/// <summary>
/// Delete one dataBlock
/// </summary>
public DataBlock Delete(CollectionPage col, PageAddress blockAddress)
{
// get page and mark as dirty
var page = _pager.GetPage <DataPage>(blockAddress.PageID);
var block = page.GetBlock(blockAddress.Index);
// if there a extended page, delete all
if (block.ExtendPageID != uint.MaxValue)
{
_pager.DeletePage(block.ExtendPageID, true);
}
// delete block inside page
page.DeleteBlock(block);
// set page as dirty here
_pager.SetDirty(page);
// if there is no more datablocks, lets delete all page
if (page.BlocksCount == 0)
{
// first, remove from free list
_pager.AddOrRemoveToFreeList(false, page, col, ref col.FreeDataPageID);
_pager.DeletePage(page.PageID);
}
else
{
// add or remove to free list
_pager.AddOrRemoveToFreeList(page.FreeBytes > DataPage.DATA_RESERVED_BYTES, page, col, ref col.FreeDataPageID);
}
col.DocumentCount--;
// mark collection page as dirty
_pager.SetDirty(col);
return(block);
}
/// <summary>
/// Create a new index and returns head page address (skip list)
/// </summary>
public CollectionIndex CreateIndex(CollectionPage col)
{
// get index slot
var index = col.GetFreeIndex();
// get a new index page for first index page
var page = _pager.NewPage <IndexPage>();
// create a empty node with full max level
var head = new IndexNode(IndexNode.MAX_LEVEL_LENGTH)
{
Key = BsonValue.MinValue,
KeyLength = (ushort)BsonValue.MinValue.GetBytesCount(false),
Slot = (byte)index.Slot,
Page = page
};
// add as first node
page.AddNode(head);
// set index page as dirty
_pager.SetDirty(index.Page);
// add indexPage on freelist if has space
_pager.AddOrRemoveToFreeList(true, page, index.Page, ref index.FreeIndexPageID);
// point the head/tail node to this new node position
index.HeadNode = head.Position;
// insert tail node
var tail = this.AddNode(index, BsonValue.MaxValue, IndexNode.MAX_LEVEL_LENGTH, null);
index.TailNode = tail.Position;
return(index);
}
/// <summary>
/// Internal implementation of insert a document
/// </summary>
private void InsertDocument(CollectionPage col, BsonDocument doc, BsonType autoId)
{
// collection Sequence was created after release current datafile version.
// In this case, Sequence will be 0 but already has documents. Let's fix this
// ** this code can be removed when datafile change from 7 (HeaderPage.FILE_VERSION) **
if (col.Sequence == 0 && col.DocumentCount > 0)
{
var max = this.Max(col.CollectionName, "_id");
// if max value is a number, convert to Sequence last value
// if not, just set sequence as document count
col.Sequence = (max.IsInt32 || max.IsInt64 || max.IsDouble || max.IsDecimal) ?
Convert.ToInt64(max.RawValue) :
Convert.ToInt64(col.DocumentCount);
}
// increase collection sequence _id
col.Sequence++;
_pager.SetDirty(col);
// if no _id, add one
if (!doc.RawValue.TryGetValue("_id", out var id))
{
doc["_id"] = id =
autoId == BsonType.ObjectId ? new BsonValue(ObjectId.NewObjectId()) :
autoId == BsonType.Guid ? new BsonValue(Guid.NewGuid()) :
autoId == BsonType.DateTime ? new BsonValue(DateTime.Now) :
autoId == BsonType.Int32 ? new BsonValue((Int32)col.Sequence) :
autoId == BsonType.Int64 ? new BsonValue(col.Sequence) : BsonValue.Null;
}
// create bubble in sequence number if _id is bigger than current sequence
else if (autoId == BsonType.Int32 || autoId == BsonType.Int64)
{
var current = id.AsInt64;
// if current id is bigger than sequence, jump sequence to this number. Other was, do not increse sequnce
col.Sequence = current >= col.Sequence ? current : col.Sequence - 1;
}
// test if _id is a valid type
if (id.IsNull || id.IsMinValue || id.IsMaxValue)
{
throw LiteException.InvalidDataType("_id", id);
}
_log.Write(Logger.COMMAND, "insert document on '{0}' :: _id = {1}", col.CollectionName, id.RawValue);
// serialize object
var bytes = _bsonWriter.Serialize(doc);
// storage in data pages - returns dataBlock address
var dataBlock = _data.Insert(col, bytes);
// store id in a PK index [0 array]
var pk = _indexer.AddNode(col.PK, id, null);
// do link between index <-> data block
pk.DataBlock = dataBlock.Position;
// for each index, insert new IndexNode
foreach (var index in col.GetIndexes(false))
{
// for each index, get all keys (support now multi-key) - gets distinct values only
// if index are unique, get single key only
var expr = new BsonExpression(index.Expression);
var keys = expr.Execute(doc, true);
// do a loop with all keys (multi-key supported)
foreach (var key in keys)
{
// insert node
var node = _indexer.AddNode(index, key, pk);
// link my index node to data block address
node.DataBlock = dataBlock.Position;
}
}
}
/// <summary>
/// Implement internal update document
/// </summary>
private bool UpdateDocument(CollectionPage col, BsonDocument doc)
{
// 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);
}
_log.Write(Logger.COMMAND, "update document on '{0}' :: _id = {1}", col.CollectionName, id.RawValue);
// find indexNode from pk index
var pkNode = _indexer.Find(col.PK, id, false, Query.Ascending);
// if not found document, no updates
if (pkNode == null)
{
return(false);
}
// serialize document in bytes
var bytes = _bsonWriter.Serialize(doc);
// update data storage
var dataBlock = _data.Update(col, pkNode.DataBlock, bytes);
// get all non-pk index nodes from this data block
var allNodes = _indexer.GetNodeList(pkNode, false).ToArray();
// delete/insert indexes - do not touch on PK
foreach (var index in col.GetIndexes(false))
{
var expr = new BsonExpression(index.Expression);
// getting all keys do check
var keys = expr.Execute(doc).ToArray();
// get a list of to delete nodes (using ToArray to resolve now)
var toDelete = allNodes
.Where(x => x.Slot == index.Slot && !keys.Any(k => k == x.Key))
.ToArray();
// get a list of to insert nodes (using ToArray to resolve now)
var toInsert = keys
.Where(x => !allNodes.Any(k => k.Slot == index.Slot && k.Key == x))
.ToArray();
// delete changed index nodes
foreach (var node in toDelete)
{
_indexer.Delete(index, node.Position);
}
// insert new nodes
foreach (var key in toInsert)
{
// and add a new one
var node = _indexer.AddNode(index, key, pkNode);
// link my node to data block
node.DataBlock = dataBlock.Position;
}
}
return(true);
}