lib: added generics package

.gitignore

@@ -11,10 +11,15 @@
 *.swp
 *.d
 *.db
+*.out
+*.6
+*.log
+*.inc
 .dirstamp
 .libs
 .deps
 _obj
+tmp*
 /autom4te.cache/*
 /config.log
 /config.h

doc/lib.rst

@@ -59,3 +59,7 @@ API reference
 
 .. doxygengroup:: utils
    :project: libkresolve
+
+.. _lib_generics:
+
+.. include:: ../lib/generic/README.rst

lib/generic/README.rst

+Generics library
+----------------
+
+This small collection of "generics" was born out of frustration that I couldn't find no
+such thing for C. It's either bloated, has poor interface, null-checking is absent or
+doesn't allow custom allocation scheme. BSD-licensed (or compatible) code is allowed here,
+as long as it comes with a test case in `tests/test_generics.c`.
+
+Data structures
+~~~~~~~~~~~~~~~
+
+- Dynamic arrays
+
+API reference and examples
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. doxygengroup:: generics
+   :project: libkresolve

lib/generic/array.h

+/*  Copyright (C) 2015 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Generics - simple dynamic array.
+ *
+ * \note The C has no generics, so it is implemented mostly using macros.
+ * Be aware of that, as direct usage of the macros in the evaluating macros
+ * may lead to different expectations, i.e.
+ * 
+ *     MIN(array_push(arr, val))
+ *
+ *  May evaluate the code twice, leading to unexpected behaviour.
+ *  This is a price to pay for absence of proper generics.
+ *
+ *  Example usage:
+ *  
+ *      array_t(const char*) arr;
+ *      array_init(arr);
+ *      
+ *      // Reserve memory in advance
+ *      if (array_reserve(arr, 2) < 0) {
+ *          return ENOMEM;
+ *      }
+ *
+ *      // Already reserved, cannot fail
+ *      array_push(arr, "princess");
+ *      array_push(arr, "leia");
+ *
+ *      // Not reserved, may fail
+ *      if (array_push(arr, "han") < 0) {
+ *          return ENOMEM;
+ *      }
+ *
+ *      // It does not hide what it really is
+ *      for (size_t i = 0; i < arr.len; ++i) {
+ *          printf("%s\n", arr.at[i]);
+ *      }
+ *
+ *      // Random delete
+ *      array_del(arr, 0);
+ * 
+ * \addtogroup generics
+ * @{ 
+ */
+
+#pragma once
+
+/** @todo Implement mreserve over custom memory context. */
+#include <libknot/internal/mem.h>
+
+/** Declare an array structure. */
+#define array_t(type) struct {type * at; size_t len; size_t cap; }
+
+/** Zero-initialize the array. */
+#define array_init(array) ((array).at = NULL, (array).len = (array).cap = 0)
+
+/** Free and zero-initialize the array. */
+#define array_clear(array) \
+	free((array).at), array_init(array)
+
+/**
+ * Reserve capacity up to 'n' bytes.
+ * @return >=0 if success
+ */
+#define array_reserve(array, n) \
+	mreserve((char **) &(array).at, sizeof((array).at[0]), n, 0, &(array).cap)
+
+/**
+ * Push value at the end of the array, resize it if necessary.
+ * @note May fail if the capacity is not reserved.
+ * @return element index on success, <0 on failure
+ */
+#define array_push(array, val) \
+	(array).len < (array).cap ? ((array).at[(array).len] = val, (array).len++) \
+		: (array_reserve(array, ((array).cap + 1) * 2) < 0 ? -1 \
+			: ((array).at[(array).len] = val, (array).len++))
+
+/**
+ * Pop value from the end of the array.
+ * @return 0 on success, <0 on failure
+ */
+#define array_pop(array) \
+	array_del((array), (array).len - 1)
+
+/**
+ * Remove value at given index.
+ * @return 0 on success, <0 on failure
+ */
+#define array_del(array, i) \
+	(i) < (array).len ? ((array).at[i] = (array).at[--(array).len], 0) : -1
+
+/** @} */

tests/test_generics.c

+/*  Copyright (C) 2015 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "tests/test.h"
+#include "lib/generic/array.h"
+
+mm_ctx_t global_mm;
+
+static void test_array(void **state)
+{
+	int ret = 0;
+	array_t(int) arr;
+	array_init(arr);
+
+	/* Basic access */
+	assert_int_equal(arr.len, 0);
+	assert_int_equal(array_push(arr, 5), 0);
+	assert_int_equal(arr.at[0], 5);
+	array_clear(arr);
+
+	/* Reserve capacity and fill. */
+	assert_true(array_reserve(arr, 5) >= 0);
+	for (unsigned i = 0; i < 100; ++i) {
+		ret = array_push(arr, i);
+		assert_true(ret >= 0);
+	}
+
+	/* Delete elements. */
+	array_del(arr, 0);
+	for (size_t i = arr.len; --i;) {
+		ret = array_pop(arr);
+		assert_true(ret == 0);
+	}
+
+	array_clear(arr);
+}
+
+int main(void)
+{
+	test_mm_ctx_init(&global_mm);
+
+	const UnitTest tests[] = {
+		unit_test(test_array),
+	};
+
+	return run_tests(tests);
+}