Disclaimed copyright. Preparing for release 2.0. (CVS 250)
FossilOrigin-Name: 4e926efe2b59adfec4086eb1d2ba830238facb4c
diff --git a/src/btree.c b/src/btree.c
index 2dc2d4c..09742e6 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -1,27 +1,15 @@
/*
-** Copyright (c) 2001 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
-** $Id: btree.c,v 1.28 2001/09/15 13:15:13 drh Exp $
+** $Id: btree.c,v 1.29 2001/09/16 00:13:26 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
@@ -53,7 +41,7 @@
** database page. If the payload is larger than MX_LOCAL_PAYLOAD bytes
** then surplus bytes are stored on overflow pages. The payload for an
** entry and the preceding pointer are combined to form a "Cell". Each
-** page has a smaller header which contains the Ptr(N+1) pointer.
+** page has a small header which contains the Ptr(N+1) pointer.
**
** The first page of the file contains a magic string used to verify that
** the file really is a valid BTree database, a pointer to a list of unused
@@ -74,7 +62,7 @@
*/
typedef unsigned int uptr;
-/* There are already definedin sqliteInt.h...
+/* There are already defined in sqliteInt.h...
** typedef unsigned int u32;
** typedef unsigned short int u16;
** typedef unsigned char u8;
@@ -122,7 +110,8 @@
** problem.
**
** The number used was obtained at random and has no special
-** significance.
+** significance other than the fact that it represents a different
+** integer on little-endian and big-endian machines.
*/
#define MAGIC 0xdae37528
diff --git a/src/btree.h b/src/btree.h
index e754427..02cd9b5 100644
--- a/src/btree.h
+++ b/src/btree.h
@@ -1,30 +1,18 @@
/*
-** Copyright (c) 2001 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.
**
-** @(#) $Id: btree.h,v 1.13 2001/09/14 18:54:08 drh Exp $
+** @(#) $Id: btree.h,v 1.14 2001/09/16 00:13:26 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_
diff --git a/src/build.c b/src/build.c
index eb9ea05..b6a5074 100644
--- a/src/build.c
+++ b/src/build.c
@@ -1,29 +1,17 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
-** This file contains C code routines that are called by the parser
-** when syntax rules are reduced. The routines in this file handle
-** the following kinds of syntax:
+** This file contains C code routines that are called by the SQLite parser
+** when syntax rules are reduced. The routines in this file handle the
+** following kinds of SQL syntax:
**
** CREATE TABLE
** DROP TABLE
@@ -32,8 +20,12 @@
** creating expressions and ID lists
** COPY
** VACUUM
+** BEGIN TRANSACTION
+** COMMIT
+** ROLLBACK
+** PRAGMA
**
-** $Id: build.c,v 1.35 2001/09/15 00:57:28 drh Exp $
+** $Id: build.c,v 1.36 2001/09/16 00:13:26 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
diff --git a/src/delete.c b/src/delete.c
index 3d2cff9..2b71230 100644
--- a/src/delete.c
+++ b/src/delete.c
@@ -1,30 +1,18 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle DELETE FROM statements.
**
-** $Id: delete.c,v 1.13 2001/09/15 00:57:29 drh Exp $
+** $Id: delete.c,v 1.14 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
diff --git a/src/expr.c b/src/expr.c
index e5d4535..7710743 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1,30 +1,18 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
-** for generating VDBE code that evaluates expressions.
+** for generating VDBE code that evaluates expressions in SQLite.
**
-** $Id: expr.c,v 1.27 2001/09/14 03:24:25 drh Exp $
+** $Id: expr.c,v 1.28 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
diff --git a/src/insert.c b/src/insert.c
index 28a13cd..3fcb61e 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -1,30 +1,18 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
-** to handle INSERT statements.
+** to handle INSERT statements in SQLite.
**
-** $Id: insert.c,v 1.17 2001/09/15 00:57:29 drh Exp $
+** $Id: insert.c,v 1.18 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
diff --git a/src/main.c b/src/main.c
index e3863e2..c882abf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,24 +1,12 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** Main file for the SQLite library. The routines in this file
@@ -26,7 +14,7 @@
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
-** $Id: main.c,v 1.36 2001/09/15 00:57:29 drh Exp $
+** $Id: main.c,v 1.37 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
#if defined(HAVE_USLEEP) && HAVE_USLEEP
diff --git a/src/pager.c b/src/pager.c
index 4ca2b20..0b8ac72 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -1,33 +1,24 @@
/*
-** Copyright (c) 2001 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
-** This is the implementation of the page cache subsystem.
