Merge pull request #214 from NyaaaWhatsUpDoc/improvement/update-storage-library

add git.iim.gay/grufwub/go-store for storage backend, replacing blob.Storage

1 files changed, 64 insertions, 0 deletions

diff --git a/vendor/git.iim.gay/grufwub/go-store/kv/iterator.go b/vendor/git.iim.gay/grufwub/go-store/kv/iterator.go
new file mode 100644
index 000000000..f2c68b87c
--- /dev/null
+++ b/vendor/git.iim.gay/grufwub/go-store/kv/iterator.go
@@ -0,0 +1,64 @@
+package kv
+
+import (
+	"git.iim.gay/grufwub/go-errors"
+	"git.iim.gay/grufwub/go-store/storage"
+)
+
+var ErrIteratorClosed = errors.Define("store/kv: iterator closed")
+
+// KVIterator provides a read-only iterator to all the key-value
+// pairs in a KVStore. While the iterator is open the store is read
+// locked, you MUST release the iterator when you are finished with
+// it.
+//
+// Please note:
+// - individual iterators are NOT concurrency safe, though it is safe to
+// have multiple iterators running concurrently
+type KVIterator struct {
+	store   *KVStore // store is the linked KVStore
+	entries []storage.StorageEntry
+	index   int
+	key     string
+	onClose func()
+}
+
+// Next attempts to set the next key-value pair, the
+// return value is if there was another pair remaining
+func (i *KVIterator) Next() bool {
+	next := i.index + 1
+	if next >= len(i.entries) {
+		i.key = ""
+		return false
+	}
+	i.key = i.entries[next].Key()
+	i.index = next
+	return true
+}
+
+// Key returns the next key from the store
+func (i *KVIterator) Key() string {
+	return i.key
+}
+
+// Release releases the KVIterator and KVStore's read lock
+func (i *KVIterator) Release() {
+	// Reset key, path, entries
+	i.store = nil
+	i.key = ""
+	i.entries = nil
+
+	// Perform requested callback
+	i.onClose()
+}
+
+// Value returns the next value from the KVStore
+func (i *KVIterator) Value() ([]byte, error) {
+	// Check store isn't closed
+	if i.store == nil {
+		return nil, ErrIteratorClosed
+	}
+
+	// Attempt to fetch from store
+	return i.store.get(i.key)
+}