1 use std::{

     2     fs::{File, OpenOptions},

     3     io::{Read, Write, Result, Error, ErrorKind}

     4 };

     5 

     6 pub trait HWServerIO {

     7     fn write_file(&mut self, name: &str, content: &str) -> Result<()>;

     8     fn read_file(&mut self, name: &str) -> Result<String>;

     9 }

    10 

    11 pub struct EmptyServerIO {}

    12 

    13 impl EmptyServerIO {

    14     pub fn new() -> Self {

    15         Self {}

    16     }

    17 }

    18 

    19 impl HWServerIO for EmptyServerIO {

    20     fn write_file(&mut self, _name: &str, _content: &str) -> Result<()> {

    21         Ok(())

    22     }

    23 

    24     fn read_file(&mut self, _name: &str) -> Result<String> {

    25         Ok("".to_string())

    26     }

    27 }

    28 

    29 pub struct FileServerIO {}

    30 

    31 impl FileServerIO {

    32     pub fn new() -> Self {

    33         Self {}

    34     }

    35 }

    36 

    37 impl HWServerIO for FileServerIO {

    38     fn write_file(&mut self, name: &str, content: &str) -> Result<()> {

    39         let mut writer = OpenOptions::new().create(true).write(true).open(name)?;

    40         writer.write_all(content.as_bytes())

    41     }

    42 

    43     fn read_file(&mut self, name: &str) -> Result<String> {

    44         let mut reader = File::open(name)?;

    45         let mut result = String::new();

    46         reader.read_to_string(&mut result)?;

    47         Ok(result)

    48     }

    49 }