diff options
Diffstat (limited to 'vendor/github.com/containerd/continuity/fs/diff.go')
-rw-r--r-- | vendor/github.com/containerd/continuity/fs/diff.go | 326 |
1 files changed, 0 insertions, 326 deletions
diff --git a/vendor/github.com/containerd/continuity/fs/diff.go b/vendor/github.com/containerd/continuity/fs/diff.go deleted file mode 100644 index e64f9e73d..000000000 --- a/vendor/github.com/containerd/continuity/fs/diff.go +++ /dev/null @@ -1,326 +0,0 @@ -/* - Copyright The containerd Authors. - - Licensed under the Apache License, Version 2.0 (the "License"); - you may not use this file except in compliance with the License. - You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. -*/ - -package fs - -import ( - "context" - "os" - "path/filepath" - "strings" - - "golang.org/x/sync/errgroup" - - "github.com/sirupsen/logrus" -) - -// ChangeKind is the type of modification that -// a change is making. -type ChangeKind int - -const ( - // ChangeKindUnmodified represents an unmodified - // file - ChangeKindUnmodified = iota - - // ChangeKindAdd represents an addition of - // a file - ChangeKindAdd - - // ChangeKindModify represents a change to - // an existing file - ChangeKindModify - - // ChangeKindDelete represents a delete of - // a file - ChangeKindDelete -) - -func (k ChangeKind) String() string { - switch k { - case ChangeKindUnmodified: - return "unmodified" - case ChangeKindAdd: - return "add" - case ChangeKindModify: - return "modify" - case ChangeKindDelete: - return "delete" - default: - return "" - } -} - -// Change represents single change between a diff and its parent. -type Change struct { - Kind ChangeKind - Path string -} - -// ChangeFunc is the type of function called for each change -// computed during a directory changes calculation. -type ChangeFunc func(ChangeKind, string, os.FileInfo, error) error - -// Changes computes changes between two directories calling the -// given change function for each computed change. The first -// directory is intended to the base directory and second -// directory the changed directory. -// -// The change callback is called by the order of path names and -// should be appliable in that order. -// Due to this apply ordering, the following is true -// - Removed directory trees only create a single change for the root -// directory removed. Remaining changes are implied. -// - A directory which is modified to become a file will not have -// delete entries for sub-path items, their removal is implied -// by the removal of the parent directory. -// -// Opaque directories will not be treated specially and each file -// removed from the base directory will show up as a removal. -// -// File content comparisons will be done on files which have timestamps -// which may have been truncated. If either of the files being compared -// has a zero value nanosecond value, each byte will be compared for -// differences. If 2 files have the same seconds value but different -// nanosecond values where one of those values is zero, the files will -// be considered unchanged if the content is the same. This behavior -// is to account for timestamp truncation during archiving. -func Changes(ctx context.Context, a, b string, changeFn ChangeFunc) error { - if a == "" { - logrus.Debugf("Using single walk diff for %s", b) - return addDirChanges(ctx, changeFn, b) - } else if diffOptions := detectDirDiff(b, a); diffOptions != nil { - logrus.Debugf("Using single walk diff for %s from %s", diffOptions.diffDir, a) - return diffDirChanges(ctx, changeFn, a, diffOptions) - } - - logrus.Debugf("Using double walk diff for %s from %s", b, a) - return doubleWalkDiff(ctx, changeFn, a, b) -} - -func addDirChanges(ctx context.Context, changeFn ChangeFunc, root string) error { - return filepath.Walk(root, func(path string, f os.FileInfo, err error) error { - if err != nil { - return err - } - - // Rebase path - path, err = filepath.Rel(root, path) - if err != nil { - return err - } - - path = filepath.Join(string(os.PathSeparator), path) - - // Skip root - if path == string(os.PathSeparator) { - return nil - } - - return changeFn(ChangeKindAdd, path, f, nil) - }) -} - -// diffDirOptions is used when the diff can be directly calculated from -// a diff directory to its base, without walking both trees. -type diffDirOptions struct { - diffDir string - skipChange