http: Move chunked buffer pos pointer while parsing

Previously, Unit didn't move the buffer pointer when parsing chunked
data because the buffer was not used after sent. It's used for upstream
response. With the new requirement to support request chunked body,
the buffer might be used for pipeline request, so it's necessary to move
the pos pointer while parsing.

Reviewed-by: Andrew Clayton <[email protected]>

src/nxt_http_chunk_parse.c

@@ -48,9 +48,7 @@ nxt_http_chunk_parse(nxt_task_t *task, nxt_http_chunk_parse_t *hcp,
 
     for (b = in; b != NULL; b = next) {
 
-        hcp->pos = b->mem.pos;
-
-        while (hcp->pos < b->mem.free) {
+        while (b->mem.pos < b->mem.free) {
             /*
              * The sw_chunk state is tested outside the switch
              * to preserve hcp->pos and to not touch memory.
@@ -76,7 +74,7 @@ nxt_http_chunk_parse(nxt_task_t *task, nxt_http_chunk_parse_t *hcp,
                 /* ret == NXT_HTTP_CHUNK_END */
             }
 
-            ch = *hcp->pos++;
+            ch = *b->mem.pos++;
 
             switch (state) {
 
@@ -203,7 +201,7 @@ nxt_http_chunk_buffer(nxt_http_chunk_parse_t *hcp, nxt_buf_t ***tail,
     size_t     size;
     nxt_buf_t  *b;
 
-    p = hcp->pos;
+    p = in->mem.pos;
     size = in->mem.free - p;
 
     b = nxt_buf_mem_alloc(hcp->mem_pool, 0, 0);
@@ -224,7 +222,7 @@ nxt_http_chunk_buffer(nxt_http_chunk_parse_t *hcp, nxt_buf_t ***tail,
 
     if (hcp->chunk_size < size) {
         p += hcp->chunk_size;
-        hcp->pos = p;
+        in->mem.pos = p;
 
         b->mem.free = p;
         b->mem.end = p;

src/nxt_http_parse.h

@@ -96,11 +96,8 @@ struct nxt_http_field_s {
 
 
 typedef struct {
-    u_char                    *pos;
     nxt_mp_t                  *mem_pool;
-
     uint64_t                  chunk_size;
-
     uint8_t                   state;
     uint8_t                   last;         /* 1 bit */
     uint8_t                   chunk_error;  /* 1 bit */