public void GetLast(DataFile fle, IdxPos pos)
{
if (Root == 0)
{
pos.PageAdr = 0;
pos.RowAdr = 0;
pos.Row = 0;
pos.Result = IdxPos.coIxBigger;
return;
}
pos.Page = new IdxPage(0, 0, 0, KeyLength);
fle.Read(pos.Page, Last, PageSize);
pos.Page.Last(pos);
}
public long Position(DataFile fle, IdxPos pos)
{
pos.OnPage = true;
long sk = 0;
while (true)
{
sk += pos.Page.Position(pos);
if (pos.PageAdr == 0)
{
return(sk);
}
fle.Read(pos.Page, pos.PageAdr, PageSize);
}
}
public bool Match(DataFile fle, string key, long adr, IdxPos pos)
{
while (true)
{
pos.Page.Match(key, adr, pos);
if (pos.Result == IdxPos.coIxMatch)
{
return(true);
}
if (pos.Result != IdxPos.coIxFound || pos.PageAdr == 0)
{
return(false);
}
fle.Read(pos.Page, pos.PageAdr, PageSize);
}
}
internal static void Create(string nm, Table obj)
{
TableFile db;
if (OpenList.TryGetValue(nm, out db))
{
throw new System.InvalidOperationException("MinBase: Cannot create table " + nm + " because there is a perviously open table with the same name.");
}
db = new TableFile();
Struct stt = new Struct();
db.File = DataFile.Open(nm, "Table", FileMode.CreateNew);
stt.RowLength = DataFile.GetSize(obj);
stt.RowCount = 0;
db.File.Append(stt, DataFile.GetSize(stt));
db.File.Close();
}
public void KeyOnParent(DataFile fle, ushort kl, int pgsz, IdxPos pos)
{
IdxPage pa = new IdxPage(0, 0, 0, kl);
long adr = this.Buffer.Position;
fle.Read(pa, Parent, pgsz);
for (ushort i = 0; i < pa.Rows; i++)
{
if (pa.Table[i].Address == adr)
{
pos.Page = pa;
pos.Row = i;
return;
}
}
throw new System.InvalidOperationException("MinBase: Index file " + fle.LoFile.Name + " corrupted: tying to find record by address");
}
public bool Jump(DataFile fle, long jmp, IdxPos pos)
{
pos.OnPage = true;
while (true)
{
jmp = pos.Page.Jump(jmp, pos);
if (jmp == 0)
{
return(true);
}
if (pos.PageAdr == 0)
{
return(false);
}
fle.Read(pos.Page, pos.PageAdr, PageSize);
}
}
internal static void Open(string nm, Table obj, mpIndexKey gkey, string xn)
{
TableFile db;
SyncOpen.WaitOne();
if (OpenList.TryGetValue(nm, out db))
{
db.OpenCount++;
}
else
{
db = new TableFile();
db.Alias = nm;
db.File = DataFile.Open(nm, "Table", FileMode.Open);
db.Struct = new Struct();
int sz = DataFile.GetSize(db.Struct);
db.File.Read(db.Struct, DataFile.coSignatureSz, sz);
db.File.Lock(db.Struct);
db.OpenCount = 1;
db.Data = DataFile.coSignatureSz + sz;
long cz = db.Data + db.Struct.RowLength * db.Struct.RowCount;
long fz = db.File.LoFile.Length;
if (cz != fz)
{
db.Struct.LastUpdate = DateTime.Now;
db.File.Write(db.Struct);
db.File.CopyTo(String.Format("{0}{1:yyyy}{1:MM}{1:dd}{1:HH}{1:mm}{1:ss}", nm, db.Struct.LastUpdate), "BackupTable");
db.File.LoFile.SetLength(cz);
}
OpenList.Add(nm, db);
}
SyncOpen.ReleaseMutex();
obj.LoTable = db;
if (gkey == null)
{
obj.Order = null;
}
else
{
obj.Order = db.SetView(obj, xn, gkey);
}
obj.First();
}
public void Check(DataFile fle)
{
if (Root == 0)
{
if (Keys > 0)
{
throw new System.InvalidOperationException("Index has no root but does contain keys.");
}
return;
}
if (Keys == 0)
{
throw new System.InvalidOperationException("Index is not empty while it should.");
}
