libunit-wasm: Add a luw_get_http_total_content_sent() function

This function returns the total amount of content that the Wasm module
has received so far.

This will be used in the rusty API's uwr_get_http_content_str() function
which returns the body content as a string. Due to the body content not
being null-terminated we need to know how much data to use for the
string, for which we are currently using uwr_get_http_content_len(),
which could in some cases return too much if a request is being split
over multiple calls the module.

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/API-C.md b/API-C.md
index f6c0bb7..c05d530 100644
--- a/API-C.md
+++ b/API-C.md
@@ -38,6 +38,7 @@ C Library for creating WebAssembly modules for use with NGINX Unit.
   * [luw_get_http_content](#luw_get_http_content)
   * [luw_get_http_content_len](#luw_get_http_content_len)
   * [luw_get_http_content_sent](#luw_get_http_content_sent)
+  * [luw_get_http_total_content_sent](#luw_get_http_total_content_sent)
   * [luw_http_is_tls](#luw_http_is_tls)
   * [luw_http_hdr_iter](#luw_http_hdr_iter)
   * [luw_http_hdr_get_value](#luw_http_hdr_get_value)
@@ -657,6 +658,16 @@ This function returns the length of the content that was sent to the
 WebAssembly module in _this_ request. Remember, a single HTTP request may be
 split over several calls to luw_request_handler().
 
+### luw_get_http_total_content_sent
+
+```C
+size_t luw_get_http_total_content_sent(const luw_ctx_t *ctx);
+```
+
+This function returns the total length of the content that was sent to the
+WebAssembly module so far. Remember, a single HTTP request may be split over
+several calls to luw_request_handler().
+
 ### luw_http_is_tls
 
 ```C