+** This is the implementation of the page cache subsystem or "pager".
**
-** The page cache is used to access a database file. The pager journals
-** all writes in order to support rollback. Locking is used to limit
-** access to one or more reader or to one writer.
+** The pager is used to access a database disk file. It implements
+** atomic commit and rollback through the use of a journal file that
+** is separate from the database file. The pager also implements file
+** locking to prevent two processes from writing the same database
+** file simultaneously, or one process from reading the database while
+** another is writing.
**
-** @(#) $Id: pager.c,v 1.19 2001/09/15 00:57:29 drh Exp $
+** @(#) $Id: pager.c,v 1.20 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
@@ -103,7 +94,7 @@
** How big to make the hash table used for locating in-memory pages
** by page number. Knuth says this should be a prime number.
*/
-#define N_PG_HASH 907
+#define N_PG_HASH 373
/*
** A open page cache is an instance of the following structure.
@@ -684,7 +675,16 @@
}
/*
-** Sync the journal and write all free dirty pages to the database file.
+** Sync the journal and then write all free dirty pages to the database
+** file.
+**
+** Writing all free dirty pages to the database after the sync is a
+** non-obvious optimization. fsync() is an expensive operation so we
+** want to minimize the number that occur. So after an fsync() is forced
+** and we are free to write dirty pages back to the database, it is best
+** to go ahead and do as much of that as possible to minimize the chance
+** of having to do another fsync() later on. Writing dirty free pages
+** in this way make database operations go up to 10 times faster.
*/
static int syncAllPages(Pager *pPager){
PgHdr *pPg;
@@ -818,6 +818,19 @@
while( pPg->dirty && 0<cnt-- && pPg->pNextFree ){
pPg = pPg->pNextFree;
}
+
+ /* If we could not find a page that has not been used recently
+ ** and which is not dirty, then sync the journal and write all
+ ** dirty free pages into the database file, thus making them
+ ** clean pages and available for recycling.
+ **
+ ** We have to sync the journal before writing a page to the main
+ ** database. But syncing is a very slow operation. So after a
+ ** sync, it is best to write everything we can back to the main
+ ** database to minimize the risk of having to sync again in the
+ ** near future. That is way we write all dirty pages after a
+ ** sync.
+ */
if( pPg==0 || pPg->dirty ){
int rc = syncAllPages(pPager);
if( rc!=0 ){
@@ -828,39 +841,6 @@
pPg = pPager->pFirst;
}
assert( pPg->nRef==0 );
-
-
-#if 0
- /**** Since putting in the call to syncAllPages() above, this code
- ** is no longer used. I've kept it here for historical reference
- ** only.
- */
- /* If the page to be recycled is dirty, sync the journal and write
- ** the old page into the database. */
- if( pPg->dirty ){
- int rc;
- assert( pPg->inJournal==1 );
- assert( pPager->state==SQLITE_WRITELOCK );
- if( pPager->needSync ){
- rc = fsync(pPager->jfd);
- if( rc!=0 ){
- rc = sqlitepager_rollback(pPager);
- *ppPage = 0;
- if( rc==SQLITE_OK ) rc = SQLITE_IOERR;
- return rc;
- }
- pPager->needSync = 0;
- }
- pager_seek(pPager->fd, (pPg->pgno-1)*SQLITE_PAGE_SIZE);
- rc = pager_write(pPager->fd, PGHDR_TO_DATA(pPg), SQLITE_PAGE_SIZE);
- if( rc!=SQLITE_OK ){
- rc = sqlitepager_rollback(pPager);
- *ppPage = 0;
- if( rc==SQLITE_OK ) rc = SQLITE_FULL;
- return rc;
- }
- }
-#endif
assert( pPg->dirty==0 );
/* Unlink the old page from the free list and the hash table
diff --git a/src/pager.h b/src/pager.h
index 3637046..0e72715 100644
--- a/src/pager.h
+++ b/src/pager.h
@@ -1,31 +1,19 @@
/*
-** Copyright (c) 2001 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem. The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
**
-** @(#) $Id: pager.h,v 1.10 2001/09/15 13:15:13 drh Exp $
+** @(#) $Id: pager.h,v 1.11 2001/09/16 00:13:27 drh Exp $
*/
/*
diff --git a/src/parse.y b/src/parse.y
index 373497d..da0eafb 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -1,24 +1,12 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains SQLite's grammar for SQL. Process this file
