Precision Math implementation

BitKeeper/etc/ignore:
  Added client/decimal.c client/my_decimal.cc client/my_decimal.h to the ignore list

1 files changed, 332 insertions, 0 deletions

diff --git a/sql/my_decimal.h b/sql/my_decimal.h
new file mode 100644
index 00000000000..63d3fb7e2e5
--- /dev/null
+++ b/sql/my_decimal.h
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+/* Copyright (C) 2004 MySQL AB & MySQL Finland AB & TCX DataKonsult 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 */
+
+/*
+  It is interface module to fixed precision decimals library.
+
+  Most functions use 'uint mask' as parameter, if during operation error
+  which fit in this mask is detected then it will be processed automatically
+  here. (errors are E_DEC_* constants, see include/decimal.h)
+
+  Most function are just inline wrappers around library calls
+*/
+
+#ifndef my_decimal_h
+#define my_decimal_h
+
+C_MODE_START
+#include <decimal.h>
+C_MODE_END
+
+#define DECIMAL_LONGLONG_DIGITS 22
+#define DECIMAL_LONG_DIGITS 10
+#define DECIMAL_LONG3_DIGITS 8
+
+/* number of digits on which we increase scale of devision result */
+#define DECIMAL_DIV_SCALE_INCREASE 5
+
+/* maximum length of buffer in our big digits (uint32) */
+#define DECIMAL_BUFF_LENGTH 8
+/*
+  maximum guaranteed length of number in decimal digits (number of our
+  digits * number of decimal digits in one our big digit - number of decimal
+  digits in one our big digit decreased on 1 (because we always put decimal
+  point on the border of our big digits))
+*/
+#define DECIMAL_MAX_LENGTH ((8 * 9) - 8)
+/*
+  maximum length of string representation (number of maximum decimal
+  digits + 1 position for sign + 1 position for decimal point)
+*/
+#define DECIMAL_MAX_STR_LENGTH (DECIMAL_MAX_LENGTH + 2)
+/*
+  maximum size of packet length
+*/
+#define DECIMAL_MAX_FIELD_SIZE DECIMAL_MAX_LENGTH
+
+
+inline uint my_decimal_size(uint precision, uint scale)
+{
+  /*
+    Always allocate more space to allow library to put decimal point
+    where it want
+  */
+  return decimal_size(precision, scale) + 1;
+}
+
+
+/* my_decimal class limits 'decimal' type to what we need in MySQL  */
+/* It internally all necessary space iside the instance so no extra */
+/* memory is needed. One should call fix_buffer_pointer() function  */
+/* when he moves my_decimal objects in memory                       */
+class my_decimal :public decimal
+{
+  decimal_digit buffer[DECIMAL_BUFF_LENGTH];
+
+public:
+
+  void init()
+  {
+    len= DECIMAL_BUFF_LENGTH;
+    buf= buffer;
+#if !defined(HAVE_purify) && !defined(DBUG_OFF)
+    for (uint i= 0; i < DECIMAL_BUFF_LENGTH; i++)
+      buffer[i]= i;
+#endif
+  }
+  my_decimal()
+  {
+    init();
+  }
+  void fix_buffer_pointer() { buf= buffer; }
+
+  bool sign() const { return decimal::sign; }
+  void sign(bool s) { decimal::sign= s; }
+};
+
+
+#ifndef DBUG_OFF
+void print_decimal(const my_decimal *dec);
+void print_decimal_buff(const my_decimal *dec, const byte* ptr, int length);
+#endif
+
+#ifndef MYSQL_CLIENT
+int decimal_operation_results(int result);
+#else
+inline int decimal_operation_results(int result)
+{
+  return result;
+}
+#endif /*MYSQL_CLIENT*/
+
+inline int check_result(uint mask, int result)
+{
+  if (result & mask)
+    decimal_operation_results(result);
+  return result;
+}
+
+
+inline
+int my_decimal_string_length(const my_decimal *d)
+{
+  return decimal_string_size(d);
+}
+
+
+inline
+int my_decimal_max_length(const my_decimal *d)
+{
+  /* -1 because we do not count \0 */
+  return decimal_string_size(d) - 1;
+}
+
+
+inline
+int my_decimal_get_binary_size(uint precision, uint scale)
+{
+  return decimal_bin_size((int)precision, (int)scale);
+}
+
+
+inline
+void my_decimal2decimal(const my_decimal *from, my_decimal *to)
+{
+  *to= *from;
+  to->fix_buffer_pointer();
+}
+
+
+int my_decimal2binary(uint mask, const my_decimal *d, byte *bin, int prec,
+		      int scale);
+
+
+inline
+int binary2my_decimal(uint mask, const byte *bin, my_decimal *d, int prec,
+		      int scale)
+{
