cheney copying collector

1 files changed, 127 insertions, 0 deletions

diff --git a/examples/string/uns_string.c b/examples/string/uns_string.c
new file mode 100644
index 0000000..e510fcf
--- /dev/null
+++ b/examples/string/uns_string.c
@@ -0,0 +1,127 @@
+/* Copyright (c) 2024, Peter McGoron
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1) Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2) Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <string.h>
+#include "uns.h"
+#include "uns_string.h"
+
+enum {
+	ALLEN_IND = 0,
+	LEN_IND = 1,
+	BYTES_IND = 2,
+	NUMBER_OF_IND = 3
+};
+
+static size_t get_size_t(struct uns_gc *gc, struct uns_root_list *root, size_t i)
+{
+	size_t r;
+
+	void *p = gc->record_get_ptr(root->p, i);
+	memcpy(&r, p, sizeof(r));
+
+	return r;
+}
+
+static void set_size_t(struct uns_gc *gc, struct uns_root_list *root, size_t i, size_t val)
+{
+	void *p = gc->record_get_ptr(root->p, i);
+	memcpy(p, &val, sizeof(val));
+}
+
+#define set_allen(gc,root,val) set_size_t(gc, root, ALLEN_IND, val)
+#define set_len(gc,root,val) set_size_t(gc, root, LEN_IND, val)
+
+static size_t uns_string_allen(struct uns_gc *gc, struct uns_root_list *root)
+{
+	return get_size_t(gc, root, ALLEN_IND);
+}
+
+size_t uns_string_len(struct uns_gc *gc, struct uns_root_list *root)
+{
+	return get_size_t(gc, root, LEN_IND);
+}
+
+char *uns_string_ptr(struct uns_gc *gc, struct uns_root_list *root)
+{
+	return gc->record_get_ptr(root->p, BYTES_IND);
+}
+
+void uns_string_alloc(struct uns_gc *gc, struct uns_root_list *root, size_t start_len)
+{
+	root->p = gc->alloc_record(gc, NUMBER_OF_IND);
+
+	gc->record_set_ptr(root->p, ALLEN_IND, gc->alloc(gc, sizeof(size_t)));
+	set_allen(gc, root, start_len);
+
+	gc->record_set_ptr(root->p, LEN_IND, gc->alloc(gc, sizeof(size_t)));
+	set_len(gc, root, 0);
+
+	gc->record_set_ptr(root->p, BYTES_IND, gc->alloc(gc, start_len));
+}
+
+void uns_string_resize(struct uns_gc *gc, struct uns_root_list *root, size_t newlen)
+{
+	char *tmp;
+
+	tmp = gc->alloc(gc, newlen);
+	set_allen(gc, root, newlen);
+
+	if (newlen <= uns_string_len(gc, root))
+		set_len(gc, root, newlen);
+	memcpy(tmp, uns_string_ptr(gc, root), uns_string_len(gc, root));
+}
+
+void uns_string_ensure(struct uns_gc *gc, struct uns_root_list *root, size_t extent)
+{
+	size_t used = uns_string_len(gc, root);
+	size_t allen = uns_string_allen(gc, root);
+
+	if (used + extent > allen)
+		uns_string_resize(gc, root, used + extent);
+}
+
+void uns_string_append_bytes(struct uns_gc *gc, struct uns_root_list *to,
+                            const void *from, size_t bytes)
+{
+	size_t len = uns_string_len(gc, to);
+	uns_string_ensure(gc, to, bytes);
+	memcpy(uns_string_ptr(gc, to) + len, from, bytes);
+	set_len(gc, to, len + bytes);
+}
+
+void uns_string_append_char(struct uns_gc *gc, struct uns_root_list *root, char c)
+{
+	uns_string_append_bytes(gc, root, &c, 1);
+}
+
+char *uns_string_cstring(struct uns_gc *gc, struct uns_root_list *root)
+{
+	char *p;
+	uns_string_ensure(gc, root, 1);
+
+	p = uns_string_ptr(gc, root);
+	p[uns_string_len(gc, root)] = 0;
+	return p;
+}