arbitrary precision decimal numbers

strings/llstr.c:
  small optimization
BitKeeper/etc/ignore:
  Added strings/test_decimal to the ignore list

1 files changed, 68 insertions, 0 deletions

diff --git a/include/decimal.h b/include/decimal.h
new file mode 100644
index 00000000000..4ac3412c4d5
--- /dev/null
+++ b/include/decimal.h
@@ -0,0 +1,68 @@
+/* Copyright (C) 2000 MySQL AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#ifndef _decimal_h
+#define _decimal_h
+
+#include <my_global.h>
+#include <m_ctype.h>
+#include <my_sys.h> /* for my_alloca */
+
+typedef enum {TRUNCATE=0, EVEN} dec_round_mode;
+typedef uint32 decimal_digit;
+
+typedef struct st_decimal {
+  int     intg, frac, len;
+  my_bool sign;
+  decimal_digit *buf;
+} decimal;
+
+int decimal2string(decimal *from, char *to, uint *to_len);
+int string2decimal(char *from, decimal *to, char **end);
+int decimal2ulonglong(decimal *from, ulonglong *to);
+int ulonglong2decimal(ulonglong from, decimal *to);
+int decimal2longlong(decimal *from, longlong *to);
+int longlong2decimal(longlong from, decimal *to);
+int decimal2double(decimal *from, double *to);
+int double2decimal(double from, decimal *to);
+
+int decimal_add(decimal *from1, decimal *from2, decimal *to);
+int decimal_sub(decimal *from1, decimal *from2, decimal *to);
+int decimal_mul(decimal *from1, decimal *from2, decimal *to);
+int decimal_div(decimal *from1, decimal *from2, decimal *to, int scale_incr);
+int decimal_mod(decimal *from1, decimal *from2, decimal *to);
+int decimal_result_size(decimal *from1, decimal *from2, char op, int param);
+int decimal_round(decimal *dec, int new_scale, dec_round_mode mode);
+
+/*
+  conventions:
+
+    decimal_smth() == 0     -- everything's ok
+    decimal_smth() <= 0     -- result is usable, precision loss is possible
+    decimal_smth() <= 1     -- result is unusable, but most significant digits
+                               can be lost
+    decimal_smth() >  1     -- no result was generated
+*/
+
+#define E_DEC_TRUNCATED        -1
+#define E_DEC_OK                0
+#define E_DEC_OVERFLOW          1
+#define E_DEC_DIV_ZERO          2
+#define E_DEC_BAD_NUM           3
+#define E_DEC_OOM               4
+
+#endif
+