f := s.last; f != nil && f.base <= int(p) && int(p) <= f.base+f.size {
return f
}
// p is not in last file touched - search all files
if i := searchFiles(s.files, int(p)); i >= 0 {
f := s.files[i]
// f.base <= int(p) by definition of searchFiles
if int(p) <= f.base+f.size {
s.last = f
return f
}
}
return nil
}
// File returns the file which contains the position p.
// If no such file is found (for instance for p == NoPos),
// the result is nil.
//
func (s *FileSet) File(p Pos) (f *File) {
if p != NoPos {
s.mutex.RLock()
f = s.file(p)
s.mutex.RUnlock()
}
return
}
func (f *File) position(p Pos) (pos Position) {
offset := int(p) - f.base
pos.Offset = offset
pos.Filename, pos.Line, pos.Column = f.info(offset)
return
}
// Position converts a Pos in the fileset into a general Position.
func (s *FileSet) Position(p Pos) (pos Position) {
if p != NoPos {
s.mutex.RLock()
if f := s.file(p); f != nil {
pos = f.position(p)
}
s.mutex.RUnlock()
}
return
}
// A lineInfo object describes alternative file and line number
// information (such as provided via a //line comment in a .go
// file) for a given file offset.
type lineInfo struct {
// fields are exported to make them accessible to gob
Offset int
Filename string
Line int
}
// AddLineInfo adds alternative file and line number information for
// a given file offset. The offset must be larger than the offset for
// the previously added alternative line info and smaller than the
// file size; otherwise the information is ignored.
//
// AddLineInfo is typically used to register alternative position
// information for //line filename:line comments in source files.
//
func (f *File) AddLineInfo(offset int, filename string, line int) {
f.set.mutex.Lock()
if i := len(f.infos); i == 0 || f.infos[i-1].Offset < offset && offset < f.size {
f.infos = append(f.infos, lineInfo{offset, filename, line})
}
f.set.mutex.Unlock()
}
// -----------------------------------------------------------------------------
// File
// A File is a handle for a file belonging to a FileSet.
// A File has a name, size, and line offset table.
......@@ -253,6 +180,32 @@ func (f *File) SetLinesForContent(content []byte) {
f.set.mutex.Unlock()
}
// A lineInfo object describes alternative file and line number
// information (such as provided via a //line comment in a .go
// file) for a given file offset.
type lineInfo struct {
// fields are exported to make them accessible to gob
Offset int
Filename string
Line int
}
// AddLineInfo adds alternative file and line number information for
// a given file offset. The offset must be larger than the offset for
// the previously added alternative line info and smaller than the
// file size; otherwise the information is ignored.
//
// AddLineInfo is typically used to register alternative position
// information for //line filename:line comments in source files.
//
func (f *File) AddLineInfo(offset int, filename string, line int) {
f.set.mutex.Lock()
if i := len(f.infos); i == 0 || f.infos[i-1].Offset < offset && offset < f.size {
f.infos = append(f.infos, lineInfo{offset, filename, line})
}
f.set.mutex.Unlock()
}
// Pos returns the Pos value for the given file offset;
// the offset must be <= f.Size().
// f.Pos(f.Offset(p)) == p.
......@@ -283,41 +236,6 @@ func (f *File) Line(p Pos) int {
return f.Position(p).Line
}
// Position returns the Position value for the given file position p;
// p must be a Pos value in that file or NoPos.
//
func (f *File) Position(p Pos) (pos Position) {
if p != NoPos {
if int(p) < f.base || int(p) > f.base+f.size {
panic("illegal Pos value")
}
pos = f.position(p)
}
return
}
func searchInts(a []int, x int) int {
// This function body is a manually inlined version of:
//
// return sort.Search(len(a), func(i int) bool { return a[i] > x }) - 1
//
// With better compiler optimizations, this may not be needed in the
// future, but at the moment this change improves the go/printer
// benchmark performance by ~30%. This has a direct impact on the
// speed of gofmt and thus seems worthwhile (2011-04-29).
i, j := 0, len(a)
for i < j {
h := i + (j-i)/2 // avoid overflow when computing h
// i ≤ h < j
if a[h] <= x {
i = h + 1
} else {
j = h
}
}
return i - 1
}
func searchLineInfos(a []lineInfo, x int) int {
return sort.Search(len(a), func(i int) bool { return a[i].Offset > x }) - 1
}
......@@ -341,6 +259,29 @@ func (f *File) info(offset int) (filename string, line, column int) {
return
}
func (f *File) position(p Pos) (pos Position) {
offset := int(p) - f.base
pos.Offset = offset
pos.Filename, pos.Line, pos.Column = f.info(offset)
return
}
// Position returns the Position value for the given file position p;
// p must be a Pos value in that file or NoPos.
