Arjens LOG functions changes with small changes and tests added to mysql-test

Docs/manual.texi:
  Manual changes to doccument new functions and function changes
mysql-test/r/func_math.result:
  Extend tests for LOG family functions
mysql-test/t/func_math.test:
  Extend tests for LOG family functions
sql/gen_lex_hash.cc:
  Lex hash changes
sql/item_create.cc:
  Rename old log function to ln
sql/item_create.h:
  More log functions
sql/item_func.cc:
  Implementation of new log function behavior
sql/item_func.h:
  Class definition for new functions
sql/lex.h:
  Function names
sql/sql_yacc.yy:
  Symbols for new LOG function
tests/function.res:
  One more test result change
tests/function.tst:
  One more test change
BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted

BitKeeper/etc/logging_ok

@@ -70,3 +70,4 @@ zak@linux.local
 salle@geopard.(none)
 walrus@mysql.com
 zgreant@mysql.com
+peter@mysql.com

Docs/manual.texi

@@ -31874,17 +31874,57 @@ mysql> SELECT EXP(2);
 mysql> SELECT EXP(-2);
         -> 0.135335
 @end example
-@findex LOG()
+
-@item LOG(X)
+@findex LN()
+@item LN(X)
 Returns the natural logarithm of @code{X}:
 @example
+mysql> SELECT LN(2);
+        -> 0.693147
+mysql> SELECT LN(-2);
+        -> NULL
+@end example
+
+This function was added in MySQL version 4.0.3.
+It is synonymous with @code{LOG(X)} in MySQL.
+
+@findex LOG()
+@item LOG([B,]X)
+When called with one parameter, this function returns the natural logarithm
+of @code{X}:
+@example
 mysql> SELECT LOG(2);
         -> 0.693147
 mysql> SELECT LOG(-2);
         -> NULL
 @end example
-If you want the log of a number @code{X} to some arbitary base @code{B}, use
+
-the formula @code{LOG(X)/LOG(B)}.
+When called with two parameters, this function returns the logarithm of
+@code{X} for an arbitary base @code{B}:
+@example
+mysql> SELECT LOG(2,65536);
+        -> 16.000000
+mysql> SELECT LOG(1,100);
+        -> NULL
+@end example
+
+The arbitrary base option was added in MySQL version 4.0.3.
+@code{LOG(B,X)} is equivalent to @code{LOG(X)/LOG(B)}.
+
+@findex LOG2()
+@item LOG2(X)
+Returns the base-2 logarithm of @code{X}:
+@example
+mysql> SELECT LOG2(65536);
+        -> 16.000000
+mysql> SELECT LOG2(-100);
+        -> NULL
+@end example
+
+@code{LOG2()} is useful for finding out how many bits a number would
+require for storage.
+This function was added in MySQL version 4.0.3.
+In earlier versions, you can use @code{LOG(X)/LOG(2)} instead.
 
 @findex LOG10()
 @item LOG10(X)
@@ -49674,12 +49714,27 @@ Our TODO section contains what we plan to have in 4.0. @xref{TODO MySQL 4.0}.
 @cindex changes, version 4.0
 
 @menu
+* News-4.0.3::                  Changes in release 4.0.3
 * News-4.0.2::                  Changes in release 4.0.2 (01 July 2002)
 * News-4.0.1::                  Changes in release 4.0.1 (23 Dec 2001)
 * News-4.0.0::                  Changes in release 4.0.0 (Oct 2001: Alpha)
 @end menu
 
-@node News-4.0.2, News-4.0.1, News-4.0.x, News-4.0.x
+@node News-4.0.3, News-4.0.2, News-4.0.x, News-4.0.x
+@appendixsubsec Changes in release 4.0.3
+
+@itemize @bullet
+@item
+Extended @code{LOG()} function to accept an optional arbitrary base parameter.
+@xref{Mathematical functions}.
+@item
+Added @code{LOG2()} function (useful for finding out how many bits a number would require for storage).
+@item
+Added @code{LN()} natural logarithm function for compatibility with other databases. It is synonymous with @code{LOG(X)}.
+@end itemize
+
+
+@node News-4.0.2, News-4.0.1, News-4.0.3, News-4.0.x
 @appendixsubsec Changes in release 4.0.2 (01 July 2002)
 
