forked from TrueCloudLab/distribution
93f92498ce
Signed-off-by: Stephen J Day <stephen.day@docker.com>
59 lines
1.7 KiB
Go
59 lines
1.7 KiB
Go
package storage
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import (
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"errors"
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"fmt"
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"sort"
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"github.com/docker/distribution/context"
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storageDriver "github.com/docker/distribution/registry/storage/driver"
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)
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// ErrSkipDir is used as a return value from onFileFunc to indicate that
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// the directory named in the call is to be skipped. It is not returned
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// as an error by any function.
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var ErrSkipDir = errors.New("skip this directory")
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// WalkFn is called once per file by Walk
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// If the returned error is ErrSkipDir and fileInfo refers
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// to a directory, the directory will not be entered and Walk
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// will continue the traversal. Otherwise Walk will return
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type WalkFn func(fileInfo storageDriver.FileInfo) error
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// Walk traverses a filesystem defined within driver, starting
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// from the given path, calling f on each file
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func Walk(ctx context.Context, driver storageDriver.StorageDriver, from string, f WalkFn) error {
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children, err := driver.List(ctx, from)
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if err != nil {
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return err
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}
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sort.Stable(sort.StringSlice(children))
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for _, child := range children {
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// TODO(stevvooe): Calling driver.Stat for every entry is quite
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// expensive when running against backends with a slow Stat
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// implementation, such as s3. This is very likely a serious
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// performance bottleneck.
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fileInfo, err := driver.Stat(ctx, child)
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if err != nil {
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return err
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}
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err = f(fileInfo)
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skipDir := (err == ErrSkipDir)
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if err != nil && !skipDir {
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return err
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}
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if fileInfo.IsDir() && !skipDir {
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if err := Walk(ctx, driver, child, f); err != nil {
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return err
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}
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}
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}
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return nil
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}
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// pushError formats an error type given a path and an error
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// and pushes it to a slice of errors
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func pushError(errors []error, path string, err error) []error {
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return append(errors, fmt.Errorf("%s: %s", path, err))
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}
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