/// <summary>
/// Insert a new node index inside an collection index.
/// </summary>
private IndexNode AddNode(CollectionIndex index, BsonValue key, byte level)
{
// creating a new index node
var node = new IndexNode(level)
{
Key = key,
KeyLength = key.GetBytesCount()
};
if (node.KeyLength > MAX_INDEX_LENGTH)
{
throw LiteException.IndexKeyTooLong();
}
// get a free page to insert my index node
var page = _pager.GetFreePage <IndexPage>(index.FreeIndexPageID, node.Length);
node.Position = new PageAddress(page.PageID, page.Nodes.NextIndex());
node.Page = page;
// add index node to page
page.Nodes.Add(node.Position.Index, node);
// update freebytes + items count
page.UpdateItemCount();
// now, let's link my index node on right place
var cur = this.GetNode(index.HeadNode);
// scan from top left
for (var i = IndexNode.MAX_LEVEL_LENGTH - 1; i >= 0; i--)
{
// for(; <while_not_this>; <do_this>) { ... }
for (; cur.Next[i].IsEmpty == false; cur = this.GetNode(cur.Next[i]))
{
// read next node to compare
var diff = this.GetNode(cur.Next[i]).Key.CompareTo(key);
// if unique and diff = 0, throw index exception (must rollback transaction - others nodes can be dirty)
if (diff == 0 && index.Options.Unique)
{
throw LiteException.IndexDuplicateKey(index.Field, key);
}
if (diff == 1)
{
break;
}
}
if (i <= (level - 1)) // level == length
{
// cur = current (imediatte before - prev)
// node = new inserted node
// next = next node (where cur is poiting)
node.Next[i] = cur.Next[i];
node.Prev[i] = cur.Position;
cur.Next[i] = node.Position;
var next = this.GetNode(node.Next[i]);
if (next != null)
{
next.Prev[i] = node.Position;
next.Page.IsDirty = true;
}
cur.Page.IsDirty = true;
}
}
// add/remove indexPage on freelist if has space
_pager.AddOrRemoveToFreeList(page.FreeBytes > IndexPage.INDEX_RESERVED_BYTES, page, index.Page, ref index.FreeIndexPageID);
page.IsDirty = true;
return(node);
}
/// <summary>
/// Wrtie any BsonValue. Use 1 byte for data type, 1 byte for length (optional), 0-255 bytes to value.
/// For document or array, use BufferWriter
/// </summary>
public static void WriteIndexKey(this BufferSlice buffer, BsonValue value, int offset)
{
ENSURE(value.GetBytesCount(false) <= MAX_INDEX_KEY_LENGTH, "index key must have less than 1023 bytes");
if (value.IsString)
{
var str = value.AsString;
var strLength = (ushort)Encoding.UTF8.GetByteCount(str);
ExtendedLengthHelper.WriteLength(BsonType.String, strLength, out var typeByte, out var lengthByte);
buffer[offset++] = typeByte;
buffer[offset++] = lengthByte;
buffer.Write(str, offset);
}
else if (value.IsBinary)
{
var arr = value.AsBinary;
ExtendedLengthHelper.WriteLength(BsonType.Binary, (ushort)arr.Length, out var typeByte, out var lengthByte);
buffer[offset++] = typeByte;
buffer[offset++] = lengthByte;
buffer.Write(arr, offset);
}
else
{
buffer[offset++] = (byte)value.Type;
switch (value.Type)
{
case BsonType.Null:
case BsonType.MinValue:
case BsonType.MaxValue:
break;
case BsonType.Int32: buffer.Write(value.AsInt32, offset); break;
case BsonType.Int64: buffer.Write(value.AsInt64, offset); break;
case BsonType.Double: buffer.Write(value.AsDouble, offset); break;
case BsonType.Decimal: buffer.Write(value.AsDecimal, offset); break;
case BsonType.Document:
using (var w = new BufferWriter(buffer))
{
w.Skip(offset); // skip offset from buffer
w.WriteDocument(value.AsDocument, true);
}
break;
case BsonType.Array:
using (var w = new BufferWriter(buffer))
{
w.Skip(offset); // skip offset from buffer
w.WriteArray(value.AsArray, true);
}
break;
case BsonType.ObjectId: buffer.Write(value.AsObjectId, offset); break;
case BsonType.Guid: buffer.Write(value.AsGuid, offset); break;
case BsonType.Boolean: buffer[offset] = (value.AsBoolean) ? (byte)1 : (byte)0; break;
case BsonType.DateTime: buffer.Write(value.AsDateTime, offset); break;
default: throw new NotImplementedException();
}
}
}
/// <summary>
/// Insert a new node index inside an collection index.
