static void UpdateVirtualTable(Parse parse, SrcList src, Table table, ExprList changes, Expr rowid, int[] xrefs, Expr where_, int onError)
{
int i;
Context ctx = parse.Ctx; // Database connection
VTable vtable = VTable.GetVTable(ctx, table);
SelectDest dest = new SelectDest();
// Construct the SELECT statement that will find the new values for all updated rows.
ExprList list = ExprList.Append(parse, 0, Expr.Expr(ctx, TK.ID, "_rowid_")); // The result set of the SELECT statement
if (rowid != null)
{
list = ExprList.Append(parse, list, Expr.Dup(ctx, rowid, 0));
}
Debug.Assert(table.PKey < 0);
for (i = 0; i < table.Cols.length; i++)
{
Expr expr = (xrefs[i] >= 0 ? Expr.Dup(ctx, changes.Ids[xrefs[i]].Expr, 0) : Expr.Expr(ctx, TK.ID, table.Cols[i].Name)); // Temporary expression
list = ExprList.Append(parse, list, expr);
}
Select select = Select.New(parse, list, src, where_, null, null, null, 0, null, null); // The SELECT statement
// Create the ephemeral table into which the update results will be stored.
Vdbe v = parse.V; // Virtual machine under construction
Debug.Assert(v != null);
int ephemTab = parse.Tabs++; // Table holding the result of the SELECT
v.AddOp2(OP.OpenEphemeral, ephemTab, table.Cols.length + 1 + (rowid != null ? 1 : 0));
v.ChangeP5(BTREE_UNORDERED);
// fill the ephemeral table
Select.DestInit(dest, SRT.Table, ephemTab);
Select.Select(parse, select, ref dest);
// Generate code to scan the ephemeral table and call VUpdate.
int regId = ++parse.Mems;// First register in set passed to OP_VUpdate
parse.Mems += table.Cols.length + 1;
int addr = v.AddOp2(OP.Rewind, ephemTab, 0); // Address of top of loop
v.AddOp3(OP.Column, ephemTab, 0, regId);
v.AddOp3(OP.Column, ephemTab, (rowid != null ? 1 : 0), regId + 1);
for (i = 0; i < table.nCol; i++)
{
v.AddOp3(OP.Column, ephemTab, i + 1 + (rowid != null ? 1 : 0), regId + 2 + i);
}
sqlite3VtabMakeWritable(parse, table);
v.AddOp4(OP_VUpdate, 0, table.Cols.length + 2, regId, vtable, P4_VTAB);
v.ChangeP5((byte)(onError == OE_Default ? OE_Abort : onError));
parse.MayAbort();
v.AddOp2(OP.Next, ephemTab, addr + 1);
v.JumpHere(addr);
v.AddOp2(OP.Close, ephemTab, 0);
// Cleanup
Select.Delete(ctx, ref select);
}
static void OpenStatTable(Parse parse, int db, int statCur, string where_, string whereType)
{
int[] roots = new int[] { 0, 0 };
byte[] createTbls = new byte[] { 0, 0 };
Context ctx = parse.Ctx;
Vdbe v = parse.GetVdbe();
if (v == null)
{
return;
}
Debug.Assert(Btree.HoldsAllMutexes(ctx));
Debug.Assert(v.Ctx == ctx);
Context.DB dbObj = ctx.DBs[db];
for (int i = 0; i < _tables.Length; i++)
{
string tableName = _tables[i].Name;
Table stat;
if ((stat = Parse.FindTable(ctx, tableName, dbObj.Name)) == null)
{
// The sqlite_stat[12] table does not exist. Create it. Note that a side-effect of the CREATE TABLE statement is to leave the rootpage
// of the new table in register pParse.regRoot. This is important because the OpenWrite opcode below will be needing it.
parse.NestedParse("CREATE TABLE %Q.%s(%s)", dbObj.Name, tableName, _tables[i].Cols);
roots[i] = parse.RegRoot;
createTbls[i] = Vdbe::OPFLAG_P2ISREG;
}
else
{
// The table already exists. If zWhere is not NULL, delete all entries associated with the table zWhere. If zWhere is NULL, delete the
// entire contents of the table.
roots[i] = stat.Id;
sqlite3TableLock(parse, db, roots[i], 1, tableName);
if (where_ == null)
{
parse.NestedParse("DELETE FROM %Q.%s WHERE %s=%Q", dbObj.Name, tableName, whereType, where_);
}
else
{
v.AddOp2(OP.Clear, roots[i], db); // The sqlite_stat[12] table already exists. Delete all rows.
