Refactor the interface to the randomness generator. (CVS 1224)

FossilOrigin-Name: f2bdccf4bb2f796aafb64c33e55f62a1794d750c

8 files changed, 59 insertions, 66 deletions

diff --git a/src/build.c b/src/build.c
index 20d574818..e7f56f7fe 100644
--- a/src/build.c
+++ b/src/build.c
@@ -23,7 +23,7 @@
 **     ROLLBACK
 **     PRAGMA
 **
-** $Id: build.c,v 1.164 2004/01/19 04:55:56 jplyon Exp $
+** $Id: build.c,v 1.165 2004/02/11 09:46:31 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -819,7 +819,9 @@ void sqliteAddCollateType(Parse *pParse, int collType){
 */
 void sqliteChangeCookie(sqlite *db, Vdbe *v){
   if( db->next_cookie==db->aDb[0].schema_cookie ){
-    db->next_cookie = db->aDb[0].schema_cookie + sqliteRandomByte() + 1;
+    unsigned char r;
+    sqliteRandomness(1, &r);
+    db->next_cookie = db->aDb[0].schema_cookie + r + 1;
     db->flags |= SQLITE_InternChanges;
     sqliteVdbeAddOp(v, OP_Integer, db->next_cookie, 0);
     sqliteVdbeAddOp(v, OP_SetCookie, 0, 0);
diff --git a/src/func.c b/src/func.c
index 68c272ac0..688f50cff 100644
--- a/src/func.c
+++ b/src/func.c
@@ -16,7 +16,7 @@
 ** sqliteRegisterBuildinFunctions() found at the bottom of the file.
 ** All other code has file scope.
 **
-** $Id: func.c,v 1.38 2004/01/30 14:49:17 drh Exp $
+** $Id: func.c,v 1.39 2004/02/11 09:46:32 drh Exp $
 */
 #include <ctype.h>
 #include <math.h>
@@ -195,7 +195,9 @@ static void ifnullFunc(sqlite_func *context, int argc, const char **argv){
 ** Implementation of random().  Return a random integer.  
 */
 static void randomFunc(sqlite_func *context, int argc, const char **argv){
-  sqlite_set_result_int(context, sqliteRandomInteger());
+  int r;
+  sqliteRandomness(sizeof(r), &r);
+  sqlite_set_result_int(context, r);
 }
 