@@ -26,7 +14,7 @@
** the parser. Lemon will also generate a header file containing
** numeric codes for all of the tokens.
**
-** @(#) $Id: parse.y,v 1.29 2001/09/14 18:54:09 drh Exp $
+** @(#) $Id: parse.y,v 1.30 2001/09/16 00:13:27 drh Exp $
*/
%token_prefix TK_
%token_type {Token}
diff --git a/src/random.c b/src/random.c
index bf666b4..416b5dc 100644
--- a/src/random.c
+++ b/src/random.c
@@ -1,24 +1,12 @@
/*
-** Copyright (c) 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code to implement a pseudo-random number
@@ -27,7 +15,7 @@
** Random numbers are used by some of the database backends in order
** to generate random integer keys for tables or random filenames.
**
-** $Id: random.c,v 1.4 2001/09/14 03:24:25 drh Exp $
+** $Id: random.c,v 1.5 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include <time.h>
diff --git a/src/select.c b/src/select.c
index 07f0fba..7b9c479 100644
--- a/src/select.c
+++ b/src/select.c
@@ -1,30 +1,18 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
-** to handle SELECT statements.
+** to handle SELECT statements in SQLite.
**
-** $Id: select.c,v 1.36 2001/09/14 03:24:25 drh Exp $
+** $Id: select.c,v 1.37 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
diff --git a/src/shell.c b/src/shell.c
index 7548e68..59c5f6a 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -1,30 +1,18 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code to implement the "sqlite" command line
** utility for accessing SQLite databases.
**
-** $Id: shell.c,v 1.32 2001/09/13 13:46:57 drh Exp $
+** $Id: shell.c,v 1.33 2001/09/16 00:13:27 drh Exp $
*/
#include <stdlib.h>
#include <string.h>
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index c22b9cb..d757cd4 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -1,30 +1,18 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
-** This header file defines the interface that the sqlite library
+** This header file defines the interface that the SQLite library
** presents to client programs.
**
-** @(#) $Id: sqlite.h.in,v 1.16 2001/09/15 13:15:13 drh Exp $
+** @(#) $Id: sqlite.h.in,v 1.17 2001/09/16 00:13:27 drh Exp $
*/
#ifndef _SQLITE_H_
#define _SQLITE_H_
@@ -109,9 +97,10 @@
** to the callback function as its first parameter.
**
** The 2nd parameter to the callback function is the number of
-** columns in the query result. The 3rd parameter is an array
-** of string holding the values for each column. The 4th parameter
-** is an array of strings holding the names of each column.
+** columns in the query result. The 3rd parameter to the callback
+** is an array of strings holding the values for each column.
+** The 4th parameter to the callback is an array of strings holding
+** the names of each column.
**
** The callback function may be NULL, even for queries. A NULL
** callback is not an error. It just means that no callback
@@ -120,18 +109,18 @@
** If an error occurs while parsing or evaluating the SQL (but
** not while executing the callback) then an appropriate error
** message is written into memory obtained from malloc() and
-** *errmsg is made to point to that message. If errmsg==NULL,
-** then no error message is ever written. The return value is
-** SQLITE_ERROR if an error occurs. The calling function is
-** responsible for freeing the memory that holds the error
-** message.
+** *errmsg is made to point to that message. The calling function
+** is responsible for freeing the memory that holds the error
+** message. If errmsg==NULL, then no error message is ever written.
+**
+** The return value is is SQLITE_OK if there are no errors and
+** some other return code if there is an error. The particular
+** return value depends on the type of error.
**
** If the query could not be executed because a database file is
** locked or busy, then this function returns SQLITE_BUSY. (This
** behavior can be modified somewhat using the sqlite_busy_handler()
-** and sqlite_busy_timeout() functions below.) If the query could
-** not be executed because a file is missing or has incorrect
-** permissions, this function returns SQLITE_ERROR.
