Added payload too large response

Signed-off-by: AlexandruCihodaru <cihodar@amazon.com>
Suggested-by: George Pisaltu <gpl@amazon.com>

src/common/mod.rs

@@ -84,6 +84,8 @@ pub enum RequestError {
     Overflow,
     /// Underflow occurred when parsing a request.
     Underflow,
+    /// Payload too large.
+    SizeLimitExceeded(usize, usize),
 }
 
 impl Display for RequestError {
@@ -104,6 +106,12 @@ impl Display for RequestError {
             Self::InvalidUri(inner) => write!(f, "Invalid URI: {}", inner),
             Self::Overflow => write!(f, "Overflow occurred when parsing a request."),
             Self::Underflow => write!(f, "Underflow occurred when parsing a request."),
+            Self::SizeLimitExceeded(limit, size) => write!(
+                f,
+                "Request payload with size {} is larger than the limit of {} \
+                 allowed by server.",
+                size, limit
+            ),
         }
     }
 }
@@ -418,6 +426,10 @@ mod tests {
             format!("{}", RequestError::Underflow),
             "Underflow occurred when parsing a request."
         );
+        assert_eq!(
+            format!("{}", RequestError::SizeLimitExceeded(4, 10)),
+            "Request payload with size 10 is larger than the limit of 4 allowed by server."
+        );
     }
 
     #[test]

src/response.rs

@@ -28,6 +28,8 @@ pub enum StatusCode {
     NotFound,
     /// 405, Method Not Allowed
     MethodNotAllowed,
+    /// 413, Payload Too Large
+    PayloadTooLarge,
     /// 500, Internal Server Error
     InternalServerError,
     /// 501, Not Implemented
@@ -47,6 +49,7 @@ impl StatusCode {
             Self::Unauthorized => b"401",
             Self::NotFound => b"404",
             Self::MethodNotAllowed => b"405",
+            Self::PayloadTooLarge => b"413",
             Self::InternalServerError => b"500",
             Self::NotImplemented => b"501",
             Self::ServiceUnavailable => b"503",
@@ -375,6 +378,7 @@ mod tests {
         assert_eq!(StatusCode::Unauthorized.raw(), b"401");
         assert_eq!(StatusCode::NotFound.raw(), b"404");
         assert_eq!(StatusCode::MethodNotAllowed.raw(), b"405");
+        assert_eq!(StatusCode::PayloadTooLarge.raw(), b"413");
         assert_eq!(StatusCode::InternalServerError.raw(), b"500");
         assert_eq!(StatusCode::NotImplemented.raw(), b"501");
         assert_eq!(StatusCode::ServiceUnavailable.raw(), b"503");