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 })
+    }
+}