+** and sqlite_busy_timeout() functions below.)
*/
int sqlite_exec(
sqlite*, /* An open database */
@@ -153,7 +142,7 @@
#define SQLITE_NOMEM 6 /* A malloc() failed */
#define SQLITE_READONLY 7 /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT 8 /* Operation terminated by sqlite_interrupt() */
-#define SQLITE_IOERR 9 /* Disk full or other I/O error */
+#define SQLITE_IOERR 9 /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT 10 /* The database disk image is malformed */
#define SQLITE_NOTFOUND 11 /* Table or record not found */
#define SQLITE_FULL 12 /* Insertion failed because database is full */
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index a22061a..9ba03cb 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1,29 +1,17 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
-** @(#) $Id: sqliteInt.h,v 1.50 2001/09/15 14:43:39 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.51 2001/09/16 00:13:27 drh Exp $
*/
#include "sqlite.h"
#include "vdbe.h"
diff --git a/src/table.c b/src/table.c
index 8f61d6f..e27c714 100644
--- a/src/table.c
+++ b/src/table.c
@@ -1,24 +1,12 @@
/*
-** Copyright (c) 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the sqlite_get_table() and sqlite_free_table()
diff --git a/src/tclsqlite.c b/src/tclsqlite.c
index ade3ddb..9537a45 100644
--- a/src/tclsqlite.c
+++ b/src/tclsqlite.c
@@ -1,29 +1,17 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** A TCL Interface to SQLite
**
-** $Id: tclsqlite.c,v 1.22 2001/08/20 00:33:58 drh Exp $
+** $Id: tclsqlite.c,v 1.23 2001/09/16 00:13:27 drh Exp $
*/
#ifndef NO_TCL /* Omit this whole file if TCL is unavailable */
diff --git a/src/test1.c b/src/test1.c
index 64cf61c..09f1b8a 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -1,31 +1,19 @@
/*
-** Copyright (c) 2001 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the printf() interface to SQLite. This code
** is not included in the SQLite library. It is used for automated
** testing of the SQLite library.
**
-** $Id: test1.c,v 1.2 2001/04/11 14:28:43 drh Exp $
+** $Id: test1.c,v 1.3 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
diff --git a/src/test2.c b/src/test2.c
index 70e06eb..e08c189 100644
--- a/src/test2.c
+++ b/src/test2.c
@@ -1,31 +1,19 @@
/*
-** Copyright (c) 2001 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the pager.c module in SQLite. This code
** is not included in the SQLite library. It is used for automated
** testing of the SQLite library.
**
-** $Id: test2.c,v 1.4 2001/08/20 00:33:58 drh Exp $
+** $Id: test2.c,v 1.5 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
diff --git a/src/test3.c b/src/test3.c
index 42f44b3..9dd0841 100644
--- a/src/test3.c
+++ b/src/test3.c
@@ -1,31 +1,19 @@
/*
-** Copyright (c) 2001 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the btree.c module in SQLite. This code
** is not included in the SQLite library. It is used for automated
** testing of the SQLite library.
**
-** $Id: test3.c,v 1.10 2001/09/13 21:53:10 drh Exp $
+** $Id: test3.c,v 1.11 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
diff --git a/src/tokenize.c b/src/tokenize.c
index 8b7e82a..be97113 100644
--- a/src/tokenize.c
+++ b/src/tokenize.c
@@ -1,24 +1,12 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** An tokenizer for SQL
@@ -27,7 +15,7 @@
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
**
-** $Id: tokenize.c,v 1.21 2001/09/14 18:54:09 drh Exp $
+** $Id: tokenize.c,v 1.22 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -305,7 +293,10 @@
/*
** Run the parser on the given SQL string. The parser structure is
-** passed in. An SQLITE_ status code.
+** passed in. An SQLITE_ status code is returned. If an error occurs
+** and pzErrMsg!=NULL then an error message might be written into
+** memory obtained from malloc() and *pzErrMsg made to point to that
+** error message. Or maybe not.