+  return check_result(mask, bin2decimal((char *)bin, (decimal *)d, prec,
+					scale));
+}
+
+
+inline
+int my_decimal_set_zero(my_decimal *d)
+{
+  decimal_make_zero(((decimal *)d));
+  return 0;
+}
+
+
+inline
+bool my_decimal_is_zero(const my_decimal *decimal_value)
+{
+  return decimal_is_zero((decimal *)decimal_value);
+}
+
+
+inline
+int my_decimal_round(uint mask, const my_decimal *from, int scale,
+                     bool truncate, my_decimal *to)
+{
+  return check_result(mask, decimal_round((decimal *)from, to, scale,
+					  (truncate ? TRUNCATE : HALF_UP)));
+}
+
+
+inline
+int my_decimal_floor(uint mask, const my_decimal *from, my_decimal *to)
+{
+  return check_result(mask, decimal_round((decimal *)from, to, 0, FLOOR));
+}
+
+
+inline
+int my_decimal_ceiling(uint mask, const my_decimal *from, my_decimal *to)
+{
+  return check_result(mask, decimal_round((decimal *)from, to, 0, CEILING));
+}
+
+
+#ifndef MYSQL_CLIENT
+int my_decimal2string(uint mask, const my_decimal *d, int fixed_prec,
+		      int fixed_dec, char filler, String *str);
+#endif
+
+inline
+int my_decimal2int(uint mask, const my_decimal *d, my_bool unsigned_flag,
+		   longlong *l)
+{
+  my_decimal rounded;
+  /* decimal_round can return only E_DEC_TRUNCATED */
+  decimal_round((decimal*)d, &rounded, 0, HALF_UP);
+  return check_result(mask, (unsigned_flag ?
+			     decimal2ulonglong(&rounded, (ulonglong *)l) :
+			     decimal2longlong(&rounded, l)));
+}
+
+
+inline
+int my_decimal2double(uint mask, const my_decimal *d, double *result)
+{
+  return check_result(mask, decimal2double((decimal *)d, result));
+}
+
+
+inline
+int str2my_decimal(uint mask, const char *str, my_decimal *d,
+                      char **end= 0)
+{
+  /* set it to 0 to avoid junk in value in case of error of conversion */
+  my_decimal_set_zero(d);
+  return check_result(mask, string2decimal((char *)str, (decimal *)d, end));
+}
+
+
+int str2my_decimal(uint mask, const char *from, uint length,
+                   CHARSET_INFO *charset, my_decimal *decimal_value);
+
+
+#ifdef MYSQL_SERVER
+inline
+int string2my_decimal(uint mask, const String *str, my_decimal *d)
+{
+  return str2my_decimal(mask, str->ptr(), str->length(), str->charset(), d);
+}
+#endif
+
+
+inline
+int double2my_decimal(uint mask, double val, my_decimal *d)
+{
+  return check_result(mask, double2decimal(val, (decimal *)d));
+}
+
+
+inline
+int int2my_decimal(uint mask, longlong i, my_bool unsigned_flag, my_decimal *d)
+{
+  return check_result(mask, (unsigned_flag ?
+			     ulonglong2decimal((ulonglong)i, d) :
+			     longlong2decimal(i, d)));
+}
+
+
+inline
+int my_decimal_neg(st_decimal *arg)
+{
+  decimal_neg(arg);
+  return 0;
+}
+
+
+inline
+int my_decimal_add(uint mask, my_decimal *res, const my_decimal *a,
+		   const my_decimal *b)
+{
+  return check_result(mask, decimal_add((decimal *)a, (decimal *)b, res));
+}
+
+
+inline
+int my_decimal_sub(uint mask, my_decimal *res, const my_decimal *a,
+		   const my_decimal *b)
+{
+  return check_result(mask, decimal_sub((decimal *)a, (decimal *)b, res));
+}
+
+
+inline
+int my_decimal_mul(uint mask, my_decimal *res, const my_decimal *a,
+		   const my_decimal *b)
+{
+  return check_result(mask, decimal_mul((decimal *)a, (decimal *)b, res));
+}
+
+
+inline
+int my_decimal_div(uint mask, my_decimal *res, const my_decimal *a,
+		   const my_decimal *b, int div_scale_inc)
+{
+  return check_result(mask, decimal_div((decimal *)a, (decimal *)b, res,
+					div_scale_inc));
+}
+
+
+inline
+int my_decimal_mod(uint mask, my_decimal *res, const my_decimal *a,
+		   const my_decimal *b)
+{
+  return check_result(mask, decimal_mod((decimal *)a, (decimal *)b, res));
+}
+
+
+/* Returns -1 if a<b, 1 if a>b and 0 if a==b */
+inline
+int my_decimal_cmp(const my_decimal *a, const my_decimal *b)
+{
+  return decimal_cmp((decimal *)a, (decimal *)b);
+}
+
+inline
+void max_my_decimal(my_decimal *to, int precision, int frac)
+{
+  DBUG_ASSERT(precision <= DECIMAL_MAX_LENGTH);
+  max_decimal(precision, frac, (decimal *)to);
+}
+
+#endif /*my_decimal_h*/
+