feat(core): Default encoding/decoding limits (#1335)

* feat(core): Default encoding/decoding limits

This PR adds new defaults for both client and server max
encoding/decoding message size limits. By default, the max message
decoding size is `4MB` and the max message encoding size is
`usize::MAX`.

This is follow up work from https://github.com/hyperium/tonic/pull/1274

BREAKING: Default max message encoding/decoding limits

* update generated code

tonic-build/src/client.rs

@@ -136,6 +136,8 @@ pub(crate) fn generate_internal<T: Service>(
                 }
 
                 /// Limits the maximum size of a decoded message.
+                ///
+                /// Default: `4MB`
                 #[must_use]
                 pub fn max_decoding_message_size(mut self, limit: usize) -> Self {
                     self.inner = self.inner.max_decoding_message_size(limit);
@@ -143,6 +145,8 @@ pub(crate) fn generate_internal<T: Service>(
                 }
 
                 /// Limits the maximum size of an encoded message.
+                ///
+                /// Default: `usize::MAX`
                 #[must_use]
                 pub fn max_encoding_message_size(mut self, limit: usize) -> Self {
                     self.inner = self.inner.max_encoding_message_size(limit);

tonic-build/src/server.rs

@@ -84,6 +84,8 @@ pub(crate) fn generate_internal<T: Service>(
 
     let configure_max_message_size_methods = quote! {
         /// Limits the maximum size of a decoded message.
+        ///
+        /// Default: `4MB`
         #[must_use]
         pub fn max_decoding_message_size(mut self, limit: usize) -> Self {
             self.max_decoding_message_size = Some(limit);
@@ -91,6 +93,8 @@ pub(crate) fn generate_internal<T: Service>(
         }
 
         /// Limits the maximum size of an encoded message.
+        ///
+        /// Default: `usize::MAX`
         #[must_use]
         pub fn max_encoding_message_size(mut self, limit: usize) -> Self {
             self.max_encoding_message_size = Some(limit);