src/filemap.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11
  12 // TODO tests
  13
  14 use strings::string_buffer::StringBuffer;
  15 use std::collections::HashMap;
  16 use std::fs::{self, File};
  17 use std::io::{self, Write, stdout};
  18 use WriteMode;
  19 use NewlineStyle;
  20 use config::Config;
  21
  22 // A map of the files of a crate, with their new content
  23 pub type FileMap = HashMap<String, StringBuffer>;
  24
  25 // Append a newline to the end of each file.
  26 pub fn append_newlines(file_map: &mut FileMap) {
  27     for (_, s) in file_map.iter_mut() {
  28         s.push_str("\n");
  29     }
  30 }
  31
  32 pub fn write_all_files(file_map: &FileMap,
  33                        mode: WriteMode,
  34                        config: &Config)
  35                        -> Result<(HashMap<String, String>), io::Error> {
  36     let mut result = HashMap::new();
  37     for filename in file_map.keys() {
  38         let one_result = try!(write_file(&file_map[filename], filename, mode, config));
  39         if let Some(r) = one_result {
  40             result.insert(filename.clone(), r);
  41         }
  42     }
  43
  44     Ok(result)
  45 }
  46
  47 fn write_file(text: &StringBuffer,
  48               filename: &str,
  49               mode: WriteMode,
  50               config: &Config)
  51               -> Result<Option<String>, io::Error> {
  52
  53     // prints all newlines either as `\n` or as `\r\n`
  54     fn write_system_newlines<T>(mut writer: T,
  55                                 text: &StringBuffer,
  56                                 config: &Config)
  57                                 -> Result<(), io::Error>
  58         where T: Write
  59     {
  60         match config.newline_style {
  61                 NewlineStyle::Unix => write!(writer, "{}", text),
  62                 NewlineStyle::Windows => {
  63                     for (c, _) in text.chars() {
  64                         match c {
  65                             '\n' => try!(write!(writer, "\r\n")),
  66                             '\r' => continue,
  67                             c => try!(write!(writer, "{}", c)),
  68                         }
  69                     }
  70                     Ok(())
  71                 },
  72             }
  73     }
  74
  75     match mode {
  76             WriteMode::Overwrite => {
  77                 // Do a little dance to make writing safer - write to a temp file
  78                 // rename the original to a .bk, then rename the temp file to the
  79                 // original.
  80                 let tmp_name = filename.to_owned() + ".tmp";
  81                 let bk_name = filename.to_owned() + ".bk";
  82                 {
  83                     // Write text to temp file
  84                     let tmp_file = try!(File::create(&tmp_name));
  85                     try!(write_system_newlines(tmp_file, text, config));
  86                 }
  87
  88                 try!(fs::rename(filename, bk_name));
  89                 try!(fs::rename(tmp_name, filename));
  90             }
  91             WriteMode::NewFile(extn) => {
  92                 let filename = filename.to_owned() + "." + extn;
  93                 let file = try!(File::create(&filename));
  94                 try!(write_system_newlines(file, text, config));
  95             }
  96             WriteMode::Display => {
  97                 println!("{}:\n", filename);
  98                 let stdout = stdout();
  99                 let stdout_lock = stdout.lock();
 100                 try!(write_system_newlines(stdout_lock, text, config));
 101             }
 102             WriteMode::Return(_) => {
 103                 // io::Write is not implemented for String, working around with Vec<u8>
 104                 let mut v = Vec::new();
 105                 try!(write_system_newlines(&mut v, text, config));
 106                 // won't panic, we are writing correct utf8
 107                 return Ok(Some(String::from_utf8(v).unwrap()));
 108             }
 109         }
 110
 111     Ok(None)
 112 }