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 // TODO: add tests
  12
  13 use std::fs::{self, File};
  14 use std::io::{self, BufWriter, Read, Write};
  15
  16 use checkstyle::{output_checkstyle_file, output_footer, output_header};
  17 use config::{Config, NewlineStyle, WriteMode};
  18 use rustfmt_diff::{make_diff, print_diff, Mismatch};
  19
  20 // A map of the files of a crate, with their new content
  21 pub type FileMap = Vec<FileRecord>;
  22
  23 pub type FileRecord = (String, String);
  24
  25 // Append a newline to the end of each file.
  26 pub fn append_newline(s: &mut String) {
  27     s.push_str("\n");
  28 }
  29
  30 pub fn write_all_files<T>(
  31     file_map: &[FileRecord],
  32     out: &mut T,
  33     config: &Config,
  34 ) -> Result<(), io::Error>
  35 where
  36     T: Write,
  37 {
  38     output_header(out, config.write_mode()).ok();
  39     for &(ref filename, ref text) in file_map {
  40         write_file(text, filename, out, config)?;
  41     }
  42     output_footer(out, config.write_mode()).ok();
  43
  44     Ok(())
  45 }
  46
  47 // Prints all newlines either as `\n` or as `\r\n`.
  48 pub fn write_system_newlines<T>(writer: T, text: &String, config: &Config) -> Result<(), io::Error>
  49 where
  50     T: Write,
  51 {
  52     // Buffer output, since we're writing a since char at a time.
  53     let mut writer = BufWriter::new(writer);
  54
  55     let style = if config.newline_style() == NewlineStyle::Native {
  56         if cfg!(windows) {
  57             NewlineStyle::Windows
  58         } else {
  59             NewlineStyle::Unix
  60         }
  61     } else {
  62         config.newline_style()
  63     };
  64
  65     match style {
  66         NewlineStyle::Unix => write!(writer, "{}", text),
  67         NewlineStyle::Windows => {
  68             for c in text.chars() {
  69                 match c {
  70                     '\n' => write!(writer, "\r\n")?,
  71                     '\r' => continue,
  72                     c => write!(writer, "{}", c)?,
  73                 }
  74             }
  75             Ok(())
  76         }
  77         NewlineStyle::Native => unreachable!(),
  78     }
  79 }
  80
  81 pub fn write_file<T>(
  82     text: &String,
  83     filename: &str,
  84     out: &mut T,
  85     config: &Config,
  86 ) -> Result<bool, io::Error>
  87 where
  88     T: Write,
  89 {
  90     fn source_and_formatted_text(
  91         text: &String,
  92         filename: &str,
  93         config: &Config,
  94     ) -> Result<(String, String), io::Error> {
  95         let mut f = File::open(filename)?;
  96         let mut ori_text = String::new();
  97         f.read_to_string(&mut ori_text)?;
  98         let mut v = Vec::new();
  99         write_system_newlines(&mut v, text, config)?;
 100         let fmt_text = String::from_utf8(v).unwrap();
 101         Ok((ori_text, fmt_text))
 102     }
 103
 104     fn create_diff(
 105         filename: &str,
 106         text: &String,
 107         config: &Config,
 108     ) -> Result<Vec<Mismatch>, io::Error> {
 109         let (ori, fmt) = source_and_formatted_text(text, filename, config)?;
 110         Ok(make_diff(&ori, &fmt, 3))
 111     }
 112
 113     match config.write_mode() {
 114         WriteMode::Replace => {
 115             if let Ok((ori, fmt)) = source_and_formatted_text(text, filename, config) {
 116                 if fmt != ori {
 117                     // Do a little dance to make writing safer - write to a temp file
 118                     // rename the original to a .bk, then rename the temp file to the
 119                     // original.
 120                     let tmp_name = filename.to_owned() + ".tmp";
 121                     let bk_name = filename.to_owned() + ".bk";
 122                     {
 123                         // Write text to temp file
 124                         let tmp_file = File::create(&tmp_name)?;
 125                         write_system_newlines(tmp_file, text, config)?;
 126                     }
 127
 128                     fs::rename(filename, bk_name)?;
 129                     fs::rename(tmp_name, filename)?;
 130                 }
 131             }
 132         }
 133         WriteMode::Overwrite => {
 134             // Write text directly over original file if there is a diff.
 135             let (source, formatted) = source_and_formatted_text(text, filename, config)?;
 136             if source != formatted {
 137                 let file = File::create(filename)?;
 138                 write_system_newlines(file, text, config)?;
 139             }
 140         }
 141         WriteMode::Plain => {
 142             write_system_newlines(out, text, config)?;
 143         }
 144         WriteMode::Display | WriteMode::Coverage => {
 145             println!("{}:\n", filename);
 146             write_system_newlines(out, text, config)?;
 147         }
 148         WriteMode::Diff => {
 149             if let Ok((ori, fmt)) = source_and_formatted_text(text, filename, config) {
 150                 let mismatch = make_diff(&ori, &fmt, 3);
 151                 let has_diff = !mismatch.is_empty();
 152                 print_diff(
 153                     mismatch,
 154                     |line_num| format!("Diff in {} at line {}:", filename, line_num),
 155                     config.color(),
 156                 );
 157                 return Ok(has_diff);
 158             }
 159         }
 160         WriteMode::Checkstyle => {
 161             let diff = create_diff(filename, text, config)?;
 162             output_checkstyle_file(out, filename, diff)?;
 163         }
 164     }
 165
 166     // when we are not in diff mode, don't indicate differing files
 167     Ok(false)
 168 }