//
func (f *File) Position(p Pos) (pos Position) {
if p != NoPos {
if int(p) < f.base || int(p) > f.base+f.size {
panic("illegal Pos value")
}
pos = f.position(p)
}
return
}
// -----------------------------------------------------------------------------
// FileSet
// A FileSet represents a set of source files.
// Methods of file sets are synchronized; multiple goroutines
// may invoke them concurrently.
......@@ -404,23 +345,91 @@ func (s *FileSet) AddFile(filename string, base, size int) *File {
return f
}
// Files returns the files added to the file set.
func (s *FileSet) Files() <-chan *File {
ch := make(chan *File)
go func() {
// Iterate calls f for the files in the file set in the order they were added
// until f returns false.
//
func (s *FileSet) Iterate(f func(*File) bool) {
for i := 0; ; i++ {
var f *File
var file *File
s.mutex.RLock()
if i < len(s.files) {
f = s.files[i]
file = s.files[i]
}
s.mutex.RUnlock()
if f == nil {
if file == nil || !f(file) {
break
}
ch <- f
}
close(ch)
}()
return ch
}
func searchFiles(a []*File, x int) int {
return sort.Search(len(a), func(i int) bool { return a[i].base > x }) - 1
}
func (s *FileSet) file(p Pos) *File {
// common case: p is in last file
if f := s.last; f != nil && f.base <= int(p) && int(p) <= f.base+f.size {
return f
}
// p is not in last file - search all files
if i := searchFiles(s.files, int(p)); i >= 0 {
f := s.files[i]
// f.base <= int(p) by definition of searchFiles
if int(p) <= f.base+f.size {
s.last = f
return f
}
}
return nil
}
// File returns the file that contains the position p.
// If no such file is found (for instance for p == NoPos),
// the result is nil.
//
func (s *FileSet) File(p Pos) (f *File) {
if p != NoPos {
s.mutex.RLock()
f = s.file(p)
s.mutex.RUnlock()
}
return
}
// Position converts a Pos in the fileset into a general Position.
func (s *FileSet) Position(p Pos) (pos Position) {
if p != NoPos {
s.mutex.RLock()
if f := s.file(p); f != nil {
pos = f.position(p)
}
s.mutex.RUnlock()
}
return
}
// -----------------------------------------------------------------------------
// Helper functions
func searchInts(a []int, x int) int {
// This function body is a manually inlined version of:
//
// return sort.Search(len(a), func(i int) bool { return a[i] > x }) - 1
//
// With better compiler optimizations, this may not be needed in the
// future, but at the moment this change improves the go/printer
// benchmark performance by ~30%. This has a direct impact on the
// speed of gofmt and thus seems worthwhile (2011-04-29).
// TODO(gri): Remove this when compilers have caught up.
i, j := 0, len(a)
for i < j {
h := i + (j-i)/2 // avoid overflow when computing h
// i ≤ h < j
if a[h] <= x {
i = h + 1
} else {
j = h
}
}
return i - 1
}
src/pkg/go/token/position_test.go
View file @ 9edabbe0
......@@ -167,12 +167,13 @@ func TestFiles(t *testing.T) {
for i, test := range tests {
fset.AddFile(test.filename, fset.Base(), test.size)
j := 0
for g := range fset.Files() {
if g.Name() != tests[j].filename {
t.Errorf("expected filename = %s; got %s", tests[j].filename, g.Name())
fset.Iterate(func(f *File) bool {
if f.Name() != tests[j].filename {
t.Errorf("expected filename = %s; got %s", tests[j].filename, f.Name())
}
j++
}
return true
})
if j != i+1 {
t.Errorf("expected %d files; got %d", i+1, j)
}
......
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