Add capn_init_malloc to provide a malloc based create function

.gitignore

@@ -1,2 +1,2 @@
-/capn.o
-/capn.so
+/*.o
+/*.so

Makefile

@@ -8,5 +8,5 @@ clean:
 %.o: %.c *.h *.inc
 	$(CC) -Wall -Werror -g -O2 -c $< -o $@
 
-capn.so: capn.o
+capn.so: capn-malloc.o capn.o
 	$(CC) -shared -Wall -Werror -fPIC -g -O2 $^ -o $@

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;
+	}
+}
+
+

capn.h

@@ -15,6 +15,8 @@
  * create is used to create or lookup an alternate segment that has at least
  * sz available (ie returned seg->len + sz <= seg->cap)
  *
+ * Allocated segments must be zero initialized.
+ *
  * create and lookup can be NULL if you don't need multiple segments and don't
  * want to support copying
  *
@@ -56,7 +58,7 @@ struct capn_tree {
  *
  * data, len, and cap must all by 8 byte aligned
  *
- * data, len, cap, id should all set by the user. Other values should be zero
+ * data, len, cap should all set by the user. Other values should be zero
  * initialized.
  */
 struct capn_segment {
@@ -150,7 +152,7 @@ int capn_write_data(struct capn_ptr *p, int off, struct capn_data tgt);
  * The function returns the number of elements read or -1 on an error.
  * off must be byte aligned for capn_read_1
  */
-int capn_read_1(const struct capn_list1 *p, int off, uint8_t *data, int sz);
+int capn_read1(const struct capn_list1 *p, int off, uint8_t *data, int sz);
 int capn_read8(const struct capn_list8 *p, int off, uint8_t *data, int sz);
 int capn_read16(const struct capn_list16 *p, int off, uint16_t *data, int sz);
 int capn_read32(const struct capn_list32 *p, int off, uint32_t *data, int sz);
@@ -162,7 +164,7 @@ int capn_read64(const struct capn_list64 *p, int off, uint64_t *data, int sz);
  * The function returns the number of elemnts written or -1 on an error.
  * off must be byte aligned for capn_read_1
  */
-int capn_write_1(struct capn_list1 *p, int off, const uint8_t *data, int sz);
+int capn_write1(struct capn_list1 *p, int off, const uint8_t *data, int sz);
 int capn_write8(struct capn_list8 *p, int off, const uint8_t *data, int sz);
 int capn_write16(struct capn_list16 *p, int off, const uint16_t *data, int sz);
 int capn_write32(struct capn_list32 *p, int off, const uint32_t *data, int sz);
@@ -201,6 +203,16 @@ CAPN_INLINE int capn_set32(struct capn_ptr *p, int off, uint32_t val);
 CAPN_INLINE int capn_set64(struct capn_ptr *p, int off, uint64_t val);
 
 
+/* capn_init_malloc inits the capn struct with a create function which
+ * allocates segments on the heap using malloc
+ *
+ * capn_free_all frees all the segment headers and data created by the create
+ * function setup by capn_init_malloc
+ */
+void capn_init_malloc(struct capn *c);
+void capn_free_all(struct capn *c);
+
+
 int capn_marshal_iptr(const union capn_iptr*, struct capn_ptr*, int off);
 
 /* Inline functions */