/// </summary>
private IndexNode AddNode(CollectionIndex index, BsonValue key, byte level, IndexNode last)
{
// calc key size
var keyLength = key.GetBytesCount(false);
if (keyLength > MAX_INDEX_LENGTH)
{
throw LiteException.IndexKeyTooLong();
}
// creating a new index node
var node = new IndexNode(level)
{
Key = key,
KeyLength = (ushort)keyLength,
Slot = (byte)index.Slot
};
// get a free page to insert my index node
var page = _pager.GetFreePage <IndexPage>(index.FreeIndexPageID, node.Length);
node.Position = new PageAddress(page.PageID, page.Nodes.NextIndex());
node.Page = page;
// add index node to page
page.Nodes.Add(node.Position.Index, node);
// update freebytes + items count
page.UpdateItemCount();
// now, let's link my index node on right place
var cur = this.GetNode(index.HeadNode);
// using as cache last
IndexNode cache = null;
// scan from top left
for (var i = IndexNode.MAX_LEVEL_LENGTH - 1; i >= 0; i--)
{
// get cache for last node
cache = cache != null && cache.Position.Equals(cur.Next[i]) ? cache : this.GetNode(cur.Next[i]);
// for(; <while_not_this>; <do_this>) { ... }
for (; cur.Next[i].IsEmpty == false; cur = cache)
{
// get cache for last node
cache = cache != null && cache.Position.Equals(cur.Next[i]) ? cache : this.GetNode(cur.Next[i]);
// read next node to compare
var diff = cache.Key.CompareTo(key);
// if unique and diff = 0, throw index exception (must rollback transaction - others nodes can be dirty)
if (diff == 0 && index.Unique)
{
throw LiteException.IndexDuplicateKey(index.Field, key);
}
if (diff == 1)
{
break;
}
}
if (i <= (level - 1)) // level == length
{
// cur = current (imediatte before - prev)
// node = new inserted node
// next = next node (where cur is poiting)
_pager.SetDirty(cur.Page);
node.Next[i] = cur.Next[i];
node.Prev[i] = cur.Position;
cur.Next[i] = node.Position;
var next = this.GetNode(node.Next[i]);
if (next != null)
{
next.Prev[i] = node.Position;
_pager.SetDirty(next.Page);
}
}
}
// add/remove indexPage on freelist if has space
_pager.AddOrRemoveToFreeList(page.FreeBytes > IndexPage.INDEX_RESERVED_BYTES, page, index.Page, ref index.FreeIndexPageID);
// if last node exists, create a double link list
if (last != null)
{
// link new node with last node
if (last.NextNode.IsEmpty == false)
{
// fix link pointer with has more nodes in list
var next = this.GetNode(last.NextNode);
next.PrevNode = node.Position;
last.NextNode = node.Position;
node.PrevNode = last.Position;
node.NextNode = next.Position;
_pager.SetDirty(next.Page);
}
else
{
last.NextNode = node.Position;
node.PrevNode = last.Position;
}
// set last node page as dirty
_pager.SetDirty(last.Page);
}
return(node);
}
/// <summary>
/// Wrtie any BsonValue. Use 1 byte for data type, 1 byte for length (optional), 0-255 bytes to value.
/// For document or array, use BufferWriter
/// </summary>
public static void WriteIndexKey(this BufferSlice buffer, BsonValue value, int offset)
{
ENSURE(value.GetBytesCount(false) < 255, "index key must have less than 255 bytes");
buffer[offset++] = (byte)value.Type;
switch (value.Type)
{
case BsonType.Null:
case BsonType.MinValue:
case BsonType.MaxValue:
break;
case BsonType.Int32: buffer.Write(value.AsInt32, offset); break;
case BsonType.Int64: buffer.Write(value.AsInt64, offset); break;
case BsonType.Double: buffer.Write(value.AsDouble, offset); break;
case BsonType.Decimal: buffer.Write(value.AsDecimal, offset); break;
case BsonType.String:
var str = value.AsString;
var strLength = (byte)Encoding.UTF8.GetByteCount(str);
buffer[offset++] = strLength;
buffer.Write(str, offset);
break;
case BsonType.Document:
using (var w = new BufferWriter(buffer))
{
w.Skip(offset); // skip offset from buffer
w.WriteDocument(value.AsDocument, true);
}
break;
case BsonType.Array:
using (var w = new BufferWriter(buffer))
{
w.Skip(offset); // skip offset from buffer
w.WriteArray(value.AsArray, true);
}
break;
case BsonType.Binary:
var arr = value.AsBinary;
buffer[offset++] = (byte)arr.Length;
buffer.Write(arr, offset);
break;
case BsonType.ObjectId: buffer.Write(value.AsObjectId, offset); break;
case BsonType.Guid: buffer.Write(value.AsGuid, offset); break;
case BsonType.Boolean: buffer[offset] = (value.AsBoolean) ? (byte)1 : (byte)0; break;
case BsonType.DateTime: buffer.Write(value.AsDateTime, offset); break;
default: throw new NotImplementedException();
}
}