}
}
}
// Open the sqlite_stat[12] tables for writing.
for (int i = 0; i < _tables.Length; i++)
{
v.AddOp3(OP.OpenWrite, statCur + i, roots[i], db);
v.ChangeP4(-1, 3, Vdbe.P4T.INT32);
v.ChangeP5(createTbls[i]);
}
}
static void CodeAttach(Parse parse, AUTH type, FuncDef func, Expr authArg, Expr filename, Expr dbName, Expr key)
{
Context ctx = parse.Ctx;
NameContext sName;
sName = new NameContext();
sName.Parse = parse;
if (ResolveAttachExpr(sName, filename) != RC.OK || ResolveAttachExpr(sName, dbName) != RC.OK || ResolveAttachExpr(sName, key) != RC.OK)
{
parse.Errs++;
goto attach_end;
}
#if !OMIT_AUTHORIZATION
if (authArg != null)
{
string authArgToken = (authArg.OP == TK.STRING ? authArg.u.Token : null);
ARC arc = Auth.Check(parse, type, authArgToken, null, null);
if (arc != ARC.OK)
{
goto attach_end;
}
}
#endif
Vdbe v = parse.GetVdbe();
int regArgs = Expr.GetTempRange(parse, 4);
Expr.Code(parse, filename, regArgs);
Expr.Code(parse, dbName, regArgs + 1);
Expr.Code(parse, key, regArgs + 2);
Debug.Assert(v != null || ctx.MallocFailed);
if (v != null)
{
v.AddOp3(OP.Function, 0, regArgs + 3 - func.Args, regArgs + 3);
Debug.Assert(func.Args == -1 || (func.Args & 0xff) == func.Args);
v.ChangeP5((byte)(func.Args));
v.ChangeP4(-1, func, Vdbe.P4T.FUNCDEF);
// Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this statement only). For DETACH, set it to false (expire all existing statements).
v.AddOp1(OP.Expire, (type == AUTH.ATTACH ? 1 : 0));
}
attach_end:
Expr.Delete(ctx, ref filename);
Expr.Delete(ctx, ref dbName);
Expr.Delete(ctx, ref key);
}
public static void DeleteFrom(Parse parse, SrcList tabList, Expr where_)
{
AuthContext sContext = new AuthContext(); // Authorization context
Context ctx = parse.Ctx; // Main database structure
if (parse.Errs != 0 || ctx.MallocFailed)
goto delete_from_cleanup;
Debug.Assert(tabList.Srcs == 1);
// Locate the table which we want to delete. This table has to be put in an SrcList structure because some of the subroutines we
// will be calling are designed to work with multiple tables and expect an SrcList* parameter instead of just a Table* parameter.
Table table = SrcList.Lookup(parse, tabList); // The table from which records will be deleted
if (table == null) goto delete_from_cleanup;
// Figure out if we have any triggers and if the table being deleted from is a view
#if !OMIT_TRIGGER
int dummy;
Trigger trigger = Triggers.Exist(parse, table, TK.DELETE, null, out dummy); // List of table triggers, if required
#if OMIT_VIEW
const bool isView = false;
#else
bool isView = (table.Select != null); // True if attempting to delete from a view
#endif
#else
const Trigger trigger = null;
bool isView = false;
#endif
// If pTab is really a view, make sure it has been initialized.
if (sqlite3ViewGetColumnNames(parse, table) != null || IsReadOnly(parse, table, (trigger != null)))
goto delete_from_cleanup;
int db = sqlite3SchemaToIndex(ctx, table.Schema); // Database number
Debug.Assert(db < ctx.DBs.length);
string dbName = ctx.DBs[db].Name; // Name of database holding pTab
ARC rcauth = Auth.Check(parse, AUTH.DELETE, table.Name, 0, dbName); // Value returned by authorization callback
Debug.Assert(rcauth == ARC.OK || rcauth == ARC.DENY || rcauth == ARC.IGNORE);
if (rcauth == ARC.DENY)
goto delete_from_cleanup;
Debug.Assert(!isView || trigger != null);
// Assign cursor number to the table and all its indices.