*/
int sqliteRunParser(Parse *pParse, char *zSql, char **pzErrMsg){
int nErr = 0;
diff --git a/src/update.c b/src/update.c
index d84aaa5..62c0241 100644
--- a/src/update.c
+++ b/src/update.c
@@ -1,30 +1,18 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
-** $Id: update.c,v 1.13 2001/09/15 00:57:29 drh Exp $
+** $Id: update.c,v 1.14 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
diff --git a/src/util.c b/src/util.c
index 58103ba..e23561e 100644
--- a/src/util.c
+++ b/src/util.c
@@ -1,24 +1,12 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** Utility functions used throughout sqlite.
@@ -26,7 +14,7 @@
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
-** $Id: util.c,v 1.24 2001/09/15 13:15:13 drh Exp $
+** $Id: util.c,v 1.25 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
diff --git a/src/vdbe.c b/src/vdbe.c
index 6adf20e..cbdae74 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -1,24 +1,12 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** The code in this file implements the Virtual Database Engine (VDBE)
@@ -33,15 +21,16 @@
** ignore all three operands.
**
** Computation results are stored on a stack. Each entry on the
-** stack is either an integer or a null-terminated string. An
-** inplicit conversion from one type to the other occurs as necessary.
+** stack is either an integer, a null-terminated string, a floating point
+** number, or the SQL "NULL" value. An inplicit conversion from one
+** type to the other occurs as necessary.
**
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
-** $Id: vdbe.c,v 1.69 2001/09/15 14:43:39 drh Exp $
+** $Id: vdbe.c,v 1.70 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -1121,8 +1110,12 @@
/* Opcode: Halt * * *
**
-** Exit immediately. All open DBs, Lists, Sorts, etc are closed
+** Exit immediately. All open cursors, Lists, Sorts, etc are closed
** automatically.
+**
+** There is an implied Halt instruction inserted at the very end of
+** every program. So a jump past the last instruction of the program
+** is the same as executing Halt.
*/
case OP_Halt: {
pc = p->nOp-1;
@@ -1185,6 +1178,8 @@
** The top of the stack is element 0. So the
** instruction "Dup 0 0 0" will make a copy of the
** top of the stack.
+**
+** Also see the Pull instruction.
*/
case OP_Dup: {
int i = p->tos - pOp->p1;
@@ -1207,7 +1202,10 @@
** The P1-th element is removed from its current location on
** the stack and pushed back on top of the stack. The
** top of the stack is element 0, so "Pull 0 0 0" is
-** a no-op.
+** a no-op. "Pull 1 0 0" swaps the top two elements of
+** the stack.
+**
+** See also the Dup instruction.
*/
case OP_Pull: {
int from = p->tos - pOp->p1;
@@ -1783,7 +1781,7 @@
** which hold the offset of the beginning of each column data from the
** beginning of the completed record including the header.
**
-** The OP_Column opcode is used to unpack a record manufactured with
+** The Column opcode is used to unpack a record manufactured with
** the opcode.
*/
case OP_MakeRecord: {
@@ -1836,10 +1834,9 @@
/* Opcode: MakeKey P1 P2 *
**
** Convert the top P1 entries of the stack into a single entry suitable
-** for use as the key in an index or a sort. The top P1 records are
-** converted to strings and merged. The null-terminator on each string
-** is retained and used as a separator. The entire string is also
-** null-terminated.
+** for use as the key in an index. The top P1 records are
+** converted to strings and merged. The null-terminators
+** are retained and used as separators.
** The lowest entry in the stack is the first field and the top of the
** stack becomes the last.
**
@@ -1956,8 +1953,12 @@
**
** Begin a transaction. The transaction ends when a Commit or Rollback
** opcode is encountered or whenever there is an execution error that causes
-** a script to abort.
+** a script to abort. A transaction is not ended by a Halt.
**
+** A write lock is obtained on the database file when a transaction is
+** started. No other process can read or write the file while the
+** transaction is underway. Starting a transaction also creates a
+** rollback journal.
** A transaction must be started before any changes can be made to the
** database.
*/
@@ -1970,7 +1971,9 @@
**
** Cause all modifications to the database that have been made since the
** last Transaction to actually take effect. No additional modifications
-** are allowed until another transaction is started.
+** are allowed until another transaction is started. The Commit instruction
+** deletes the journal file and releases the write lock on the database.
+** A read lock continues to be held if there are still cursors open.
