Add capn_init_malloc to provide a malloc based create function

capn-malloc.c

@@ -0,0 +1,42 @@
+/* vim: set sw=8 ts=8 sts=8 noet: */
+#include "capn.h"
+#include <stdlib.h>
+#include <string.h>
+
+static struct capn_segment *create(void *u, uint32_t id, int sz) {
+	struct capn_segment *s;
+	if (sz < 4096) {
+		sz = 4096;
+	} else {
+		sz = (sz + 4095) & ~4095;
+	}
+	s = (struct capn_segment*) calloc(1, sizeof(*s));
+	s->data = calloc(1, sz);
+	s->len = 0;
+	s->cap = sz;
+	return s;
+}
+
+void capn_init_malloc(struct capn *c) {
+	memset(c, 0, sizeof(*c));
+	c->create = &create;
+}
+
+void capn_free_all(struct capn *c) {
+	struct capn_segment *s = c->seglist;
+	while (s != NULL) {
+		struct capn_segment *n = s->next;
+		free(s->data);
+		free(s);
+		s = n;
+	}
+	s = c->copylist;
+	while (s != NULL) {
+		struct capn_segment *n = s->next;
+		free(s->data);
+		free(s);
+		s = n;
+	}
+}
+
+