rgw: remove buffering from RGWMongoose.

Completely remove buffering from RGWMongoose class actually representing the civetweb frontend of rgw. Buffering was present there in order to: (1) calculate content-length if upper layers have not specified it; (2) enforce precedence of HTTP status in response even if an upper layer has sent any HTTP header before. Please be aware that this patch cannot be backported without fixing such layers or taking RGWClientEngineReorderer class. Fixes: ceph#12713 Signed-off-by: Radoslaw Zarzynski <[email protected]>
rzarzynski · Aug 21, 2015 · 6a82ad5 · 6a82ad5
1 parent 929cf29
commit 6a82ad5
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Showing 2 changed files with 30 additions and 93 deletions.
diff --git a/src/rgw/rgw_civetweb.cc b/src/rgw/rgw_civetweb.cc
@@ -11,24 +11,21 @@
 
 int RGWMongoose::write_data(const char *buf, int len)
 {
-  if (!header_done) {
-    header_data.append(buf, len);
-    return len;
+  const int ret = mg_write(conn, buf, len);
+  if (ret > 0) {
+    return ret;
   }
-  if (!sent_header) {
-    data.append(buf, len);
-    return len;
-  }
-  int r = mg_write(conn, buf, len);
-  if (r == 0) {
-    /* didn't send anything, error out */
-    return -EIO;
-  }
-  return r;
+
+  /* didn't send anything, error out */
+  dout(3) << "mg_write() returned " << ret << dendl;
+  return -EIO;
 }
 
-RGWMongoose::RGWMongoose(mg_connection *_conn, int _port) : conn(_conn), port(_port), header_done(false), sent_header(false), has_content_length(false),
-                                                 explicit_keepalive(false), explicit_conn_close(false)
+RGWMongoose::RGWMongoose(mg_connection *_conn, int _port)
+  : conn(_conn),
+    port(_port),
+    explicit_keepalive(false),
+    explicit_conn_close(false)
 {
 }
 
@@ -39,44 +36,16 @@ int RGWMongoose::read_data(char *buf, int len)
 
 void RGWMongoose::flush()
 {
-}
-
-int RGWMongoose::complete_request()
-{
-  if (!sent_header) {
-    if (!has_content_length) {
-      header_done = false; /* let's go back to writing the header */
-
-      if (0 && data.length() == 0) {
-        has_content_length = true;
-        print("Transfer-Enconding: %s\r\n", "chunked");
-        data.append("0\r\n\r\n", sizeof("0\r\n\r\n")-1);
-      } else {
-        int r = send_content_length(data.length());
-        if (r < 0)
-	  return r;
-      }
-    }
-
-    complete_header();
-  }
-
-  if (data.length()) {
-    int r = write_data(data.c_str(), data.length());
-    if (r < 0)
-      return r;
-    data.clear();
-  }
-
-  return 0;
+  /* NOP */
 }
 
 void RGWMongoose::init_env(CephContext *cct)
 {
   env.init(cct);
   struct mg_request_info *info = mg_get_request_info(conn);
-  if (!info)
+  if (!info) {
     return;
+  }
 
   for (int i = 0; i < info->num_headers; i++) {
     struct mg_request_info::mg_header *header = &info->http_headers[i];
@@ -129,22 +98,19 @@ void RGWMongoose::init_env(CephContext *cct)
   env.set("SERVER_PORT", port_buf);
 }
 
-int RGWMongoose::send_status(const char *status, const char *status_name)
+int RGWMongoose::send_status(const char * status,
+                             const char * status_name)
 {
-  char buf[128];
+  int status_num = atoi(status);
+  mg_set_http_status(conn, status_num);
 
-  if (!status_name)
+  if (!status_name) {
     status_name = "";
+  }
 
+  char buf[128];
   snprintf(buf, sizeof(buf), "HTTP/1.1 %s %s\r\n", status, status_name);
-
-  bufferlist bl;
-  bl.append(buf);
-  bl.append(header_data);
-  header_data = bl;
-
-  int status_num = atoi(status);
-  mg_set_http_status(conn, status_num);
+  write_data(buf, strlen(buf));
 
   return 0;
 }
@@ -156,45 +122,22 @@ int RGWMongoose::send_100_continue()
   return mg_write(conn, buf, sizeof(buf) - 1);
 }
 
-static void dump_date_header(bufferlist &out)
-{
-  char timestr[TIME_BUF_SIZE];
-  const time_t gtime = time(NULL);
-  struct tm result;
-  struct tm const * const tmp = gmtime_r(&gtime, &result);
-
-  if (tmp == NULL)
-    return;
-
-  if (strftime(timestr, sizeof(timestr), "Date: %a, %d %b %Y %H:%M:%S %Z\r\n", tmp))
-    out.append(timestr);
-}
-
 int RGWMongoose::complete_header()
 {
-  header_done = true;
-
-  if (!has_content_length) {
-    return 0;
+  string str;
+  if (explicit_keepalive) {
+    str = "Connection: Keep-Alive\r\n";
+  } else if (explicit_conn_close) {
+    str = "Connection: close\r\n";
   }
 
-  dump_date_header(header_data);
-
-  if (explicit_keepalive)
-    header_data.append("Connection: Keep-Alive\r\n");
-  else if (explicit_conn_close)
-    header_data.append("Connection: close\r\n");
-
-  header_data.append("\r\n");
-
-  sent_header = true;
+  str.append("\r\n");
 
-  return write_data(header_data.c_str(), header_data.length());
+  return write_data(str.c_str(), str.length());
 }
 
 int RGWMongoose::send_content_length(uint64_t len)
 {
-  has_content_length = true;
   char buf[21];
   snprintf(buf, sizeof(buf), "%" PRIu64, len);
   return print("Content-Length: %s\r\n", buf);

diff --git a/src/rgw/rgw_civetweb.h b/src/rgw/rgw_civetweb.h
@@ -15,14 +15,8 @@ class RGWMongoose : public RGWClientIO
 {
   mg_connection *conn;
 
-  bufferlist header_data;
-  bufferlist data;
-
   int port;
 
-  bool header_done;
-  bool sent_header;
-  bool has_content_length;
   bool explicit_keepalive;
   bool explicit_conn_close;