/*
** Write a 64-bit variable-length integer to memory starting at p[0].
** The length of data write will be between 1 and 9 bytes. The number
** of bytes written is returned.
**
** A variable-length integer consists of the lower 7 bits of each byte
** for all bytes that have the 8th bit set and one byte with the 8th
** bit clear. Except, if we get to the 9th byte, it stores the full
** 8 bits and is the last byte.
*/
SQLITE_PRIVATE int sqlite3PutVarint(unsigned char *p, u64 v){
int i, j, n;
u8 buf[10];
if( v & (((u64)0xff000000)<<32) ){
p[8] = v;
v >>= 8;
for(i=7; i>=0; i--){
p[i] = (v & 0x7f) | 0x80;
v >>= 7;
}
return 9;
}
n = 0;
do{
buf[n++] = (v & 0x7f) | 0x80;
v >>= 7;
}while( v!=0 );
buf[0] &= 0x7f;
assert( n<=9 );
for(i=0, j=n-1; j>=0; j--, i++){
p[i] = buf[j];
}
return n;
}