package storm import ( "bytes" "github.com/boltdb/bolt" ) // A BucketScanner scans a Node for a list of buckets type BucketScanner interface { // PrefixScan scans the root buckets for keys matching the given prefix. PrefixScan(prefix string) []Node // PrefixScan scans the buckets in this node for keys matching the given prefix. RangeScan(min, max string) []Node } // PrefixScan scans the buckets in this node for keys matching the given prefix. func (n *node) PrefixScan(prefix string) []Node { if n.tx != nil { return n.prefixScan(n.tx, prefix) } var nodes []Node n.readTx(func(tx *bolt.Tx) error { nodes = n.prefixScan(tx, prefix) return nil }) return nodes } func (n *node) prefixScan(tx *bolt.Tx, prefix string) []Node { var ( prefixBytes = []byte(prefix) nodes []Node c = n.cursor(tx) ) for k, v := c.Seek(prefixBytes); k != nil && bytes.HasPrefix(k, prefixBytes); k, v = c.Next() { if v != nil { continue } nodes = append(nodes, n.From(string(k))) } return nodes } // RangeScan scans the buckets in this node over a range such as a sortable time range. func (n *node) RangeScan(min, max string) []Node { if n.tx != nil { return n.rangeScan(n.tx, min, max) } var nodes []Node n.readTx(func(tx *bolt.Tx) error { nodes = n.rangeScan(tx, min, max) return nil }) return nodes } func (n *node) rangeScan(tx *bolt.Tx, min, max string) []Node { var ( minBytes = []byte(min) maxBytes = []byte(max) nodes []Node c = n.cursor(tx) ) for k, v := c.Seek(minBytes); k != nil && bytes.Compare(k, maxBytes) <= 0; k, v = c.Next() { if v != nil { continue } nodes = append(nodes, n.From(string(k))) } return nodes } func (n *node) cursor(tx *bolt.Tx) *bolt.Cursor { var c *bolt.Cursor if len(n.rootBucket) > 0 { c = n.GetBucket(tx).Cursor() } else { c = tx.Cursor() } return c }