make size limit public

Signed-off-by: Jay Lee <BusyJayLee@gmail.com>

src/codec.rs

@@ -8,7 +8,7 @@ pub type SerializeFn<T> = fn(&T, &mut Vec<u8>) -> Result<()>;
 
 /// According to https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md, grpc uses
 /// a four bytes to describe the length of a message, so it should not exceed u32::MAX.
-const MAX_MESSAGE_SIZE: usize = u32::MAX as usize;
+pub const MAX_MESSAGE_SIZE: usize = u32::MAX as usize;
 
 /// Defines how to serialize and deserialize between the specialized type and byte slice.
 pub struct Marshaller<T> {

src/lib.rs

@@ -67,7 +67,7 @@ pub use crate::codec::pb_codec::{de as pb_de, ser as pb_ser};
 pub use crate::codec::pr_codec::{de as pr_de, ser as pr_ser};
 
 pub use crate::auth_context::{AuthContext, AuthProperty, AuthPropertyIter};
-pub use crate::codec::Marshaller;
+pub use crate::codec::{Marshaller, MAX_MESSAGE_SIZE};
 pub use crate::env::{EnvBuilder, Environment};
 pub use crate::error::{Error, Result};
 pub use crate::log_util::redirect_log;