//static readonly Brush indexBrush = new LinearGradientBrush(new Rectangle(0, 0, Consts.indexBlockLength, bmpHeight), Color.DarkGoldenrod, Color.LightGoldenrodYellow, 0f);
private static void DrawIndex(FileDBContext db, Bitmap[] bmps)
{
TableBlock tableBlockHead = db.GetTableBlockHeadNode();
TableBlock previousTable = tableBlockHead;
while (previousTable.NextPos != 0)
{
//previousTable.TryLoadNextObj(fs);
TableBlock table = previousTable.NextObj;
IndexBlock currentIndex = table.IndexBlockHead;
while (currentIndex != null)
{
long index = currentIndex.ThisPos.PagePos() / Consts.pageSize;
Bitmap bmp = bmps[index];
Graphics g = Graphics.FromImage(bmp);
int startPos = (int)(currentIndex.ThisPos - Consts.pageSize * index);
int length = currentIndex.ToBytes().Length;
Brush brush = new LinearGradientBrush(new Point(startPos, 0), new Point(startPos + length, 0), Color.DarkGray, Color.LightGray);
g.FillRectangle(brush, startPos, 1, length, bmpHeight - 1);
g.DrawRectangle(boundPen, startPos, 1, length, bmpHeight - 1);
g.Dispose();
currentIndex.TryLoadNextObj(db.GetFileStream());
currentIndex = currentIndex.NextObj;
}
//while (currentIndex.NextPos != 0)
//{
// long index = currentIndex.NextObj.ThisPos.PagePos() / Consts.pageSize;
// Bitmap bmp = bmps[index];
// Graphics g = Graphics.FromImage(bmp);
// int startPos = (int)(currentIndex.NextObj.ThisPos - Consts.pageSize * index);
// int length = currentIndex.NextObj.ToBytes().Length;
// Brush brush = new LinearGradientBrush(new Point(startPos, 0), new Point(startPos + length, 0), Color.DarkGray, Color.LightGray);
// g.FillRectangle(brush, startPos, 1, length, bmpHeight - 1);
// g.DrawRectangle(boundPen, startPos, 1, length, bmpHeight - 1);
// g.Dispose();
// currentIndex = currentIndex.NextObj;
//}
previousTable = table;
}
}
/// <summary>
/// 系统启动时初始化各项常量。
/// </summary>
static Consts()
{
{
PropertyInfo[] properties = typeof(Table).GetProperties();
foreach (var property in properties)
{
TableIndexAttribute attr = property.GetCustomAttribute <TableIndexAttribute>();
if (attr != null && property.PropertyType == typeof(ObjectId))
{
Consts.TableIdString = property.Name;
break;
}
}
}
{
PageHeaderBlock page = new PageHeaderBlock();
using (MemoryStream ms = new MemoryStream())
{
formatter.Serialize(ms, page);
if (ms.Length > Consts.pageSize / 10)
{
throw new Exception("Page header block takes too much space!");
}
Consts.pageHeaderBlockLength = (Int16)ms.Length;
Consts.maxAvailableSpaceInPage = (Int16)(Consts.pageSize - ms.Length);
Consts.minOccupiedBytes = (Int16)(Consts.pageSize - Consts.maxAvailableSpaceInPage);
}
BlockCache.TryRemoveFloatingBlock(page);
}
{
PageHeaderBlock page = new PageHeaderBlock();
DBHeaderBlock dbHeader = new DBHeaderBlock();
TableBlock tableHead = new TableBlock();
Int16 usedSpaceInFirstPage;
using (MemoryStream ms = new MemoryStream())
{
formatter.Serialize(ms, page);
dbHeader.ThisPos = ms.Length;
formatter.Serialize(ms, dbHeader);
tableHead.ThisPos = ms.Length;
Consts.dbHeaderBlockLength = (Int16)(ms.Length - Consts.pageHeaderBlockLength);
formatter.Serialize(ms, tableHead);
Consts.tableBlockLength = (Int16)(ms.Length - tableHead.ThisPos);
usedSpaceInFirstPage = (Int16)ms.Length;
}
if (usedSpaceInFirstPage > Consts.pageSize)
{
throw new Exception("First page is full!");
}
BlockCache.TryRemoveFloatingBlock(page);
BlockCache.TryRemoveFloatingBlock(dbHeader);
BlockCache.TryRemoveFloatingBlock(tableHead);
}
{
IndexBlock block = new IndexBlock();
int length = block.ToBytes().Length;
if (length > Consts.pageSize / 10)
{
throw new Exception("index block takes too much space!");
}
Consts.indexBlockLength = (Int16)length;
BlockCache.TryRemoveFloatingBlock(block);
}
{
SkipListNodeBlock block = new SkipListNodeBlock();
int length = block.ToBytes().Length;
if (length > Consts.pageSize / 10)
{
throw new Exception("index block takes too much space!");
}
Consts.skipListNodeBlockLength = (Int16)length;
BlockCache.TryRemoveFloatingBlock(block);
}
{
PageHeaderBlock page = new PageHeaderBlock();
DataBlock dataBlock = new DataBlock();
dataBlock.Data = new byte[0];
Int16 minValue;
using (MemoryStream ms = new MemoryStream())
{
formatter.Serialize(ms, page);
long pos = ms.Length;
formatter.Serialize(ms, dataBlock);
Consts.dataBlockLength = (Int16)(ms.Length - pos);
if (ms.Length > Consts.pageSize / 10)
{
throw new Exception("data block's metadata takes too much space!");
}
minValue = (Int16)ms.Length;
}
Consts.maxDataBytes = (Int16)(Consts.pageSize - minValue);
BlockCache.TryRemoveFloatingBlock(page);
BlockCache.TryRemoveFloatingBlock(dataBlock);
}
}