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Change the SRT_Subroutine mode into SRT_Coroutine. Use co-routines in

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the INSERT processing logic. (CVS 5255)

FossilOrigin-Name: 6b9d92fc3f265ef75c9182e537812490bb818950
This commit is contained in:
drh
2008-06-20 15:24:01 +00:00
parent 2d1d86fbbe
commit e00ee6eb37
6 changed files with 179 additions and 101 deletions
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203
src/insert.c
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@@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.240 2008/06/06 15:04:37 drh Exp $
** $Id: insert.c,v 1.241 2008/06/20 15:24:02 drh Exp $
*/
#include "sqliteInt.h"
@@ -269,7 +269,8 @@ static int xferOptimization(
**
** The code generated follows one of four templates. For a simple
** select with data coming from a VALUES clause, the code executes
** once straight down through. The template looks like this:
** once straight down through. Pseudo-code follows (we call this
** the "1st template"):
**
** open write cursor to <table> and its indices
** puts VALUES clause expressions onto the stack
@@ -287,7 +288,7 @@ static int xferOptimization(
** schemas, including all the same indices, then a special optimization
** is invoked that copies raw records from <table2> over to <table1>.
** See the xferOptimization() function for the implementation of this
** template. This is the second template.
** template. This is the 2nd template.
**
** open a write cursor to <table>
** open read cursor on <table2>
@@ -300,45 +301,58 @@ static int xferOptimization(
** close cursors
** end foreach
**
** The third template is for when the second template does not apply
** The 3rd template is for when the second template does not apply
** and the SELECT clause does not read from <table> at any time.
** The generated code follows this template:
**
** EOF <- 0
** X <- A
** goto B
** A: setup for the SELECT
** loop over the rows in the SELECT
** gosub C
** load values into registers R..R+n
** yield X
** end loop
** cleanup after the SELECT
** goto D
** B: open write cursor to <table> and its indices
** EOF <- 1
** yield X
** goto A
** C: insert the select result into <table>
** return
** B: open write cursor to <table> and its indices
** C: yield X
** if EOF goto D
** insert the select result into <table> from R..R+n
** goto C
** D: cleanup
**
** The fourth template is used if the insert statement takes its
** The 4th template is used if the insert statement takes its
** values from a SELECT but the data is being inserted into a table
** that is also read as part of the SELECT. In the third form,
** we have to use a intermediate table to store the results of
** the select. The template is like this:
**
** EOF <- 0
** X <- A
** goto B
** A: setup for the SELECT
** loop over the tables in the SELECT
** gosub C
** load value into register R..R+n
** yield X
** end loop
** cleanup after the SELECT
** goto D
** C: insert the select result into the intermediate table
** return
** B: open a cursor to an intermediate table
** goto A
** D: open write cursor to <table> and its indices
** loop over the intermediate table
** EOF <- 1
** yield X
** halt-error
** B: open temp table
** L: yield X
** if EOF goto M
** insert row from R..R+n into temp table
** goto L
** M: open write cursor to <table> and its indices
** rewind temp table
** C: loop over rows of intermediate table
** transfer values form intermediate table into <table>
** end the loop
** cleanup
** end loop
** D: cleanup
*/
void sqlite3Insert(
Parse *pParse, /* Parser context */
@@ -362,10 +376,9 @@ void sqlite3Insert(
int endOfLoop; /* Label for the end of the insertion loop */
int useTempTable = 0; /* Store SELECT results in intermediate table */
int srcTab = 0; /* Data comes from this temporary cursor if >=0 */
int iCont=0,iBreak=0; /* Beginning and end of the loop over srcTab */
