Add experiment to produce precompiled builds of serde_derive

precompiled/proc-macro2/src/watt/buffer.rs

@@ -0,0 +1,69 @@
+use std::str;
+
+pub struct OutputBuffer {
+    bytes: Vec<u8>,
+}
+
+impl OutputBuffer {
+    pub fn new() -> Self {
+        OutputBuffer { bytes: Vec::new() }
+    }
+
+    pub fn write_u8(&mut self, value: u8) {
+        self.bytes.push(value);
+    }
+
+    pub fn write_u16(&mut self, value: u16) {
+        self.bytes.extend_from_slice(&value.to_le_bytes());
+    }
+
+    pub fn write_u32(&mut self, value: u32) {
+        self.bytes.extend_from_slice(&value.to_le_bytes());
+    }
+
+    pub fn write_str(&mut self, value: &str) {
+        self.bytes.extend_from_slice(value.as_bytes());
+    }
+
+    pub fn into_bytes(self) -> Vec<u8> {
+        self.bytes
+    }
+}
+
+pub struct InputBuffer<'a> {
+    bytes: &'a [u8],
+}
+
+impl<'a> InputBuffer<'a> {
+    pub fn new(bytes: &'a [u8]) -> Self {
+        InputBuffer { bytes }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.bytes.is_empty()
+    }
+
+    pub fn read_u8(&mut self) -> u8 {
+        let (first, rest) = self.bytes.split_first().unwrap();
+        self.bytes = rest;
+        *first
+    }
+
+    pub fn read_u16(&mut self) -> u16 {
+        let (value, rest) = self.bytes.split_at(2);
+        self.bytes = rest;
+        u16::from_le_bytes([value[0], value[1]])
+    }
+
+    pub fn read_u32(&mut self) -> u32 {
+        let (value, rest) = self.bytes.split_at(4);
+        self.bytes = rest;
+        u32::from_le_bytes([value[0], value[1], value[2], value[3]])
+    }
+
+    pub fn read_str(&mut self, len: usize) -> &'a str {
+        let (string, rest) = self.bytes.split_at(len);
+        self.bytes = rest;
+        str::from_utf8(string).unwrap()
+    }
+}