Method read1

crates/vm/src/stdlib/_io.rs:1881–1906

(&self, size: OptionalSize, vm: &VirtualMachine)

        #[pymethod]
        fn read1(&self, size: OptionalSize, vm: &VirtualMachine) -> PyResult<Vec<u8>> {
            let mut data = self.reader().lock(vm)?;
            let raw = data.check_init(vm)?;
            ensure_unclosed(raw, "read of closed file", vm)?;
            let n = size.to_usize().unwrap_or(data.buffer.len());
            if n == 0 {
                return Ok(Vec::new());
            }
            let have = data.readahead();
            if have > 0 {
                let n = core::cmp::min(have as usize, n);
                return Ok(data.read_fast(n).unwrap());
            }
            // Flush write buffer before reading
            if data.writable() {
                data.flush_rewind(vm)?;
            }
            let mut v = vec![0; n];
            data.reset_read();
            let r = data
                .raw_read(Either::A(Some(&mut v)), 0..n, vm)?
                .unwrap_or(0);
            v.truncate(r);
            v.shrink_to_fit();
            Ok(v)
        }

        #[pymethod]
        fn readinto(&self, buf: ArgMemoryBuffer, vm: &VirtualMachine) -> PyResult<Option<usize>> {