Debug.Assert(tabList.Srcs == 1);
int curId = tabList.Ids[0].Cursor = parse.Tabs++; // VDBE VdbeCursor number for pTab
Index idx; // For looping over indices of the table
for (idx = table.Index; idx != null; idx = idx.Next)
parse.Tabs++;
// Start the view context
if (isView)
Auth.ContextPush(parse, sContext, table.Name);
// Begin generating code.
Vdbe v = parse.GetVdbe(); // The virtual database engine
if (v == null)
goto delete_from_cleanup;
if (parse.Nested == 0) v.CountChanges();
parse.BeginWriteOperation(1, db);
// If we are trying to delete from a view, realize that view into a ephemeral table.
#if !OMIT_VIEW && !OMIT_TRIGGER
if (isView)
MaterializeView(parse, table, where_, curId);
#endif
// Resolve the column names in the WHERE clause.
NameContext sNC = new NameContext(); // Name context to resolve expressions in
sNC.Parse = parse;
sNC.SrcList = tabList;
if (sqlite3ResolveExprNames(sNC, ref where_) != 0)
goto delete_from_cleanup;
// Initialize the counter of the number of rows deleted, if we are counting rows.
int memCnt = -1; // Memory cell used for change counting
if ((ctx.Flags & Context.FLAG.CountRows) != 0)
{
memCnt = ++parse.Mems;
v.AddOp2(OP.Integer, 0, memCnt);
}
#if !OMIT_TRUNCATE_OPTIMIZATION
// Special case: A DELETE without a WHERE clause deletes everything. It is easier just to erase the whole table. Prior to version 3.6.5,
// this optimization caused the row change count (the value returned by API function sqlite3_count_changes) to be set incorrectly.
if (rcauth == ARC.OK && where_ == null && trigger == null && !IsVirtual(table) && !FKey.FkRequired(parse, table, null, 0))
{
Debug.Assert(!isView);
v.AddOp4(OP.Clear, table.Id, db, memCnt, table.Name, Vdbe.P4T.STATIC);
for (idx = table.Index; idx != null; idx = idx.Next)
{
Debug.Assert(idx.Schema == table.Schema);
v.AddOp2(OP.Clear, idx.Id, db);
}
}
else
#endif
// The usual case: There is a WHERE clause so we have to scan through the table and pick which records to delete.
{
int rowSet = ++parse.Mems; // Register for rowset of rows to delete
int rowid = ++parse.Mems; // Used for storing rowid values.
// Collect rowids of every row to be deleted.
v.AddOp2(OP.Null, 0, rowSet);
ExprList dummy = null;
WhereInfo winfo = Where.Begin(parse, tabList, where_, ref dummy, WHERE_DUPLICATES_OK, 0); // Information about the WHERE clause
if (winfo == null) goto delete_from_cleanup;
int regRowid = Expr.CodeGetColumn(parse, table, -1, curId, rowid); // Actual register containing rowids
v.AddOp2(OP.RowSetAdd, rowSet, regRowid);
if ((ctx.Flags & Context.FLAG.CountRows) != 0)
v.AddOp2(OP.AddImm, memCnt, 1);
Where.End(winfo);
// Delete every item whose key was written to the list during the database scan. We have to delete items after the scan is complete
// because deleting an item can change the scan order.
int end = v.MakeLabel();
// Unless this is a view, open cursors for the table we are deleting from and all its indices. If this is a view, then the
// only effect this statement has is to fire the INSTEAD OF triggers.
if (!isView)
sqlite3OpenTableAndIndices(parse, table, curId, OP.OpenWrite);
int addr = v.AddOp3(OP.RowSetRead, rowSet, end, rowid);
// Delete the row
#if !OMIT_VIRTUALTABLE
if (IsVirtual(table))
{
VTable vtable = VTable.GetVTable(ctx, table);
VTable.MakeWritable(parse, table);
v.AddOp4(OP.VUpdate, 0, 1, rowid, vtable, Vdbe.P4T.VTAB);
v.ChangeP5(OE.Abort);
sqlite3MayAbort(parse);
}
else
#endif
{
int count = (parse.Nested == 0; // True to count changes
GenerateRowDelete(parse, table, curId, rowid, count, trigger, OE.Default);
}
// End of the delete loop
v.AddOp2(OP.Goto, 0, addr);
v.ResolveLabel(end);
// Close the cursors open on the table and its indexes.
