Comment updates most. Also some small changes to the VDBE. (CVS 339)

FossilOrigin-Name: 9b0be4fcc1cbca69f5fee906f86dfb36a323fe84

manifest

@@ -1,5 +1,5 @@
-C An\sattempt\sto\sdelete\sa\ssingle\srow\susing\sa\sWHERE\sclause\sthat\sspecifies\nthe\srowid\swould\sresult\sin\san\serror\sif\sthe\srowid\sdid\snot\sexist.\s\sThis\nproblem\shas\sbeen\sresolved.\s(CVS\s338)
+C Comment\supdates\smost.\s\sAlso\ssome\ssmall\schanges\sto\sthe\sVDBE.\s(CVS\s339)
-D 2002-01-04T03:09:29
+D 2002-01-06T17:07:40
 F Makefile.in 352fed589f09dd94347e0bb391d047118ebd6105
 F Makefile.template c88ffcb9c339e718f434d0c7f045bcd7eea125af
 F README a4c0ba11354ef6ba0776b400d057c59da47a4cc0
@@ -23,24 +23,24 @@ F src/btree.c c796e387da340cb628dc1e41f684fc20253f561e
 F src/btree.h 9ead7f54c270d8a554e59352ca7318fdaf411390
 F src/build.c 6c01002e98204ad2b993d0d043ee56c8c7dc8692
 F src/delete.c f7690efc09ad6a2f1f3f0490e1b0cbb676bb95cf
-F src/expr.c fcdb7416e502cb7e26b933ccd44b0baff5b78420
+F src/expr.c 8169261ac56e96c860407a8773ca10b779e32328
-F src/hash.c 6f1a7712ae3aac8351662969aec5693740a2fbf7
+F src/hash.c 838a6f2af547dfdc5ff2b438e8f981ea4b74f224
 F src/hash.h a5f5b3ce2d086a172c5879b0b06a27a82eac9fac
-F src/insert.c 7b36ce2e0b555d9d12bbbdbcd579728ad518ec80
+F src/insert.c 813c37719866c583e6ca7660f94f10230f4e385d
-F src/main.c 00a9f5603e130fc0b1a05f731731c9c99ebdc2dc
+F src/main.c 567e472a1ca22f7d9970b1f96b9be91d45ccd7e2
 F src/md5.c 52f677bfc590e09f71d07d7e327bd59da738d07c
 F src/os.c 07882cde5c61f26751b8ee76fd84726c1f7e453c
 F src/os.h 00a18e0ae1139a64f1d3ead465ae2b9ff43f3db2
-F src/pager.c dde0eb5bf9af0ac0ff8a4429b2bee2aec2194ec9
+F src/pager.c ad8a3574d88b3b2d9048206d00ebeaac5ef83fe5
 F src/pager.h f78d064c780855ff70beacbeba0e2324471b26fe
-F src/parse.y f050644e7a2586227686e8c1709aa2662b9bcf9c
+F src/parse.y f3fc4fb5766393003577bd175eb611495f6efd9f
 F src/printf.c 300a90554345751f26e1fc0c0333b90a66110a1d
 F src/random.c 2a9cc2c9716d14815fd4c2accf89d87a1143e46b
 F src/select.c bddd8b5d07ffdae0d798c10b20dc7167469a3904
-F src/shell.c 407095aaeeae78f42deb3e846b1ad77f8ed3b4ef
+F src/shell.c f8008f0607f9523ca0f9562b8975c1bcc427d2b3
 F src/shell.tcl 27ecbd63dd88396ad16d81ab44f73e6c0ea9d20e
 F src/sqlite.h.in a4c11d38d62b1bfbd50a5804edee8ca54c1adc9b
-F src/sqliteInt.h d2bfc012fb2c91652d67401e5d7a646a0c30a675
+F src/sqliteInt.h 5b613b2c30965051135641e98e41b066cc0f8245
 F src/table.c c89698bd5bb4b8d14722d6ee7e9be014c383d24a
 F src/tclsqlite.c b82e4faeae89fdb7304b3c970979ade299336a1f
 F src/test1.c 41eabe255970ef947263b94145c9b2766bab8675
@@ -49,9 +49,9 @@ F src/test3.c d6775f95fd91f5b3cf0e2382a28e5aaeb68f745b
 F src/tokenize.c 830e9ef684334070a26583d94770bb869e2727bf
 F src/update.c f9f48e78c13c79e32a55840414bea84479f9848d
 F src/util.c 8e9ca72d8288cae39c57c6f397abd14a56b14a38
-F src/vdbe.c 90a561f7b9bd8711dd01dbdc491b8eff134af476
+F src/vdbe.c b27b256a5930da1e8fc347a272357be72de0f853
 F src/vdbe.h e5cc6fb13d1905a4339db4d6dba4ab393c0765fa
-F src/where.c d673265cad96f790923210707b45fdcaec9408f1
+F src/where.c ed7343344a30d62eb91464f1580490b80a6275ac
 F test/all.test 2a51e5395ac7c2c539689b123b9782a05e3837fe
 F test/bigrow.test 8ab252dba108f12ad64e337b0f2ff31a807ac578
 F test/btree.test 6ab4dc5f595905a276ef588fad3c9236dc07a47b
@@ -119,7 +119,7 @@ F www/speed.tcl 83457b2bf6bb430900bd48ca3dd98264d9a916a5
 F www/sqlite.tcl 8b5884354cb615049aed83039f8dfe1552a44279
 F www/tclsqlite.tcl 880ef67cb4f2797b95bf1368fc4e0d8ca0fda956
 F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
-P 18e606f7486eb3a4ab128504d88a44f53d39e5b2
+P 011be9a9d2632d261489005d97c69b0a0bc5a108
-R 0880ebdecbc9a3b9787a721d544d5701
+R 6344d21046bf26426615521a28ec7ddb
 U drh
-Z cf2abd860be64f6e25eafc52151b0f16
+Z d9e4a308acd11d4e3b3d3caeececa822

