Merge pull request #1227 from stevvooe/walk-sorted

storage: enforce sorted traversal during Walk
This commit is contained in:
Stephen Day 2015-12-02 18:37:44 -08:00
commit b66bb1287c
2 changed files with 50 additions and 11 deletions

View file

@ -3,6 +3,7 @@ package storage
import (
"errors"
"fmt"
"sort"
"github.com/docker/distribution/context"
storageDriver "github.com/docker/distribution/registry/storage/driver"
@ -26,7 +27,12 @@ func Walk(ctx context.Context, driver storageDriver.StorageDriver, from string,
if err != nil {
return err
}
sort.Stable(sort.StringSlice(children))
for _, child := range children {
// TODO(stevvooe): Calling driver.Stat for every entry is quite
// expensive when running against backends with a slow Stat
// implementation, such as s3. This is very likely a serious
// performance bottleneck.
fileInfo, err := driver.Stat(ctx, child)
if err != nil {
return err
@ -38,7 +44,9 @@ func Walk(ctx context.Context, driver storageDriver.StorageDriver, from string,
}
if fileInfo.IsDir() && !skipDir {
Walk(ctx, driver, child, f)
if err := Walk(ctx, driver, child, f); err != nil {
return err
}
}
}
return nil

View file

@ -2,6 +2,7 @@ package storage
import (
"fmt"
"sort"
"testing"
"github.com/docker/distribution/context"
@ -11,14 +12,7 @@ import (
func testFS(t *testing.T) (driver.StorageDriver, map[string]string, context.Context) {
d := inmemory.New()
c := []byte("")
ctx := context.Background()
if err := d.PutContent(ctx, "/a/b/c/d", c); err != nil {
t.Fatalf("Unable to put to inmemory fs")
}
if err := d.PutContent(ctx, "/a/b/c/e", c); err != nil {
t.Fatalf("Unable to put to inmemory fs")
}
expected := map[string]string{
"/a": "dir",
@ -26,6 +20,22 @@ func testFS(t *testing.T) (driver.StorageDriver, map[string]string, context.Cont
"/a/b/c": "dir",
"/a/b/c/d": "file",
"/a/b/c/e": "file",
"/a/b/f": "dir",
"/a/b/f/g": "file",
"/a/b/f/h": "file",
"/a/b/f/i": "file",
"/z": "dir",
"/z/y": "file",
}
for p, typ := range expected {
if typ != "file" {
continue
}
if err := d.PutContent(ctx, p, []byte(p)); err != nil {
t.Fatalf("unable to put content into fixture: %v", err)
}
}
return d, expected, ctx
@ -41,20 +51,27 @@ func TestWalkErrors(t *testing.T) {
t.Error("Expected invalid root err")
}
errEarlyExpected := fmt.Errorf("Early termination")
err = Walk(ctx, d, "/", func(fileInfo driver.FileInfo) error {
// error on the 2nd file
if fileInfo.Path() == "/a/b" {
return fmt.Errorf("Early termination")
return errEarlyExpected
}
delete(expected, fileInfo.Path())
return nil
})
if len(expected) != fileCount-1 {
t.Error("Walk failed to terminate with error")
}
if err != nil {
if err != errEarlyExpected {
if err == nil {
t.Fatalf("expected an error due to early termination")
} else {
t.Error(err.Error())
}
}
err = Walk(ctx, d, "/nonexistant", func(fileInfo driver.FileInfo) error {
return nil
@ -67,6 +84,7 @@ func TestWalkErrors(t *testing.T) {
func TestWalk(t *testing.T) {
d, expected, ctx := testFS(t)
var traversed []string
err := Walk(ctx, d, "/", func(fileInfo driver.FileInfo) error {
filePath := fileInfo.Path()
filetype, ok := expected[filePath]
@ -82,13 +100,26 @@ func TestWalk(t *testing.T) {
if filetype != "file" {
t.Errorf("Unexpected file type: %q", filePath)
}
// each file has its own path as the contents. If the length
// doesn't match the path length, fail.
if fileInfo.Size() != int64(len(fileInfo.Path())) {
t.Fatalf("unexpected size for %q: %v != %v",
fileInfo.Path(), fileInfo.Size(), len(fileInfo.Path()))
}
}
delete(expected, filePath)
traversed = append(traversed, filePath)
return nil
})
if len(expected) > 0 {
t.Errorf("Missed files in walk: %q", expected)
}
if !sort.StringsAreSorted(traversed) {
t.Errorf("result should be sorted: %v", traversed)
}
if err != nil {
t.Fatalf(err.Error())
}