Initial commit

1 files changed, 56 insertions, 0 deletions

diff --git a/minecraft-protocol/src/friendly_byte_buf.rs b/minecraft-protocol/src/friendly_byte_buf.rs
new file mode 100644
index 00000000..2babe398
--- /dev/null
+++ b/minecraft-protocol/src/friendly_byte_buf.rs
@@ -0,0 +1,56 @@
+//! Minecraft calls it a "friendly byte buffer".
+
+use byteorder::{BigEndian, WriteBytesExt};
+// use std::io::Write;
+
+const MAX_VARINT_SIZE: u32 = 5;
+const MAX_VARLONG_SIZE: u32 = 10;
+const DEFAULT_NBT_QUOTA: u32 = 2097152;
+const MAX_STRING_LENGTH: u16 = 32767;
+const MAX_COMPONENT_STRING_LENGTH: u32 = 262144;
+
+pub struct FriendlyByteBuf<'a> {
+    source: &'a mut Vec<u8>,
+}
+
+impl FriendlyByteBuf<'_> {
+    pub fn write_byte(&mut self, n: u8) {
+        self.source.write_u8(n).unwrap();
+        println!("write_byte: {}", n);
+    }
+
+    pub fn write_bytes(&mut self, bytes: &[u8]) {
+        self.source.extend_from_slice(bytes);
+    }
+
+    pub fn write_varint(&mut self, mut n: u32) {
+        loop {
+            if (n & 0xFFFFFF80) == 0 {
+                self.write_byte(n as u8);
+                return ();
+            }
+            self.write_byte((n & 0x7F | 0x80) as u8);
+            n >>= 7;
+        }
+    }
+
+    pub fn write_utf_with_len(&mut self, string: &String, len: usize) {
+        if string.len() > len {
+            panic!(
+                "String too big (was {} bytes encoded, max {})",
+                string.len(),
+                len
+            );
+        }
+        self.write_varint(string.len() as u32);
+        self.write_bytes(string.as_bytes());
+    }
+
+    pub fn write_utf(&mut self, string: &String) {
+        self.write_utf_with_len(string, MAX_STRING_LENGTH as usize);
+    }
+
+    pub fn write_short(&mut self, n: u16) {
+        self.source.write_u16::<BigEndian>(n).unwrap();
+    }
+}