*/
case OP_Commit: {
rc = sqliteBtreeCommit(pBt);
@@ -1988,6 +1991,9 @@
** last Transaction to be undone. The database is restored to its state
** before the Transaction opcode was executed. No additional modifications
** are allowed until another transaction is started.
+**
+** This instruction automatically closes all cursors and releases both
+** the read and write locks on the database.
*/
case OP_Rollback: {
rc = sqliteBtreeRollback(pBt);
@@ -1997,15 +2003,15 @@
/* Opcode: ReadCookie * * *
**
-** Read the magic cookie from the database file and push it onto the
-** stack. The magic cookie is an integer that is used like a version
+** Read the schema cookie from the database file and push it onto the
+** stack. The schema cookie is an integer that is used like a version
** number for the database schema. Everytime the schema changes, the
** cookie changes to a new random value. This opcode is used during
** initialization to read the initial cookie value so that subsequent
** database accesses can verify that the cookie has not changed.
**
** There must be a read-lock on the database (either a transaction
-** must be started or there must be a prior OP_Open opcode) before
+** must be started or there must be an open cursor) before
** executing this instruction.
*/
case OP_ReadCookie: {
@@ -2020,10 +2026,10 @@
/* Opcode: SetCookie P1 * *
**
-** This operation changes the value of the cookie on the database.
+** This operation changes the value of the schema cookie on the database.
** The new value is P1.
**
-** The cookie changes its value whenever the database schema changes.
+** The schema cookie changes its value whenever the database schema changes.
** That way, other processes can recognize when the schema has changed
** and reread it.
**
@@ -2041,11 +2047,11 @@
/* Opcode: VerifyCookie P1 * *
**
-** Check the current value of the database cookie and make sure it is
+** Check the current value of the schema cookie and make sure it is
** equal to P1. If it is not, abort with an SQLITE_SCHEMA error.
**
** The cookie changes its value whenever the database schema changes.
-** This operation is used to detech when that the cookie has changed
+** This operation is used to detect when that the cookie has changed
** and that the current process needs to reread the schema.
**
** Either a transaction needs to have been started or an OP_Open needs
@@ -2071,6 +2077,15 @@
**
** If P2==0 then take the root page number from the top of the stack.
**
+** There will be a read lock on the database whenever there is an
+** open cursor. If the database was unlocked prior to this instruction
+** then a read lock is acquired as part of this instruction. A read
+** lock allows other processes to read the database but prohibits
+** any other process from modifying the database. The read lock is
+** released when all cursors are closed. If this instruction attempts
+** to get a read lock but fails, the script terminates with an
+** SQLITE_BUSY error code.
+**
** The P3 value is the name of the table or index being opened.
** The P3 value is not actually used by this opcode and may be
** omitted. But the code generator usually inserts the index or
@@ -2129,7 +2144,7 @@
/* Opcode: OpenTemp P1 * *
**
** Open a new cursor that points to a table in a temporary database
-** file. The temporary file is opened read/write event if the main
+** file. The temporary file is opened read/write even if the main
** database is read-only. The temporary file is deleted when the
** cursor is closed.
*/
@@ -2178,6 +2193,8 @@
** cursor P1 so that it points to an entry with a matching key. If
** the table contains no record with a matching key, then the cursor
** is left pointing at a nearby record.
+**
+** See also: Found, NotFound, Distinct
*/
case OP_MoveTo: {
int i = pOp->p1;
@@ -2204,7 +2221,7 @@
/* Opcode: Fcnt * * *
**
** Push an integer onto the stack which is the total number of
-** OP_Fetch opcodes that have been executed by this virtual machine.
+** MoveTo opcodes that have been executed by this virtual machine.
