Merge pull request #476 from CrowCpp/ws-error-reason

The-EDev · web-flow · commit 8d7e53d40e9e · 2022-06-21T14:29:57.000+03:00
Add error message to Websocket `onerror` handler
diff --git a/docs/guides/websockets.md b/docs/guides/websockets.md
@@ -7,9 +7,9 @@ A websocket route differs from a normal route quite a bit. It uses A slightly al
 
 - `#!cpp onaccept([&](const crow::request& req, void** userdata){handler code goes here})`
 - `#!cpp onopen([&](crow::websocket::connection& conn){handler code goes here})`
-- `#!cpp onmessage([&](crow::websocket::connection& conn, const std::string message, bool is_binary){handler code goes here})`
-- `#!cpp onerror([&](crow::websocket::connection& conn){handler code goes here})`
-- `#!cpp onclose([&](crow::websocket::connection& conn, const std::string reason){handler code goes here})`
+- `#!cpp onmessage([&](crow::websocket::connection& conn, const std::string& message, bool is_binary){handler code goes here})`
+- `#!cpp onerror([&](crow::websocket::connection& conn, const std::string& error_message){handler code goes here})`
+- `#!cpp onclose([&](crow::websocket::connection& conn, const std::string& reason){handler code goes here})`
 
 !!! note
 
diff --git a/include/crow/json.h b/include/crow/json.h
@@ -1836,36 +1836,38 @@ namespace crow
                             enum
                             {
                                 start,
-                                decp,
+                                decp, // Decimal point
                                 zero
                             } f_state;
                             char outbuf[128];
                             MSC_COMPATIBLE_SPRINTF(outbuf, "%f", v.num.d);
-                            char *p = &outbuf[0], *o = nullptr;
+                            char *p = &outbuf[0], *o = nullptr; // o is the position of the first trailing 0
                             f_state = start;
                             while (*p != '\0')
                             {
                                 //std::cout << *p << std::endl;
                                 char ch = *p;
                                 switch (f_state)
                                 {
-                                    case start:
+                                    case start: // Loop and lookahead until a decimal point is found
                                         if (ch == '.')
                                         {
-                                            if (p + 1 && *(p + 1) == '0') p++;
+                                            char fch = *(p + 1);
+                                            // if the first character is 0, leave it be (this is so that "1.00000" becomes "1.0" and not "1.")
+                                            if (fch != '\0' && fch == '0') p++;
                                             f_state = decp;
                                         }
                                         p++;
                                         break;
-                                    case decp:
+                                    case decp: // Loop until a 0 is found, if found, record its position
                                         if (ch == '0')
                                         {
                                             f_state = zero;
                                             o = p;
                                         }
                                         p++;
                                         break;
-                                    case zero:
+                                    case zero: // if a non 0 is found (e.g. 1.00004) remove the earlier recorded 0 position and look for more trailing 0s
                                         if (ch != '0')
                                         {
                                             o = nullptr;
@@ -1875,7 +1877,7 @@ namespace crow
                                         break;
                                 }
                             }
-                            if (o != nullptr)
+                            if (o != nullptr) // if any trailing 0s are found, terminate the string where they begin
                                 *o = '\0';
                             out += outbuf;
 #undef MSC_COMPATIBLE_SPRINTF
diff --git a/include/crow/routing.h b/include/crow/routing.h
@@ -508,7 +508,7 @@ namespace crow
         std::function<void(crow::websocket::connection&)> open_handler_;
         std::function<void(crow::websocket::connection&, const std::string&, bool)> message_handler_;
         std::function<void(crow::websocket::connection&, const std::string&)> close_handler_;
-        std::function<void(crow::websocket::connection&)> error_handler_;
+        std::function<void(crow::websocket::connection&, const std::string&)> error_handler_;
         std::function<bool(const crow::request&, void**)> accept_handler_;
         uint64_t max_payload_;
         bool max_payload_override_ = false;
diff --git a/include/crow/websocket.h b/include/crow/websocket.h
@@ -75,7 +75,7 @@ namespace crow
                        std::function<void(crow::websocket::connection&)> open_handler,
                        std::function<void(crow::websocket::connection&, const std::string&, bool)> message_handler,
                        std::function<void(crow::websocket::connection&, const std::string&)> close_handler,
-                       std::function<void(crow::websocket::connection&)> error_handler,
+                       std::function<void(crow::websocket::connection&, const std::string&)> error_handler,
                        std::function<bool(const crow::request&, void**)> accept_handler):
               adaptor_(std::move(adaptor)),
               handler_(handler),
@@ -315,7 +315,7 @@ namespace crow
                                       adaptor_.shutdown_readwrite();
                                       adaptor_.close();
                                       if (error_handler_)
-                                          error_handler_(*this);
+                                          error_handler_(*this, "Client connection not masked.");
                                       check_destroy();
 #endif
                                   }
@@ -341,7 +341,7 @@ namespace crow
                                   adaptor_.shutdown_readwrite();
                                   adaptor_.close();
                                   if (error_handler_)
-                                      error_handler_(*this);
+                                      error_handler_(*this, ec.message());
                                   check_destroy();
                               }
                           });
@@ -379,7 +379,7 @@ namespace crow
                                   adaptor_.shutdown_readwrite();
                                   adaptor_.close();
                                   if (error_handler_)
-                                      error_handler_(*this);
+                                      error_handler_(*this, ec.message());
                                   check_destroy();
                               }
                           });
@@ -414,7 +414,7 @@ namespace crow
                                   adaptor_.shutdown_readwrite();
                                   adaptor_.close();
                                   if (error_handler_)
-                                      error_handler_(*this);
+                                      error_handler_(*this, ec.message());
                                   check_destroy();
                               }
                           });
@@ -426,7 +426,7 @@ namespace crow
                             close_connection_ = true;
                             adaptor_.close();
                             if (error_handler_)
-                                error_handler_(*this);
+                                error_handler_(*this, "Message length exceeds maximum paylaod.");
                             check_destroy();
                         }
                         else if (has_mask_)
@@ -455,7 +455,7 @@ namespace crow
                                   {
                                       close_connection_ = true;
                                       if (error_handler_)
-                                          error_handler_(*this);
+                                          error_handler_(*this, ec.message());
                                       adaptor_.shutdown_readwrite();
                                       adaptor_.close();
                                       check_destroy();
@@ -497,7 +497,7 @@ namespace crow
                               {
                                   close_connection_ = true;
                                   if (error_handler_)
-                                      error_handler_(*this);
+                                      error_handler_(*this, ec.message());
                                   adaptor_.shutdown_readwrite();
                                   adaptor_.close();
                                   check_destroy();
@@ -685,7 +685,7 @@ namespace crow
             std::function<void(crow::websocket::connection&)> open_handler_;
             std::function<void(crow::websocket::connection&, const std::string&, bool)> message_handler_;
             std::function<void(crow::websocket::connection&, const std::string&)> close_handler_;
-            std::function<void(crow::websocket::connection&)> error_handler_;
+            std::function<void(crow::websocket::connection&, const std::string&)> error_handler_;
             std::function<bool(const crow::request&, void**)> accept_handler_;
         };
     } // namespace websocket

