distribution/registry/storage/catalog.go
Edgar Lee 379312c148 Stop ErrFinishedWalk from escaping from Repositories walk
Signed-off-by: Edgar Lee <edgar.lee@docker.com>
2016-08-05 17:21:48 -07:00

122 lines
2.7 KiB
Go

package storage
import (
"errors"
"io"
"path"
"strings"
"github.com/docker/distribution/context"
"github.com/docker/distribution/registry/storage/driver"
)
// Returns a list, or partial list, of repositories in the registry.
// Because it's a quite expensive operation, it should only be used when building up
// an initial set of repositories.
func (reg *registry) Repositories(ctx context.Context, repos []string, last string) (n int, err error) {
var foundRepos []string
if len(repos) == 0 {
return 0, errors.New("no space in slice")
}
root, err := pathFor(repositoriesRootPathSpec{})
if err != nil {
return 0, err
}
// errFinishedWalk signals an early exit to the walk when the current query
// is satisfied.
errFinishedWalk := errors.New("finished walk")
err = Walk(ctx, reg.blobStore.driver, root, func(fileInfo driver.FileInfo) error {
filePath := fileInfo.Path()
// lop the base path off
repoPath := filePath[len(root)+1:]
_, file := path.Split(repoPath)
if file == "_layers" {
repoPath = strings.TrimSuffix(repoPath, "/_layers")
if pathGreaterThan(repoPath, last) {
foundRepos = append(foundRepos, repoPath)
}
return ErrSkipDir
} else if strings.HasPrefix(file, "_") {
return ErrSkipDir
}
// if we've filled our array, no need to walk any further
if len(foundRepos) == len(repos) {
return errFinishedWalk
}
return nil
})
n = copy(repos, foundRepos)
switch err {
case nil:
// nil means that we completed walk and didn't fill buffer. No more
// records are available.
err = io.EOF
case errFinishedWalk:
// more records are available.
err = nil
}
return n, err
}
// Enumerate applies ingester to each repository
func (reg *registry) Enumerate(ctx context.Context, ingester func(string) error) error {
repoNameBuffer := make([]string, 100)
var last string
for {
n, err := reg.Repositories(ctx, repoNameBuffer, last)
if err != nil && err != io.EOF {
return err
}
if n == 0 {
break
}
last = repoNameBuffer[n-1]
for i := 0; i < n; i++ {
repoName := repoNameBuffer[i]
err = ingester(repoName)
if err != nil {
return err
}
}
if err == io.EOF {
break
}
}
return nil
}
func pathGreaterThan(pathX, pathY string) (b bool) {
splitPathX := strings.SplitN(pathX, "/", 2)
splitPathY := strings.SplitN(pathY, "/", 2)
if splitPathX[0] == splitPathY[0] {
if len(splitPathX) == 1 && len(splitPathY) == 1 {
return false
} else if len(splitPathX) == 1 && len(splitPathY) != 1 {
return false
} else if len(splitPathX) != 1 && len(splitPathY) == 1 {
return true
}
return pathGreaterThan(splitPathX[1], splitPathY[1])
}
return splitPathX[0] > splitPathY[0]
}