manifest.uuid

@@ -1 +1 @@
-011be9a9d2632d261489005d97c69b0a0bc5a108
+9b0be4fcc1cbca69f5fee906f86dfb36a323fe84

src/expr.c

@@ -12,7 +12,7 @@
 ** This file contains routines used for analyzing expressions and
 ** for generating VDBE code that evaluates expressions in SQLite.
 **
-** $Id: expr.c,v 1.36 2002/01/04 03:09:30 drh Exp $
+** $Id: expr.c,v 1.37 2002/01/06 17:07:40 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -49,7 +49,9 @@ static int isConstant(Expr *p){
 ** These operators have to be processed before column names are
 ** resolved because each such operator increments pParse->nTab
 ** to reserve cursor numbers for its own use.  But pParse->nTab
-** needs to be constant once we begin resolving column names.
+** needs to be constant once we begin resolving column names.  For
+** that reason, this procedure needs to be called on every expression
+** before sqliteExprResolveIds() is called on any expression.
 **
 ** Actually, the processing of IN-SELECT is only started by this
 ** routine.  This routine allocates a cursor number to the IN-SELECT
@@ -86,11 +88,15 @@ static int sqliteIsRowid(const char *z){
 /*
 ** This routine walks an expression tree and resolves references to
 ** table columns.  Nodes of the form ID.ID or ID resolve into an
-** index to the table in the table list and a column offset.  The opcode
+** index to the table in the table list and a column offset.  The 
-** for such nodes is changed to TK_COLUMN.  The iTable value is changed
+** Expr.opcode for such nodes is changed to TK_COLUMN.  The Expr.iTable
-** to the index of the referenced table in pTabList plus the pParse->nTab
+** value is changed to the index of the referenced table in pTabList
-** value.  The iColumn value is changed to the index of the column of the 
+** plus the pParse->nTab value.  This value will ultimately become the
-** referenced table.
+** VDBE cursor number for a cursor that is pointing into the referenced
+** table.  The Expr.iColumn value is changed to the index of the column 
+** of the referenced table.  The Expr.iColumn value for the special
+** ROWID column is -1.  Any INTEGER PRIMARY KEY column is tried as an
+** alias for ROWID.
 **
 ** We also check for instances of the IN operator.  IN comes in two
 ** forms:

