/// <summary>
/// Find witch index will be used and run Execute method
/// </summary>
public virtual IEnumerable <IndexNode> Run(CollectionPage col, IndexService indexer)
{
// get index for this query
var index = col.GetCollectionIndex(this.Name);
if (index == null)
{
throw LiteException.IndexNotFound(this.Name);
}
// execute query to get all IndexNodes
return(this.Execute(indexer, index));
}
/// <summary>
/// Find witch index will be used and run Execute method
/// </summary>
public virtual async IAsyncEnumerable <IndexNode> Run(CollectionPage col, IndexService indexer)
{
// get index for this query
var index = col.GetCollectionIndex(this.Name);
if (index == null)
{
throw LiteException.IndexNotFound(this.Name);
}
var distinct = new HashSet <PageAddress>();
await foreach (var node in this.Execute(indexer, index))
{
// distinct by dataBlock
if (distinct.Contains(node.DataBlock) == false)
{
distinct.Add(node.DataBlock);
yield return(node);
}
}
}
/// <summary>
/// Implement internal update document
/// </summary>
private bool UpdateDocument(Snapshot snapshot, CollectionPage col, BsonDocument doc, IndexService indexer, DataService data)
{
// normalize id before find
var id = doc["_id"];
// validate id for null, min/max values
if (id.IsNull || id.IsMinValue || id.IsMaxValue)
{
throw LiteException.InvalidDataType("_id", id);
}
// find indexNode from pk index
var pkNode = indexer.Find(col.PK, id, false, LiteDB.Query.Ascending);
// if not found document, no updates
if (pkNode == null)
{
return(false);
}
// update data storage
data.Update(col, pkNode.DataBlock, doc);
// get all current non-pk index nodes from this data block (slot, key, nodePosition)
var oldKeys = indexer.GetNodeList(pkNode.NextNode)
.Select(x => new Tuple <byte, BsonValue, PageAddress>(x.Slot, x.Key, x.Position))
.ToArray();
// build a list of all new key index keys
var newKeys = new List <Tuple <byte, BsonValue, string> >();
foreach (var index in col.GetCollectionIndexes().Where(x => x.Name != "_id"))
{
// getting all keys from expression over document
var keys = index.BsonExpr.Execute(doc, _header.Pragmas.Collation);
foreach (var key in keys)
{
newKeys.Add(new Tuple <byte, BsonValue, string>(index.Slot, key, index.Name));
}
}
if (oldKeys.Length == 0 && newKeys.Count == 0)
{
return(true);
}
// get a list of all nodes that are in oldKeys but not in newKeys (must delete)
var toDelete = new HashSet <PageAddress>(oldKeys
.Where(x => newKeys.Any(n => n.Item1 == x.Item1 && n.Item2 == x.Item2) == false)
.Select(x => x.Item3));
// get a list of all keys that are not in oldKeys (must insert)
var toInsert = newKeys
.Where(x => oldKeys.Any(o => o.Item1 == x.Item1 && o.Item2 == x.Item2) == false)
.ToArray();
// if nothing to change, just exit
if (toDelete.Count == 0 && toInsert.Length == 0)
{
return(true);
}
// delete nodes and return last keeped node in list
var last = indexer.DeleteList(pkNode.Position, toDelete);
// now, insert all new nodes
foreach (var elem in toInsert)
{
var index = col.GetCollectionIndex(elem.Item3);
last = indexer.AddNode(index, elem.Item2, pkNode.DataBlock, last);
}
return(true);
}