IdxPage pg = new IdxPage(0, 0, 0, KeyLength);
fle.Read(pg, Root, PageSize);
pg.Check(fle, this, Levels);
}
public static DataFile Open(string name, string type, FileMode mo)
{
DataFile fle = new DataFile();
string fname = dbPath + "/" + name + "." + type;
bool exists = File.Exists(fname);
switch (mo)
{
case FileMode.CreateNew:
if (exists)
{
throw new System.InvalidOperationException("MinBase: Cannot create file " + fname + " because it already exists.");
}
if (!Directory.Exists(dbPath))
{
Directory.CreateDirectory(dbPath);
}
break;
case FileMode.Open:
if (!exists)
{
throw new System.InvalidOperationException("MinBase: Cannot open file " + fname + " becuase it does not exist.");
}
break;
}
fle.LoFile = new FileStream(fname, mo);
if (mo == FileMode.CreateNew)
{
byte[] si = BitConverter.GetBytes(coSignature);
fle.LoFile.Write(si, 0, sizeof(long));
}
else
{
byte[] si = new byte[sizeof(long)];
fle.LoFile.Read(si, 0, sizeof(long));
if (BitConverter.ToInt64(si, 0) != coSignature)
{
throw new System.InvalidOperationException("MinBase: File " + fle.LoFile.Name + " is not in a valid MinBase format.");
}
}
return(fle);
}
internal void Blank(Table obj)
{
DataFile.Blank(obj, Struct.RowLength);
}
internal static bool Exists(string nm)
{
return(DataFile.Exists(nm, "Table"));
}
public void Check(DataFile fle, IdxRoot root, ushort lvl)
{
int pgsz = root.PageSize;
ushort kyln = root.KeyLength;
long fa, la, pa, na, xa, va;
int i, j, c, ct;
IdxPage fr, ls, mp, mn, pp;
string ok;
bool err, cr;
if (Parent != 0)
{
throw new System.InvalidOperationException("Wrong root page.");
}
if (root.Root != Buffer.Position)
{
throw new System.InvalidOperationException("Wrong root page.");
}
fr = new IdxPage(0, 0, 0, kyln);
ls = new IdxPage(0, 0, 0, kyln);
pp = new IdxPage(0, 0, 0, kyln);
cr = true;
ct = 0;
fa = root.First;
la = root.Last;
while (true)
{
fle.Read(fr, fa, pgsz);
if (fr.Previous != 0)
{
throw new System.InvalidOperationException("Wrong first page.");
}
fle.Read(ls, la, pgsz);
if (ls.Next != 0)
{
throw new System.InvalidOperationException("Wrong last page.");
}
mp = fr;
mn = ls;
while (true)
{
if (mp.Rows > coOrder || (mp.Rows < coMin && mp.Parent != 0))
{
throw new System.InvalidOperationException("Wrong number of rows.");
}
if (mp.Parent != 0)
{
fle.Read(pp, mp.Parent, pgsz);
err = true;
for (j = 0; j < pp.Rows; j++)
{
if (pp.Table[j].Address == mp.Buffer.Position)
{
if (pp.Table[j].Key != mp.Table[mp.Rows - 1].Key)
{
throw new System.InvalidOperationException("Last key on this page does not match link key on parent page.");
}
err = false;
break;
}
}
if (err)
{
throw new System.InvalidOperationException("Link with parent page is wrong.");
}
}
if (cr)
{
ct += mp.Rows;
}
ok = "";
for (i = 0; i < mp.Rows; i++)
{
c = string.Compare(ok, mp.Table[i].Key);
if (c > 0)
{
throw new System.InvalidOperationException("Wrong key order.");
}
ok = mp.Table[i].Key;
}
if (mp.Next == 0)
{
if (mn.Previous != 0)
{
throw new System.InvalidOperationException("Wrong sibling link.");
}
break;
}
pa = mp.Buffer.Position;
na = mn.Buffer.Position;
xa = mp.Next;
va = mn.Previous;
mp = new IdxPage(0, 0, 0, kyln);
mn = new IdxPage(0, 0, 0, kyln);
