Comment changes (CVS 308)

FossilOrigin-Name: 2d2ad264aad6fbdcef586e73d750e3fde842252f

manifest

@@ -1,5 +1,5 @@
-C Minor\sbugs\sfixed.\s(CVS\s307)
-D 2001-11-09T22:41:45
+C Comment\schanges\s(CVS\s308)
+D 2001-11-10T13:51:08
 F Makefile.in 6801df952cb1df64aa32e4de85fed24511d28efd
 F Makefile.template 1fdb891f14083ee0b63cf7282f91529634438e7a
 F README a4c0ba11354ef6ba0776b400d057c59da47a4cc0
@@ -19,7 +19,7 @@ F libtool c56e618713c9510a103bda6b95f3ea3900dcacd6
 F ltmain.sh e9ed72eb1d690f447c13945eaf69e28af531eda1
 F publish.sh 33cbe6798969f637698044023c139080e5d772a6
 F src/TODO af7f3cab0228e34149cf98e073aa83d45878e7e6
-F src/btree.c add522fad1b18c0face24e6f9f7468a6c696c5cc
+F src/btree.c 2c89ac317a43d03c389eea1a882b7bbfad2ae89a
 F src/btree.h 0250a0a577a98cc64ddf1582d50c08b8d2451650
 F src/build.c 40b7d14435e2cfc5298e8b7bab5e92ed26f42310
 F src/delete.c 5d93a21c1388cfb1359bda01c072f25583a2f4f2
@@ -31,8 +31,8 @@ F src/main.c 0b0e7244c7af91613111d5b72387e33f8789ed72
 F src/md5.c 52f677bfc590e09f71d07d7e327bd59da738d07c
 F src/os.c d1c5c12bcc52ac28cc4d62f442d84f54a33241bc
 F src/os.h bed702c9e3b768bc3cb1b12c90b83d099c1546be
-F src/pager.c 0bd0b4b693edb43c72774e3e749d8667e2ae7094
-F src/pager.h a0d4c5ae271914aa07b62aee0707997d6932b6ca
+F src/pager.c 442ea25d808dd9c0f522cd4317af7dbb50f8ff3f
+F src/pager.h df1fb8a759ab69112ea88b9f14601a7633d0ccc0
 F src/parse.y 5295f393f41ea89958287e5738e6c12c7cd67482
 F src/printf.c 300a90554345751f26e1fc0c0333b90a66110a1d
 F src/random.c 2a9cc2c9716d14815fd4c2accf89d87a1143e46b
@@ -49,7 +49,7 @@ F src/test3.c d6775f95fd91f5b3cf0e2382a28e5aaeb68f745b
 F src/tokenize.c 830e9ef684334070a26583d94770bb869e2727bf
 F src/update.c b1e315e20b98a013d30fd9ff3b7d9dc4f29b39b3
 F src/util.c ac83973ecc647d3d3c58708f148442365abf9b94
-F src/vdbe.c b4cdc0017bf0574ededf17d7ff5f1d66a58bf430
+F src/vdbe.c 807d648da2113eb65b2d5c59c18e51cd8896a972
 F src/vdbe.h cd4c8647051a0c22c0e133c375f1cd17bb8b1e06
 F src/where.c d51e6380dcd0ddb6767add378f266ffb1555403a
 F test/all.test 2a51e5395ac7c2c539689b123b9782a05e3837fe
@@ -115,7 +115,7 @@ F www/speed.tcl 212a91d555384e01873160d6a189f1490c791bc2
 F www/sqlite.tcl 6a21242a272e9c0939a04419a51c3d50cae33e3e
 F www/tclsqlite.tcl 13d50723f583888fc80ae1a38247c0ab415066fa
 F www/vdbe.tcl bb7d620995f0a987293e9d4fb6185a3b077e9b44
-P 84997fda33fd6ce93b821d3da3a7251cf60e06ec
-R a47e24dd20101d53a150f47918c7f27d
+P 6e7e7dbf8e93d00eced88404aed792fcf9e75b7d
+R 18e925419ed8c85ff1b4931f4627f2c0
 U drh
-Z 9171d3d0184d7481a06db73ab6bf05b3
+Z a3df24ec6e762840d7c455a8f753602e

manifest.uuid

@@ -1 +1 @@
-6e7e7dbf8e93d00eced88404aed792fcf9e75b7d
+2d2ad264aad6fbdcef586e73d750e3fde842252f

src/btree.c

@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.38 2001/11/07 14:22:00 drh Exp $
+** $Id: btree.c,v 1.39 2001/11/10 13:51:08 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -175,10 +175,17 @@ struct CellHdr {
   Pgno leftChild; /* Child page that comes before this cell */
   u16 nKey;       /* Number of bytes in the key */
   u16 iNext;      /* Index in MemPage.u.aDisk[] of next cell in sorted order */
-  u8 nKeyHi;
-  u8 nDataHi;
+  u8 nKeyHi;      /* Upper 8 bits of key size for keys larger than 64K bytes */
+  u8 nDataHi;     /* Upper 8 bits of data size when the size is more than 64K */
   u16 nData;      /* Number of bytes of data */
 };
+
+/*
+** The key and data size are split into a lower 16-bit segment and an
+** upper 8-bit segment in order to pack them together into a smaller
+** space.  The following macros reassembly a key or data size back
+** into an integer.
+*/
 #define NKEY(h)  (h.nKey + h.nKeyHi*65536)
 #define NDATA(h) (h.nData + h.nDataHi*65536)
 

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.29 2001/10/22 02:58:10 drh Exp $
+** @(#) $Id: pager.c,v 1.30 2001/11/10 13:51:09 drh Exp $
 */
 #include "sqliteInt.h"
 #include "pager.h"
@@ -605,7 +605,7 @@ static int syncAllPages(Pager *pPager){
 /*
 ** Acquire a page.
 **
-** A read lock on the disk file is obtained when the first page acquired. 
+** A read lock on the disk file is obtained when the first page is acquired. 
 ** This read lock is dropped when the last page is released.
 **
 ** A _get works for any page number greater than 0.  If the database

src/pager.h

@@ -13,11 +13,16 @@
 ** 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 1.11 2001/09/16 00:13:27 drh Exp $
+** @(#) $Id: pager.h,v 1.12 2001/11/10 13:51:09 drh Exp $
 */
 
 /*
 ** The size of one page
+**
+** You can change this value to another (reasonable) power of two
+** such as 512, 2048, 4096, or 8192 and things will still work.  But
+** experiments show that a page size of 1024 gives the best speed.
+** (The speed differences are minimal.)
 */
 #define SQLITE_PAGE_SIZE 1024
 

src/vdbe.c

@@ -30,7 +30,7 @@
 ** But other routines are also provided to help in building up
 ** a program instruction by instruction.
 **
-** $Id: vdbe.c,v 1.96 2001/11/08 00:45:22 drh Exp $
+** $Id: vdbe.c,v 1.97 2001/11/10 13:51:09 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -1098,7 +1098,7 @@ int sqliteVdbeExec(
 ** we transition back to normal indentation.
 *****************************************************************************/
 
-/* Opcode:  Goto P2 * *
+/* Opcode:  Goto * P2 *
 **
 ** An unconditional jump to address P2.
 ** The next instruction executed will be