func_math: Three new dialplan functions

Introduces three new dialplan functions, MIN and MAX,
which can be used to calculate the minimum or
maximum of up to two numbers, and ABS, an absolute
value function.

ASTERISK-29431

Change-Id: I2bda9269d18f9d54833c85e48e41fce0e0ce4d8d

diff --git a/doc/CHANGES-staging/func_min_max.txt b/doc/CHANGES-staging/func_min_max.txt
new file mode 100644 (file)
index 0000000..df2b665
--- /dev/null
+++ b/doc/CHANGES-staging/func_min_max.txt
@@ -0,0 +1,4 @@
+Subject: func_math: Three new dialplan functions
+
+Introduce three new functions, MIN, MAX, and ABS, which can be used to
+obtain the minimum or maximum of up to two integers or absolute value.

diff --git a/funcs/func_math.c b/funcs/func_math.c
index 6fc725581b130e280dc60fc94559bde75aed22b3..b8a6eb6fdef70a58fe7e464d29fa1ab4181fdfec 100644 (file)
--- a/funcs/func_math.c
+++ b/funcs/func_math.c
@@ -5,6 +5,7 @@
  *
  * Updated by Mark Spencer <markster@digium.com>
  * Updated by Nir Simionovich <nirs@greenfieldtech.net>
+ * Updated by Naveen Albert <asterisk@phreaknet.org>
  *
  * See http://www.asterisk.org for more information about
  * the Asterisk project. Please do not directly contact
@@ -24,6 +25,7 @@
  * \author Andy Powell
  * \author Mark Spencer <markster@digium.com>
  * \author Nir Simionovich <nirs@greenfieldtech.net>
+ * \author Naveen Albert <asterisk@phreaknet.org>
  *
  * \ingroup functions
  */
@@ -40,6 +42,7 @@
 #include "asterisk/channel.h"
 #include "asterisk/pbx.h"
 #include "asterisk/utils.h"
+#include "asterisk/conversions.h"
 #include "asterisk/app.h"
 #include "asterisk/config.h"
 #include "asterisk/test.h"
@@ -105,6 +108,47 @@
                        <para>Note: DEC(${MyVAR}) - Is wrong, as DEC expects the variable name, not its value</para>
                </description>
        </function>
+       <function name="MIN" language="en_US">
+               <synopsis>
+                       Returns the minimum of two numbers.
+               </synopsis>
+               <syntax>
+                       <parameter name="num1" />
+                       <parameter name="num2" />
+               </syntax>
+               <description>
+                       <para>Returns the minimum of two numbers <replaceable>num1</replaceable> and <replaceable>num2</replaceable>.</para>
+                       <para>Example:  Set(min=${MIN(7,4)});
+                       Sets the min variable equal to 4.</para>
+               </description>
+       </function>
+       <function name="MAX" language="en_US">
+               <synopsis>
+                       Returns the maximum of two numbers.
+               </synopsis>
+               <syntax>
+                       <parameter name="num1" />
+                       <parameter name="num2" />
+               </syntax>
+               <description>
+                       <para>Returns the maximum of two numbers <replaceable>num1</replaceable> and <replaceable>num2</replaceable>.</para>
+                       <para>Example:  Set(max=${MAX(4,7)});
+                       Sets the max variable equal to 7.</para>
+               </description>
+       </function>
+       <function name="ABS" language="en_US">
+               <synopsis>
+                       Returns absolute value of a number.
+               </synopsis>
+               <syntax>
+                       <parameter name="num" />
+               </syntax>
+               <description>
+                       <para>Returns the absolute value of a number <replaceable>num</replaceable>.</para>
+                       <para>Example:  Set(absval=${ABS(-13)});
+                       Sets the absval variable equal to 13.</para>
+               </description>
+       </function>
  ***/
 
 enum TypeOfFunctions {
@@ -444,6 +488,111 @@ static int crement_function_read(struct ast_channel *chan, const char *cmd,
        return ret;
 }
 