if (!isView && !IsVirtual(table))
{
for (int i = 1, idx = table.Index; idx != null; i++, idx = idx.Next)
v.AddOp2(OP.Close, curId + i, idx.Id);
v.AddOp1(OP.Close, curId);
}
}
// Update the sqlite_sequence table by storing the content of the maximum rowid counter values recorded while inserting into
// autoincrement tables.
if (parse.Nested == 0 && parse.TriggerTab == null)
sqlite3AutoincrementEnd(parse);
// Return the number of rows that were deleted. If this routine is generating code because of a call to sqlite3NestedParse(), do not
// invoke the callback function.
if ((ctx.Flags & Context.FLAG.CountRows) != 0 && parse.Nested == 0 && parse.TriggerTab == null)
{
v.AddOp2(OP.ResultRow, memCnt, 1);
v.SetNumCols(1);
v.SetColName(0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);
}
delete_from_cleanup:
Auth.ContextPop(sContext);
SrcList.Delete(ctx, ref tabList);
Expr.Delete(ctx, ref where_);
return;
}
static void AnalyzeOneTable(Parse parse, Table table, Index onlyIdx, int statCurId, int memId)
{
Context ctx = parse.Ctx; // Database handle
int i; // Loop counter
int regTabname = memId++; // Register containing table name
int regIdxname = memId++; // Register containing index name
int regSampleno = memId++; // Register containing next sample number
int regCol = memId++; // Content of a column analyzed table
int regRec = memId++; // Register holding completed record
int regTemp = memId++; // Temporary use register
int regRowid = memId++; // Rowid for the inserted record
Vdbe v = parse.GetVdbe(); // The virtual machine being built up
if (v == null || C._NEVER(table == null))
{
return;
}
// Do not gather statistics on views or virtual tables or system tables
if (table.Id == 0 || table.Name.StartsWith("sqlite_", StringComparison.OrdinalIgnoreCase))
{
return;
}
Debug.Assert(Btree.HoldsAllMutexes(ctx));
int db = sqlite3SchemaToIndex(ctx, table.Schema); // Index of database containing pTab
Debug.Assert(db >= 0);
Debug.Assert(Btree.SchemaMutexHeld(ctx, db, null));
#if !OMIT_AUTHORIZATION
if (Auth.Check(parse, AUTH.ANALYZE, table.Name, 0, ctx.DBs[db].Name))
{
return;
}
#endif
// Establish a read-lock on the table at the shared-cache level.
sqlite3TableLock(parse, db, table.Id, 0, table.Name);
int zeroRows = -1; // Jump from here if number of rows is zero
int idxCurId = parse.Tabs++; // Cursor open on index being analyzed
v.AddOp4(OP.String8, 0, regTabname, 0, table.Name, 0);
for (Index idx = table.Index; idx != null; idx = idx.Next) // An index to being analyzed
{
if (onlyIdx != null && onlyIdx != idx)
{
continue;
}
v.NoopComment("Begin analysis of %s", idx.Name);
int cols = idx.Columns.length;
int[] chngAddrs = C._tagalloc <int>(ctx, cols); // Array of jump instruction addresses
if (chngAddrs == null)
{
continue;
}
KeyInfo key = sqlite3IndexKeyinfo(parse, idx);
if (memId + 1 + (cols * 2) > parse.Mems)
{
parse.Mems = memId + 1 + (cols * 2);
}
// Open a cursor to the index to be analyzed.
