1 files changed, 26 insertions, 71 deletions

diff --git a/src/random.c b/src/random.c
index f4a9f1912..ee55b7a9f 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 1.6 2001/09/19 13:22:40 drh Exp $
+** $Id: random.c,v 1.7 2001/09/23 19:46:52 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -23,103 +23,58 @@
 /*
 ** Get a single 8-bit random value from the RC4 PRNG.
 */
-int sqliteRandomByte(void){
+int sqliteRandomByte(sqlite *db){
   int t;
 
-  /*
-  ** The following structure holds the current state of the RC4 algorithm.
-  ** We use RC4 as a random number generator.  Each call to RC4 gives
-  ** a random 8-bit number.
-  **
-  ** Nothing in this file or anywhere else in SQLite does any kind of
-  ** encryption.  The RC4 algorithm is being used as a PRNG (pseudo-random
-  ** number generator) not as an encryption device.
-  */
-  static struct {
-    int isInit;
-    int i, j;
-    int s[256];
-  } prng_state;
- 
   /* Initialize the state of the random number generator once,
   ** the first time this routine is called.  The seed value does
   ** not need to contain a lot of randomness since we are not
   ** trying to do secure encryption or anything like that...
+  **
+  ** Nothing in this file or anywhere else in SQLite does any kind of
+  ** encryption.  The RC4 algorithm is being used as a PRNG (pseudo-random
+  ** number generator) not as an encryption device.
   */
-  if( !prng_state.isInit ){
+  if( !db->prng.isInit ){
     int i;
-    static char seed[] = "    sqlite random seed abcdefghijklmnop";
     char k[256];
-    sqliteOsRandomSeed(seed);
-    prng_state.j = 0;
-    prng_state.i = 0;
+    db->prng.j = 0;
+    db->prng.i = 0;
+    sqliteOsRandomSeed(k);
     for(i=0; i<256; i++){
-      prng_state.s[i] = i;
-      k[i] = seed[i%sizeof(seed)];
+      db->prng.s[i] = i;
     }
     for(i=0; i<256; i++){
       int t;
-      prng_state.j = (prng_state.j + prng_state.s[i] + k[i]) & 0xff;
-      t = prng_state.s[prng_state.j];
-      prng_state.s[prng_state.j] = prng_state.s[i];
-      prng_state.s[i] = t;
+      db->prng.j = (db->prng.j + db->prng.s[i] + k[i]) & 0xff;
+      t = db->prng.s[db->prng.j];
+      db->prng.s[db->prng.j] = db->prng.s[i];
+      db->prng.s[i] = t;
     }
-    prng_state.isInit = 1;
+    db->prng.isInit = 1;
   }
 
   /* Generate and return single random byte
   */
-  prng_state.i = (prng_state.i + 1) & 0xff;
-  prng_state.j = (prng_state.j + prng_state.s[prng_state.i]) & 0xff;
-  t = prng_state.s[prng_state.i];
-  prng_state.s[prng_state.i] = prng_state.s[prng_state.j];
-  prng_state.s[prng_state.j] = t;
-  t = prng_state.s[prng_state.i] + prng_state.s[prng_state.j];
-  return prng_state.s[t & 0xff];
+  db->prng.i = (db->prng.i + 1) & 0xff;
+  db->prng.j = (db->prng.j + db->prng.s[db->prng.i]) & 0xff;
+  t = db->prng.s[db->prng.i];
+  db->prng.s[db->prng.i] = db->prng.s[db->prng.j];
+  db->prng.s[db->prng.j] = t;
+  t = db->prng.s[db->prng.i] + db->prng.s[db->prng.j];
+  return db->prng.s[t & 0xff];
 }
 
 /*
 ** Return a random 32-bit integer.  The integer is generated by making
 ** 4 calls to sqliteRandomByte().
 */
-int sqliteRandomInteger(void){
+int sqliteRandomInteger(sqlite *db){
   int r;
   int i;
-  r = sqliteRandomByte();
+  r = sqliteRandomByte(db);
   for(i=1; i<4; i++){
-    r = (r<<8) + sqliteRandomByte();
+    r = (r<<8) + sqliteRandomByte(db);
   }
   return r;
 }
-
-/*
-** Return a random 16-bit unsigned integer.  The integer is generated by
-** making 2 calls to sqliteRandomByte().
-*/
-int sqliteRandomShort(void){
-  int r;
-  r = sqliteRandomByte();
-  r = (r<<8) + sqliteRandomByte();
-  return r;
-}
-
-/*
-** Generate a random filename with the given prefix.  The new filename
-** is written into zBuf[].  The calling function must insure that
-** zBuf[] is big enough to hold the prefix plus 20 or so extra
-** characters.
-**
-** Very random names are chosen so that the chance of a
-** collision with an existing filename is very very small.
-*/
-void sqliteRandomName(char *zBuf, char *zPrefix){
-  int i, j;
-  static const char zRandomChars[] = "abcdefghijklmnopqrstuvwxyz0123456789";
-  strcpy(zBuf, zPrefix);
-  j = strlen(zBuf);
-  for(i=0; i<15; i++){
-    int c = sqliteRandomByte() % (sizeof(zRandomChars) - 1);
-    zBuf[j++] = zRandomChars[c];
-  }
-  zBuf[j] = 0;
-}