src/hash.c

@@ -12,13 +12,22 @@
 ** This is the implementation of generic hash-tables
 ** used in SQLite.
 **
-** $Id: hash.c,v 1.4 2001/11/21 02:21:12 drh Exp $
+** $Id: hash.c,v 1.5 2002/01/06 17:07:40 drh Exp $
 */
 #include "sqliteInt.h"
 #include <assert.h>
 
 /* Turn bulk memory into a hash table object by initializing the
 ** fields of the Hash structure.
+**
+** "new" is a pointer to the hash table that is to be initialized.
+** keyClass is one of the constants SQLITE_HASH_INT, SQLITE_HASH_POINTER,
+** SQLITE_HASH_BINARY, or SQLITE_HASH_STRING.  The value of keyClass 
+** determines what kind of key the hash table will use.  "copyKey" is
+** true if the hash table should make its own private copy of keys and
+** false if it should just use the supplied pointer.  CopyKey only makes
+** sense for SQLITE_HASH_STRING and SQLITE_HASH_BINARY and is ignored
+** for other key classes.
 */
 void sqliteHashInit(Hash *new, int keyClass, int copyKey){
   assert( new!=0 );
@@ -33,6 +42,8 @@ void sqliteHashInit(Hash *new, int keyClass, int copyKey){
 }
 
 /* Remove all entries from a hash table.  Reclaim all memory.
+** Call this routine to delete a hash table or to reset a hash table
+** to the empty state.
 */
 void sqliteHashClear(Hash *pH){
   HashElem *elem;         /* For looping over all elements of the table */
@@ -107,6 +118,15 @@ static int binCompare(const void *pKey1, int n1, const void *pKey2, int n2){
 
 /*
 ** Return a pointer to the appropriate hash function given the key class.
+**
+** The C syntax in this function definition may be unfamilar to some 
+** programmers, so we provide the following additional explanation:
+**
+** The name of the function is "hashFunction".  The function takes a
+** single parameter "keyClass".  The return value of hashFunction()
+** is a pointer to another function.  Specifically, the return value
+** of hashFunction() is a pointer to a function that takes two parameters
+** with types "const void*" and "int" and returns an "int".
 */
 static int (*hashFunction(int keyClass))(const void*,int){
   switch( keyClass ){
@@ -121,6 +141,9 @@ static int (*hashFunction(int keyClass))(const void*,int){
 
 /*
 ** Return a pointer to the appropriate hash function given the key class.
+**
+** For help in interpreted the obscure C code in the function definition,
+** see the header comment on the previous function.
 */
 static int (*compareFunction(int keyClass))(const void*,int,const void*,int){
   switch( keyClass ){
@@ -134,8 +157,9 @@ static int (*compareFunction(int keyClass))(const void*,int,const void*,int){
 }
 
 
-/* Resize the hash table. new_size must be a power of 2.
+/* Resize the hash table so that it cantains "new_size" buckets.
-** The hash table might fail to resize if sqliteMalloc() fails.
+** "new_size" must be a power of 2.  The hash table might fail 
+** to resize if sqliteMalloc() fails.
 */
 static void rehash(Hash *pH, int new_size){
   struct _ht *new_ht;            /* The new hash table */
@@ -172,8 +196,8 @@ static void rehash(Hash *pH, int new_size){
 }
 
 /* This function (for internal use only) locates an element in an
-** pH that matches the given key.  The hash for this key has
+** hash table that matches the given key.  The hash for this key has
-** already been computed and is passed as the 3rd parameter.
+** already been computed and is passed as the 4th parameter.
 */
 static HashElem *findElementGivenHash(
   const Hash *pH,     /* The pH to be searched */
@@ -205,7 +229,7 @@ static HashElem *findElementGivenHash(
 static void removeElementGivenHash(
   Hash *pH,         /* The pH containing "elem" */
   HashElem* elem,   /* The element to be removed from the pH */
-  int h              /* Hash value for the element */
+  int h             /* Hash value for the element */
 ){
   if( elem->prev ){
     elem->prev->next = elem->next; 
@@ -229,9 +253,9 @@ static void removeElementGivenHash(
   pH->count--;
 }
 
