docs: guide to launch project

* build: parser

* docs: write readme

* docs: more docs

README.md

@@ -1,4 +1,31 @@
 # Yet another kvs store
 
-## Todo:
-* compact log file
+## run
+Launch server first
+```
+cargo run --bin kvs-server --addr 127.0.0.1:4000
+```
+then launch client
+```
+cargo run --bin kvs-client set key value --addr 127.0.0.1:4000
+```
+
+available commands:
+```
+set key value
+rm key
+get key
+```
+
+## build
+```
+cargo build
+```
+## benchmark
+```
+cargo bench
+```
+## test
+```
+cargo test
+```

src/protocol/connection.rs

@@ -8,7 +8,7 @@ use tokio::{
 
 use crate::error::Result;
 
-use super::protocol::Frame;
+use super::frame::Frame;
 
 struct Connection {
     stream: BufWriter<TcpStream>,

src/protocol/mod.rs

@@ -1,2 +1,3 @@
 mod connection;
-mod protocol;
+mod frame;
+mod parser;

src/protocol/parser.rs

@@ -0,0 +1,57 @@
+use std::{str, vec};
+
+use super::frame::Frame;
+use crate::error::{Error, Result};
+use atoi::atoi;
+use bytes::Bytes;
+
+/// Parse a frame to command
+pub struct Parser {
+    contents: vec::IntoIter<Frame>,
+}
+
+impl Parser {
+    pub fn new(&self, frame: Frame) -> Result<Self> {
+        let array = match frame {
+            Frame::Array(array) => array,
+            _ => return Err(Error::from("invalid frame".to_string())),
+        };
+
+        let contents = array.into_iter();
+
+        Ok(Parser { contents })
+    }
+
+    pub fn next(&mut self) -> Result<Frame> {
+        self.contents
+            .next()
+            .ok_or(Error::from("frame empty".to_string()))
+    }
+
+    pub fn next_string(&mut self) -> Result<String> {
+        match self.next()? {
+            Frame::Simple(v) => Ok(v),
+            Frame::Bulk(v) => Ok(str::from_utf8(&v)?.to_string()),
+            _ => Err(Error::from("invalid frame".to_string())),
+        }
+    }
+
+    pub fn next_int(&mut self) -> Result<u64> {
+        match self.next()? {
+            Frame::Simple(v) => {
+                atoi(&v.as_bytes()).ok_or(Error::from(format!("cannot convert {} to int", v)))
+            }
+            Frame::Integers(v) => Ok(v),
+            Frame::Bulk(v) => atoi(&v).ok_or(Error::from(format!("cannot convert {:?} to int", v))),
+            _ => Err(Error::from("invalid frame".to_string())),
+        }
+    }
+
+    pub fn next_bytes(&mut self) -> Result<Bytes> {
+        match self.next()? {
+            Frame::Simple(v) => Ok(Bytes::from(v.into_bytes())),
+            Frame::Bulk(v) => Ok(v),
+            _ => Err(Error::from("invalid frame".to_string())),
+        }
+    }
+}