optimize

rnex-core/src/rmc/structures/helpers.rs

@@ -0,0 +1,48 @@
+use std::{fmt, io};
+
+pub struct DummyFormatWriter(u32);
+
+impl fmt::Write for DummyFormatWriter{
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        self.0 += s.as_bytes().len() as u32;
+        Ok(())
+    }
+}
+
+impl DummyFormatWriter{
+    pub const fn new() -> Self{ Self(0) }
+    pub const fn serialize_str_len(&self) -> u32 {
+        2 + self.0 + 1
+    }
+}
+
+pub struct DummyWriter(u32);
+
+impl io::Write for DummyWriter{
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.0 += buf.len() as u32;
+        Ok(buf.len())
+    }
+    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
+        self.0 += buf.len() as u32;
+        Ok(())
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl DummyWriter{
+    pub const fn new() -> Self{ Self(0) }
+    pub const fn get_total_len(&self) -> u32{
+        self.0
+    }
+}
+
+
+pub fn len_of_write(f: impl FnOnce(&mut DummyWriter) -> anyhow::Result<()>) -> u32{
+    let mut dummy = DummyWriter::new();
+    f(&mut dummy).ok();
+    dummy.get_total_len()
+}