fle.Read(mp, xa, pgsz);
fle.Read(mn, va, pgsz);
if (mp.Previous != pa)
{
throw new System.InvalidOperationException("Wrong next page.");
}
if (mn.Next != na)
{
throw new System.InvalidOperationException("Wrong previous page.");
}
c = string.Compare(ok, mp.Table[0].Key);
if (c > 0)
{
throw new System.InvalidOperationException("Wrong page-to-page key order.");
}
}
if (cr)
{
cr = false;
if (ct != root.Keys)
{
throw new System.InvalidOperationException("Wrong parent link.");
}
}
fa = fr.Parent;
la = ls.Parent;
if (fa == 0 || la == 0)
{
if (la != 0 || fa != 0)
{
throw new System.InvalidOperationException("Wrong parent link.");
}
break;
}
}
}
public void Remove(DataFile fle, string key, long adr, bool branch, IdxRoot root, IdxPos pos)
{
ushort i;
ushort row = pos.Row;
int pgsz = root.PageSize;
ushort kyln = root.KeyLength;
if (Rows > coMin || Parent == 0)
{
if (Rows == 1)
{
root.Root = root.First = root.Last = 0;
root.Levels = 0;
fle.Write(root);
return;
}
Rows--;
if (row == Rows)
{
LinkParent(fle, kyln, pgsz);
}
else
{
for (i = row; i < Rows; i++)
{
Table[i].Key = Table[i + 1].Key;
Table[i].Address = Table[i + 1].Address;
}
}
fle.Write(this);
fle.Write(root);
return;
}
ushort pz, nz, f, t, dx;
IdxPage pv, nx;
if (Previous > 0)
{
pv = new IdxPage(0, 0, 0, kyln);
fle.Read(pv, Previous, pgsz);
pz = pv.Rows;
}
else
{
pv = null;
pz = coOrder + coOrder;
}
if (Next > 0)
{
nx = new IdxPage(0, 0, 0, kyln);
fle.Read(nx, Next, pgsz);
nz = nx.Rows;
}
else
{
nx = null;
nz = coOrder + coOrder;
}
Rows--;
if (pz < nz)
{
if (pv.Rows == coMin)
{
t = coMin;
f = 0;
for (i = 0; i < Rows; i++)
{
if (i == row)
{
f++;
}
pv.Table[t].Key = Table[f].Key;
pv.Table[t].Address = Table[f].Address;
if (branch)
{
pv.LinkChild(fle, Table[f].Address, kyln, pgsz);
}
t++;
f++;
}
pv.Rows += Rows;
pv.Next = Next;
if (Next == 0)
{
if (!branch)
{
root.Last = Previous;
}
if (pv.Previous == 0)
{
pv.Parent = 0;
fle.Write(pv);
root.Root = Previous;
root.Levels--;
fle.Write(root);
return;
}
}
else
{
nx.Previous = Previous;
fle.Write(nx);
}
pv.LinkParent(fle, kyln, pgsz);
fle.Write(pv);
KeyOnParent(fle, kyln, pgsz, pos);
pos.Page.Remove(fle, Table[Rows].Key, this.Buffer.Position, true, root, pos);
return;
}
dx = (ushort)((pv.Rows - coMin) / 2);
if (dx == 0)
{
dx = 1;
}
t = (ushort)(Rows + dx - 1);
f = Rows;
for (i = 0; i < Rows; i++)
{
if (f == row)
{
f--;
}
Table[t].Key = Table[f].Key;
Table[t].Address = Table[f].Address;
f--;
t--;
}
f = (ushort)(pv.Rows - 1);
for (i = 0; i < dx; i++)
{
Table[t].Key = pv.Table[f].Key;
Table[t].Address = pv.Table[f].Address;
if (branch)
{
LinkChild(fle, Table[t].Address, kyln, pgsz);
}
t--;
f--;
}
pv.Rows -= dx;
Rows += dx;
if (row + dx == Rows)
{
LinkParent(fle, kyln, pgsz);
}
pv.LinkParent(fle, kyln, pgsz);
fle.Write(pv);
fle.Write(this);
fle.Write(root);
return;
}
if (nx.Rows == coMin)
{
f = (ushort)(nx.Rows - 1);
t = (ushort)(f + Rows);
for (i = 0; i < nx.Rows; i++)
{
nx.Table[t].Key = nx.Table[f].Key;
nx.Table[t].Address = nx.Table[f].Address;
t--;
f--;
}
f = Rows;
for (i = 0; i < Rows; i++)
{
if (f == row)
{
f--;
}
nx.Table[t].Key = Table[f].Key;
nx.Table[t].Address = Table[f].Address;
