Replace impl Read with Cursor<&[u8]> (#26)

* Start getting rid of Cursor

* try to make the tests pass and fail

* make the tests pass

* remove unused uses

* fix clippy warnings

* fix potential OOM exploits

* fix OOM in az-nbt

* fix nbt benchmark

* fix a test

* start replacing it with Cursor<Vec<u8>>

* wip

* fix all the issues

* fix all tests

* fix nbt benchmark

* fix warnings

3 files changed, 11 insertions, 31 deletions

diff --git a/azalea-protocol/src/packets/login/clientbound_login_compression_packet.rs b/azalea-protocol/src/packets/login/clientbound_login_compression_packet.rs
index 6ecbfb66..6976298a 100755
--- a/azalea-protocol/src/packets/login/clientbound_login_compression_packet.rs
+++ b/azalea-protocol/src/packets/login/clientbound_login_compression_packet.rs
@@ -1,31 +1,9 @@
-use super::ClientboundLoginPacket;
-use azalea_buf::{BufReadError, McBufVarReadable, McBufVarWritable};
-use std::{
-    hash::Hash,
-    io::{Read, Write},
-};
+use azalea_buf::McBuf;
+use azalea_protocol_macros::ClientboundLoginPacket;
+use std::hash::Hash;
 
-#[derive(Hash, Clone, Debug)]
+#[derive(Hash, Clone, Debug, ClientboundLoginPacket, McBuf)]
 pub struct ClientboundLoginCompressionPacket {
+    #[var]
     pub compression_threshold: i32,
 }
-
-impl ClientboundLoginCompressionPacket {
-    pub fn get(self) -> ClientboundLoginPacket {
-        ClientboundLoginPacket::LoginCompression(self)
-    }
-
-    pub fn write(&self, buf: &mut impl Write) -> Result<(), std::io::Error> {
-        self.compression_threshold.var_write_into(buf)?;
-        Ok(())
-    }
-
-    pub fn read(buf: &mut impl Read) -> Result<ClientboundLoginPacket, BufReadError> {
-        let compression_threshold = i32::var_read_from(buf)?;
-
-        Ok(ClientboundLoginCompressionPacket {
-            compression_threshold,
-        }
-        .get())
-    }
-}
diff --git a/azalea-protocol/src/packets/login/serverbound_hello_packet.rs b/azalea-protocol/src/packets/login/serverbound_hello_packet.rs
index 4d94092e..5e1422fb 100755
--- a/azalea-protocol/src/packets/login/serverbound_hello_packet.rs
+++ b/azalea-protocol/src/packets/login/serverbound_hello_packet.rs
@@ -18,6 +18,8 @@ pub struct ProfilePublicKeyData {
 
 #[cfg(test)]
 mod tests {
+    use std::io::Cursor;
+
     use super::*;
     use azalea_buf::{McBufReadable, McBufWritable};
 
@@ -28,9 +30,9 @@ mod tests {
             public_key: None,
             profile_id: Some(Uuid::from_u128(0)),
         };
-        let mut buf = Vec::new();
+        let mut buf: Vec<u8> = Vec::new();
         packet.write_into(&mut buf).unwrap();
-        let packet2 = ServerboundHelloPacket::read_from(&mut buf.as_slice()).unwrap();
+        let packet2 = ServerboundHelloPacket::read_from(&mut Cursor::new(&buf)).unwrap();
         assert_eq!(packet, packet2);
     }
 }
diff --git a/azalea-protocol/src/packets/login/serverbound_key_packet.rs b/azalea-protocol/src/packets/login/serverbound_key_packet.rs
index ba4bcb8a..23b3659b 100644
--- a/azalea-protocol/src/packets/login/serverbound_key_packet.rs
+++ b/azalea-protocol/src/packets/login/serverbound_key_packet.rs
@@ -1,7 +1,7 @@
 use azalea_buf::{BufReadError, McBuf};
 use azalea_crypto::SaltSignaturePair;
 use azalea_protocol_macros::ServerboundLoginPacket;
-use std::io::{Read, Write};
+use std::io::{Cursor, Write};
 
 use azalea_buf::{McBufReadable, McBufWritable};
 
@@ -18,7 +18,7 @@ pub enum NonceOrSaltSignature {
 }
 
 impl McBufReadable for NonceOrSaltSignature {
-    fn read_from(buf: &mut impl Read) -> Result<Self, BufReadError> {
+    fn read_from(buf: &mut Cursor<&[u8]>) -> Result<Self, BufReadError> {
         let is_nonce = bool::read_from(buf)?;
         if is_nonce {
             Ok(NonceOrSaltSignature::Nonce(Vec::<u8>::read_from(buf)?))