/// <summary>
/// Find incoming or outgoing edge by "srcId and _offset"
/// Output the edgeObject, as well as the edgeDocId (null for small-degree edges)
/// </summary>
/// <param name="connection"></param>
/// <param name="vertexObject"></param>
/// <param name="srcVertexId"></param>
/// <param name="edgeOffset"></param>
/// <param name="isReverseEdge"></param>
/// <param name="edgeObject"></param>
/// <param name="edgeDocId"></param>
public static void FindEdgeBySourceAndOffset(
GraphViewConnection connection,
JObject vertexObject, string srcVertexId, long edgeOffset, bool isReverseEdge,
out JObject edgeObject, out string edgeDocId)
{
if (!isReverseEdge)
{
Debug.Assert((string)vertexObject["id"] == srcVertexId);
}
JToken edgeContainer = vertexObject[isReverseEdge ? "_reverse_edge" : "_edge"];
if (edgeContainer is JArray) // for small-degree vertexes
{
if (isReverseEdge)
{
edgeObject = (from edgeObj in edgeContainer.Children <JObject>()
where (string)edgeObj["_srcV"] == srcVertexId
where (long)edgeObj["_offset"] == edgeOffset
select edgeObj
).FirstOrDefault();
}
else
{
edgeObject = (from edgeObj in edgeContainer.Children <JObject>()
where (long)edgeObj["_offset"] == edgeOffset
select edgeObj
).FirstOrDefault();
}
edgeDocId = null;
}
else if (edgeContainer is JObject) // for large-degree vertexes
{
string edgeIdList = string.Join(", ", edgeContainer["_edges"].Children <JObject>().Select(e => $"'{e["id"]}'"));
string query;
if (isReverseEdge)
{
query = $"SELECT doc.id, edge\n" +
$"FROM doc\n" +
$"JOIN edge IN doc._edge\n" +
$"WHERE doc.id IN ({edgeIdList})\n" +
$" AND (edge._srcV = '{srcVertexId}')\n" +
$" AND (edge._offset = {edgeOffset})\n";
}
else
{
query = $"SELECT doc.id, edge\n" +
$"FROM doc\n" +
$"JOIN edge IN doc._edge\n" +
$"WHERE doc.id IN ({edgeIdList})\n" +
$" AND (edge._offset = {edgeOffset})\n";
}
JObject result = connection.ExecuteQueryUnique(query);
edgeDocId = (string)result?["id"];
edgeObject = (JObject)result?["edge"];
}
else
{
throw new Exception($"BUG: edgeContainer should either be JObject or JArray, but now: {edgeContainer?.GetType()}");
}
}
/// <summary>
/// Find incoming or outgoing edge by "srcId and edgeId"
/// Output the edgeObject, as well as the edgeDocId (null for small-degree edges)
/// </summary>
/// <param name="connection"></param>
/// <param name="vertexObject"></param>
/// <param name="srcVertexId"></param>
/// <param name="edgeId"></param>
/// <param name="isReverseEdge"></param>
/// <param name="edgeObject"></param>
/// <param name="edgeDocId"></param>
public static void FindEdgeBySourceAndEdgeId(
GraphViewConnection connection,
JObject vertexObject, string srcVertexId, string edgeId, bool isReverseEdge,
out JObject edgeObject, out string edgeDocId)
{
if (!isReverseEdge)
{
Debug.Assert((string)vertexObject[KW_DOC_ID] == srcVertexId);
}
JToken edgeContainer = vertexObject[isReverseEdge ? KW_VERTEX_REV_EDGE : KW_VERTEX_EDGE];
if (!IsSpilledVertex(vertexObject, isReverseEdge))
{
// for small-degree vertexes
if (isReverseEdge)
{
edgeObject = (from edgeObj in edgeContainer.Children <JObject>()
where (string)edgeObj[KW_EDGE_SRCV] == srcVertexId
where (string)edgeObj[KW_EDGE_ID] == edgeId
select edgeObj
).FirstOrDefault();
}
else
{
edgeObject = (from edgeObj in edgeContainer.Children <JObject>()
where (string)edgeObj[KW_EDGE_ID] == edgeId
select edgeObj
).FirstOrDefault();
}
edgeDocId = null;
}
else // For large-degree vertices
// Now the vertex document stores the last(latest) spilled edge document only.
//string edgeDocIdList = string.Join(", ", edgeContainer.Children<JObject>().Select(e => $"'{e[KW_DOC_ID]}'"));
{
const string EDGE_SELECT_TAG = "edge";
string query = $"SELECT doc.{KW_DOC_ID}, {EDGE_SELECT_TAG}\n" +
$"FROM doc\n" +
$"JOIN {EDGE_SELECT_TAG} IN doc.{KW_EDGEDOC_EDGE}\n" +
$"WHERE (doc.{KW_EDGEDOC_ISREVERSE} = {isReverseEdge.ToString().ToLowerInvariant()})\n" +
$" AND ({EDGE_SELECT_TAG}.{KW_EDGE_ID} = '{edgeId}')\n";
JObject result = connection.ExecuteQueryUnique(query);
edgeDocId = (string)result?[KW_DOC_ID];
edgeObject = (JObject)result?[EDGE_SELECT_TAG];
}
}