 @itemize @bullet

mysql-test/r/func_math.result

@@ -16,9 +16,18 @@ round(5.64,1)	round(5.64,2)	round(5.64,-1)	round(5.64,-2)
 select abs(-10), sign(-5), sign(5), sign(0);
 abs(-10)	sign(-5)	sign(5)	sign(0)
 10	-1	1	0
-select log(exp(10)),exp(log(sqrt(10))*2);
+select log(exp(10)),exp(log(sqrt(10))*2),log(-1),log(NULL),log(1,1),log(3,9),log(-1,2),log(NULL,2);
-log(exp(10))	exp(log(sqrt(10))*2)
+log(exp(10))	exp(log(sqrt(10))*2)	log(-1)	log(NULL)	log(1,1)	log(3,9)	log(-1,2)	log(NULL,2)
-10.000000	10.000000
+10.000000	10.000000	NULL	NULL	NULL	2.000000	NULL	NULL
+select ln(exp(10)),exp(ln(sqrt(10))*2),ln(-1),ln(0),ln(NULL);
+ln(exp(10))	exp(ln(sqrt(10))*2)	ln(-1)	ln(0)	ln(NULL)
+10.000000	10.000000	NULL	NULL	NULL
+select log2(8),log2(15),log2(-2),log2(0),log2(NULL);
+log2(8)	log2(15)	log2(-2)	log2(0)	log2(NULL)
+3.000000	3.906891	NULL	NULL	NULL
+select log10(100),log10(18),log10(-4),log10(0),log10(NULL);
+log10(100)	log10(18)	log10(-4)	log10(0)	log10(NULL)
+2.000000	1.255273	NULL	NULL	NULL
 select pow(10,log10(10)),power(2,4);
 pow(10,log10(10))	power(2,4)
 10.000000	16.000000

mysql-test/t/func_math.test

@@ -8,7 +8,10 @@ select truncate(52.64,1),truncate(52.64,2),truncate(52.64,-1),truncate(52.64,-2)
 select round(5.5),round(-5.5);
 select round(5.64,1),round(5.64,2),round(5.64,-1),round(5.64,-2);
 select abs(-10), sign(-5), sign(5), sign(0);
-select log(exp(10)),exp(log(sqrt(10))*2);
+select log(exp(10)),exp(log(sqrt(10))*2),log(-1),log(NULL),log(1,1),log(3,9),log(-1,2),log(NULL,2);
+select ln(exp(10)),exp(ln(sqrt(10))*2),ln(-1),ln(0),ln(NULL);
+select log2(8),log2(15),log2(-2),log2(0),log2(NULL);
+select log10(100),log10(18),log10(-4),log10(0),log10(NULL);
 select pow(10,log10(10)),power(2,4);
 select rand(999999),rand();
 select pi(),sin(pi()/2),cos(pi()/2),abs(tan(pi())),cot(1),asin(1),acos(0),atan(1);

sql/gen_lex_hash.cc

@@ -74,13 +74,13 @@ static struct my_option my_long_options[] =
   {"version", 'V', "Output version information and exit",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"rnd1", 'r', "Set 1 part of rnd value for hash generator",
-   (gptr*) &best_t1, (gptr*) &best_t1, 0, GET_ULONG, REQUIRED_ARG, 6657025L,
+   (gptr*) &best_t1, (gptr*) &best_t1, 0, GET_ULONG, REQUIRED_ARG, 5075635L,
    0, 0, 0, 0, 0},
   {"rnd2", 'R', "Set 2 part of rnd value for hash generator",
-   (gptr*) &best_t2, (gptr*) &best_t2, 0, GET_ULONG, REQUIRED_ARG, 6114496L,
+   (gptr*) &best_t2, (gptr*) &best_t2, 0, GET_ULONG, REQUIRED_ARG, 1345933L,
    0, 0, 0, 0, 0},
   {"type", 't', "Set type of char table to generate",
-   (gptr*) &best_type, (gptr*) &best_type, 0, GET_UINT, REQUIRED_ARG, 1, 0, 0,
+   (gptr*) &best_type, (gptr*) &best_type, 0, GET_UINT, REQUIRED_ARG, 4, 0, 0,
    0, 0, 0},
   { 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
 };
@@ -479,7 +479,7 @@ int main(int argc,char **argv)
 
