From 2d02383ae774f1eef9898e48a8d6ad1fca50d950 Mon Sep 17 00:00:00 2001
From: IrfanMohammad <irfan@graphiant.com>
Date: Tue, 22 Aug 2023 11:56:51 +0000
Subject: [PATCH] Add lyd_print_mem_len API to return printed size

It can be useful to know how many bytes were written, and avoid an
expensive and redundant strlen by the application.
---
 src/printer_data.c | 18 ++++++++++++++++++
 src/printer_data.h |  5 +++++
 2 files changed, 23 insertions(+)

diff --git a/src/printer_data.c b/src/printer_data.c
index ea330c739..d44a3d25a 100644
--- a/src/printer_data.c
+++ b/src/printer_data.c
@@ -102,6 +102,24 @@ lyd_print_mem(char **strp, const struct lyd_node *root, LYD_FORMAT format, uint3
     return ret;
 }
 
+LIBYANG_API_DEF LY_ERR
+lyd_print_mem_len(char **strp, const struct lyd_node *root, LYD_FORMAT format, uint32_t options, size_t *len)
+{
+    LY_ERR ret;
+    struct ly_out *out;
+
+    LY_CHECK_ARG_RET(NULL, strp && len, LY_EINVAL);
+
+    /* init */
+    *strp = NULL;
+
+    LY_CHECK_RET(ly_out_new_memory(strp, 0, &out));
+    ret = lyd_print_(out, root, format, options);
+    *len = out->printed;
+    ly_out_free(out, NULL, 0);
+    return ret;
+}
+
 LIBYANG_API_DEF LY_ERR
 lyd_print_fd(int fd, const struct lyd_node *root, LYD_FORMAT format, uint32_t options)
 {
diff --git a/src/printer_data.h b/src/printer_data.h
index fb2a5fb50..6823d843f 100644
--- a/src/printer_data.h
+++ b/src/printer_data.h
@@ -133,6 +133,11 @@ LIBYANG_API_DECL LY_ERR lyd_print_tree(struct ly_out *out, const struct lyd_node
  */
 LIBYANG_API_DECL LY_ERR lyd_print_mem(char **strp, const struct lyd_node *root, LYD_FORMAT format, uint32_t options);
 
+/**
+ * @brief Same as lyd_print_mem but also return the length of buffer written
+ */
+LIBYANG_API_DEF LY_ERR lyd_print_mem_len(char **strp, const struct lyd_node *root, LYD_FORMAT format, uint32_t options, size_t *len);
+
 /**
  * @brief Print data tree in the specified format.
  *