/* Internal routines used by SQUAT.
* Robert O'Callahan
*
* Copyright (c) 1994-2008 Carnegie Mellon University. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any legal
* details, please contact
* Carnegie Mellon University
* Center for Technology Transfer and Enterprise Creation
* 4615 Forbes Avenue
* Suite 302
* Pittsburgh, PA 15213
* (412) 268-7393, fax: (412) 268-7395
* innovation@andrew.cmu.edu
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "config.h"
#include "assert.h"
#include "squat_internal.h"
static int last_err = SQUAT_ERR_OK;
EXPORTED char const squat_index_file_header[8] = "SQUAT 1\n";
EXPORTED void squat_set_last_error(int err)
{
last_err = err;
}
EXPORTED int squat_get_last_error(void)
{
return last_err;
}
EXPORTED SquatInt32 squat_decode_32(char const* s)
{
unsigned char* v = (unsigned char*)s;
return ((SquatInt32)v[0] << 24) | ((SquatInt32)v[1] << 16) |
((SquatInt32)v[2] << 8) | (SquatInt32)v[3];
}
EXPORTED char *squat_encode_32(char* s, SquatInt32 v)
{
s[0] = (unsigned char)(v >> 24);
s[1] = (unsigned char)(v >> 16);
s[2] = (unsigned char)(v >> 8);
s[3] = (unsigned char)v;
return s + 4;
}
EXPORTED SquatInt64 squat_decode_64(char const *s)
{
unsigned char* v = (unsigned char*)s;
return ((SquatInt64)v[0] << 56) | ((SquatInt64)v[1] << 48) |
((SquatInt64)v[2] << 40) | ((SquatInt64)v[3] << 32) |
((SquatInt64)v[4] << 24) | ((SquatInt64)v[5] << 16) |
((SquatInt64)v[6] << 8) | (SquatInt64)v[7];
}
EXPORTED char *squat_encode_64(char* s, SquatInt64 v)
{
s[0] = (unsigned char)(v >> 56);
s[1] = (unsigned char)(v >> 48);
s[2] = (unsigned char)(v >> 40);
s[3] = (unsigned char)(v >> 32);
s[4] = (unsigned char)(v >> 24);
s[5] = (unsigned char)(v >> 16);
s[6] = (unsigned char)(v >> 8);
s[7] = (unsigned char)v;
return s + 8;
}
EXPORTED SquatInt64 squat_decode_I(char const** s)
{
int ch;
SquatInt64 r;
ch = (unsigned char)*(*s)++;
r = ch;
while ((ch & 0x80) != 0) {
ch = (unsigned char)**s;
++(*s);
r = ((r - 0x80) << 7) + ch;
}
return r;
}
HIDDEN char const *squat_decode_skip_I(char const* s, int num_to_skip)
{
while (num_to_skip > 0) {
while ((*s & 0x80) != 0) {
s++;
}
s++;
num_to_skip--;
}
return s;
}
EXPORTED int squat_count_encode_I(SquatInt64 v64)
{
int v = (int)v64;
int shift = 56;
int result;
assert(v64 >= 0);
if (v == v64) {
if (v < (1 << 7)) {
return 1;
} else if (v < (1 << 14)) {
return 2;
} else if (v < (1 << 21)) {
return 3;
} else if (v < (1 << 28)) {
return 4;
}
}
while ((int)(v64 >> shift) == 0) {
shift -= 7;
}
result = 0;
while (shift >= 0) {
shift -= 7;
result++;
}
return result;
}
EXPORTED char *squat_encode_I(char* s, SquatInt64 v64)
{
int v = (int)v64;
int shift = 56;
int v64_shifted;
assert(v64 >= 0);
if (v == v64) {
if (v < (1 << 7)) {
s[0] = (unsigned char)v;
return s + 1;
} else if (v < (1 << 14)) {
s[0] = (unsigned char)((v >> 7) | 0x80);
s[1] = (unsigned char)(v & 0x7F);
return s + 2;
} else if (v < (1 << 21)) {
s[0] = (unsigned char)((v >> 14) | 0x80);
s[1] = (unsigned char)(((v >> 7) & 0x7F) | 0x80);
s[2] = (unsigned char)(v & 0x7F);
return s + 3;
} else if (v < (1 << 28)) {
s[0] = (unsigned char)((v >> 21) | 0x80);
s[1] = (unsigned char)(((v >> 14) & 0x7F) | 0x80);
s[2] = (unsigned char)(((v >> 7) & 0x7F) | 0x80);
s[3] = (unsigned char)(v & 0x7F);
return s + 4;
}
}
while ((v64_shifted = (int)(v64 >> shift)) == 0) {
shift -= 7;
}
while (shift > 7) {
*s++ = (unsigned char)((v64_shifted & 0x7F) | 0x80);
shift -= 7;
v64_shifted = (int)(v64 >> shift);
}
s[0] = (unsigned char)((v64_shifted & 0x7F) + 0x80);
s[1] = (unsigned char)(v & 0x7F);
return s + 2;
}