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-rw-r--r--ldb/ldb_sqlite3/base160.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/ldb/ldb_sqlite3/base160.c b/ldb/ldb_sqlite3/base160.c
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index 000000000..423e2b684
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+++ b/ldb/ldb_sqlite3/base160.c
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+/*
+ 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
+ */
+void
+lsqlite3_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;
+}