Debug.Assert(db == sqlite3SchemaToIndex(ctx, idx.Schema));
v.AddOp4(OP.OpenRead, idxCurId, idx.Id, db, key, Vdbe.P4T.KEYINFO_HANDOFF);
v.VdbeComment("%s", idx.Name);
// Populate the registers containing the index names.
v.AddOp4(OP.String8, 0, regIdxname, 0, idx.Name, 0);
#if ENABLE_STAT3
bool once = false; // One-time initialization
if (once)
{
once = false;
sqlite3OpenTable(parse, tabCurId, db, table, OP.OpenRead);
}
v.AddOp2(OP.Count, idxCurId, regCount);
v.AddOp2(OP.Integer, STAT3_SAMPLES, regTemp1);
v.AddOp2(OP.Integer, 0, regNumEq);
v.AddOp2(OP.Integer, 0, regNumLt);
v.AddOp2(OP.Integer, -1, regNumDLt);
v.AddOp3(OP.Null, 0, regSample, regAccum);
v.AddOp4(OP.Function, 1, regCount, regAccum, (object)_stat3InitFuncdef, Vdbe.P4T.FUNCDEF);
v.ChangeP5(2);
#endif
// The block of memory cells initialized here is used as follows.
//
// iMem:
// The total number of rows in the table.
//
// iMem+1 .. iMem+nCol:
// Number of distinct entries in index considering the left-most N columns only, where N is between 1 and nCol,
// inclusive.
//
// iMem+nCol+1 .. Mem+2*nCol:
// Previous value of indexed columns, from left to right.
//
// Cells iMem through iMem+nCol are initialized to 0. The others are initialized to contain an SQL NULL.
for (i = 0; i <= cols; i++)
{
v.AddOp2(OP.Integer, 0, memId + i);
}
for (i = 0; i < cols; i++)
{
v.AddOp2(OP.Null, 0, memId + cols + i + 1);
}
// Start the analysis loop. This loop runs through all the entries in the index b-tree.
int endOfLoop = v.MakeLabel(); // The end of the loop
v.AddOp2(OP.Rewind, idxCurId, endOfLoop);
int topOfLoop = v.CurrentAddr(); // The top of the loop
v.AddOp2(OP.AddImm, memId, 1);
int addrIfNot = 0; // address of OP_IfNot
for (i = 0; i < cols; i++)
{
v.AddOp3(OP.Column, idxCurId, i, regCol);
if (i == 0) // Always record the very first row
{
addrIfNot = v.AddOp1(OP.IfNot, memId + 1);
}
Debug.Assert(idx.CollNames != null && idx.CollNames[i] != null);
CollSeq coll = sqlite3LocateCollSeq(parse, idx.CollNames[i]);
chngAddrs[i] = v.AddOp4(OP.Ne, regCol, 0, memId + cols + i + 1, coll, Vdbe.P4T.COLLSEQ);
v.ChangeP5(SQLITE_NULLEQ);
v.VdbeComment("jump if column %d changed", i);
#if ENABLE_STAT3
if (i == 0)
{
v.AddOp2(OP.AddImm, regNumEq, 1);
v.VdbeComment("incr repeat count");
}
#endif
}
v.AddOp2(OP.Goto, 0, endOfLoop);
for (i = 0; i < cols; i++)
{
v.JumpHere(chngAddrs[i]); // Set jump dest for the OP_Ne
if (i == 0)
{
v.JumpHere(addrIfNot); // Jump dest for OP_IfNot
#if ENABLE_STAT3
v.AddOp4(OP.Function, 1, regNumEq, regTemp2, (object)Stat3PushFuncdef, Vdbe.P4T.FUNCDEF);
v.ChangeP5(5);
v.AddOp3(OP.Column, idxCurId, idx.Columns.length, regRowid);
v.AddOp3(OP.Add, regNumEq, regNumLt, regNumLt);
v.AddOp2(OP.AddImm, regNumDLt, 1);
v.AddOp2(OP.Integer, 1, regNumEq);
#endif
}
v.AddOp2(OP.AddImm, memId + i + 1, 1);
v.AddOp3(OP.Column, idxCurId, i, memId + cols + i + 1);
}
C._tagfree(ctx, chngAddrs);
// Always jump here after updating the iMem+1...iMem+1+nCol counters
v.ResolveLabel(endOfLoop);
v.AddOp2(OP.Next, idxCurId, topOfLoop);
v.AddOp1(OP.Close, idxCurId);
#if ENABLE_STAT3
v.AddOp4(OP.Function, 1, regNumEq, regTemp2, (object)Stat3PushFuncdef, Vdbe.P4T.FUNCDEF);
