/*    base160 code used by ldb_sqlite3   Copyright (C) 2004 Derrell Lipman   This library is free software; you can redistribute it and/or   modify it under the terms of the GNU Lesser General Public   License as published by the Free Software Foundation; either   version 3 of the License, or (at your option) any later version.   This library is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU   Lesser General Public License for more details.   You should have received a copy of the GNU Lesser General Public   License along with this library; if not, see <http://www.gnu.org/licenses/>.*//* * ldb_sqlite3_base160() * * Convert an integer value to a string containing the base 160 representation * of the integer.  We always convert to a string representation that is 4 * bytes in length, and we always null terminate. * * Parameters: *   val -- *     The value to be converted * *   result -- *     Buffer in which the result is to be placed * * Returns: *   nothing */static unsigned char        base160tab[161] ={    48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , /* 0-9 */    58 , 59 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , /* : ; A-H */    73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , /* I-R */    83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 97 , 98 , /* S-Z , a-b */    99 , 100, 101, 102, 103, 104, 105, 106, 107, 108, /* c-l */    109, 110, 111, 112, 113, 114, 115, 116, 117, 118, /* m-v */    119, 120, 121, 122, 160, 161, 162, 163, 164, 165, /* w-z, latin1 */    166, 167, 168, 169, 170, 171, 172, 173, 174, 175, /* latin1 */    176, 177, 178, 179, 180, 181, 182, 183, 184, 185, /* latin1 */    186, 187, 188, 189, 190, 191, 192, 193, 194, 195, /* latin1 */    196, 197, 198, 199, 200, 201, 202, 203, 204, 205, /* latin1 */    206, 207, 208, 209, 210, 211, 212, 213, 214, 215, /* latin1 */    216, 217, 218, 219, 220, 221, 222, 223, 224, 225, /* latin1 */    226, 227, 228, 229, 230, 231, 232, 233, 234, 235, /* latin1 */    236, 237, 238, 239, 240, 241, 242, 243, 244, 245, /* latin1 */    246, 247, 248, 249, 250, 251, 252, 253, 254, 255, /* latin1 */    '\0'};/* * lsqlite3_base160() * * Convert an unsigned long integer into a base160 representation of the * number. * * Parameters: *   val -- *     value to be converted * *   result -- *     character array, 5 bytes long, into which the base160 representation *     will be placed.  The result will be a four-digit representation of the *     number (with leading zeros prepended as necessary), and null *     terminated. * * Returns: *   Nothing */voidlsqlite3_base160(unsigned long val,                 unsigned char result[5]){    int             i;    for (i = 3; i >= 0; i--) {                result[i] = base160tab[val % 160];        val /= 160;    }    result[4] = '\0';}/* * lsqlite3_base160Next() * * Retrieve the next-greater number in the base160 sequence for the terminal * tree node (the last four digits).  Only one tree level (four digits) are * operated on. * * Parameters: *   base160 -- a character array containing either an empty string (in which *              case no operation is performed), or a string of base160 digits *              with a length of a multiple of four digits. * *              Upon return, the trailing four digits (one tree level) will *              have been incremented by 1. * * Returns: *   base160 -- the modified array */char *lsqlite3_base160Next(char base160[]){    int             i;    int             len;    unsigned char * pTab;    char *          pBase160 = base160;    /*     * We need a minimum of four digits, and we will always get a multiple of     * four digits.     */    if (len = strlen(pBase160)) >= 4)    {        pBase160 += strlen(pBase160) - 1;        /* We only carry through four digits: one level in the tree */        for (i = 0; i < 4; i++) {            /* What base160 value does this digit have? */            pTab = strchr(base160tab, *pBase160);            /* Is there a carry? */            if (pTab < base160tab + sizeof(base160tab) - 1) {                /* Nope.  Just increment this value and we're done. */                *pBase160 = *++pTab;                break;            } else {                /*                 * There's a carry.  This value gets base160tab[0], we                 * decrement the buffer pointer to get the next higher-order                 * digit, and continue in the loop.                 */                *pBase160-- = base160tab[0];            }        }    }    return base160;}