Update the test logic and the comments on the encoder.c module. (CVS 546)

FossilOrigin-Name: 18c28519d973944756694b2c213bfef3153f4b1b

manifest

@@ -1,5 +1,5 @@
-C Added\sthe\s"encode.c"\ssource\sfile\sthat\scontains\stwo\sutility\ssubroutines\sthat\ncan\sbe\sused\sto\sencode\sbinary\sdata\sfor\suse\sin\sINSERT\sand\sUPDATE\sstatements.\nThis\sis\sjust\san\sinitial\schecking.\s\sThe\scode\shas\snot\syet\sbeen\sintegrated\sinto\nthe\slibrary.\s(CVS\s545)
-D 2002-04-25T11:45:42
+C Update\sthe\stest\slogic\sand\sthe\scomments\son\sthe\sencoder.c\smodule.\s(CVS\s546)
+D 2002-04-25T23:06:47
 F Makefile.in 50f1b3351df109b5774771350d8c1b8d3640130d
 F Makefile.template 89e373b2dad0321df00400fa968dc14b61a03296
 F README a4c0ba11354ef6ba0776b400d057c59da47a4cc0
@@ -24,7 +24,7 @@ F src/btree.c 7dd7ddc66459982dd0cb9800958c1f8d65a32d9f
 F src/btree.h 8abeabfe6e0b1a990b64fa457592a6482f6674f3
 F src/build.c d01b81f41481e733e27ab2fa8e1bfcc64f24257d
 F src/delete.c 6a6b8192cdff5e4b083da3bc63de099f3790d01f
-F src/encode.c cf929a63c3db5d893c24c89377871cb89ede44e2
+F src/encode.c 346b12b46148506c32038524b95c4631ab46d760
 F src/expr.c cf8d2ea17e419fc83b23e080195b2952e0be4164
 F src/func.c a31dcba85bc2ecb9b752980289cf7e6cd0cafbce
 F src/hash.c cc259475e358baaf299b00a2c7370f2b03dda892
@@ -132,7 +132,7 @@ F www/speed.tcl da8afcc1d3ccc5696cfb388a68982bc3d9f7f00f
 F www/sqlite.tcl 8b5884354cb615049aed83039f8dfe1552a44279
 F www/tclsqlite.tcl 1db15abeb446aad0caf0b95b8b9579720e4ea331
 F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
-P 18b31b7ab90ab330e271e0ed5d316f63846845be
-R 6048f8bfc097ad26d4d3ee4d7998e4f3
+P 57f7c59713299b03b10ba9c1a5883e2c08a8b138
+R 1d03be9386f27dabc02ae6f5664f26fc
 U drh
-Z fcb6af942153d3111f8e4a67cbb6971e
+Z 518e7e975793406e2b9482ce10c2312d

manifest.uuid

@@ -1 +1 @@
-57f7c59713299b03b10ba9c1a5883e2c08a8b138
+18c28519d973944756694b2c213bfef3153f4b1b

src/encode.c

@@ -15,21 +15,21 @@
 ** data in an SQLite database.  The code in this file is used by any other
 ** part of the SQLite library.
 **
-** $Id: encode.c,v 1.1 2002/04/25 11:45:42 drh Exp $
+** $Id: encode.c,v 1.2 2002/04/25 23:06:47 drh Exp $
 */
-#include "sqliteInt.h"
-#include "encode.h"
 
 /*
 ** Encode a binary buffer "in" of size n bytes so that it contains
 ** no instances of characters '\'' or '\000'.  The output is 
 ** null-terminated and can be used as a string value in an INSERT
-** or UPDATE statement.
+** or UPDATE statement.  Use sqlite_decode_binary() to convert the
+** string back into its original binary.
 **
 ** The result is written into a preallocated output buffer "out".
-** "out" must be able to hold at least 2 + (n+255)*3/256 + n bytes.
+** "out" must be able to hold at least (256*n + 1262)/253 bytes.
 ** In other words, the output will be expanded by as much as 3
-** bytes for every 256 bytes of input plus 2 bytes of fixed overhead.
+** bytes for every 253 bytes of input plus 2 bytes of fixed overhead.
+** (This is approximately 2 + 1.019*n or about a 2% size increase.)
 */
 void sqlite_encode_binary(const unsigned char *in, int n, unsigned char *out){
   int i, j, e, m;
@@ -107,16 +107,25 @@ int sqlite_decode_binary(const unsigned char *in, unsigned char *out){
 */
 int main(int argc, char **argv){
   int i, j, n, m;
-  unsigned char in[20000];
-  unsigned char out[30000];
+  unsigned char in[30000];
+  unsigned char out[33000];
 
-  for(i=0; i<10000; i++){
+  for(i=0; i<sizeof(in); i++){
     printf("Test %d: ", i+1);
-    n = rand() % sizeof(in);
-    for(j=0; j<n; j++) in[j] = rand() & 0xff;
+    n = rand() % (i+1);
+    if( i%100==0 ){
+      int k;
+      for(j=k=0; j<n; j++){
+        /* if( k==0 || k=='\'' ) k++; */
+        in[j] = k;
+        k = (k+1)&0xff;
+      }
+    }else{
+      for(j=0; j<n; j++) in[j] = rand() & 0xff;
+    }
     sqlite_encode_binary(in, n, out);
-    printf("size %d->%d ", n, strlen(out)+1);
-    m = 2 + (n+255)*3/256 + n;
+    m = (256*n + 1262)/253;
+    printf("size %d->%d (max %d)", n, strlen(out)+1, m);
     if( strlen(out)+1>m ){
       printf(" ERROR output too big\n");
       exit(1);