Bump github.com/containers/storage@d10d868

Update the vendored copy of github.com/containers/storage to revision
d10d8680af74070b362637408a7fe28c4b1f1eff.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

vendor/github.com/containers/storage/pkg/truncindex/truncindex.go

@@ -0,0 +1,137 @@
+// Package truncindex provides a general 'index tree', used by Docker
+// in order to be able to reference containers by only a few unambiguous
+// characters of their id.
+package truncindex
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"sync"
+
+	"github.com/tchap/go-patricia/patricia"
+)
+
+var (
+	// ErrEmptyPrefix is an error returned if the prefix was empty.
+	ErrEmptyPrefix = errors.New("Prefix can't be empty")
+
+	// ErrIllegalChar is returned when a space is in the ID
+	ErrIllegalChar = errors.New("illegal character: ' '")
+
+	// ErrNotExist is returned when ID or its prefix not found in index.
+	ErrNotExist = errors.New("ID does not exist")
+)
+
+// ErrAmbiguousPrefix is returned if the prefix was ambiguous
+// (multiple ids for the prefix).
+type ErrAmbiguousPrefix struct {
+	prefix string
+}
+
+func (e ErrAmbiguousPrefix) Error() string {
+	return fmt.Sprintf("Multiple IDs found with provided prefix: %s", e.prefix)
+}
+
+// TruncIndex allows the retrieval of string identifiers by any of their unique prefixes.
+// This is used to retrieve image and container IDs by more convenient shorthand prefixes.
+type TruncIndex struct {
+	sync.RWMutex
+	trie *patricia.Trie
+	ids  map[string]struct{}
+}
+
+// NewTruncIndex creates a new TruncIndex and initializes with a list of IDs.
+func NewTruncIndex(ids []string) (idx *TruncIndex) {
+	idx = &TruncIndex{
+		ids: make(map[string]struct{}),
+
+		// Change patricia max prefix per node length,
+		// because our len(ID) always 64
+		trie: patricia.NewTrie(patricia.MaxPrefixPerNode(64)),
+	}
+	for _, id := range ids {
+		idx.addID(id)
+	}
+	return
+}
+
+func (idx *TruncIndex) addID(id string) error {
+	if strings.Contains(id, " ") {
+		return ErrIllegalChar
+	}
+	if id == "" {
+		return ErrEmptyPrefix
+	}
+	if _, exists := idx.ids[id]; exists {
+		return fmt.Errorf("id already exists: '%s'", id)
+	}
+	idx.ids[id] = struct{}{}
+	if inserted := idx.trie.Insert(patricia.Prefix(id), struct{}{}); !inserted {
+		return fmt.Errorf("failed to insert id: %s", id)
+	}
+	return nil
+}
+
+// Add adds a new ID to the TruncIndex.
+func (idx *TruncIndex) Add(id string) error {
+	idx.Lock()
+	defer idx.Unlock()
+	if err := idx.addID(id); err != nil {
+		return err
+	}
+	return nil
+}
+
+// Delete removes an ID from the TruncIndex. If there are multiple IDs
+// with the given prefix, an error is thrown.
+func (idx *TruncIndex) Delete(id string) error {
+	idx.Lock()
+	defer idx.Unlock()
+	if _, exists := idx.ids[id]; !exists || id == "" {
+		return fmt.Errorf("no such id: '%s'", id)
+	}
+	delete(idx.ids, id)
+	if deleted := idx.trie.Delete(patricia.Prefix(id)); !deleted {
+		return fmt.Errorf("no such id: '%s'", id)
+	}
+	return nil
+}
+
+// Get retrieves an ID from the TruncIndex. If there are multiple IDs
+// with the given prefix, an error is thrown.
+func (idx *TruncIndex) Get(s string) (string, error) {
+	if s == "" {
+		return "", ErrEmptyPrefix
+	}
+	var (
+		id string
+	)
+	subTreeVisitFunc := func(prefix patricia.Prefix, item patricia.Item) error {
+		if id != "" {
+			// we haven't found the ID if there are two or more IDs
+			id = ""
+			return ErrAmbiguousPrefix{prefix: string(prefix)}
+		}
+		id = string(prefix)
+		return nil
+	}
+
+	idx.RLock()
+	defer idx.RUnlock()
+	if err := idx.trie.VisitSubtree(patricia.Prefix(s), subTreeVisitFunc); err != nil {
+		return "", err
+	}
+	if id != "" {
+		return id, nil
+	}
+	return "", ErrNotExist
+}
+
+// Iterate iterates over all stored IDs, and passes each of them to the given handler.
+func (idx *TruncIndex) Iterate(handler func(id string)) {
+	idx.trie.Visit(func(prefix patricia.Prefix, item patricia.Item) error {
+		handler(string(prefix))
+		return nil
+	})
+}