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Add the "varint.c" utility program in the tool directory.

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FossilOrigin-Name: ea5d56be5fe14934e4dbe9c17d46b058f487a231
This commit is contained in:
drh
2014-10-31 10:31:59 +00:00
parent 768f29002e
commit 9c0153457a
3 changed files with 130 additions and 6 deletions
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tool/varint.c Normal file
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@ -0,0 +1,123 @@
/*
** A utility program to translate SQLite varints into decimal and decimal
** integers into varints.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#if defined(_MSC_VER) || defined(__BORLANDC__)
typedef __int64 i64;
typedef unsigned __int64 u64;
#else
typedef long long int i64;
typedef unsigned long long int u64;
#endif
static int hexValue(char c){
if( c>='0' && c<='9' ) return c - '0';
if( c>='a' && c<='f' ) return c - 'a' + 10;
if( c>='A' && c<='F' ) return c - 'A' + 10;
return -1;
}
static char toHex(unsigned char c){
return "0123456789abcdef"[c&0xf];
}
static int putVarint(unsigned char *p, u64 v){
int i, j, n;
unsigned char buf[10];
if( v & (((u64)0xff000000)<<32) ){
p[8] = (unsigned char)v;
v >>= 8;
for(i=7; i>=0; i--){
p[i] = (unsigned char)((v & 0x7f) | 0x80);
v >>= 7;
}
return 9;
}
n = 0;
do{
buf[n++] = (unsigned char)((v & 0x7f) | 0x80);
v >>= 7;
}while( v!=0 );
buf[0] &= 0x7f;
for(i=0, j=n-1; j>=0; j--, i++){
p[i] = buf[j];
}
return n;
}
int main(int argc, char **argv){
int i;
u64 x;
u64 uX = 0;
i64 iX;
int n;
unsigned char zHex[20];
if( argc==1 ){
fprintf(stderr,
"Usage:\n"
" %s HH HH HH ... Convert varint to decimal\n"
" %s DDDDD Convert decimal to varint\n"
" Add '+' or '-' before DDDDD to disambiguate.\n",
argv[0], argv[0]);
exit(1);
}
if( argc>2
|| (strlen(argv[1])==2 && hexValue(argv[1][0])>=0 && hexValue(argv[1][1])>=0)
){
/* Hex to decimal */
for(i=1; i<argc && i<9; i++){
if( strlen(argv[i])!=2 ){
fprintf(stderr, "Not a hex byte: %s\n", argv[i]);
exit(1);
}
x = (hexValue(argv[i][0])<<4) + hexValue(argv[i][1]);
uX = (uX<<7) + (x&0x7f);
if( (x&0x80)==0 ) break;
}
if( i==9 && i<argc ){
if( strlen(argv[i])!=2 ){
fprintf(stderr, "Not a hex byte: %s\n", argv[i]);
exit(1);
}
x = (hexValue(argv[i][0])<<4) + hexValue(argv[i][1]);
uX = (uX<<8) + x;
}
i++;
if( i<argc ){
fprintf(stderr, "Extra arguments: %s...\n", argv[i]);
exit(1);
}
}else{
char *z = argv[1];
int sign = 1;
if( z[0]=='+' ) z++;
else if( z[0]=='-' ){ z++; sign = -1; }
uX = 0;
while( z[0] ){
if( z[0]<'0' || z[0]>'9' ){
fprintf(stderr, "Not a decimal number: %s", argv[1]);
exit(1);
}
uX = uX*10 + z[0] - '0';
z++;
}
if( sign<0 ){
memcpy(&iX, &uX, 8);
iX = -iX;
memcpy(&uX, &iX, 8);
}
}
n = putVarint(zHex, uX);
printf("%lld =", (i64)uX);
for(i=0; i<n; i++){
printf(" %c%c", toHex(zHex[i]>>4), toHex(zHex[i]&0x0f));
}
printf("\n");
return 0;
}