-/* Attempt to locate an element of the associative pH with a key
+/* Attempt to locate an element of the hash table pH with a key
 ** that matches pKey,nKey.  Return the data for this element if it is
-** found, or NULL if no match is found.
+** found, or NULL if there is no match.
 */
 void *sqliteHashFind(const Hash *pH, const void *pKey, int nKey){
   int h;             /* A hash on key */
@@ -257,7 +281,7 @@ void *sqliteHashFind(const Hash *pH, const void *pKey, int nKey){
 ** If another element already exists with the same key, then the
 ** new data replaces the old data and the old data is returned.
 ** The key is not copied in this instance.  If a malloc fails, then
-** new data is returned.
+** the new data is returned and the hash table is unchanged.
 **
 ** If the "data" parameter to this function is NULL, then the
 ** element corresponding to "key" is removed from the hash table.

src/insert.c

@@ -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 1.31 2002/01/04 03:09:30 drh Exp $
+** $Id: insert.c,v 1.32 2002/01/06 17:07:40 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -163,7 +163,7 @@ void sqliteInsert(
     }
   }
 
-  /* If there is not IDLIST term but the table has an integer primary
+  /* If there is no IDLIST term but the table has an integer primary
   ** key, the set the keyColumn variable to the primary key column index
   ** in the original table definition.
   */
@@ -220,15 +220,15 @@ void sqliteInsert(
     sqliteVdbeAddOp(v, OP_Dup, 0, 0);
   }
 
-  /* Push onto the stack data for all columns of the new entry, beginning
+  /* Push onto the stack, data for all columns of the new entry, beginning
   ** with the first column.
   */
   for(i=0; i<pTab->nCol; i++){
     if( i==pTab->iPKey ){
       /* The value of the INTEGER PRIMARY KEY column is always a NULL.
-      ** Whenever this column is used, the record number will be substituted
+      ** Whenever this column is read, the record number will be substituted
-      ** in its place, so there is no point in it taking up space in
+      ** in its place.  So will fill this column with a NULL to avoid
-      ** the data record. */
+      ** taking up data space with information that will never be used. */
       sqliteVdbeAddOp(v, OP_String, 0, 0);
       continue;
     }

src/main.c

@@ -14,7 +14,7 @@
 ** other files are for internal use by SQLite and should not be
 ** accessed by users of the library.
 **
-** $Id: main.c,v 1.52 2001/12/21 14:30:43 drh Exp $
+** $Id: main.c,v 1.53 2002/01/06 17:07:40 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -67,9 +67,9 @@ static int sqliteOpenCb(void *pDb, int argc, char **argv, char **azColName){
       }else{
         /* If the SQL column is blank it means this is an index that
         ** was created to be the PRIMARY KEY or to fulfill a UNIQUE
-        ** constraint or a CREATE TABLE.  The index should have already
+        ** constraint for a CREATE TABLE.  The index should have already
         ** been created when we processed the CREATE TABLE.  All we have
-        ** to do here is record the root page.
+        ** to do here is record the root page number for that index.
         */
         Index *pIndex = sqliteFindIndex(db, argv[1]);
         if( pIndex==0 || pIndex->tnum!=0 ){
@@ -118,7 +118,7 @@ static int sqliteInit(sqlite *db, char **pzErrMsg){
      ")"
   ;
 
