ber.h

00001 //
00002 // Part of the ht://Dig package <http://www.htdig.org/>
00003 // Copyright (c) 1999, 2000, 2001 The ht://Dig Group
00004 // For copyright details, see the file COPYING in your distribution
00005 // or the GNU General Public License version 2 or later 
00006 // <http://www.gnu.org/copyleft/gpl.html>
00007 //
00008 
00009 #ifndef _ber_h
00010 #define _ber_h
00011 
00012 #include <stdio.h>
00013 #include <errno.h>
00014 
00015 typedef unsigned int ber_t;
00016 
00017 #define BER_MAX_BYTES (sizeof(ber_t) + 1)
00018 
00019 inline int ber_buf2value(const unsigned char* buf, int buf_len, ber_t& result) {
00020 result = 0;
00021 unsigned int bits = 0;
00022 int length = 1;
00023 while(*buf & 0x80) {
00024 if(bits > sizeof(ber_t) * 8) return EINVAL;
00025 result |= (*buf & 0x7f) << bits;
00026 bits += 7;
00027 buf++;
00028 length++;
00029 if(length > buf_len) return EINVAL;
00030 }
00031 result |= (*buf & 0x7f) << bits;
00032 
00033 return length;
00034 }
00035 
00036 inline int ber_file2value(FILE* fp, ber_t& result) {
00037 result = 0;
00038 unsigned int bits = 0;
00039 int c;
00040 int length = 1;
00041 while((c = fgetc(fp)) != EOF && (c & 0x80)) {
00042 if(bits > sizeof(ber_t) * 8) return EINVAL;
00043 result |= (c & 0x7f) << bits;
00044 bits += 7;
00045 length++;
00046 }
00047 
00048 if(c == EOF) return EINVAL;
00049 
00050 result |= (c & 0x7f) << bits;
00051 
00052 return length;
00053 }
00054 
00055 inline int ber_value2buf(unsigned char* buf, int buf_len, ber_t value)
00056 {
00057 if(buf_len <= 0) return EINVAL;
00058 int buf_idx = 0;
00059 buf[buf_idx++] = (value & 0x7f);
00060 while(value >>= 7) {
00061 if(buf_idx >= buf_len) return EINVAL;
00062 buf[buf_idx - 1] |= 0x80;
00063 buf[buf_idx++] = (value & 0x7f);
00064 }
00065 return buf_idx;
00066 }
00067 
00068 inline int ber_value2file(FILE* fp, ber_t value)
00069 {
00070 int length = 1;
00071 unsigned char current;
00072 current = (value & 0x7f);
00073 while(value >>= 7) {
00074 current |= 0x80;
00075 if(fputc(current, fp) == EOF) return EINVAL;
00076 current = (value & 0x7f);
00077 length++;
00078 }
00079 
00080 if(fputc(current, fp) == EOF) return EINVAL;
00081 
00082 return length;
00083 }
00084 
00085 #endif /* _ber_h */