Request body: introduced rb->last_saved flag.

It indicates that the last buffer was received by the save filter,
and can be used to check this at higher levels.  To be used in the
following changes.

Author: mdounin

src/http/ngx_http_request.h

@@ -302,6 +302,7 @@ typedef struct {
     ngx_chain_t                      *busy;
     ngx_http_chunked_t               *chunked;
     ngx_http_client_body_handler_pt   post_handler;
+    unsigned                          last_saved:1;
 } ngx_http_request_body_t;
 
 

src/http/ngx_http_request_body.c

@@ -69,6 +69,7 @@ ngx_http_read_client_request_body(ngx_http_request_t *r,
      *     rb->busy = NULL;
      *     rb->chunked = NULL;
      *     rb->received = 0;
+     *     rb->last_saved = 0;
      */
 
     rb->rest = -1;
@@ -941,15 +942,32 @@ ngx_http_request_body_length_filter(ngx_http_request_t *r, ngx_chain_t *in)
 
     rb = r->request_body;
 
+    out = NULL;
+    ll = &out;
+
     if (rb->rest == -1) {
         ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                        "http request body content length filter");
 
         rb->rest = r->headers_in.content_length_n;
-    }
 
-    out = NULL;
-    ll = &out;
+        if (rb->rest == 0) {
+
+            tl = ngx_chain_get_free_buf(r->pool, &rb->free);
+            if (tl == NULL) {
+                return NGX_HTTP_INTERNAL_SERVER_ERROR;
+            }
+
+            b = tl->buf;
+
+            ngx_memzero(b, sizeof(ngx_buf_t));
+
+            b->last_buf = 1;
+
+            *ll = tl;
+            ll = &tl->next;
+        }
+    }
 
     for (cl = in; cl; cl = cl->next) {
 
@@ -1013,6 +1031,9 @@ ngx_http_request_body_chunked_filter(ngx_http_request_t *r, ngx_chain_t *in)
 
     rb = r->request_body;
 
+    out = NULL;
+    ll = &out;
+
     if (rb->rest == -1) {
 
         ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
@@ -1029,9 +1050,6 @@ ngx_http_request_body_chunked_filter(ngx_http_request_t *r, ngx_chain_t *in)
         rb->rest = cscf->large_client_header_buffers.size;
     }
 
-    out = NULL;
-    ll = &out;
-
     for (cl = in; cl; cl = cl->next) {
 
         b = NULL;
@@ -1188,15 +1206,16 @@ ngx_int_t
 ngx_http_request_body_save_filter(ngx_http_request_t *r, ngx_chain_t *in)
 {
     ngx_buf_t                 *b;
-    ngx_chain_t               *cl;
+    ngx_chain_t               *cl, *tl, **ll;
     ngx_http_request_body_t   *rb;
 
     rb = r->request_body;
 
-#if (NGX_DEBUG)
+    ll = &rb->bufs;
 
-#if 0
     for (cl = rb->bufs; cl; cl = cl->next) {
+
+#if 0
         ngx_log_debug7(NGX_LOG_DEBUG_EVENT, r->connection->log, 0,
                        "http body old buf t:%d f:%d %p, pos %p, size: %z "
                        "file: %O, size: %O",
@@ -1205,10 +1224,13 @@ ngx_http_request_body_save_filter(ngx_http_request_t *r, ngx_chain_t *in)
                        cl->buf->last - cl->buf->pos,
                        cl->buf->file_pos,
                        cl->buf->file_last - cl->buf->file_pos);
-    }
 #endif
 
+        ll = &cl->next;
+    }
+
     for (cl = in; cl; cl = cl->next) {
+
         ngx_log_debug7(NGX_LOG_DEBUG_EVENT, r->connection->log, 0,
                        "http body new buf t:%d f:%d %p, pos %p, size: %z "
                        "file: %O, size: %O",
@@ -1217,16 +1239,32 @@ ngx_http_request_body_save_filter(ngx_http_request_t *r, ngx_chain_t *in)
                        cl->buf->last - cl->buf->pos,
                        cl->buf->file_pos,
                        cl->buf->file_last - cl->buf->file_pos);
-    }
 
-#endif
+        if (cl->buf->last_buf) {
 
-    /* TODO: coalesce neighbouring buffers */
+            if (rb->last_saved) {
+                ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                              "duplicate last buf in save filter");
+                *ll = NULL;
+                return NGX_HTTP_INTERNAL_SERVER_ERROR;
+            }
 
-    if (ngx_chain_add_copy(r->pool, &rb->bufs, in) != NGX_OK) {
-        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+            rb->last_saved = 1;
+        }
+
+        tl = ngx_alloc_chain_link(r->pool);
+        if (tl == NULL) {
+            *ll = NULL;
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+
+        tl->buf = cl->buf;
+        *ll = tl;
+        ll = &tl->next;
     }
 
+    *ll = NULL;
+
     if (r->request_body_no_buffering) {
         return NGX_OK;
     }