internal void SavePage(Page <T> node)
{
lock (_fileLock)
{
int pnum = node.DiskPageNumber;
if (pnum > _LastPageNumber)
{
throw new Exception("should not be here: page out of bounds");
}
SeekPage(pnum);
byte[] page = new byte[_PageLength];
byte[] blockheader = CreateBlockHeader(0, (ushort)node.tree.Count, node.RightPageNumber);
Buffer.BlockCopy(blockheader, 0, page, 0, blockheader.Length);
int index = blockheader.Length;
int i = 0;
byte[] b = null;
T[] keys = node.tree.Keys();
Array.Sort(keys); // sort keys on save for read performance
// node children
foreach (var kp in keys)
{
var val = node.tree[kp];
int idx = index + _rowSize * i++;
// key bytes
byte[] kk = _T.GetBytes(kp);
byte size = (byte)kk.Length;
if (size > _maxKeySize)
{
size = _maxKeySize;
}
// key size = 1 byte
page[idx] = size;
Buffer.BlockCopy(kk, 0, page, idx + 1, page[idx]);
// offset = 4 bytes
b = Helper.GetBytes(val.RecordNumber, false);
Buffer.BlockCopy(b, 0, page, idx + 1 + _maxKeySize, b.Length);
// duplicatepage = 4 bytes
b = Helper.GetBytes(val.DuplicateBitmapNumber, false);
Buffer.BlockCopy(b, 0, page, idx + 1 + _maxKeySize + 4, b.Length);
}
_file.Write(page, 0, page.Length);
}
}
public bool RemoveKey(T key)
{
// remove and store key in storage file
byte[] bkey = _T.GetBytes(key);
MemoryStream ms = new MemoryStream();
ms.Write(Helper.GetBytes(bkey.Length, false), 0, 4);
ms.Write(bkey, 0, bkey.Length);
return(Delete(key, ms.ToArray()));
}
public int WriteData(T key, byte[] data, bool deleted)
{
byte[] k = _T.GetBytes(key);
int kl = k.Length;
// seek end of file
long offset = _lastWriteOffset;
byte[] hdr = CreateRowHeader(kl, (data == null?0:data.Length));
if (deleted)
{
hdr[(int)HDR_POS.Flags] = (byte)1;
}
// write header info
_writefile.Write(hdr, 0, hdr.Length);
// write key
_writefile.Write(k, 0, kl);
if (data != null)
{
// write data block
_writefile.Write(data, 0, data.Length);
if (Global.FlushStorageFileImmetiatley)
{
_writefile.Flush();
}
_lastWriteOffset += data.Length;
}
// update pointer
_lastWriteOffset += hdr.Length;
_lastWriteOffset += kl;
// return starting offset -> recno
int recno = _lastRecordNum++;
_recordfile.Write(Helper.GetBytes(offset, false), 0, 8);
if (Global.FlushStorageFileImmetiatley)
{
_recordfile.Flush();
}
_flushNeeded = true;
return(recno);
}
internal void SavePage(Page <T> node)
{
lock (_fileLock)
{
int pnum = node.DiskPageNumber;
if (pnum > _LastPageNumber)
{
throw new Exception("should not be here: page out of bounds");
}
SeekPage(pnum);
byte[] page = new byte[_PageLength];
byte[] blockheader = CreateBlockHeader(0, (ushort)node.tree.Count(), node.RightPageNumber);
Buffer.BlockCopy(blockheader, 0, page, 0, blockheader.Length);
int index = blockheader.Length;
int i = 0;
byte[] b = null;
T[] keys = node.tree.Keys();
Array.Sort(keys); // sort keys on save for read performance
int blocknum = 0;
if (_externalStrings)
{
// free old blocks
if (node.allocblocks != null)
{
_strings.FreeBlocks(node.allocblocks);
}
blocknum = _strings.SaveData(node.DiskPageNumber.ToString(), BJSON.ToBJSON(keys,
new BJSONParameters {
UseUnicodeStrings = false, UseTypedArrays = false
}));
}
// node children
foreach (var kp in keys)
{
var val = node.tree[kp];
int idx = index + _rowSize * i;
// key bytes
byte[] kk;
byte size;
if (_externalStrings == false)
{
kk = _T.GetBytes(kp);
size = (byte)kk.Length;
if (size > _maxKeySize)
{
size = _maxKeySize;
}
}
else
{
kk = new byte[4];
Buffer.BlockCopy(Helper.GetBytes(blocknum, false), 0, kk, 0, 4);
size = 4;
}
// key size = 1 byte
page[idx] = size;
Buffer.BlockCopy(kk, 0, page, idx + 1, page[idx]);
// offset = 4 bytes
b = Helper.GetBytes(val.RecordNumber, false);
Buffer.BlockCopy(b, 0, page, idx + 1 + _maxKeySize, b.Length);
// duplicatepage = 4 bytes
b = Helper.GetBytes(val.DuplicateBitmapNumber, false);
Buffer.BlockCopy(b, 0, page, idx + 1 + _maxKeySize + 4, b.Length);
i++;
}
_file.Write(page, 0, page.Length);
}
}