   MY_INIT(argv[0]);
 
-  start_value=1109118L;   /* mode=4903  add=3  type: 0 */
+  start_value=3807640L;   /* mode=6971  add=3  type: 0 */
   if (get_options(argc,(char **) argv))
     exit(1);
 

sql/item_create.cc

@@ -220,9 +220,14 @@ Item *create_func_char_length(Item* a)
   return new Item_func_char_length(a);
 }
 
-Item *create_func_log(Item* a)
+Item *create_func_ln(Item* a)
 {
-  return new Item_func_log(a);
+  return new Item_func_ln(a);
+}
+
+Item *create_func_log2(Item* a)
+{
+  return new Item_func_log2(a);
 }
 
 Item *create_func_log10(Item* a)

sql/item_create.h

@@ -52,8 +52,9 @@ Item *create_func_instr(Item* a, Item *b);
 Item *create_func_isnull(Item* a);
 Item *create_func_lcase(Item* a);
 Item *create_func_length(Item* a);
+Item *create_func_ln(Item* a);
 Item *create_func_locate(Item* a, Item *b);
-Item *create_func_log(Item* a);
+Item *create_func_log2(Item* a);
 Item *create_func_log10(Item* a);
 Item *create_func_lpad(Item* a, Item *b, Item *c);
 Item *create_func_ltrim(Item* a);

sql/item_func.cc

@@ -437,14 +437,43 @@ void Item_func_abs::fix_length_and_dec()
   hybrid_type= args[0]->result_type() == INT_RESULT ? INT_RESULT : REAL_RESULT;
 }
 
+/* Gateway to natural LOG function */
+double Item_func_ln::val()
+{
+  double value=args[0]->val();
+  if ((null_value=(args[0]->null_value || value <= 0.0)))
+    return 0.0;
+  return log(value);
+}
+
+/* 
+ Extended but so slower LOG function
+ We have to check if all values are > zero and first one is not one
+ as these are the cases then result is not a number.
+*/ 
 double Item_func_log::val()
 {
   double value=args[0]->val();
   if ((null_value=(args[0]->null_value || value <= 0.0)))
-    return 0.0; /* purecov: inspected */
+    return 0.0;
+  if (arg_count == 2)
+  {
+    double value2= args[1]->val();
+    if ((null_value=(args[1]->null_value || value2 <= 0.0 || value == 1.0)))
+      return 0.0;
+    return log(value2) / log(value);
+  }
   return log(value);
 }
 
+double Item_func_log2::val()
+{
+  double value=args[0]->val();
+  if ((null_value=(args[0]->null_value || value <= 0.0)))
+    return 0.0;
+  return log(value) / log(2.0);
+}
+
 double Item_func_log10::val()
 {
   double value=args[0]->val();

sql/item_func.h

@@ -338,15 +338,35 @@ public:
   const char *func_name() const { return "exp"; }
 };
 
+
+class Item_func_ln :public Item_dec_func
+{
+public:
+  Item_func_ln(Item *a) :Item_dec_func(a) {}
+  double val();
+  const char *func_name() const { return "ln"; }
+};
+
+
 class Item_func_log :public Item_dec_func
 {
 public:
   Item_func_log(Item *a) :Item_dec_func(a) {}
+  Item_func_log(Item *a,Item *b) :Item_dec_func(a,b) {}
   double val();
   const char *func_name() const { return "log"; }
 };
 
