refactor commands

src/commands/delete.rs

@@ -0,0 +1,42 @@
+use std::io::Cursor;
+
+use bytes::{Buf as _, BufMut as _, BytesMut};
+
+use crate::{Result, connection::Connection, database::Database, errors::AppError};
+
+#[derive(Debug, Clone)]
+pub struct Delete {
+    key: String,
+}
+
+impl Delete {
+    pub async fn execute(self, db: &Database, connection: &mut Connection) -> Result<()> {
+        let value = db.delete(&self.key).await;
+
+        let mut buf = BytesMut::new();
+        match value {
+            Some(v) => {
+                buf.put_u8(1);
+                buf.put_u32(v.len() as u32);
+                buf.put_slice(&v);
+            }
+            None => buf.put_u8(0),
+        }
+
+        connection.write(buf.into()).await?;
+
+        Ok(())
+    }
+
+    pub fn parse(bytes: &mut Cursor<&[u8]>) -> Result<Self> {
+        let key_length = bytes.try_get_u16()? as usize;
+
+        if bytes.remaining() < key_length {
+            return Err(AppError::IncompleteCommandBuffer);
+        }
+
+        let key = String::from_utf8(bytes.copy_to_bytes(key_length).to_vec())?;
+
+        Ok(Self { key })
+    }
+}

src/commands/get.rs

@@ -0,0 +1,44 @@
+use std::io::Cursor;
+
+use bytes::{Buf as _, BufMut as _, BytesMut};
+
+use crate::{Result, connection::Connection, database::Database, errors::AppError};
+
+#[derive(Debug, Clone)]
+pub struct Get {
+    key: String,
+}
+
+impl Get {
+    pub async fn execute(self, db: &Database, connection: &mut Connection) -> Result<()> {
+        let value = db.get(&self.key).await;
+
+        let mut buf = BytesMut::new();
+        match value {
+            Some(v) => {
+                buf.put_u8(1);
+                buf.put_u32(v.len() as u32);
+                buf.put_slice(&v);
+            }
+            None => {
+                buf.put_u8(0);
+            }
+        }
+
+        connection.write(buf.into()).await?;
+
+        Ok(())
+    }
+
+    pub fn parse(bytes: &mut Cursor<&[u8]>) -> Result<Self> {
+        let key_length = bytes.try_get_u16()? as usize;
+
+        if bytes.remaining() < key_length {
+            return Err(AppError::IncompleteCommandBuffer);
+        }
+
+        let key = String::from_utf8(bytes.copy_to_bytes(key_length).to_vec())?;
+
+        Ok(Self { key })
+    }
+}

src/commands/has.rs

@@ -0,0 +1,34 @@
+use std::io::Cursor;
+
+use bytes::{Buf as _, Bytes};
+
+use crate::{Result, connection::Connection, database::Database, errors::AppError};
+
+#[derive(Debug, Clone)]
+pub struct Has {
+    key: String,
+}
+
+impl Has {
+    pub async fn execute(self, db: &Database, connection: &mut Connection) -> Result<()> {
+        let value = db.has(&self.key).await;
+
+        let buf = Bytes::copy_from_slice(&[if value { 1 } else { 0 }]);
+
+        connection.write(buf.into()).await?;
+
+        Ok(())
+    }
+
+    pub fn parse(bytes: &mut Cursor<&[u8]>) -> Result<Self> {
+        let key_length = bytes.try_get_u16()? as usize;
+
+        if bytes.remaining() < key_length {
+            return Err(AppError::IncompleteCommandBuffer);
+        }
+
+        let key = String::from_utf8(bytes.copy_to_bytes(key_length).to_vec())?;
+
+        Ok(Self { key })
+    }
+}

src/commands/mod.rs

@@ -0,0 +1,64 @@
+pub mod delete;
+mod get;
+pub mod has;
+pub mod set;
+
+use std::io::Cursor;
+
+use bytes::{Buf, BytesMut};
+use delete::Delete;
+use get::Get;
+use has::Has;
+use set::Set;
+
+use crate::{
+    Result,
+    connection::Connection,
+    database::{Database, Value},
+    errors::AppError,
+};
+
+#[derive(Debug)]
+pub enum Command {
+    Get(Get),
+    Set(Set),
+    Delete(Delete),
+    Has(Has),
+}
+
+impl Command {
+    pub async fn execute(self, db: &Database, connection: &mut Connection) -> Result<()> {
+        match self {
+            Command::Get(get) => get.execute(db, connection).await,
+            Command::Set(set) => set.execute(db, connection).await,
+            Command::Delete(delete) => delete.execute(db, connection).await,
+            Command::Has(has) => has.execute(db, connection).await,
+        }
+    }
+
+    pub fn parse(bytes: &BytesMut) -> Result<(Self, u64)> {
+        let mut buffer = Cursor::new(&bytes[..]);
+
+        let name_length = buffer.try_get_u16()? as usize;
+
+        if buffer.remaining() < name_length {
+            return Err(AppError::IncompleteCommandBuffer);
+        }
+
+        let name = String::from_utf8(buffer.copy_to_bytes(name_length).to_vec())?;
+
+        Self::parse_inner(name, &mut buffer)
+    }
+
+    fn parse_inner(command_name: String, bytes: &mut Cursor<&[u8]>) -> Result<(Self, u64)> {
+        let command = match command_name.to_lowercase().as_str() {
+            "get" => Self::Get(Get::parse(bytes)?),
+            "set" => Self::Set(Set::parse(bytes)?),
+            "delete" => Self::Delete(Delete::parse(bytes)?),
+            "has" => Self::Has(Has::parse(bytes)?),
+            _ => return Err(AppError::UnknownCommand(command_name)),
+        };
+
+        Ok((command, bytes.position()))
+    }
+}

src/commands/set.rs

@@ -0,0 +1,49 @@
+use std::io::Cursor;
+
+use bytes::{Buf as _, Bytes};
+
+use crate::{
+    Result,
+    connection::Connection,
+    database::{Database, Value},
+    errors::AppError,
+};
+
+#[derive(Debug, Clone)]
+pub struct Set {
+    key: String,
+    value: Value,
+}
+
+impl Set {
+    pub async fn execute(self, db: &Database, connection: &mut Connection) -> Result<()> {
+        db.set(self.key, self.value).await?;
+
+        connection.write(Bytes::from_static(&[1])).await?;
+
+        Ok(())
+    }
+
+    pub fn parse(bytes: &mut Cursor<&[u8]>) -> Result<Self> {
+        let key_length = bytes.try_get_u16()? as usize;
+
+        if bytes.remaining() < key_length {
+            return Err(AppError::IncompleteCommandBuffer);
+        }
+
+        let key = String::from_utf8(bytes.copy_to_bytes(key_length).to_vec())?;
+
+        let value_length = bytes.try_get_u32()? as usize;
+
+        if bytes.remaining() < value_length {
+            return Err(AppError::IncompleteCommandBuffer);
+        }
+
+        let data = bytes.copy_to_bytes(value_length);
+
+        Ok(Self {
+            key,
+            value: Value::new(data),
+        })
+    }
+}