X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=src%2Fcommon%2Fdynamic-array.hpp;fp=src%2Fcommon%2Fdynamic-array.hpp;h=23f3a39b9fe2b78eb41be42af592270204191496;hb=7532fa3bd22e403958f46cd35c824f490d93292d;hp=0000000000000000000000000000000000000000;hpb=985aea182b618c85c51651f224abedfe367c75ee;p=lttng-tools.git

diff --git a/src/common/dynamic-array.hpp b/src/common/dynamic-array.hpp
new file mode 100644
index 000000000..23f3a39b9
--- /dev/null
+++ b/src/common/dynamic-array.hpp
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#ifndef LTTNG_DYNAMIC_ARRAY_H
+#define LTTNG_DYNAMIC_ARRAY_H
+
+#include <common/dynamic-buffer.hpp>
+
+typedef void (*lttng_dynamic_array_element_destructor)(void *element);
+typedef void (*lttng_dynamic_pointer_array_destructor)(void *ptr);
+
+struct lttng_dynamic_array {
+	struct lttng_dynamic_buffer buffer;
+	size_t element_size;
+	size_t size;
+	lttng_dynamic_array_element_destructor destructor;
+};
+
+struct lttng_dynamic_pointer_array {
+	struct lttng_dynamic_array array;
+};
+
+/*
+ * Initialize a resizable array of fixed-size elements. This performs no
+ * allocation and can't fail.
+ */
+void lttng_dynamic_array_init(struct lttng_dynamic_array *array,
+		size_t element_size,
+		lttng_dynamic_array_element_destructor destructor);
+
+/*
+ * Returns the number of elements in the dynamic array.
+ */
+static inline
+size_t lttng_dynamic_array_get_count(
+		const struct lttng_dynamic_array *array)
+{
+	return array->size;
+}
+
+/*
+ * Returns a pointer to the element. Mutating operations on the array invalidate
+ * the returned pointer.
+ */
+static inline
+void *lttng_dynamic_array_get_element(const struct lttng_dynamic_array *array,
+		size_t element_index)
+{
+	LTTNG_ASSERT(element_index < array->size);
+	return array->buffer.data + (element_index * array->element_size);
+}
+
+/*
+ * Set the array's element count to new_element_count. Any added element will
+ * be zeroed.
+ *
+ * Be careful to expand the array's element count _before_ calling out external
+ * APIs (e.g. read(3)) which may populate the buffer as setting the element
+ * count after will zero-out the result of the operation.
+ *
+ * Shrinking an array does not zero the old content. If the buffer may contain
+ * sensititve information, it must be cleared manually _before_ changing the
+ * size.
+ *
+ * NOTE: It is striclty _invalid_ to access memory after _size_, regardless
+ *       of prior calls to set_capacity().
+ */
+int lttng_dynamic_array_set_count(struct lttng_dynamic_array *array,
+		size_t new_element_count);
+
+/*
+ * Add an element to the end of a dynamic array. The array's element count is
+ * increased by one and its underlying capacity is adjusted automatically.
+ *
+ * element is a pointer to the element to add (copy) to the array.
+ */
+int lttng_dynamic_array_add_element(struct lttng_dynamic_array *array,
+		const void *element);
+
+/*
+ * Remove an element from the dynamic array. The array's element count is
+ * decreased by one and the following elements are shifted to take its place
+ * (when applicable).
+ */
+int lttng_dynamic_array_remove_element(struct lttng_dynamic_array *array,
+		size_t element_index);
+
+/* Release any memory used by the dynamic array. */
+void lttng_dynamic_array_reset(struct lttng_dynamic_array *array);
+
+/* Remove all elements from the dynamic array. */
+void lttng_dynamic_array_clear(struct lttng_dynamic_array *array);
+
+/*
+ * Specialization of lttng_dynamic_array for pointers. This utility
+ * is built under the assumption that pointer sizes are equal
+ * for all data types on supported architectures. Revisit this in the event
+ * of a port to an Harvard architecture.
+ */
+
+/*
+ * Initialize a resizable array of fixed-size elements. This performs no
+ * allocation and can't fail.
+ */
+void lttng_dynamic_pointer_array_init(
+		struct lttng_dynamic_pointer_array *array,
+		lttng_dynamic_pointer_array_destructor destructor);
+
+/*
+ * Returns the number of pointers in the dynamic pointer array.
+ */
+static inline
+size_t lttng_dynamic_pointer_array_get_count(
+		const struct lttng_dynamic_pointer_array *array)
+{
+	return lttng_dynamic_array_get_count(&array->array);
+}
+
+/*
+ * Returns the pointer at index `index`.
+ */
+static inline
+void *lttng_dynamic_pointer_array_get_pointer(
+		const struct lttng_dynamic_pointer_array *array, size_t index)
+{
+	void **element = (void **) lttng_dynamic_array_get_element(&array->array, index);
+
+	return *element;
+}
+
+/*
+ * Returns the pointer at index `index`, sets the array slot to NULL. Does not
+ * run the destructor.
+ */
+
+static inline
+void *lttng_dynamic_pointer_array_steal_pointer(
+		struct lttng_dynamic_pointer_array *array, size_t index)
+{
+	void **p_element = (void **) lttng_dynamic_array_get_element(&array->array, index);
+	void *element = *p_element;
+
+	*p_element = NULL;
+
+	return element;
+}
+
+/*
+ * Add a pointer to the end of a dynamic pointer array. The array's element
+ * count is increased by one and its underlying capacity is adjusted
+ * automatically.
+ */
+static inline
+int lttng_dynamic_pointer_array_add_pointer(
+		struct lttng_dynamic_pointer_array *array, void *pointer)
+{
+	return lttng_dynamic_array_add_element(&array->array, &pointer);
+}
+
+/*
+ * Remove a pointer from a dynamic pointer array. The array's element
+ * count is decreased by one and the following pointers are shifted to
+ * take the place of the removed pointer (if applicable).
+ */
+int lttng_dynamic_pointer_array_remove_pointer(
+		struct lttng_dynamic_pointer_array *array, size_t index);
+
+/* Release any memory used by the dynamic array. */
+void lttng_dynamic_pointer_array_reset(
+		struct lttng_dynamic_pointer_array *array);
+
+/* Remove all elements from the dynamic pointer array. */
+void lttng_dynamic_pointer_array_clear(
+		struct lttng_dynamic_pointer_array *array);
+
+#endif /* LTTNG_DYNAMIC_ARRAY_H */