libunit-wasm: Remove the idx argument from luw_http_add_header()

This was used to specify the index of the response header being added,
starting at 0 and incrementing by one for each header.

Instead of having the programmer specify this, track it internally.

We add an extra check in luw_http_add_header() to make sure we aren't
trying to add more headers than we said with luw_http_init_headers(), if
we are, simply return.

This updates the API-C.md and the various examples and 'rusty' API
wrapper.

Suggested-by: Liam Crilly <liam@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/src/rust/unit-wasm-sys/rusty.rs b/src/rust/unit-wasm-sys/rusty.rs
index 79c38f3..fbfecd3 100644
--- a/src/rust/unit-wasm-sys/rusty.rs
+++ b/src/rust/unit-wasm-sys/rusty.rs
@@ -43,6 +43,7 @@ pub const fn UWR_CTX_INITIALIZER() -> luw_ctx_t {
         req_buf: null_mut(),
         hdrp: null_mut(),
         reqp: null_mut(),
+        resp_hdr_idx: -1,
     }
 }
 
@@ -173,14 +174,12 @@ pub fn uwr_http_init_headers(ctx: *mut luw_ctx_t, nr: usize, offset: usize) {
 
 pub fn uwr_http_add_header(
     ctx: *mut luw_ctx_t,
-    idx: u16,
     name: &str,
     value: &str,
 ) {
     unsafe {
         luw_http_add_header(
             ctx,
-            idx,
             S2C!(name).as_ptr() as *const i8,
             S2C!(value).as_ptr() as *const i8,
         );