1 files changed, 123 insertions, 0 deletions
diff --git a/tool/varint.c b/tool/varint.c
new file mode 100644
index 0000000..f4a5111
--- /dev/null
+++ b/tool/varint.c
@@ -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;
+}