start improving packet macros

1 files changed, 180 insertions, 0 deletions

diff --git a/azalea-protocol/src/mc_buf/write.rs b/azalea-protocol/src/mc_buf/write.rs
new file mode 100644
index 00000000..3c3375b9
--- /dev/null
+++ b/azalea-protocol/src/mc_buf/write.rs
@@ -0,0 +1,180 @@
+use async_trait::async_trait;
+use azalea_core::resource_location::ResourceLocation;
+use byteorder::{BigEndian, WriteBytesExt};
+use std::io::Write;
+
+use super::MAX_STRING_LENGTH;
+
+#[async_trait]
+pub trait Writable {
+    fn write_list<F, T>(&mut self, list: &[T], writer: F) -> Result<(), std::io::Error>
+    where
+        F: FnOnce(&mut Self, &T) -> Result<(), std::io::Error> + Copy,
+        T: Sized,
+        Self: Sized;
+    fn write_int_id_list(&mut self, list: Vec<i32>) -> Result<(), std::io::Error>;
+    fn write_map<KF, VF, KT, VT>(
+        &mut self,
+        map: Vec<(KT, VT)>,
+        key_writer: KF,
+        value_writer: VF,
+    ) -> Result<(), std::io::Error>
+    where
+        KF: Fn(&mut Self, KT) -> Result<(), std::io::Error> + Copy,
+        VF: Fn(&mut Self, VT) -> Result<(), std::io::Error> + Copy,
+        Self: Sized;
+
+    fn write_byte(&mut self, n: u8) -> Result<(), std::io::Error>;
+    fn write_bytes(&mut self, bytes: &[u8]) -> Result<(), std::io::Error>;
+    fn write_varint(&mut self, value: i32) -> Result<(), std::io::Error>;
+    fn write_utf_with_len(&mut self, string: &str, len: usize) -> Result<(), std::io::Error>;
+    fn write_utf(&mut self, string: &str) -> Result<(), std::io::Error>;
+    fn write_short(&mut self, n: i16) -> Result<(), std::io::Error>;
+    fn write_byte_array(&mut self, bytes: &[u8]) -> Result<(), std::io::Error>;
+    fn write_int(&mut self, n: i32) -> Result<(), std::io::Error>;
+    fn write_boolean(&mut self, b: bool) -> Result<(), std::io::Error>;
+    fn write_nbt(&mut self, nbt: &azalea_nbt::Tag) -> Result<(), std::io::Error>;
+    fn write_long(&mut self, n: i64) -> Result<(), std::io::Error>;
+    fn write_resource_location(
+        &mut self,
+        location: &ResourceLocation,
+    ) -> Result<(), std::io::Error>;
+}
+
+#[async_trait]
+impl Writable for Vec<u8> {
+    fn write_list<F, T>(&mut self, list: &[T], writer: F) -> Result<(), std::io::Error>
+    where
+        F: FnOnce(&mut Self, &T) -> Result<(), std::io::Error> + Copy,
+        Self: Sized,
+    {
+        self.write_varint(list.len() as i32)?;
+        for item in list {
+            writer(self, item)?;
+        }
+        Ok(())
+    }
+
+    fn write_int_id_list(&mut self, list: Vec<i32>) -> Result<(), std::io::Error> {
+        self.write_list(&list, |buf, n| buf.write_varint(*n))
+    }
+
+    fn write_map<KF, VF, KT, VT>(
+        &mut self,
+        map: Vec<(KT, VT)>,
+        key_writer: KF,
+        value_writer: VF,
+    ) -> Result<(), std::io::Error>
+    where
+        KF: Fn(&mut Self, KT) -> Result<(), std::io::Error> + Copy,
+        VF: Fn(&mut Self, VT) -> Result<(), std::io::Error> + Copy,
+        Self: Sized,
+    {
+        self.write_varint(map.len() as i32)?;
+        for (key, value) in map {
+            key_writer(self, key)?;
+            value_writer(self, value)?;
+        }
+        Ok(())
+    }
+
+    fn write_byte(&mut self, n: u8) -> Result<(), std::io::Error> {
+        WriteBytesExt::write_u8(self, n)
+    }
+
+    fn write_bytes(&mut self, bytes: &[u8]) -> Result<(), std::io::Error> {
+        self.extend_from_slice(bytes);
+        Ok(())
+    }
+
+    fn write_varint(&mut self, mut value: i32) -> Result<(), std::io::Error> {
+        let mut buffer = [0];
+        if value == 0 {
+            self.write_all(&buffer).unwrap();
+        }
+        while value != 0 {
+            buffer[0] = (value & 0b0111_1111) as u8;
+            value = (value >> 7) & (i32::max_value() >> 6);
+            if value != 0 {
+                buffer[0] |= 0b1000_0000;
+            }
+            self.write_all(&buffer)?;
+        }
+        Ok(())
+    }
+
+    fn write_utf_with_len(&mut self, string: &str, len: usize) -> Result<(), std::io::Error> {
+        if string.len() > len {
+            panic!(
+                "String too big (was {} bytes encoded, max {})",
+                string.len(),
+                len
+            );
+        }
+        self.write_varint(string.len() as i32)?;
+        self.write_bytes(string.as_bytes())
+    }
+
+    fn write_utf(&mut self, string: &str) -> Result<(), std::io::Error> {
+        self.write_utf_with_len(string, MAX_STRING_LENGTH.into())
+    }
+
+    fn write_short(&mut self, n: i16) -> Result<(), std::io::Error> {
+        WriteBytesExt::write_i16::<BigEndian>(self, n)
+    }
+
+    fn write_byte_array(&mut self, bytes: &[u8]) -> Result<(), std::io::Error> {
+        self.write_varint(bytes.len() as i32)?;
+        self.write_bytes(bytes)
+    }
+
+    fn write_int(&mut self, n: i32) -> Result<(), std::io::Error> {
+        WriteBytesExt::write_i32::<BigEndian>(self, n)
+    }
+
+    fn write_boolean(&mut self, b: bool) -> Result<(), std::io::Error> {
+        self.write_byte(if b { 1 } else { 0 })
+    }
+
+    fn write_nbt(&mut self, nbt: &azalea_nbt::Tag) -> Result<(), std::io::Error> {
+        nbt.write(self)
+            .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e.to_string()))
+    }
+
+    fn write_long(&mut self, n: i64) -> Result<(), std::io::Error> {
+        WriteBytesExt::write_i64::<BigEndian>(self, n)
+    }
+
+    fn write_resource_location(
+        &mut self,
+        location: &ResourceLocation,
+    ) -> Result<(), std::io::Error> {
+        self.write_utf(&location.to_string())
+    }
+}
+
+pub trait McBufWritable
+where
+    Self: Sized,
+{
+    fn write_into(&self, buf: &mut Vec<u8>) -> Result<(), std::io::Error>;
+}
+
+pub trait McBufVarintWritable
+where
+    Self: Sized,
+{
+    fn varint_write_into(&self, buf: &mut Vec<u8>) -> Result<(), std::io::Error>;
+}
+
+impl McBufWritable for i32 {
+    fn write_into(&self, buf: &mut Vec<u8>) -> Result<(), std::io::Error> {
+        Writable::write_int(buf, *self)
+    }
+}
+
+impl McBufVarintWritable for i32 {
+    fn varint_write_into(&self, buf: &mut Vec<u8>) -> Result<(), std::io::Error> {
+        buf.write_varint(*self)
+    }
+}