abuf: Add a helper for initing and allocating a buffer

This construct appears in various places. Reduce code size by adding a
function for it.

It inits the abuf, then allocates it to the requested size.

Signed-off-by: Simon Glass <sjg@chromium.org>

boot/cedit.c

@@ -449,8 +449,7 @@ int cedit_write_settings(struct expo *exp, struct abuf *buf)
 	void *fdt;
 	int ret;
 
-	abuf_init(buf);
+	if (!abuf_init_size(buf, CEDIT_SIZE_INC))
-	if (!abuf_realloc(buf, CEDIT_SIZE_INC))
 		return log_msg_ret("buf", -ENOMEM);
 
 	fdt = abuf_data(buf);

boot/scene.c

@@ -31,8 +31,7 @@ int scene_new(struct expo *exp, const char *name, uint id, struct scene **scnp)
 		return log_msg_ret("name", -ENOMEM);
 	}
 
-	abuf_init(&scn->buf);
+	if (!abuf_init_size(&scn->buf, EXPO_MAX_CHARS + 1)) {
-	if (!abuf_realloc(&scn->buf, EXPO_MAX_CHARS + 1)) {
 		free(scn->name);
 		free(scn);
 		return log_msg_ret("buf", -ENOMEM);

boot/scene_textline.c

@@ -31,8 +31,7 @@ int scene_textline(struct scene *scn, const char *name, uint id, uint max_chars,
 			    (struct scene_obj **)&tline);
 	if (ret < 0)
 		return log_msg_ret("obj", -ENOMEM);
-	abuf_init(&tline->buf);
+	if (!abuf_init_size(&tline->buf, max_chars + 1))
-	if (!abuf_realloc(&tline->buf, max_chars + 1))
 		return log_msg_ret("buf", -ENOMEM);
 	buf = abuf_data(&tline->buf);
 	*buf = '\0';

include/abuf.h

@@ -170,6 +170,17 @@ void abuf_init_set(struct abuf *abuf, void *data, size_t size);
  */
 void abuf_init_const(struct abuf *abuf, const void *data, size_t size);
 
+/**
+ * abuf_init_size() - Set up an allocated abuf
+ *
+ * Init a new abuf and allocate its size.
+ *
+ * @abuf: abuf to set up
+ * @data: New contents of abuf
+ * @size: New size of abuf
+ */
+bool abuf_init_size(struct abuf *buf, size_t size);
+
 /**
  * abuf_uninit() - Free any memory used by an abuf
  *

lib/abuf.c

@@ -119,6 +119,15 @@ void abuf_init_set(struct abuf *abuf, void *data, size_t size)
 	abuf_set(abuf, data, size);
 }
 
+bool abuf_init_size(struct abuf *buf, size_t size)
+{
+	abuf_init(buf);
+	if (!abuf_realloc(buf, size))
+		return false;
+
+	return true;
+}
+
 void abuf_init_const(struct abuf *abuf, const void *data, size_t size)
 {
 	/* for now there is no flag indicating that the abuf data is constant */

lib/of_live.c

@@ -448,8 +448,7 @@ int of_live_flatten(const struct device_node *root, struct abuf *buf)
 {
 	int ret;
 
-	abuf_init(buf);
+	if (!abuf_init_size(buf, BUF_STEP))
-	if (!abuf_realloc(buf, BUF_STEP))
 		return log_msg_ret("ini", -ENOMEM);
 
 	ret = fdt_create(abuf_data(buf), abuf_size(buf));

test/lib/abuf.c

@@ -419,3 +419,24 @@ static int lib_test_abuf_init(struct unit_test_state *uts)
 	return 0;
 }
 LIB_TEST(lib_test_abuf_init, 0);
+
+/* Test abuf_init_size() */
+static int lib_test_abuf_init_size(struct unit_test_state *uts)
+{
+	struct abuf buf;
+	ulong start;
+
+	start = ut_check_free();
+
+	ut_assert(abuf_init_size(&buf, TEST_DATA_LEN));
+	ut_assertnonnull(buf.data);
+	ut_asserteq(TEST_DATA_LEN, buf.size);
+	ut_asserteq(true, buf.alloced);
+	abuf_uninit(&buf);
+
+	/* Check for memory leaks */
+	ut_assertok(ut_check_delta(start));
+
+	return 0;
+}
+LIB_TEST(lib_test_abuf_init_size, 0);