v.ChangeP5(5);
v.AddOp2(OP.Integer, -1, regLoop);
int shortJump = v.AddOp2(OP_AddImm, regLoop, 1); // Instruction address
v.AddOp4(OP.Function, 1, regAccum, regTemp1, (object)Stat3GetFuncdef, Vdbe.P4T.FUNCDEF);
v.ChangeP5(2);
v.AddOp1(OP.IsNull, regTemp1);
v.AddOp3(OP.NotExists, tabCurId, shortJump, regTemp1);
v.AddOp3(OP.Column, tabCurId, idx->Columns[0], regSample);
sqlite3ColumnDefault(v, table, idx->Columns[0], regSample);
v.AddOp4(OP.Function, 1, regAccum, regNumEq, (object)Stat3GetFuncdef, Vdbe.P4T.FUNCDEF);
v.ChangeP5(3);
v.AddOp4(OP.Function, 1, regAccum, regNumLt, (object)Stat3GetFuncdef, Vdbe.P4T.FUNCDEF);
v.ChangeP5(4);
v.AddOp4(OP.Function, 1, regAccum, regNumDLt, (object)Stat3GetFuncdef, Vdbe.P4T.FUNCDEF);
v.ChangeP5(5);
v.AddOp4(OP.MakeRecord, regTabname, 6, regRec, "bbbbbb", 0);
v.AddOp2(OP.NewRowid, statCurId + 1, regNewRowid);
v.AddOp3(OP.Insert, statCurId + 1, regRec, regNewRowid);
v.AddOp2(OP.Goto, 0, shortJump);
v.JumpHere(shortJump + 2);
#endif
// Store the results in sqlite_stat1.
//
// The result is a single row of the sqlite_stat1 table. The first two columns are the names of the table and index. The third column
// is a string composed of a list of integer statistics about the index. The first integer in the list is the total number of entries
// in the index. There is one additional integer in the list for each column of the table. This additional integer is a guess of how many
// rows of the table the index will select. If D is the count of distinct values and K is the total number of rows, then the integer is computed
// as:
// I = (K+D-1)/D
// If K==0 then no entry is made into the sqlite_stat1 table.
// If K>0 then it is always the case the D>0 so division by zero is never possible.
v.AddOp2(OP_SCopy, memId, regStat1);
if (zeroRows < 0)
{
zeroRows = v.AddOp1(OP.IfNot, memId);
}
for (i = 0; i < cols; i++)
{
v.AddOp4(OP.String8, 0, regTemp, 0, " ", 0);
v.AddOp3(OP.Concat, regTemp, regStat1, regStat1);
v.AddOp3(OP.Add, memId, memId + i + 1, regTemp);
v.AddOp2(OP.AddImm, regTemp, -1);
v.AddOp3(OP.Divide, memId + i + 1, regTemp, regTemp);
v.AddOp1(OP.ToInt, regTemp);
v.AddOp3(OP.Concat, regTemp, regStat1, regStat1);
}
v.AddOp4(OP.MakeRecord, regTabname, 3, regRec, "aaa", 0);
v.AddOp2(OP.NewRowid, statCurId, regNewRowid);
v.AddOp3(OP.Insert, statCurId, regRec, regNewRowid);
v.ChangeP5(OPFLAG_APPEND);
}
// If the table has no indices, create a single sqlite_stat1 entry containing NULL as the index name and the row count as the content.
if (table.Index == null)
{
v.AddOp3(OP.OpenRead, idxCurId, table->Id, db);
v.VdbeComment("%s", table->Name);
v.AddOp2(OP.Count, idxCurId, regStat1);
v.AddOp1(OP.Close, idxCurId);
zeroRows = v.AddOp1(OP.IfNot, regStat1);
}
else
{
v.JumpHere(zeroRows);
zeroRows = v.AddOp0(OP_Goto);
}
v.AddOp2(OP.Null, 0, regIdxname);
v.AddOp4(OP.MakeRecord, regTabname, 3, regRec, "aaa", 0);
v.AddOp2(OP.NewRowid, statCurId, regNewRowid);
v.AddOp3(OP.Insert, statCurId, regRec, regNewRowid);
v.ChangeP5(OPFLAG_APPEND);
if (parse.Mems < regRec)
{
parse.Mems = regRec;
}
v.JumpHere(zeroRows);
}