**
** This instruction is used to implement the special fcnt() function
** in the SQL dialect that SQLite understands. fcnt() is used for
@@ -2220,30 +2237,36 @@
/* Opcode: Distinct P1 P2 *
**
-** Use the top of the stack as a key. If a record with that key
-** does not exist in file P1, then jump to P2. If the record
+** Use the top of the stack as a key. If a record with that key does
+** not exist in the table of cursor P1, then jump to P2. If the record
** does already exist, then fall thru. The cursor is left pointing
** at the record if it exists. The key is not popped from the stack.
**
** This operation is similar to NotFound except that this operation
** does not pop the key from the stack.
+**
+** See also: Found, NotFound, MoveTo
*/
/* Opcode: Found P1 P2 *
**
** Use the top of the stack as a key. If a record with that key
-** does exist in file P1, then jump to P2. If the record
+** does exist in table of P1, then jump to P2. If the record
** does not exist, then fall thru. The cursor is left pointing
** to the record if it exists. The key is popped from the stack.
+**
+** See also: Distinct, NotFound, MoveTo
*/
/* Opcode: NotFound P1 P2 *
**
** Use the top of the stack as a key. If a record with that key
-** does not exist in file P1, then jump to P2. If the record
+** does not exist in table of P1, then jump to P2. If the record
** does exist, then fall thru. The cursor is left pointing to the
** record if it exists. The key is popped from the stack.
**
** The difference between this operation and Distinct is that
** Distinct does not pop the key from the stack.
+**
+** See also: Distinct, Found, MoveTo
*/
case OP_Distinct:
case OP_NotFound:
@@ -2278,8 +2301,8 @@
/* Opcode: NewRecno P1 * *
**
** Get a new integer record number used as the key to a table.
-** The record number is not previous used by the database file
-** associated with cursor P1. The new record number pushed
+** The record number is not previously used as a key in the database
+** table that cursor P1 points to. The new record number pushed
** onto the stack.
*/
case OP_NewRecno: {
@@ -2321,7 +2344,7 @@
/* Opcode: Put P1 * *
**
** Write an entry into the database file P1. A new entry is
-** created if it doesn't already exist, or the data for an existing
+** created if it doesn't already exist or the data for an existing
** entry is overwritten. The data is the value on the top of the
** stack. The key is the next value down on the stack. The stack
** is popped twice by this instruction.
@@ -2356,8 +2379,8 @@
**
** The cursor will be left pointing at either the next or the previous
** record in the table. If it is left pointing at the next record, then
-** the next OP_Next will be a no-op. Hence it is OK to delete a record
-** from within an OP_Next loop.
+** the next Next instruction will be a no-op. Hence it is OK to delete
+** a record from within an Next loop.
*/
case OP_Delete: {
int i = pOp->p1;
@@ -2370,7 +2393,7 @@
/* Opcode: KeyAsData P1 P2 *
**
** Turn the key-as-data mode for cursor P1 either on (if P2==1) or
-** off (if P2==0). In key-as-data mode, the OP_Field opcode pulls
+** off (if P2==0). In key-as-data mode, the Field opcode pulls
** data off of the key rather than the data. This is useful for
** processing compound selects.
*/
@@ -2507,9 +2530,12 @@
/* Opcode: FullKey P1 * *
**
-** Push a string onto the stack which is the full text key associated
-** with the last Next operation on file P1. Compare this with the
-** Key operator which pushs an integer key.
+** Extract the complete key from the record that cursor P1 is currently
+** pointing to and push the key onto the stack as a string.
+**
+** Compare this opcode to Recno. The Recno opcode extracts the first
+** 4 bytes of the key and pushes those bytes onto the stack as an
+** integer. This instruction pushes the entire key as a string.
*/
case OP_FullKey: {
int i = pOp->p1;
@@ -2622,9 +2648,9 @@
**
** The P1 cursor points to an SQL index for which a BeginIdx operation
** has been issued. This operation retrieves the next record from that
-** cursor and verifies that the key on the record matches the key that
-** was pulled from the stack by the BeginIdx instruction. If they do
-** match, then the last 4 bytes of the key on the record hold a record
+** cursor and verifies that the key on the record minus the last 4 bytes
+** matches the key that was pulled from the stack by the BeginIdx instruction.
+** If they match, then the last 4 bytes of the key on the record hold a record
** number and that record number is extracted and pushed on the stack.
** If the keys do not match, there is an immediate jump to instruction P2.
*/
@@ -2707,6 +2733,8 @@
**
** Delete an entire database table or index whose root page in the database
** file is given by P1.
+**
+** See also: Clear
*/
case OP_Destroy: {
sqliteBtreeDropTable(pBt, pOp->p1);