if (branch)
{
nx.LinkChild(fle, Table[f].Address, kyln, pgsz);
}
t--;
f--;
}
nx.Rows += Rows;
nx.Previous = Previous;
if (Previous == 0)
{
if (!branch)
{
root.First = Next;
}
if (nx.Next == 0)
{
nx.Parent = 0;
fle.Write(nx);
root.Root = Next;
root.Levels--;
fle.Write(root);
return;
}
}
else
{
pv.Next = Next;
fle.Write(pv);
}
fle.Write(nx);
KeyOnParent(fle, kyln, pgsz, pos);
pos.Page.Remove(fle, Table[Rows].Key, this.Buffer.Position, true, root, pos);
return;
}
for (i = row; i < Rows; i++)
{
Table[i].Key = Table[i + 1].Key;
Table[i].Address = Table[i + 1].Address;
}
dx = (ushort)((nx.Rows - coMin) / 2);
if (dx == 0)
{
dx = 1;
}
t = Rows;
f = 0;
for (i = 0; i < dx; i++)
{
Table[t].Key = nx.Table[f].Key;
Table[t].Address = nx.Table[f].Address;
if (branch)
{
LinkChild(fle, Table[t].Address, kyln, pgsz);
}
f++;
t++;
}
Rows += dx;
nx.Rows -= dx;
t = 0;
for (i = 0; i < nx.Rows; i++)
{
nx.Table[t].Key = nx.Table[f].Key;
nx.Table[t].Address = nx.Table[f].Address;
t++;
f++;
}
LinkParent(fle, kyln, pgsz);
fle.Write(this);
fle.Write(nx);
fle.Write(root);
}
public void Add(DataFile fle, string key, long adr, bool branch, IdxRoot root, IdxPos pos)
{
int i;
ushort j, mx, p, q, m, dx;
int pgsz = root.PageSize;
ushort kyln = root.KeyLength;
ushort row = pos.Row;
if (pos.Result == IdxPos.coIxSmaller)
{
row++;
}
if (Rows < coOrder)
{
for (i = Rows; i > row; i--)
{
Table[i].Key = Table[i - 1].Key;
Table[i].Address = Table[i - 1].Address;
}
Table[row].Key = key;
Table[row].Address = adr;
Rows++;
if (row == Rows - 1)
{
LinkParent(fle, kyln, pgsz);
}
if (root.Root == 0)
{
fle.Append(this, pgsz);
root.Levels = 1;
root.Root = root.First = root.Last = this.Buffer.Position;
}
else
{
fle.Write(this);
if (branch)
{
LinkChild(fle, adr, kyln, pgsz);
}
}
fle.Write(root);
return;
}
IdxPage si = new IdxPage(0, 0, 0, kyln);
if (Previous > 0)
{
fle.Read(si, Previous, root.PageSize);
if (si.Rows < coOrder)
{
dx = (ushort)((coOrder - si.Rows) / 2);
if (dx == 0)
{
dx = 1;
}
if (row < dx)
{
p = (ushort)(si.Rows + row);
q = coOrder + 1;
if (dx == 1)
{
si.Table[si.Rows].Key = key;
si.Table[si.Rows].Address = adr;
si.Rows++;
fle.Write(si);
si.LinkParent(fle, kyln, pgsz);
if (branch)
{
si.LinkChild(fle, adr, kyln, pgsz);
}
return;
}
}
else
{
p = coOrder + 1;
q = (ushort)(row - dx);
}
for (i = 0; i < dx; i++)
{
if (si.Rows == p)
{
si.Table[si.Rows].Key = key;
si.Table[si.Rows].Address = adr;
si.Rows++;
if (branch)
{
si.LinkChild(fle, adr, kyln, pgsz);
}
dx--;
if (dx == i)
{
break;
}
}
si.Table[si.Rows].Key = Table[i].Key;
si.Table[si.Rows].Address = Table[i].Address;
si.Rows++;
if (branch)
{
si.LinkChild(fle, Table[i].Address, kyln, pgsz);
}
}
si.LinkParent(fle, kyln, pgsz);
fle.Write(si);
mx = (ushort)(coOrder - dx);
j = dx;
m = 0;
for (i = 0; i < mx; i++)
{
if (m == q)
{
Table[m].Key = key;
Table[m].Address = adr;
if (branch)
{
LinkChild(fle, adr, kyln, pgsz);
}
m++;
dx--;
if (m == j)
{
break;
}
}
Table[m].Key = Table[j].Key;
Table[m].Address = Table[j].Address;
m++;
j++;
}
Rows -= dx;
if (q == Rows)
{
Table[q].Key = key;
Table[q].Address = adr;
Rows++;
if (branch)
{
LinkChild(fle, adr, kyln, pgsz);
}
}
