public Page <T> LoadPageFromPageNumber(int number)
{
lock (_fileLock)
{
SeekPage(number);
byte[] b = new byte[_PageLength];
_file.Read(b, 0, _PageLength);
if (b[0] == _BlockHeader[0] && b[1] == _BlockHeader[1] && b[2] == _BlockHeader[2] && b[3] == _BlockHeader[3])
{
// create node here
Page <T> page = new Page <T>();
short count = Helper.ToInt16(b, 5);
if (count > _PageNodeCount)
{
throw new Exception("Count > node size");
}
page.DiskPageNumber = number;
page.RightPageNumber = Helper.ToInt32(b, 11);
int index = _BlockHeader.Length;
object[] keys = null;
for (int i = 0; i < count; i++)
{
int idx = index + _rowSize * i;
byte ks = b[idx];
T key = default(T);
if (_externalStrings == false)
{
key = _T.GetObject(b, idx + 1, ks);
}
else
{
if (keys == null)
{
int blknum = Helper.ToInt32(b, idx + 1, false);
List <int> ablocks = new List <int>();
byte[] bb = _strings.GetData(blknum, out ablocks);
page.allocblocks = ablocks;
keys = (object[])BJSON.ToObject(bb);
}
key = (T)keys[i];
}
int offset = Helper.ToInt32(b, idx + 1 + _maxKeySize);
int duppage = Helper.ToInt32(b, idx + 1 + _maxKeySize + 4);
page.tree.Add(key, new KeyInfo(offset, duppage));
}
return(page);
}
else
{
throw new Exception("Page read error header invalid, number = " + number);
}
}
}
private int NodeHeaderCount(int nextpage, ref long c)
{
SeekPage(nextpage);
byte[] b = new byte[_BlockHeader.Length];
_file.Read(b, 0, _BlockHeader.Length);
if (b[0] == _BlockHeader[0] && b[1] == _BlockHeader[1] && b[2] == _BlockHeader[2] && b[3] == _BlockHeader[3])
{
short count = Helper.ToInt16(b, 5);
int rightpage = Helper.ToInt32(b, 11);
c += count;
return(rightpage);
}
return(0);
}
private bool ReadFileHeader()
{
_file.Seek(0L, SeekOrigin.Begin);
byte[] b = new byte[_FileHeader.Length];
_file.Read(b, 0, _FileHeader.Length);
if (b[0] == _FileHeader[0] && b[1] == _FileHeader[1] && b[2] == _FileHeader[2])
{
byte maxks = b[3];
ushort nodes = (ushort)Helper.ToInt16(b, 4);
//int root = Helper.ToInt32(b, 6);
_maxKeySize = maxks;
_PageNodeCount = nodes;
_FileHeader = b;
}
return(false);
}
private int LoadPageListData(int page, SafeSortedList <T, PageInfo> PageList)
{
lock (_fileLock)
{
// load page list data
int nextpage = -1;
SeekPage(page);
byte[] b = new byte[_PageLength];
_file.Read(b, 0, _PageLength);
if (b[0] == _BlockHeader[0] && b[1] == _BlockHeader[1] && b[2] == _BlockHeader[2] && b[3] == _BlockHeader[3])
{
short count = Helper.ToInt16(b, 5);
if (count > _PageNodeCount)
{
throw new Exception("Count > node size");
}
nextpage = Helper.ToInt32(b, 11);
int index = _BlockHeader.Length;
for (int i = 0; i < count; i++)
{
int idx = index + _rowSize * i;
byte ks = b[idx];
T key = _T.GetObject(b, idx + 1, ks);
int pagenum = Helper.ToInt32(b, idx + 1 + _maxKeySize);
// add counts
int unique = Helper.ToInt32(b, idx + 1 + _maxKeySize + 4);
// FEATURE : add dup count
PageList.Add(key, new PageInfo(pagenum, unique, 0));
}
}
else
{
throw new Exception("Page List header is invalid");
}
return(nextpage);
}
}
public Page <T> LoadPageFromPageNumber(int number)
{
lock (_fileLock)
{
SeekPage(number);
byte[] b = new byte[_PageLength];
_file.Read(b, 0, _PageLength);
if (b[0] == _BlockHeader[0] && b[1] == _BlockHeader[1] && b[2] == _BlockHeader[2] && b[3] == _BlockHeader[3])
{
// create node here
Page <T> page = new Page <T>();
short count = Helper.ToInt16(b, 5);
if (count > _PageNodeCount)
{
throw new Exception("Count > node size");
}
page.DiskPageNumber = number;
page.RightPageNumber = Helper.ToInt32(b, 11);
int index = _BlockHeader.Length;
for (int i = 0; i < count; i++)
{
int idx = index + _rowSize * i;
byte ks = b[idx];
T key = _T.GetObject(b, idx + 1, ks);
int offset = Helper.ToInt32(b, idx + 1 + _maxKeySize);
int duppage = Helper.ToInt32(b, idx + 1 + _maxKeySize + 4);
page.tree.Add(key, new KeyInfo(offset, duppage));
}
return(page);
}
else
{
throw new Exception("Page read error header invalid, number = " + number);
}
}
}
private int LoadPageListData(int page, SafeSortedList <T, PageInfo> PageList)
{
lock (_fileLock)
{
// load page list data
int nextpage = -1;
SeekPage(page);
byte[] b = new byte[_PageLength];
_file.Read(b, 0, _PageLength);
if (b[0] == _BlockHeader[0] && b[1] == _BlockHeader[1] && b[2] == _BlockHeader[2] && b[3] == _BlockHeader[3])
{
short count = Helper.ToInt16(b, 5);
if (count > _PageNodeCount)
{
throw new Exception("Count > node size");
}
nextpage = Helper.ToInt32(b, 11);
int index = _BlockHeader.Length;
object[] keys = null;
// TODO : needed??
//if (File.Exists(_FileName + ".pagelist"))
//{
// var bn = File.ReadAllBytes(_FileName + ".pagelist");
// int blknum = Helper.ToInt32(bn, 0);
// byte[] bb = _strings.GetData(blknum, out _pagelistalllocblock);
// keys = (object[])BJSON.ToObject(bb);
//}
for (int i = 0; i < count; i++)
{
int idx = index + _rowSize * i;
byte ks = b[idx];
T key;
if (_externalStrings == false)
{
key = _T.GetObject(b, idx + 1, ks);
}
else
{
if (keys == null)
{
key = _T.GetObject(b, idx + 1, ks); // do old way until better way
}
else
{
key = (T)keys[i];
}
}
int pagenum = Helper.ToInt32(b, idx + 1 + _maxKeySize);
// add counts
int unique = Helper.ToInt32(b, idx + 1 + _maxKeySize + 4);
// FEATURE : add dup count
PageList.Add(key, new PageInfo(pagenum, unique, 0));
}
}
else
{
throw new Exception("Page List header is invalid");
}
return(nextpage);
}
}
public short GetObject(byte[] buffer, int offset, int count)
{
return(Helper.ToInt16(buffer, offset));
}