-  /* The following program is used to initialize the internal
+  /* The following VDBE program is used to initialize the internal
   ** structure holding the tables and indexes of the database.
   ** The database contains a special table named "sqlite_master"
   ** defined as follows:
@@ -210,6 +210,11 @@ static int sqliteInit(sqlite *db, char **pzErrMsg){
     sqliteSetString(pzErrMsg, "unsupported file format", 0);
     rc = SQLITE_ERROR;
   }
+
+  /* The schema for the SQLITE_MASTER table is not stored in the
+  ** database itself.  We have to invoke the callback one extra
+  ** time to get it to process the SQLITE_MASTER table defintion.
+  */
   if( rc==SQLITE_OK ){
     Table *pTab;
     char *azArg[6];
@@ -270,9 +275,7 @@ sqlite *sqlite_open(const char *zFilename, int mode, char **pzErrMsg){
   if( rc!=SQLITE_OK ){
     switch( rc ){
       default: {
-        if( pzErrMsg ){
+        sqliteSetString(pzErrMsg, "unable to open database: ", zFilename, 0);
-          sqliteSetString(pzErrMsg, "unable to open database: ", zFilename, 0);
-        }
       }
     }
     sqliteFree(db);
@@ -289,7 +292,7 @@ sqlite *sqlite_open(const char *zFilename, int mode, char **pzErrMsg){
     sqlite_close(db);
     sqliteStrRealloc(pzErrMsg);
     return 0;
-  }else /* if( pzErrMsg ) */{
+  }else if( pzErrMsg ){
     sqliteFree(*pzErrMsg);
     *pzErrMsg = 0;
   }
@@ -304,7 +307,7 @@ no_mem_on_open:
 /*
 ** Erase all schema information from the schema hash table.  Except
 ** tables that are created using CREATE TEMPORARY TABLE are preserved
-** if the preserverTemps flag is true.
+** if the preserveTemps flag is true.
 **
 ** The database schema is normally read in once when the database
 ** is first opened and stored in a hash table in the sqlite structure.

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.34 2001/12/15 14:22:19 drh Exp $
+** @(#) $Id: pager.c,v 1.35 2002/01/06 17:07:40 drh Exp $
 */
 #include "sqliteInt.h"
 #include "pager.h"
@@ -993,7 +993,7 @@ int sqlitepager_write(void *pData){
 }
 
 /*
-** Return TRUE if the page given in the argument was previous passed
+** Return TRUE if the page given in the argument was previously passed
 ** to sqlitepager_write().  In other words, return TRUE if it is ok
 ** to change the content of the page.
 */

src/parse.y

@@ -14,7 +14,7 @@
 ** the parser.  Lemon will also generate a header file containing
 ** numeric codes for all of the tokens.
 **
-** @(#) $Id: parse.y,v 1.41 2001/12/22 14:49:25 drh Exp $
+** @(#) $Id: parse.y,v 1.42 2002/01/06 17:07:40 drh Exp $
 */
 %token_prefix TK_
 %token_type {Token}
@@ -102,6 +102,7 @@ id(A) ::= CLUSTER(X).    {A = X;}
 id(A) ::= ID(X).         {A = X;}
 id(A) ::= TEMP(X).       {A = X;}
 id(A) ::= OFFSET(X).     {A = X;}
+id(A) ::= KEY(X).        {A = X;}
 
 // And "ids" is an identifer-or-string.
 //

src/shell.c

@@ -12,7 +12,7 @@
 ** This file contains code to implement the "sqlite" command line
 ** utility for accessing SQLite databases.
 **
-** $Id: shell.c,v 1.40 2001/11/25 13:18:24 drh Exp $
+** $Id: shell.c,v 1.41 2002/01/06 17:07:40 drh Exp $
 */
 #include <stdlib.h>
 #include <string.h>
@@ -92,7 +92,7 @@ static char *getline(char *zPrompt, FILE *in){
 ** Retrieve a single line of input text.  "isatty" is true if text
 ** is coming from a terminal.  In that case, we issue a prompt and
 ** attempt to use "readline" for command-line editing.  If "isatty"
-** is false, use "getline" instead of "readline" and issue to prompt.
+** is false, use "getline" instead of "readline" and issue no prompt.
 **
 ** zPrior is a string of prior text retrieved.  If not the empty
 ** string, then issue a continuation prompt.

