tool/varint.c

   1 /*
   2 ** A utility program to translate SQLite varints into decimal and decimal
   3 ** integers into varints.
   4 */
   5 #include <stdio.h>
   6 #include <string.h>
   7 #include <stdlib.h>
   8
   9 #if defined(_MSC_VER) || defined(__BORLANDC__)
  10   typedef __int64 i64;
  11   typedef unsigned __int64 u64;
  12 #else
  13   typedef long long int i64;
  14   typedef unsigned long long int u64;
  15 #endif
  16
  17 static int hexValue(char c){
  18   if( c>='0' && c<='9' ) return c - '0';
  19   if( c>='a' && c<='f' ) return c - 'a' + 10;
  20   if( c>='A' && c<='F' ) return c - 'A' + 10;
  21   return -1;
  22 }
  23
  24 static char toHex(unsigned char c){
  25   return "0123456789abcdef"[c&0xf];
  26 }
  27
  28 static int putVarint(unsigned char *p, u64 v){
  29   int i, j, n;
  30   unsigned char buf[10];
  31   if( v & (((u64)0xff000000)<<32) ){
  32     p[8] = (unsigned char)v;
  33     v >>= 8;
  34     for(i=7; i>=0; i--){
  35       p[i] = (unsigned char)((v & 0x7f) | 0x80);
  36       v >>= 7;
  37     }
  38     return 9;
  39   }
  40   n = 0;
  41   do{
  42     buf[n++] = (unsigned char)((v & 0x7f) | 0x80);
  43     v >>= 7;
  44   }while( v!=0 );
  45   buf[0] &= 0x7f;
  46   for(i=0, j=n-1; j>=0; j--, i++){
  47     p[i] = buf[j];
  48   }
  49   return n;
  50 }
  51
  52
  53 int main(int argc, char **argv){
  54   int i;
  55   u64 x;
  56   u64 uX = 0;
  57   i64 iX;
  58   int n;
  59   unsigned char zHex[20];
  60
  61   if( argc==1 ){
  62     fprintf(stderr,
  63          "Usage:\n"
  64          "  %s HH HH HH ...   Convert varint to decimal\n"
  65          "  %s DDDDD          Convert decimal to varint\n"
  66          "                    Add '+' or '-' before DDDDD to disambiguate.\n",
  67          argv[0], argv[0]);
  68     exit(1);
  69   }
  70   if( argc>2
  71    || (strlen(argv[1])==2 && hexValue(argv[1][0])>=0 && hexValue(argv[1][1])>=0)
  72   ){
  73     /* Hex to decimal */
  74     for(i=1; i<argc && i<9; i++){
  75       if( strlen(argv[i])!=2 ){
  76         fprintf(stderr, "Not a hex byte: %s\n", argv[i]);
  77         exit(1);
  78       }
  79       x = (hexValue(argv[i][0])<<4) + hexValue(argv[i][1]);
  80       uX = (uX<<7) + (x&0x7f);
  81       if( (x&0x80)==0 ) break;
  82     }
  83     if( i==9 && i<argc ){
  84       if( strlen(argv[i])!=2 ){
  85         fprintf(stderr, "Not a hex byte: %s\n", argv[i]);
  86         exit(1);
  87       }
  88       x = (hexValue(argv[i][0])<<4) + hexValue(argv[i][1]);
  89       uX = (uX<<8) + x;
  90     }
  91     i++;
  92     if( i<argc ){
  93       fprintf(stderr, "Extra arguments: %s...\n", argv[i]);
  94       exit(1);
  95     }
  96   }else{
  97     char *z = argv[1];
  98     int sign = 1;
  99     if( z[0]=='+' ) z++;
 100     else if( z[0]=='-' ){ z++; sign = -1; }
 101     uX = 0;
 102     while( z[0] ){
 103       if( z[0]<'0' || z[0]>'9' ){
 104         fprintf(stderr, "Not a decimal number: %s", argv[1]);
 105         exit(1);
 106       }
 107       uX = uX*10 + z[0] - '0';
 108       z++;
 109     }
 110     if( sign<0 ){
 111       memcpy(&iX, &uX, 8);
 112       iX = -iX;
 113       memcpy(&uX, &iX, 8);
 114     }
 115   }
 116   n = putVarint(zHex, uX);
 117   printf("%lld =", (i64)uX);
 118   for(i=0; i<n; i++){
 119     printf(" %c%c", toHex(zHex[i]>>4), toHex(zHex[i]&0x0f));
 120   }
 121   printf("\n");
 122   return 0;
 123 }