func(string) (bool, error) - deleteChange func(string, string, os.FileInfo) (string, error) -} - -// diffDirChanges walks the diff directory and compares changes against the base. -func diffDirChanges(ctx context.Context, changeFn ChangeFunc, base string, o *diffDirOptions) error { - changedDirs := make(map[string]struct{}) - return filepath.Walk(o.diffDir, func(path string, f os.FileInfo, err error) error { - if err != nil { - return err - } - - // Rebase path - path, err = filepath.Rel(o.diffDir, path) - if err != nil { - return err - } - - path = filepath.Join(string(os.PathSeparator), path) - - // Skip root - if path == string(os.PathSeparator) { - return nil - } - - // TODO: handle opaqueness, start new double walker at this - // location to get deletes, and skip tree in single walker - - if o.skipChange != nil { - if skip, err := o.skipChange(path); skip { - return err - } - } - - var kind ChangeKind - - deletedFile, err := o.deleteChange(o.diffDir, path, f) - if err != nil { - return err - } - - // Find out what kind of modification happened - if deletedFile != "" { - path = deletedFile - kind = ChangeKindDelete - f = nil - } else { - // Otherwise, the file was added - kind = ChangeKindAdd - - // ...Unless it already existed in a base, in which case, it's a modification - stat, err := os.Stat(filepath.Join(base, path)) - if err != nil && !os.IsNotExist(err) { - return err - } - if err == nil { - // The file existed in the base, so that's a modification - - // However, if it's a directory, maybe it wasn't actually modified. - // If you modify /foo/bar/baz, then /foo will be part of the changed files only because it's the parent of bar - if stat.IsDir() && f.IsDir() { - if f.Size() == stat.Size() && f.Mode() == stat.Mode() && sameFsTime(f.ModTime(), stat.ModTime()) { - // Both directories are the same, don't record the change - return nil - } - } - kind = ChangeKindModify - } - } - - // If /foo/bar/file.txt is modified, then /foo/bar must be part of the changed files. - // This block is here to ensure the change is recorded even if the - // modify time, mode and size of the parent directory in the rw and ro layers are all equal. - // Check https://github.com/docker/docker/pull/13590 for details. - if f.IsDir() { - changedDirs[path] = struct{}{} - } - if kind == ChangeKindAdd || kind == ChangeKindDelete { - parent := filepath.Dir(path) - if _, ok := changedDirs[parent]; !ok && parent != "/" { - pi, err := os.Stat(filepath.Join(o.diffDir, parent)) - if err := changeFn(ChangeKindModify, parent, pi, err); err != nil { - return err - } - changedDirs[parent] = struct{}{} - } - } - - return changeFn(kind, path, f, nil) - }) -} - -// doubleWalkDiff walks both directories to create a diff -func doubleWalkDiff(ctx context.Context, changeFn ChangeFunc, a, b string) (err error) { - g, ctx := errgroup.WithContext(ctx) - - var ( - c1 = make(chan *currentPath) - c2 = make(chan *currentPath) - - f1, f2 *currentPath - rmdir string - ) - g.Go(func() error { - defer close(c1) - return pathWalk(ctx, a, c1) - }) - g.Go(func() error { - defer close(c2) - return pathWalk(ctx, b, c2) - }) - g.Go(func() error { - for c1 != nil || c2 != nil { - if f1 == nil && c1 != nil { - f1, err = nextPath(ctx, c1) - if err != nil { - return err - } - if f1 == nil { - c1 = nil - } - } - - if f2 == nil && c2 != nil { - f2, err = nextPath(ctx, c2) - if err != nil { - return err - } - if f2 == nil { - c2 = nil - } - } - if f1 == nil && f2 == nil { - continue - } - - var f os.FileInfo - k, p := pathChange(f1, f2) - switch k { - case ChangeKindAdd: - if rmdir != "" { - rmdir = "" - } - f = f2.f - f2 = nil - case ChangeKindDelete: - // Check if this file is already removed by being - // under of a removed directory - if rmdir != "" && strings.HasPrefix(f1.path, rmdir) { - f1 = nil - continue - } else if f1.f.IsDir() { - rmdir = f1.path + string(os.PathSeparator) - } else if rmdir != "" { - rmdir = "" - } - f1 = nil - case ChangeKindModify: - same, err := sameFile(f1, f2) - if err != nil { - return err - } - if f1.f.IsDir() && !f2.f.IsDir() { - rmdir = f1.path + string(os.PathSeparator) - } else if rmdir != "" { - rmdir = "" - } - f = f2.f - f1 = nil - f2 = nil - if same { - if !isLinked(f) { - continue - } - k = ChangeKindUnmodified - } - } - if err := changeFn(k, p, f, nil); err != nil { - return err - } - } - return nil - }) - - return g.Wait() -} |