 
+class Item_func_log2 :public Item_dec_func
+{
+public:
+  Item_func_log2(Item *a) :Item_dec_func(a) {}
+  double val();
+  const char *func_name() const { return "log2"; }
+};
+
+
 class Item_func_log10 :public Item_dec_func
 {
 public:

sql/lex.h

@@ -461,9 +461,11 @@ static SYMBOL sql_functions[] = {
   { "LCASE",		SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_lcase)},
   { "LEAST",		SYM(LEAST_SYM),0,0},
   { "LENGTH",		SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_length)},
+  { "LN",		SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_ln)},
   { "LOAD_FILE",	SYM(FUNC_ARG1),0,CREATE_FUNC(create_load_file)},
   { "LOCATE",		SYM(LOCATE),0,0},
-  { "LOG",		SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_log)},
+  { "LOG",		SYM(LOG_SYM),0,0},
+  { "LOG2",		SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_log2)},
   { "LOG10",		SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_log10)},
   { "LOWER",		SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_lcase)},
   { "LPAD",		SYM(FUNC_ARG3),0,CREATE_FUNC(create_func_lpad)},

sql/sql_yacc.yy

@@ -231,6 +231,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 %token	LIKE
 %token	LINES
 %token	LOCAL_SYM
+%token	LOG_SYM
 %token	LOGS_SYM
 %token	LONG_NUM
 %token	LONG_SYM
@@ -1779,6 +1780,10 @@ simple_expr:
 	  { $5->push_front($3); $$= new Item_func_max(*$5); }
 	| LEAST_SYM '(' expr ',' expr_list ')'
 	  { $5->push_front($3); $$= new Item_func_min(*$5); }
+	| LOG_SYM '(' expr ')'
+		{ $$= new Item_func_log($3); }
+	| LOG_SYM '(' expr ',' expr ')'
+		{ $$= new Item_func_log($3, $5); }
 	| MINUTE_SYM '(' expr ')'
 	  { $$= new Item_func_minute($3); }
 	| MONTH_SYM '(' expr ')'

tests/function.res

@@ -11,11 +11,11 @@ select floor(5.5),floor(-5.5),ceiling(5.5),ceiling(-5.5),round(5.5),round(-5.5)
 floor(5.5)	floor(-5.5)	ceiling(5.5)	ceiling(-5.5)	round(5.5)	round(-5.5)
 5	-6	6	-5	6	-6
 --------------
-select abs(-10),log(exp(10)),exp(log(sqrt(10))*2),pow(10,log10(10)),rand(999999),rand()
+select abs(-10),log(exp(10)),ln(exp(10)),log2(65535),log(2,65535),exp(log(sqrt(10))*2),pow(10,log10(10)),rand(999999),rand()
 --------------
 
-abs(-10)	log(exp(10))	exp(log(sqrt(10))*2)	pow(10,log10(10))	rand(999999)	rand()
+abs(-10)	log(exp(10))	ln(exp(10))	log2(65535)	log(2,65535)	exp(log(sqrt(10))*2)	pow(10,log10(10))	rand(999999)	rand()
-10	10.000000	10.000000	10.000000	0.1844	0.7637
+10	10.000000	10.000000	2.000000	2.000000	10.000000	10.000000	0.1844	0.7637
 --------------
 select least(6,1.0,2.0),greatest(3,4,5,0)
 --------------

tests/function.tst

@@ -7,7 +7,7 @@
 #
 select 1+1,1-1,1+1*2,8/5,8%5,mod(8,5),mod(8,5)|0,-(1+1)*-2,sign(-5) ;
 select floor(5.5),floor(-5.5),ceiling(5.5),ceiling(-5.5),round(5.5),round(-5.5);
-select abs(-10),log(exp(10)),exp(log(sqrt(10))*2),pow(10,log10(10)),rand(999999),rand();
+select abs(-10),log(exp(10)),ln(exp(10)),log2(65535),log(2,65535),exp(log(sqrt(10))*2),pow(10,log10(10)),rand(999999),rand();
 select least(6,1.0,2.0),greatest(3,4,5,0) ;
 select 1 | (1+1),5 & 3,bit_count(7) ;
 #