 /*
@@ -341,13 +343,13 @@ static void soundexFunc(sqlite_func *context, int argc, const char **argv){
 ** generating test data.
 */
 static void randStr(sqlite_func *context, int argc, const char **argv){
-  static const char zSrc[] = 
+  static const unsigned char zSrc[] = 
      "abcdefghijklmnopqrstuvwxyz"
      "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
      "0123456789"
      ".-!,:*^+=_|?/<> ";
   int iMin, iMax, n, r, i;
-  char zBuf[1000];
+  unsigned char zBuf[1000];
   if( argc>=1 ){
     iMin = atoi(argv[0]);
     if( iMin<0 ) iMin = 0;
@@ -364,14 +366,14 @@ static void randStr(sqlite_func *context, int argc, const char **argv){
   }
   n = iMin;
   if( iMax>iMin ){
-    r = sqliteRandomInteger() & 0x7fffffff;
+    sqliteRandomness(sizeof(r), &r);
+    r &= 0x7fffffff;
     n += r%(iMax + 1 - iMin);
   }
   assert( n<sizeof(zBuf) );
-  r = 0;
+  sqliteRandomness(n, zBuf);
   for(i=0; i<n; i++){
-    r = (r + sqliteRandomByte())% (sizeof(zSrc)-1);
-    zBuf[i] = zSrc[r];
+    zBuf[i] = zSrc[zBuf[i]%(sizeof(zSrc)-1)];
   }
   zBuf[n] = 0;
   sqlite_set_result_string(context, zBuf, n);
diff --git a/src/os.c b/src/os.c
index 2c5707830..fb987f3ca 100644
--- a/src/os.c
+++ b/src/os.c
@@ -785,7 +785,7 @@ int sqliteOsTempFileName(char *zBuf){
      "/tmp",
      ".",
   };
-  static char zChars[] =
+  static unsigned char zChars[] =
     "abcdefghijklmnopqrstuvwxyz"
     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
     "0123456789";
@@ -802,9 +802,9 @@ int sqliteOsTempFileName(char *zBuf){
   do{
     sprintf(zBuf, "%s/"TEMP_FILE_PREFIX, zDir);
     j = strlen(zBuf);
-    for(i=0; i<15; i++){
-      int n = sqliteRandomByte() % (sizeof(zChars)-1);
-      zBuf[j++] = zChars[n];
+    sqliteRandomness(15, &zBuf[j]);
+    for(i=0; i<15; i++, j++){
+      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
     }
     zBuf[j] = 0;
   }while( access(zBuf,0)==0 );
@@ -822,9 +822,9 @@ int sqliteOsTempFileName(char *zBuf){
   for(;;){
     sprintf(zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath);
     j = strlen(zBuf);
-    for(i=0; i<15; i++){
-      int n = sqliteRandomByte() % (sizeof(zChars) - 1);
-      zBuf[j++] = zChars[n];
+    sqliteRandomness(15, &zBuf[j]);
+    for(i=0; i<15; i++, j++){
+      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
     }
     zBuf[j] = 0;
     if( !sqliteOsFileExists(zBuf) ) break;
@@ -865,9 +865,9 @@ int sqliteOsTempFileName(char *zBuf){
   for(;;){
     sprintf(zBuf, "%s"TEMP_FILE_PREFIX, zTempPath);
     j = strlen(zBuf);
-    for(i=0; i<15; i++){
-      int n = sqliteRandomByte() % sizeof(zChars);
-      zBuf[j++] = zChars[n];
+    sqliteRandomness(15, &zBuf[j]);
+    for(i=0; i<15; i++, j++){
+      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
     }
     zBuf[j] = 0;
     if( !sqliteOsFileExists(zBuf) ) break;
@@ -1325,9 +1325,11 @@ int sqliteOsReadLock(OsFile *id){
   if( id->locked>0 ){
     rc = SQLITE_OK;
   }else{
-    int lk = (sqliteRandomInteger() & 0x7ffffff)%N_LOCKBYTE+1;
+    int lk;
     int res;
     int cnt = 100;
+    sqliteRandomness(sizeof(lk), &lk);
+    lk = (lk & 0x7fffffff)%N_LOCKBYTE + 1;
     while( cnt-->0 && (res = LockFile(id->h, FIRST_LOCKBYTE, 0, 1, 0))==0 ){
       Sleep(1);
     }
@@ -1359,10 +1361,12 @@ int sqliteOsReadLock(OsFile *id){
   if( id->locked>0 || id->refNumRF == -1 ){
     rc = SQLITE_OK;
   }else{
-    int lk = (sqliteRandomInteger() & 0x7ffffff)%N_LOCKBYTE+1;
+    int lk;
     OSErr res;
     int cnt = 5;
     ParamBlockRec params;
+    sqliteRandomness(sizeof(lk), &lk);
+    lk = (lk & 0x7fffffff)%N_LOCKBYTE + 1;
     memset(&params, 0, sizeof(params));
     params.ioParam.ioRefNum = id->refNumRF;
     params.ioParam.ioPosMode = fsFromStart;
diff --git a/src/pager.c b/src/pager.c
index 990f41253..223de8e63 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.99 2004/02/11 02:18:07 drh Exp $
+** @(#) $Id: pager.c,v 1.100 2004/02/11 09:46:32 drh Exp $
 */
 #include "os.h"         /* Must be first to enable large file support */
 #include "sqliteInt.h"
@@ -1664,7 +1664,7 @@ static int pager_open_journal(Pager *pPager){
       rc = write32bits(&pPager->jfd, pPager->noSync ? 0xffffffff : 0);
     }
     if( rc==SQLITE_OK ){
-      pPager->cksumInit = (u32)sqliteRandomInteger();
+      sqliteRandomness(sizeof(pPager->cksumInit), &pPager->cksumInit);
       rc = write32bits(&pPager->jfd, pPager->cksumInit);
     }
   }else if( journal_format==JOURNAL_FORMAT_2 ){
diff --git a/src/random.c b/src/random.c
index 39148b490..bf4b6d0a9 100644
--- a/src/random.c
+++ b/src/random.c
@@ -15,7 +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 1.10 2002/02/19 13:39:23 drh Exp $
+** $Id: random.c,v 1.11 2004/02/11 09:46:33 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -35,15 +35,15 @@
 ** on RC4, which we know works very well.
 */
 static int randomByte(){
-  int t;
+  unsigned char t;
 
   /* All threads share a single random number generator.
   ** This structure is the current state of the generator.
   */
   static struct {
-    int isInit;          /* True if initialized */
-    int i, j;            /* State variables */
-    int s[256];          /* State variables */
+    unsigned char isInit;          /* True if initialized */
+    unsigned char i, j;            /* State variables */
+    unsigned char s[256];          /* State variables */
   } prng;
 
