Added pgv_exists(package) function

Author: Artur Zakirov

README.md

@@ -145,6 +145,7 @@ Function | Returns | Description
 Function | Returns | Description
 -------- | ------- | -----------
 `pgv_exists(package text, name text)` | `bool` | Returns **true** if package and variable exists.
+`pgv_exists(package text)` | `bool` | Returns **true** if package exists.
 `pgv_remove(package text, name text)` | `void` | Removes the variable with the corresponding name. Required package and variable must exists, otherwise the error will be raised.
 `pgv_remove(package text)` | `void` | Removes the package and all package variables with the corresponding name. Required package must exists, otherwise the error will be raised.
 `pgv_free()` | `void` | Removes all packages and variables.

expected/pg_variables.out

@@ -64,6 +64,18 @@ SELECT pgv_exists('vars', 'int1');
  t
 (1 row)
 
+SELECT pgv_exists('vars2');
+ pgv_exists 
+------------
+ f
+(1 row)
+
+SELECT pgv_exists('vars');
+ pgv_exists 
+------------
+ t
+(1 row)
+
 SELECT pgv_set_int('vars', 'intNULL', NULL);
  pgv_set_int 
 -------------
@@ -669,6 +681,12 @@ SELECT pgv_remove('vars', 'int1');
 
 SELECT pgv_get_int('vars', 'int1');
 ERROR:  unrecognized variable "int1"
+SELECT pgv_exists('vars');
+ pgv_exists 
+------------
+ t
+(1 row)
+
 SELECT pgv_remove('vars2');
  pgv_remove 
 ------------
@@ -677,6 +695,12 @@ SELECT pgv_remove('vars2');
 
 SELECT pgv_get_jsonb('vars2', 'j1');
 ERROR:  unrecognized package "vars2"
+SELECT pgv_exists('vars2');
+ pgv_exists 
+------------
+ f
+(1 row)
+
 SELECT * FROM pgv_list() order by package, name;
  package |   name   
 ---------+----------
@@ -707,6 +731,12 @@ SELECT pgv_free();
 
 (1 row)
 
+SELECT pgv_exists('vars');
+ pgv_exists 
+------------
+ f
+(1 row)
+
 SELECT * FROM pgv_list() order by package, name;
  package | name 
 ---------+------

pg_variables--1.0.sql

@@ -113,6 +113,11 @@ RETURNS bool
 AS 'MODULE_PATHNAME', 'variable_exists'
 LANGUAGE C VOLATILE;
 
+CREATE FUNCTION pgv_exists(package text)
+RETURNS bool
+AS 'MODULE_PATHNAME', 'package_exists'
+LANGUAGE C VOLATILE;
+
 CREATE FUNCTION pgv_remove(package text, name text)
 RETURNS void
 AS 'MODULE_PATHNAME', 'remove_variable'

pg_variables.c

@@ -52,6 +52,7 @@ PG_FUNCTION_INFO_V1(variable_select_by_values);
 
 /* Functions to work with packages */
 PG_FUNCTION_INFO_V1(variable_exists);
+PG_FUNCTION_INFO_V1(package_exists);
 PG_FUNCTION_INFO_V1(remove_variable);
 PG_FUNCTION_INFO_V1(remove_package);
 PG_FUNCTION_INFO_V1(remove_packages);
@@ -956,6 +957,28 @@ variable_exists(PG_FUNCTION_ARGS)
 	PG_RETURN_BOOL(found);
 }
 
+/*
+ * Check if package exists.
+ */
+Datum
+package_exists(PG_FUNCTION_ARGS)
+{
+	text	   *package_name;
+	bool		res;
+
+	if (PG_ARGISNULL(0))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("package name can not be NULL")));
+
+	package_name = PG_GETARG_TEXT_PP(0);
+
+	res = getPackageByName(package_name, false, false) != NULL;
+
+	PG_FREE_IF_COPY(package_name, 0);
+	PG_RETURN_BOOL(res);
+}
+
 /*
  * Remove variable from package by name.
  */

sql/pg_variables.sql

@@ -16,6 +16,8 @@ SELECT pgv_get_int('vars', 'int3');
 SELECT pgv_get_int('vars', 'int3', false);
 SELECT pgv_exists('vars', 'int3');
 SELECT pgv_exists('vars', 'int1');
+SELECT pgv_exists('vars2');
+SELECT pgv_exists('vars');
 
 SELECT pgv_set_int('vars', 'intNULL', NULL);
 SELECT pgv_get_int('vars', 'intNULL');
@@ -176,12 +178,15 @@ SELECT * FROM pgv_list() order by package, name;
 SELECT pgv_remove('vars', 'int3');
 SELECT pgv_remove('vars', 'int1');
 SELECT pgv_get_int('vars', 'int1');
+SELECT pgv_exists('vars');
 
 SELECT pgv_remove('vars2');
 SELECT pgv_get_jsonb('vars2', 'j1');
+SELECT pgv_exists('vars2');
 
 SELECT * FROM pgv_list() order by package, name;
 
 SELECT pgv_free();
+SELECT pgv_exists('vars');
 
 SELECT * FROM pgv_list() order by package, name;