http2: move lots of state data to the 'stream' struct

... from the connection struct. The stream one being the 'struct HTTP'
which is kept in the SessionHandle struct (easy handle).

lookup streams for incoming frames in the stream hash, hashing is based
on the stream id and we get the SessionHandle for the incoming stream
that way.

lib/http.c

@@ -153,12 +153,22 @@ CURLcode Curl_http_setup_conn(struct connectdata *conn)
 {
   /* allocate the HTTP-specific struct for the SessionHandle, only to survive
      during this request */
+  struct HTTP *http;
   DEBUGASSERT(conn->data->req.protop == NULL);
 
-  conn->data->req.protop = calloc(1, sizeof(struct HTTP));
-  if(!conn->data->req.protop)
+  http = calloc(1, sizeof(struct HTTP));
+  if(!http)
     return CURLE_OUT_OF_MEMORY;
 
+  conn->data->req.protop = http;
+
+  http->header_recvbuf = Curl_add_buffer_init();
+  http->nread_header_recvbuf = 0;
+  http->bodystarted = FALSE;
+  http->status_code = -1;
+  http->data = NULL;
+  http->datalen = 0;
+
   return CURLE_OK;
 }
 

lib/http.h

@@ -153,13 +153,17 @@ struct HTTP {
   void *send_buffer; /* used if the request couldn't be sent in one chunk,
                         points to an allocated send_buffer struct */
 
-  /* for HTTP/2 we store stream-local data here */
+  /*********** for HTTP/2 we store stream-local data here *************/
   int32_t stream_id; /* stream we are interested in */
 
+  bool bodystarted;
   /* We store non-final and final response headers here, per-stream */
   Curl_send_buffer *header_recvbuf;
   size_t nread_header_recvbuf; /* number of bytes in header_recvbuf fed into
                                   upper layer */
+  int status_code; /* HTTP status code */
+  const uint8_t *data; /* pointer to data chunk, received in on_data_chunk */
+  size_t datalen; /* the number of bytes left in data */
 };
 
 typedef int (*sending)(void); /* Curl_send */
@@ -173,14 +177,10 @@ struct http_conn {
   size_t  binlen; /* length of the binsettings data */
   char *mem;     /* points to a buffer in memory to store */
   size_t len;    /* size of the buffer 'mem' points to */
-  bool bodystarted;
   sending send_underlying; /* underlying send Curl_send callback */
   recving recv_underlying; /* underlying recv Curl_recv callback */
   bool closed; /* TRUE on HTTP2 stream close */
   uint32_t error_code; /* HTTP/2 error code */
-  const uint8_t *data; /* pointer to data chunk, received in
-                          on_data_chunk */
-  size_t datalen; /* the number of bytes left in data */
   char *inbuf; /* buffer to receive data from underlying socket */
   /* We need separate buffer for transmission and reception because we
      may call nghttp2_session_send() after the
@@ -190,7 +190,6 @@ struct http_conn {
   const uint8_t *upload_mem; /* points to a buffer to read from */
   size_t upload_len; /* size of the buffer 'upload_mem' points to */
   size_t upload_left; /* number of bytes left to upload */
-  int status_code; /* HTTP status code */
 
   /* this is a hash of all individual streams (SessionHandle structs) */
   struct curl_hash streamsh;