if (q == Rows - 1)
{
LinkParent(fle, kyln, pgsz);
}
fle.Write(this);
fle.Write(root);
return;
}
}
if (Next > 0)
{
fle.Read(si, Next, pgsz);
if (si.Rows < coOrder)
{
dx = (ushort)((coOrder - si.Rows) / 2);
if (dx == 0)
{
dx = 1;
}
mx = (ushort)(Rows - dx);
if (row > mx)
{
p = (ushort)(row - mx - 1);
}
else
{
p = coOrder + 1;
}
m = (ushort)(si.Rows + dx - 1);
j = (ushort)(m - dx);
for (i = 0; i < si.Rows; i++)
{
si.Table[m].Key = si.Table[j].Key;
si.Table[m].Address = si.Table[j].Address;
m--;
j--;
}
si.Rows += dx;
m = (ushort)(dx - 1);
j = coOrder - 1;
for (i = 0; i < dx; i++)
{
if (m == p)
{
si.Table[m].Key = key;
si.Table[m].Address = adr;
if (branch)
{
si.LinkChild(fle, adr, kyln, pgsz);
}
dx--;
if (m == 0)
{
break;
}
m--;
}
si.Table[m].Key = Table[j].Key;
si.Table[m].Address = Table[j].Address;
if (branch)
{
si.LinkChild(fle, Table[j].Address, kyln, pgsz);
}
m--;
j--;
}
Rows -= dx;
if (p == coOrder + 1)
{
for (i = Rows; i > row; i--)
{
Table[i].Key = Table[i - 1].Key;
Table[i].Address = Table[i - 1].Address;
}
Table[row].Key = key;
Table[row].Address = adr;
if (branch)
{
LinkChild(fle, adr, kyln, pgsz);
}
Rows++;
}
LinkParent(fle, kyln, pgsz);
fle.Write(this);
fle.Write(si);
fle.Write(root);
return;
}
}
si = new IdxPage(Parent, this.Buffer.Position, Next, kyln);
IdxPage pa;
ushort mv = si.Rows = Rows = coMin;
ushort hp, wr;
long thad;
string skey;
if (row >= coMin)
{
hp = (ushort)(row - coMin);
}
else
{
hp = coOrder;
}
wr = 0;
for (i = 0; i < coMin; i++)
{
if (i == hp)
{
si.Table[wr].Key = key;
si.Table[wr].Address = adr;
wr++;
si.Rows++;
}
si.Table[wr].Key = Table[mv].Key;
si.Table[wr].Address = Table[mv].Address;
wr++;
mv++;
}
if (hp == coMin)
{
si.Table[coMin].Key = key;
si.Table[coMin].Address = adr;
si.Rows++;
}
fle.Append(si, pgsz);
Next = si.Buffer.Position;
if (branch)
{
for (i = 0; i < si.Rows; i++)
{
si.LinkChild(fle, si.Table[i].Address, kyln, pgsz);
}
}
if (si.Rows == Rows)
{
for (i = Rows; i > row; i--)
{
Table[i].Key = Table[i - 1].Key;
Table[i].Address = Table[i - 1].Address;
}
Table[row].Key = key;
Table[row].Address = adr;
if (branch)
{
LinkChild(fle, adr, kyln, pgsz);
}
Rows++;
}
if (si.Next == 0)
{
if (!branch)
{
root.Last = Next;
}
if (Parent == 0)
{
pa = new IdxPage(0, 0, 0, kyln);
pa.Rows = 2;
pa.Table[0].Key = Table[Rows - 1].Key;
pa.Table[0].Address = si.Previous;
pa.Table[1].Key = si.Table[si.Rows - 1].Key;
pa.Table[1].Address = Next;
fle.Append(pa, pgsz);
Parent = si.Parent = pa.Buffer.Position;
fle.Write(this);
fle.Write(si);
root.Root = Parent;
root.Levels++;
fle.Write(root);
return;
}
}
else
{
IdxPage ss = new IdxPage(0, 0, 0, kyln);
fle.Read(ss, si.Next, pgsz);
ss.Previous = Next;
fle.Write(ss);
}
LinkParent(fle, kyln, pgsz);
fle.Write(this);
skey = si.Table[si.Rows - 1].Key;
thad = this.Buffer.Position;
pa = new IdxPage(0, 0, 0, kyln);
fle.Read(pa, Parent, pgsz);
for (j = 0; j < pa.Rows; j++)
{
if (pa.Table[j].Address == thad)
{
pos.Row = j;
pos.Result = IdxPos.coIxSmaller;
pa.Add(fle, skey, Next, true, root, pos);
return;
}
}
throw new System.InvalidOperationException("MinBase: Index file " + fle.LoFile.Name + " corrupted, trying to add key.");
}