+static int acf_min_exec(struct ast_channel *chan, const char *cmd,
+                        char *parse, char *buffer, size_t buflen)
+{
+       double num1, num2, response_num = 0;
+       AST_DECLARE_APP_ARGS(args,
+                            AST_APP_ARG(num1);
+                            AST_APP_ARG(num2);
+       );
+
+       AST_STANDARD_APP_ARGS(args, parse);
+
+       if (ast_strlen_zero(args.num1) && ast_strlen_zero(args.num2)) {
+               ast_log(LOG_ERROR, "Missing argument for number(s).");
+               return -1;
+       }
+
+       if (ast_strlen_zero(args.num1)) {
+               response_num = -1; /* couldn't read num1 successfully */
+       } else if (sscanf(args.num1, "%30lf", &num1) != 1) {
+               ast_log(LOG_WARNING, "'%s' is not a valid number\n", args.num1);
+               return -1;
+       }
+
+       if (ast_strlen_zero(args.num2)) {
+               num2 = num1; /* num1 must be a valid integer here */
+       } else if (sscanf(args.num2, "%30lf", &num2) != 1) {
+               ast_log(LOG_WARNING, "'%s' is not a valid number\n", args.num2);
+               return -1;
+       }
+
+       if (response_num == -1) { /* could only read num2 */
+               response_num = num2;
+       } else {
+               response_num = (num1 > num2) ? num2 : num1;
+       }
+
+       ast_debug(1, "%f is the minimum of [%f,%f]\n", response_num, num1, num2);
+       snprintf(buffer, buflen, "%f", response_num);
+
+       return 0;
+}
+
+static int acf_max_exec(struct ast_channel *chan, const char *cmd,
+                        char *parse, char *buffer, size_t buflen)
+{
+       double num1, num2, response_num = 0;
+       AST_DECLARE_APP_ARGS(args,
+                            AST_APP_ARG(num1);
+                            AST_APP_ARG(num2);
+       );
+
+       AST_STANDARD_APP_ARGS(args, parse);
+
+       if (ast_strlen_zero(args.num1) && ast_strlen_zero(args.num2)) {
+               ast_log(LOG_ERROR, "Missing argument for number(s).");
+               return -1;
+       }
+
+       if (ast_strlen_zero(args.num1)) {
+               response_num = -1; /* couldn't read num1 successfully */
+       } else if (sscanf(args.num1, "%30lf", &num1) != 1) {
+               ast_log(LOG_WARNING, "'%s' is not a valid number\n", args.num1);
+               return -1;
+       }
+
+       if (ast_strlen_zero(args.num2)) {
+               num2 = num1; /* num1 must be a valid integer here */
+       } else if (sscanf(args.num2, "%30lf", &num2) != 1) {
+               ast_log(LOG_WARNING, "'%s' is not a valid number\n", args.num2);
+               return -1;
+       }
+
+       if (response_num == -1) { /* could only read num2 */
+               response_num = num2;
+       } else {
+               response_num = (num1 < num2) ? num2 : num1;
+       }
+
+       ast_debug(1, "%f is the maximum of [%f,%f]\n", response_num, num1, num2);
+       snprintf(buffer, buflen, "%f", response_num);
+
+       return 0;
+}
+
+static int acf_abs_exec(struct ast_channel *chan, const char *cmd,
+                        char *parse, char *buffer, size_t buflen)
+{
+       double num1, response_num;
+       AST_DECLARE_APP_ARGS(args,
+                            AST_APP_ARG(num1);
+       );
+
+       AST_STANDARD_APP_ARGS(args, parse);
+
+       if (ast_strlen_zero(args.num1) || sscanf(args.num1, "%30lf", &num1) != 1) {
+               ast_log(LOG_WARNING, "Bad or missing argument for number: %s", args.num1);
+               return -1;
+       }
+
+       response_num = fabs(num1);
+       ast_debug(1, "%f is the absolute value of %f\n", response_num, num1);
+       snprintf(buffer, buflen, "%f", response_num);
+
+       return 0;
+}
 
 static struct ast_custom_function math_function = {
        .name = "MATH",
@@ -460,6 +609,24 @@ static struct ast_custom_function decrement_function = {
        .read = crement_function_read,
 };
 
+static struct ast_custom_function acf_min = {
+       .name = "MIN",
+       .read = acf_min_exec,
+       .read_max = 12,
+};
+
+static struct ast_custom_function acf_max = {
+       .name = "MAX",
+       .read = acf_max_exec,
+       .read_max = 12,
+};
+
+static struct ast_custom_function acf_abs = {
+       .name = "ABS",
+       .read = acf_abs_exec,
+       .read_max = 12,
+};
+
 #ifdef TEST_FRAMEWORK
 AST_TEST_DEFINE(test_MATH_function)
 {
@@ -518,6 +685,9 @@ static int unload_module(void)
        res |= ast_custom_function_unregister(&math_function);
        res |= ast_custom_function_unregister(&increment_function);
        res |= ast_custom_function_unregister(&decrement_function);
+       res |= ast_custom_function_unregister(&acf_min);
+       res |= ast_custom_function_unregister(&acf_max);
+       res |= ast_custom_function_unregister(&acf_abs);
        AST_TEST_UNREGISTER(test_MATH_function);
 
        return res;
@@ -530,6 +700,9 @@ static int load_module(void)
        res |= ast_custom_function_register(&math_function);
        res |= ast_custom_function_register(&increment_function);
        res |= ast_custom_function_register(&decrement_function);
+       res |= ast_custom_function_register(&acf_min);
+       res |= ast_custom_function_register(&acf_max);
+       res |= ast_custom_function_register(&acf_abs);
        AST_TEST_REGISTER(test_MATH_function);
 
        return res;