src/sqliteInt.h

@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.74 2001/12/31 02:48:51 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.75 2002/01/06 17:07:40 drh Exp $
 */
 #include "sqlite.h"
 #include "hash.h"
@@ -119,13 +119,6 @@ extern int sqlite_nFree;         /* Number of sqliteFree() calls */
 extern int sqlite_iMallocFail;   /* Fail sqliteMalloc() after this many calls */
 #endif
 
-/*
-** The number of entries in the in-memory hash array holding the
-** database schema.  (Collision resolution is by chaining, so the
-** table will hold more than this many entries.)
-*/
-#define N_HASH        51
-
 /*
 ** Name of the master database table.  The master database table
 ** is a special table that holds the names and attributes of all

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 1.104 2002/01/04 03:09:30 drh Exp $
+** $Id: vdbe.c,v 1.105 2002/01/06 17:07:41 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -456,11 +456,12 @@ void sqliteVdbeCompressSpace(Vdbe *p, int addr){
   Op *pOp;
   if( p->aOp==0 || addr<0 || addr>=p->nOp ) return;
   pOp = &p->aOp[addr];
+  if( pOp->p3type==P3_POINTER ){
+    return;
+  }
   if( pOp->p3type!=P3_DYNAMIC ){
     pOp->p3 = sqliteStrDup(pOp->p3);
     pOp->p3type = P3_DYNAMIC;
-  }else if( pOp->p3type!=P3_STATIC ){
-    return;
   }
   z = pOp->p3;
   if( z==0 ) return;
@@ -474,10 +475,8 @@ void sqliteVdbeCompressSpace(Vdbe *p, int addr){
       z[j++] = z[i++];
     }
   }
-  while( i>0 && isspace(z[i-1]) ){
+  while( j>0 && isspace(z[j-1]) ){ j--; }
-    z[i-1] = 0;
+  z[j] = 0;
-    i--;
-  }
 }
 
 /*
@@ -922,7 +921,6 @@ int sqliteVdbeList(
   azValue[3] = zP2;
   azValue[5] = 0;
   rc = SQLITE_OK;
-  /* if( pzErrMsg ){ *pzErrMsg = 0; } */
   for(i=0; rc==SQLITE_OK && i<p->nOp; i++){
     if( p->db->flags & SQLITE_Interrupt ){
       p->db->flags &= ~SQLITE_Interrupt;
@@ -1028,8 +1026,9 @@ static int byteSwap(int x){
 ** from sqliteMalloc() and *pzErrMsg is made to point to that memory.
 ** The return parameter is the number of errors.
 **
-** If the callback every returns non-zero, then the program exits
+** If the callback ever returns non-zero, then the program exits
-** immediately.  No error message but the function does return SQLITE_ABORT.
+** immediately.  There will be no error message but the function
+** does return SQLITE_ABORT.
 **
 ** A memory allocation error causes this routine to return SQLITE_NOMEM
 ** and abandon furture processing.
@@ -1089,7 +1088,6 @@ int sqliteVdbeExec(
     p->trace = stdout;
   }
 #endif
-  /* if( pzErrMsg ){ *pzErrMsg = 0; } */
   if( sqlite_malloc_failed ) goto no_mem;
   for(pc=0; !sqlite_malloc_failed && rc==SQLITE_OK && pc<p->nOp
              VERIFY(&& pc>=0); pc++){

src/where.c

@@ -13,7 +13,7 @@
 ** the WHERE clause of SQL statements.  Also found here are subroutines
 ** to generate VDBE code to evaluate expressions.
 **
-** $Id: where.c,v 1.30 2002/01/04 03:09:30 drh Exp $
+** $Id: where.c,v 1.31 2002/01/06 17:07:41 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -572,8 +572,8 @@ WhereInfo *sqliteWhereBegin(
       pLevel->p2 = start;
       haveKey = 0;
     }else{
-      /* Case 5: The contraints on the right-most index field are
+      /* Case 5: The contraint on the right-most index field is
-      **         inequalities.
+      **         an inequality.
       */
       int score = pLevel->score;
       int nEqColumn = score/4;