Original file line number	Diff line number	Diff line change
`@@ -1836,36 +1836,38 @@ namespace crow`
`1836`	`1836`	`enum`
`1837`	`1837`	`{`
`1838`	`1838`	`start,`
`1839`		`- decp,`
	`1839`	`+ decp, // Decimal point`
`1840`	`1840`	`zero`
`1841`	`1841`	`} f_state;`
`1842`	`1842`	`char outbuf[128];`
`1843`	`1843`	`MSC_COMPATIBLE_SPRINTF(outbuf, "%f", v.num.d);`
`1844`		`- char p = &outbuf[0], o = nullptr;`
	`1844`	`+ char p = &outbuf[0], o = nullptr; // o is the position of the first trailing 0`
`1845`	`1845`	`f_state = start;`
`1846`	`1846`	`while (*p != '\0')`
`1847`	`1847`	`{`
`1848`	`1848`	`//std::cout << *p << std::endl;`
`1849`	`1849`	`char ch = *p;`
`1850`	`1850`	`switch (f_state)`
`1851`	`1851`	`{`
`1852`		`- case start:`
	`1852`	`+ case start: // Loop and lookahead until a decimal point is found`
`1853`	`1853`	`if (ch == '.')`
`1854`	`1854`	`{`
`1855`		`- if (p + 1 && *(p + 1) == '0') p++;`
	`1855`	`+ char fch = *(p + 1);`
	`1856`	`+ // if the first character is 0, leave it be (this is so that "1.00000" becomes "1.0" and not "1.")`
	`1857`	`+ if (fch != '\0' && fch == '0') p++;`
`1856`	`1858`	`f_state = decp;`
`1857`	`1859`	`}`
`1858`	`1860`	`p++;`
`1859`	`1861`	`break;`
`1860`		`- case decp:`
	`1862`	`+ case decp: // Loop until a 0 is found, if found, record its position`
`1861`	`1863`	`if (ch == '0')`
`1862`	`1864`	`{`
`1863`	`1865`	`f_state = zero;`
`1864`	`1866`	`o = p;`
`1865`	`1867`	`}`
`1866`	`1868`	`p++;`
`1867`	`1869`	`break;`
`1868`		`- case zero:`
	`1870`	`+ case zero: // if a non 0 is found (e.g. 1.00004) remove the earlier recorded 0 position and look for more trailing 0s`
`1869`	`1871`	`if (ch != '0')`
`1870`	`1872`	`{`
`1871`	`1873`	`o = nullptr;`
`@@ -1875,7 +1877,7 @@ namespace crow`
`1875`	`1877`	`break;`
`1876`	`1878`	`}`
`1877`	`1879`	`}`
`1878`		`- if (o != nullptr)`
	`1880`	`+ if (o != nullptr) // if any trailing 0s are found, terminate the string where they begin`
`1879`	`1881`	`*o = '\0';`
`1880`	`1882`	`out += outbuf;`
`1881`	`1883`	`#undef MSC_COMPATIBLE_SPRINTF`