lgraph_edge_index_iterator

namespace lgraph

namespace lgraph_api

class EdgeIndexIterator

#include <lgraph_edge_index_iterator.h>

EdgeIndexIterator can be used to access a set of edges that has the same indexed value. If the index is unique (that is, each Edge has a unique index value), then each EdgeIndexIterator will only have one edge unique id, and will become invalid after Next() is called.

An EdgeIndexIterator is valid iff it points to a valid (index_value, euid) pair, otherwise it is invalid. Calling member function on an invalid EdgeIndexIterator throws an exception, except for the IsValid() function.

Public Functions

EdgeIndexIterator(EdgeIndexIterator &&rhs)

EdgeIndexIterator &operator=(EdgeIndexIterator&&)

~EdgeIndexIterator()

void Close(): Closes this iterator.

bool IsValid() const

Query if this iterator is valid, i.e. the Key and Vid can be queried.

Returns: True if valid, false if not.

bool Next()

Move to the next edge unique id in the list, which consists of all the valid edge unique ids of the iterator and is sorted from small to large. If we hit the end of the list, iterator will become invalid and false is returned.

Returns: True if it succeeds, otherwise false.

FieldData GetIndexValue() const

Gets the current index value. The euids are sorted in ( EdgeIndexValue, euid) order. When Next() is called, the iterator moves from one euid to next, possibly moving from one EdgeIndexValue to another. This function tells the EdgeIndexValue currently pointed to.

Returns: The key.

EdgeUid GetUid() const

Gets the Edge Unique Id.

Returns: The UID.

int64_t GetSrc() const

Gets the source vertex id.

Returns: The source vertex id.

int64_t GetDst() const

Gets destination of the edge.

Returns: The destination vertex id.

size_t GetLabelId() const

Gets label id of this edge.

Returns: The label identifier.

int64_t GetEdgeId() const

Gets edge id.

Returns: The edge identifier.

Private Functions

EdgeIndexIterator(lgraph::EdgeIndexIterator &&it, const std::shared_ptr<lgraph::Transaction> &txn)

EdgeIndexIterator(const EdgeIndexIterator&) = delete

EdgeIndexIterator &operator=(const EdgeIndexIterator&) = delete

Private Members

std::unique_ptr<lgraph::EdgeIndexIterator> it_

std::shared_ptr<lgraph::Transaction> txn_

Friends

friend class Transaction