Refactor protocol modules

src/io/aio.rs

@@ -25,8 +25,9 @@ use {
     crate::{
         error::{ClientResult, ConnectionSetupError, Error},
         protocol::{
-            ClientHandshake, DecodeState, Decoder, MRespState, PipelineResult, RState,
-            ServerHandshake,
+            handshake::{ClientHandshake, ServerHandshake},
+            state_init::{DecodeState, MRespState, PipelineResult, RState},
+            Decoder,
         },
         query::Pipeline,
         response::{FromResponse, Response},

src/io/sync.rs

@@ -27,8 +27,9 @@ use {
         config::Config,
         error::{ClientResult, ConnectionSetupError, Error},
         protocol::{
-            ClientHandshake, DecodeState, Decoder, MRespState, PipelineResult, RState,
-            ServerHandshake,
+            handshake::{ClientHandshake, ServerHandshake},
+            state_init::{DecodeState, MRespState, PipelineResult, RState},
+            Decoder,
         },
         query::Pipeline,
         response::{FromResponse, Response},

src/protocol/handshake.rs

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2024, Sayan Nandan <nandansayan@outlook.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+*/
+
+use crate::{
+    error::{ConnectionSetupError, Error},
+    ClientResult, Config,
+};
+
+pub struct ClientHandshake(Box<[u8]>);
+impl ClientHandshake {
+    pub(crate) fn new(cfg: &Config) -> Self {
+        let mut v = Vec::with_capacity(6 + cfg.username().len() + cfg.password().len() + 5);
+        v.extend(b"H\x00\x00\x00\x00\x00");
+        pushlen!(v, cfg.username().len());
+        pushlen!(v, cfg.password().len());
+        v.extend(cfg.username().as_bytes());
+        v.extend(cfg.password().as_bytes());
+        Self(v.into_boxed_slice())
+    }
+    pub(crate) fn inner(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+#[derive(Debug)]
+pub enum ServerHandshake {
+    Okay(u8),
+    Error(u8),
+}
+impl ServerHandshake {
+    pub fn parse(v: [u8; 4]) -> ClientResult<Self> {
+        Ok(match v {
+            [b'H', 0, 0, msg] => Self::Okay(msg),
+            [b'H', 0, 1, msg] => Self::Error(msg),
+            _ => {
+                return Err(Error::ConnectionSetupErr(
+                    ConnectionSetupError::InvalidServerHandshake,
+                ))
+            }
+        })
+    }
+}