Add a generic implementation of a dynamic array to libutil

The intention is to get rid of all the ad-hoc array implementations
in the other components and cut down code size.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 79 insertions, 0 deletions

diff --git a/include/array.h b/include/array.h
new file mode 100644
index 0000000..cbac7c2
--- /dev/null
+++ b/include/array.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * array.h
+ *
+ * Copyright (C) 2021 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef ARRAY_H
+#define ARRAY_H
+
+#include "sqfs/predef.h"
+#include "sqfs/error.h"
+
+#include <stddef.h>
+#include <string.h>
+#include <stdlib.h>
+
+typedef struct {
+	/* sizeof a single element */
+	size_t size;
+
+	/* total number of elements available */
+	size_t count;
+
+	/* actually used number of elements available */
+	size_t used;
+
+	void *data;
+} array_t;
+
+static SQFS_INLINE void *array_get(array_t *array, size_t index)
+{
+	if (index >= array->used)
+		return NULL;
+
+	return (char *)array->data + array->size * index;
+}
+
+static SQFS_INLINE int array_set(array_t *array, size_t index, const void *data)
+{
+	if (index >= array->used)
+		return SQFS_ERROR_OUT_OF_BOUNDS;
+
+	memcpy((char *)array->data + array->size * index, data, array->size);
+	return 0;
+}
+
+static SQFS_INLINE void array_sort_range(array_t *array, size_t start,
+					 size_t count,
+					 int (*compare_fun)(const void *a,
+							    const void *b))
+{
+	if (start < array->used) {
+		if (count > (array->used - start))
+			count = array->used - start;
+
+		qsort((char *)array->data + array->size * start, count,
+		      array->size, compare_fun);
+	}
+}
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+SQFS_INTERNAL int array_init(array_t *array, size_t size, size_t capacity);
+
+SQFS_INTERNAL int array_init_copy(array_t *array, const array_t *src);
+
+SQFS_INTERNAL void array_cleanup(array_t *array);
+
+SQFS_INTERNAL int array_append(array_t *array, const void *data);
+
+SQFS_INTERNAL int array_set_capacity(array_t *array, size_t capacity);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ARRAY_H */