@@ -2716,8 +2744,10 @@
/* Opcode: Clear P1 * *
**
** Delete all contents of the database table or index whose root page
-** in the database file is given by P1. But, unlike OP_Destroy, do not
+** in the database file is given by P1. But, unlike Destroy, do not
** remove the table or index from the database file.
+**
+** See also: Destroy
*/
case OP_Clear: {
sqliteBtreeClearTable(pBt, pOp->p1);
@@ -2735,6 +2765,8 @@
** memory location. This writing of the page number into a memory location
** is used by the SQL parser to record the page number in its internal
** data structures.
+**
+** See also: CreateIndex
*/
case OP_CreateTable: {
int i = ++p->tos;
@@ -2754,19 +2786,19 @@
break;
}
-/* Opcode: CreateIndex * * *
+/* Opcode: CreateIndex P1 * *
**
** Allocate a new Index in the main database file. Push the page number
** for the root page of the new table onto the stack.
**
-** If P1>=0 then open a cursor named P1 on the newly created index.
-**
** The root page number is also written to a memory location which has
** be set up by the parser. The difference between CreateTable and
** CreateIndex is that each writes its root page number into a different
** memory location. This writing of the page number into a memory location
** is used by the SQL parser to record the page number in its internal
** data structures.
+**
+** See also: CreateTable
*/
case OP_CreateIndex: {
int i = ++p->tos;
@@ -2790,6 +2822,8 @@
**
** Compress, optimize, and tidy up table or index whose root page in the
** database file is P1.
+**
+** In the current implementation, this is a no-op.
*/
case OP_Reorganize: {
/* This is currently a no-op */
@@ -2799,8 +2833,7 @@
/* Opcode: ListOpen P1 * *
**
** Open a "List" structure used for temporary storage of integer
-** table keys. P1
-** will server as a handle to this list for future
+** record numbers. P1 will server as a handle to this list for future
** interactions. If another list with the P1 handle is
** already opened, the prior list is closed and a new one opened
** in its place.
@@ -3004,7 +3037,7 @@
** in the result. The whole key is terminated by two \000 characters
** in a row.
**
-** See also the MakeKey opcode.
+** See also the MakeKey and MakeIdxKey opcodes.
*/
case OP_SortMakeKey: {
char *zNewKey;
@@ -3217,7 +3250,7 @@
** a delimiter. There should be P1 fields. If the input line contains
** more than P1 fields, ignore the excess. If the input line contains
** fewer than P1 fields, assume the remaining fields contain an
-** empty string.
+** empty strings.
*/
case OP_FileRead: {
int n, eol, nField, i, c, nDelim;
@@ -3301,7 +3334,7 @@
/* Opcode: FileColumn P1 * *
**
-** Push onto the stack the P1-th field of the most recently read line
+** Push onto the stack the P1-th column of the most recently read line
** from the input file.
*/
case OP_FileColumn: {
diff --git a/src/vdbe.h b/src/vdbe.h
index 46ebf99..b563498 100644
--- a/src/vdbe.h
+++ b/src/vdbe.h
@@ -1,24 +1,12 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
@@ -27,7 +15,7 @@
** or VDBE. The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
-** $Id: vdbe.h,v 1.22 2001/09/15 00:57:29 drh Exp $
+** $Id: vdbe.h,v 1.23 2001/09/16 00:13:27 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
diff --git a/src/where.c b/src/where.c
index bc99942..d03be7e 100644
--- a/src/where.c
+++ b/src/where.c
@@ -1,31 +1,19 @@
/*
-** Copyright (c) 1999, 2000 D. Richard Hipp
+** 2001 September 15
**
-** This program is free software; you can redistribute it and/or
-** modify it under the terms of the GNU General Public
-** License as published by the Free Software Foundation; either
-** version 2 of the License, or (at your option) any later version.
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
**
-** This program is distributed in the hope that it will be useful,
-** but WITHOUT ANY WARRANTY; without even the implied warranty of
-** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-** General Public License for more details.
-**
-** You should have received a copy of the GNU General Public
-** License along with this library; if not, write to the
-** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-** Boston, MA 02111-1307, USA.
-**
-** Author contact information:
-** drh@hwaci.com
-** http://www.hwaci.com/drh/
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements. Also found here are subroutines
** to generate VDBE code to evaluate expressions.
**
-** $Id: where.c,v 1.19 2001/09/15 00:57:29 drh Exp $
+** $Id: where.c,v 1.20 2001/09/16 00:13:27 drh Exp $
*/
#include "sqliteInt.h"