Add support for REQUEST_TIME_FLOAT which returns secs.usec since epoch

Zend compat http://php.net/manual/en/reserved.variables.server.php

closes 778

hphp/runtime/base/program_functions.cpp

@@ -445,6 +445,7 @@ static const StaticString
   s_HHVM_JIT("HHVM_JIT"),
   s_REQUEST_START_TIME("REQUEST_START_TIME"),
   s_REQUEST_TIME("REQUEST_TIME"),
+  s_REQUEST_TIME_FLOAT("REQUEST_TIME_FLOAT"),
   s_DOCUMENT_ROOT("DOCUMENT_ROOT"),
   s_SCRIPT_FILENAME("SCRIPT_FILENAME"),
   s_SCRIPT_NAME("SCRIPT_NAME"),
@@ -480,9 +481,19 @@ void execute_command_line_begin(int argc, char **argv, int xhprof) {
 
   Variant &server = g->GV(_SERVER);
   process_env_variables(server);
-  time_t now = time(nullptr);
+  time_t now;
+  struct timeval tp = {0};
+  double now_double;
+  if (!gettimeofday(&tp, nullptr)) {
+    now_double = (double)(tp.tv_sec + tp.tv_usec / 1000000.00);
+    now = tp.tv_sec;
+  } else {
+    now = time(nullptr);
+    now_double = (double)now;
+  }
   server.set(s_REQUEST_START_TIME, now);
   server.set(s_REQUEST_TIME, now);
+  server.set(s_REQUEST_TIME_FLOAT, now_double);
   server.set(s_DOCUMENT_ROOT, empty_string);
   server.set(s_SCRIPT_FILENAME, argv[0]);
   server.set(s_SCRIPT_NAME, argv[0]);

hphp/runtime/base/server/http_protocol.cpp

@@ -14,9 +14,8 @@
    +----------------------------------------------------------------------+
 */
 
-
-#include "hphp/runtime/base/hphp_system.h"
 #include "hphp/runtime/base/server/http_protocol.h"
+#include "hphp/runtime/base/hphp_system.h"
 #include "hphp/runtime/base/zend/zend_url.h"
 #include "hphp/runtime/base/zend/zend_string.h"
 #include "hphp/runtime/base/program_functions.h"
@@ -111,6 +110,7 @@ static const StaticString
   s_HTTPS("HTTPS"),
   s_1("1"),
   s_REQUEST_TIME("REQUEST_TIME"),
+  s_REQUEST_TIME_FLOAT("REQUEST_TIME_FLOAT"),
   s_QUERY_STRING("QUERY_STRING"),
   s_REMOTE_ADDR("REMOTE_ADDR"),
   s_REMOTE_HOST("REMOTE_HOST"),
@@ -388,8 +388,19 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
     break;
   default:              server.set(s_REQUEST_METHOD, empty_string);     break;
   }
+  time_t now;
+  struct timeval tp = {0};
+  double now_double;
+  if (!gettimeofday(&tp, nullptr)) {
+    now_double = (double)(tp.tv_sec + tp.tv_usec / 1000000.00);
+    now = tp.tv_sec;
+  } else {
+    now = time(nullptr);
+    now_double = (double)now;
+  }
   server.set(s_HTTPS, transport->isSSL() ? s_1 : empty_string);
-  server.set(s_REQUEST_TIME, time(nullptr));
+  server.set(s_REQUEST_TIME, now);
+  server.set(s_REQUEST_TIME_FLOAT, now_double);
   server.set(s_QUERY_STRING, r.queryString());
 
   server.set(s_REMOTE_ADDR, String(transport->getRemoteHost(), CopyString));