   /* Initialize the state of the random number generator once,
@@ -65,8 +65,7 @@ static int randomByte(){
       prng.s[i] = i;
     }
     for(i=0; i<256; i++){
-      int t;
-      prng.j = (prng.j + prng.s[i] + k[i]) & 0xff;
+      prng.j += prng.s[i] + k[i];
       t = prng.s[prng.j];
       prng.s[prng.j] = prng.s[i];
       prng.s[i] = t;
@@ -76,38 +75,23 @@ static int randomByte(){
 
   /* Generate and return single random byte
   */
-  prng.i = (prng.i + 1) & 0xff;
-  prng.j = (prng.j + prng.s[prng.i]) & 0xff;
+  prng.i++;
   t = prng.s[prng.i];
+  prng.j += t;
   prng.s[prng.i] = prng.s[prng.j];
   prng.s[prng.j] = t;
-  t = prng.s[prng.i] + prng.s[prng.j];
-  return prng.s[t & 0xff];
+  t += prng.s[prng.i];
+  return prng.s[t];
 }
 
 /*
-** Return an random 8-bit integer.
+** Return N random bytes.
 */
-int sqliteRandomByte(){
-  int r;
+void sqliteRandomness(int N, void *pBuf){
+  unsigned char *zBuf = pBuf;
   sqliteOsEnterMutex();
-  r = randomByte();
-  sqliteOsLeaveMutex();
-  return r;
-}
-
-/*
-** Return a random 32-bit integer.  The integer is generated by making
-** 4 calls to sqliteRandomByte().
-*/
-int sqliteRandomInteger(){
-  int r;
-  int i;
-  sqliteOsEnterMutex();
-  r = randomByte();
-  for(i=1; i<4; i++){
-    r = (r<<8) + randomByte();
+  while( N-- ){
+    *(zBuf++) = randomByte();
   }
   sqliteOsLeaveMutex();
-  return r;
 }
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 381b538e6..4b6402c82 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.209 2004/01/16 15:55:38 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.210 2004/02/11 09:46:33 drh Exp $
 */
 #include "config.h"
 #include "sqlite.h"
@@ -1151,8 +1151,7 @@ int sqliteFuncId(Token*);
 int sqliteExprResolveIds(Parse*, SrcList*, ExprList*, Expr*);
 int sqliteExprAnalyzeAggregates(Parse*, Expr*);
 Vdbe *sqliteGetVdbe(Parse*);
-int sqliteRandomByte(void);
-int sqliteRandomInteger(void);
+void sqliteRandomness(int, void*);
 void sqliteRollbackAll(sqlite*);
 void sqliteCodeVerifySchema(Parse*, int);
 void sqliteBeginTransaction(Parse*, int);
diff --git a/src/vacuum.c b/src/vacuum.c
index 95e7add47..623bc3fc1 100644
--- a/src/vacuum.c
+++ b/src/vacuum.c
@@ -14,7 +14,7 @@
 ** Most of the code in this file may be omitted by defining the
 ** SQLITE_OMIT_VACUUM macro.
 **
-** $Id: vacuum.c,v 1.9 2003/12/07 00:24:35 drh Exp $
+** $Id: vacuum.c,v 1.10 2004/02/11 09:46:33 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -185,14 +185,14 @@ static int vacuumCallback3(void *pArg, int argc, char **argv, char **NotUsed){
 /*
 ** Generate a random name of 20 character in length.
 */
-static void randomName(char *zBuf){
-  static const char zChars[] =
+static void randomName(unsigned char *zBuf){
+  static const unsigned char zChars[] =
     "abcdefghijklmnopqrstuvwxyz"
     "0123456789";
   int i;
+  sqliteRandomness(20, zBuf);
   for(i=0; i<20; i++){
-    int n = sqliteRandomByte() % (sizeof(zChars)-1);
-    zBuf[i] = zChars[n];
+    zBuf[i] = zChars[ zBuf[i]%(sizeof(zChars)-1) ];
   }
 }
 #endif
diff --git a/src/vdbe.c b/src/vdbe.c
index 0e3d8bc33..1288502cd 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -43,7 +43,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.258 2004/02/10 13:41:52 drh Exp $
+** $Id: vdbe.c,v 1.259 2004/02/11 09:46:33 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -2893,10 +2893,12 @@ case OP_NewRecno: {
       cnt = 0;
       do{
         if( v==0 || cnt>2 ){
-          v = sqliteRandomInteger();
+          sqliteRandomness(sizeof(v), &v);
           if( cnt<5 ) v &= 0xffffff;
         }else{
-          v += sqliteRandomByte() + 1;
+          unsigned char r;
+          sqliteRandomness(1, &r);
+          v += r + 1;
         }
         if( v==0 ) continue;
         x = intToKey(v);