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-rw-r--r--vendor/github.com/allegro/bigcache/iterator.go122
1 files changed, 122 insertions, 0 deletions
diff --git a/vendor/github.com/allegro/bigcache/iterator.go b/vendor/github.com/allegro/bigcache/iterator.go
new file mode 100644
index 000000000..70b98d900
--- /dev/null
+++ b/vendor/github.com/allegro/bigcache/iterator.go
@@ -0,0 +1,122 @@
+package bigcache
+
+import "sync"
+
+type iteratorError string
+
+func (e iteratorError) Error() string {
+ return string(e)
+}
+
+// ErrInvalidIteratorState is reported when iterator is in invalid state
+const ErrInvalidIteratorState = iteratorError("Iterator is in invalid state. Use SetNext() to move to next position")
+
+// ErrCannotRetrieveEntry is reported when entry cannot be retrieved from underlying
+const ErrCannotRetrieveEntry = iteratorError("Could not retrieve entry from cache")
+
+var emptyEntryInfo = EntryInfo{}
+
+// EntryInfo holds informations about entry in the cache
+type EntryInfo struct {
+ timestamp uint64
+ hash uint64
+ key string
+ value []byte
+}
+
+// Key returns entry's underlying key
+func (e EntryInfo) Key() string {
+ return e.key
+}
+
+// Hash returns entry's hash value
+func (e EntryInfo) Hash() uint64 {
+ return e.hash
+}
+
+// Timestamp returns entry's timestamp (time of insertion)
+func (e EntryInfo) Timestamp() uint64 {
+ return e.timestamp
+}
+
+// Value returns entry's underlying value
+func (e EntryInfo) Value() []byte {
+ return e.value
+}
+
+// EntryInfoIterator allows to iterate over entries in the cache
+type EntryInfoIterator struct {
+ mutex sync.Mutex
+ cache *BigCache
+ currentShard int
+ currentIndex int
+ elements []uint32
+ elementsCount int
+ valid bool
+}
+
+// SetNext moves to next element and returns true if it exists.
+func (it *EntryInfoIterator) SetNext() bool {
+ it.mutex.Lock()
+
+ it.valid = false
+ it.currentIndex++
+
+ if it.elementsCount > it.currentIndex {
+ it.valid = true
+ it.mutex.Unlock()
+ return true
+ }
+
+ for i := it.currentShard + 1; i < it.cache.config.Shards; i++ {
+ it.elements, it.elementsCount = it.cache.shards[i].copyKeys()
+
+ // Non empty shard - stick with it
+ if it.elementsCount > 0 {
+ it.currentIndex = 0
+ it.currentShard = i
+ it.valid = true
+ it.mutex.Unlock()
+ return true
+ }
+ }
+ it.mutex.Unlock()
+ return false
+}
+
+func newIterator(cache *BigCache) *EntryInfoIterator {
+ elements, count := cache.shards[0].copyKeys()
+
+ return &EntryInfoIterator{
+ cache: cache,
+ currentShard: 0,
+ currentIndex: -1,
+ elements: elements,
+ elementsCount: count,
+ }
+}
+
+// Value returns current value from the iterator
+func (it *EntryInfoIterator) Value() (EntryInfo, error) {
+ it.mutex.Lock()
+
+ if !it.valid {
+ it.mutex.Unlock()
+ return emptyEntryInfo, ErrInvalidIteratorState
+ }
+
+ entry, err := it.cache.shards[it.currentShard].getEntry(int(it.elements[it.currentIndex]))
+
+ if err != nil {
+ it.mutex.Unlock()
+ return emptyEntryInfo, ErrCannotRetrieveEntry
+ }
+ it.mutex.Unlock()
+
+ return EntryInfo{
+ timestamp: readTimestampFromEntry(entry),
+ hash: readHashFromEntry(entry),
+ key: readKeyFromEntry(entry),
+ value: readEntry(entry),
+ }, nil
+}