int iSelectLoop = 0; /* Address of code that implements the SELECT */
int iCleanup = 0; /* Address of the cleanup code */
int iInsertBlock = 0; /* Address of the subroutine used to insert data */
int addrInsTop = 0; /* Jump to label "D" */
int addrCont = 0; /* Top of insert loop. Label "C" in templates 3 and 4 */
int addrSelect = 0; /* Address of coroutine that implements the SELECT */
SelectDest dest; /* Destination for SELECT on rhs of INSERT */
int newIdx = -1; /* Cursor for the NEW pseudo-table */
int iDb; /* Index of database holding TABLE */
@@ -380,6 +393,7 @@ void sqlite3Insert(
int regRowid; /* registers holding insert rowid */
int regData; /* register holding first column to insert */
int regRecord; /* Holds the assemblied row record */
int regEof; /* Register recording end of SELECT data */
int *aRegIdx = 0; /* One register allocated to each index */
@@ -461,6 +475,8 @@ void sqlite3Insert(
**
** Then special optimizations can be applied that make the transfer
** very fast and which reduce fragmentation of indices.
**
** This is the 2nd template.
*/
if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){
assert( !triggers_exist );
@@ -475,75 +491,104 @@ void sqlite3Insert(
regAutoinc = autoIncBegin(pParse, iDb, pTab);
/* Figure out how many columns of data are supplied. If the data
** is coming from a SELECT statement, then this step also generates
** all the code to implement the SELECT statement and invoke a subroutine
** to process each row of the result. (Template 2.) If the SELECT
** statement uses the the table that is being inserted into, then the
** subroutine is also coded here. That subroutine stores the SELECT
** results in a temporary table. (Template 3.)
** is coming from a SELECT statement, then generate a co-routine that
** produces a single row of the SELECT on each invocation. The
** co-routine is the common header to the 3rd and 4th templates.
*/
if( pSelect ){
/* Data is coming from a SELECT. Generate code to implement that SELECT
** as a co-routine. The code is common to both the 3rd and 4th
** templates:
**
** EOF <- 0
** X <- A
** goto B
** A: setup for the SELECT
** loop over the tables in the SELECT
** load value into register R..R+n
** yield X
** end loop
** cleanup after the SELECT
** EOF <- 1
** yield X
** halt-error
**
** On each invocation of the co-routine, it puts a single row of the
** SELECT result into registers dest.iMem...dest.iMem+dest.nMem-1.
** (These output registers are allocated by sqlite3Select().) When
** the SELECT completes, it sets the EOF flag stored in regEof.
*/
int rc, iInitCode;
int rc, j1;
iInitCode = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
iSelectLoop = sqlite3VdbeCurrentAddr(v);
iInsertBlock = sqlite3VdbeMakeLabel(v);
sqlite3SelectDestInit(&dest, SRT_Subroutine, iInsertBlock);
dest.regReturn = ++pParse->nMem;
regEof = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regEof); /* EOF <- 0 */
VdbeComment((v, "SELECT eof flag"));
sqlite3SelectDestInit(&dest, SRT_Coroutine, 0);
dest.regCoroutine = ++pParse->nMem;
addrSelect = sqlite3VdbeCurrentAddr(v)+2;
sqlite3VdbeAddOp2(v, OP_Integer, addrSelect-1, dest.regCoroutine);
j1 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
VdbeComment((v, "Jump over SELECT coroutine"));
/* Resolve the expressions in the SELECT statement and execute it. */
rc = sqlite3Select(pParse, pSelect, &dest, 0, 0, 0, 0);
if( rc || pParse->nErr || db->mallocFailed ){
goto insert_cleanup;
}
sqlite3VdbeAddOp2(v, OP_Integer, 1, regEof); /* EOF <- 1 */
sqlite3VdbeAddOp1(v, OP_Yield, dest.regCoroutine); /* yield X */
sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_INTERNAL, OE_Abort);
VdbeComment((v, "End of SELECT coroutine"));
sqlite3VdbeJumpHere(v, j1); /* label B: */
regFromSelect = dest.iMem;
iCleanup = sqlite3VdbeMakeLabel(v);
sqlite3VdbeAddOp2(v, OP_Goto, 0, iCleanup);
assert( pSelect->pEList );
nColumn = pSelect->pEList->nExpr;
assert( dest.nMem==nColumn );
/* Set useTempTable to TRUE if the result of the SELECT statement
** should be written into a temporary table. Set to FALSE if each
** row of the SELECT can be written directly into the result table.
** should be written into a temporary table (template 4). Set to
** FALSE if each* row of the SELECT can be written directly into
** the destination table (template 3).
**
** A temp table must be used if the table being updated is also one
** of the tables being read by the SELECT statement. Also use a
** temp table in the case of row triggers.
*/
if( triggers_exist || readsTable(v, iSelectLoop, iDb, pTab) ){
if( triggers_exist || readsTable(v, addrSelect, iDb, pTab) ){
useTempTable = 1;
}
if( useTempTable ){
/* Generate the subroutine that SELECT calls to process each row of
** the result. Store the result in a temporary table
/* Invoke the coroutine to extract information from the SELECT
** and add it to a transient table srcTab. The code generated
** here is from the 4th template:
**
** B: open temp table
** L: yield X
** if EOF goto M
** insert row from R..R+n into temp table
** goto L
** M: ...
*/
int regRec, regRowid;
int regRec; /* Register to hold packed record */
int regRowid; /* Register to hold temp table ROWID */
int addrTop; /* Label "L" */
int addrIf; /* Address of jump to M */
srcTab = pParse->nTab++;
regRec = sqlite3GetTempReg(pParse);
regRowid = sqlite3GetTempReg(pParse);
sqlite3VdbeResolveLabel(v, iInsertBlock);
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
addrTop = sqlite3VdbeAddOp1(v, OP_Yield, dest.regCoroutine);
addrIf = sqlite3VdbeAddOp1(v, OP_If, regEof);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regRowid);
sqlite3VdbeAddOp1(v, OP_Return, dest.regReturn);
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
sqlite3VdbeJumpHere(v, addrIf);
sqlite3ReleaseTempReg(pParse, regRec);
sqlite3ReleaseTempReg(pParse, regRowid);
/* The following code runs first because the GOTO at the very top
** of the program jumps to it. Create the temporary table, then jump
** back up and execute the SELECT code above.
*/
sqlite3VdbeJumpHere(v, iInitCode);
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
sqlite3VdbeAddOp2(v, OP_Goto, 0, iSelectLoop);
sqlite3VdbeResolveLabel(v, iCleanup);
}else{
sqlite3VdbeJumpHere(v, iInitCode);
}
}else{
/* This is the case if the data for the INSERT is coming from a VALUES
@@ -657,18 +702,31 @@ void sqlite3Insert(
}
}
/* If the data source is a temporary table, then we have to create
** a loop because there might be multiple rows of data. If the data
** source is a subroutine call from the SELECT statement, then we need
** to launch the SELECT statement processing.
*/
/* This is the top of the main insertion loop */
if( useTempTable ){
iBreak = sqlite3VdbeMakeLabel(v);
sqlite3VdbeAddOp2(v, OP_Rewind, srcTab, iBreak);
iCont = sqlite3VdbeCurrentAddr(v);
/* This block codes the top of loop only. The complete loop is the
** following pseudocode (template 4):
**
** rewind temp table
** C: loop over rows of intermediate table
** transfer values form intermediate table into <table>
** end loop
** D: ...
*/
addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab);
addrCont = sqlite3VdbeCurrentAddr(v);
}else if( pSelect ){
sqlite3VdbeAddOp2(v, OP_Goto, 0, iSelectLoop);
sqlite3VdbeResolveLabel(v, iInsertBlock);
/* This block codes the top of loop only. The complete loop is the
** following pseudocode (template 3):
**
** C: yield X
** if EOF goto D
** insert the select result into <table> from R..R+n
** goto C
** D: ...
*/
addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.regCoroutine);
addrInsTop = sqlite3VdbeAddOp1(v, OP_If, regEof);
}
/* Allocate registers for holding the rowid of the new row,
@@ -893,16 +951,17 @@ void sqlite3Insert(
}
}
/* The bottom of the loop, if the data source is a SELECT statement
/* The bottom of the main insertion loop, if the data source
** is a SELECT statement.
*/
sqlite3VdbeResolveLabel(v, endOfLoop);
if( useTempTable ){
sqlite3VdbeAddOp2(v, OP_Next, srcTab, iCont);
sqlite3VdbeResolveLabel(v, iBreak);
sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont);
sqlite3VdbeJumpHere(v, addrInsTop);
sqlite3VdbeAddOp1(v, OP_Close, srcTab);
}else if( pSelect ){
sqlite3VdbeAddOp1(v, OP_Return, dest.regReturn);
sqlite3VdbeResolveLabel(v, iCleanup);
sqlite3VdbeAddOp2(v, OP_Goto, 0, addrCont);
sqlite3VdbeJumpHere(v, addrInsTop);
}
if( !IsVirtual(pTab) && !isView ){