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: add tests
  13
  14 use std::fs::{self, File};
  15 use std::io::{self, BufWriter, Read, Write};
  16
  17 use strings::string_buffer::StringBuffer;
  18
  19 use checkstyle::{output_checkstyle_file, output_footer, output_header};
  20 use config::{Config, NewlineStyle, WriteMode};
  21 use rustfmt_diff::{make_diff, print_diff, Mismatch};
  22
  23 // A map of the files of a crate, with their new content
  24 pub type FileMap = Vec<FileRecord>;
  25
  26 pub type FileRecord = (String, StringBuffer);
  27
  28 // Append a newline to the end of each file.
  29 pub fn append_newline(s: &mut StringBuffer) {
  30     s.push_str("\n");
  31 }
  32
  33 pub fn write_all_files<T>(
  34     file_map: &[FileRecord],
  35     out: &mut T,
  36     config: &Config,
  37 ) -> Result<(), io::Error>
  38 where
  39     T: Write,
  40 {
  41     output_header(out, config.write_mode()).ok();
  42     for &(ref filename, ref text) in file_map {
  43         write_file(text, filename, out, config)?;
  44     }
  45     output_footer(out, config.write_mode()).ok();
  46
  47     Ok(())
  48 }
  49
  50 // Prints all newlines either as `\n` or as `\r\n`.
  51 pub fn write_system_newlines<T>(
  52     writer: T,
  53     text: &StringBuffer,
  54     config: &Config,
  55 ) -> Result<(), io::Error>
  56 where
  57     T: Write,
  58 {
  59     // Buffer output, since we're writing a since char at a time.
  60     let mut writer = BufWriter::new(writer);
  61
  62     let style = if config.newline_style() == NewlineStyle::Native {
  63         if cfg!(windows) {
  64             NewlineStyle::Windows
  65         } else {
  66             NewlineStyle::Unix
  67         }
  68     } else {
  69         config.newline_style()
  70     };
  71
  72     match style {
  73         NewlineStyle::Unix => write!(writer, "{}", text),
  74         NewlineStyle::Windows => {
  75             for (c, _) in text.chars() {
  76                 match c {
  77                     '\n' => write!(writer, "\r\n")?,
  78                     '\r' => continue,
  79                     c => write!(writer, "{}", c)?,
  80                 }
  81             }
  82             Ok(())
  83         }
  84         NewlineStyle::Native => unreachable!(),
  85     }
  86 }
  87
  88 pub fn write_file<T>(
  89     text: &StringBuffer,
  90     filename: &str,
  91     out: &mut T,
  92     config: &Config,
  93 ) -> Result<bool, io::Error>
  94 where
  95     T: Write,
  96 {
  97     fn source_and_formatted_text(
  98         text: &StringBuffer,
  99         filename: &str,
 100         config: &Config,
 101     ) -> Result<(String, String), io::Error> {
 102         let mut f = File::open(filename)?;
 103         let mut ori_text = String::new();
 104         f.read_to_string(&mut ori_text)?;
 105         let mut v = Vec::new();
 106         write_system_newlines(&mut v, text, config)?;
 107         let fmt_text = String::from_utf8(v).unwrap();
 108         Ok((ori_text, fmt_text))
 109     }
 110
 111     fn create_diff(
 112         filename: &str,
 113         text: &StringBuffer,
 114         config: &Config,
 115     ) -> Result<Vec<Mismatch>, io::Error> {
 116         let (ori, fmt) = source_and_formatted_text(text, filename, config)?;
 117         Ok(make_diff(&ori, &fmt, 3))
 118     }
 119
 120     match config.write_mode() {
 121         WriteMode::Replace => {
 122             if let Ok((ori, fmt)) = source_and_formatted_text(text, filename, config) {
 123                 if fmt != ori {
 124                     // Do a little dance to make writing safer - write to a temp file
 125                     // rename the original to a .bk, then rename the temp file to the
 126                     // original.
 127                     let tmp_name = filename.to_owned() + ".tmp";
 128                     let bk_name = filename.to_owned() + ".bk";
 129                     {
 130                         // Write text to temp file
 131                         let tmp_file = File::create(&tmp_name)?;
 132                         write_system_newlines(tmp_file, text, config)?;
 133                     }
 134
 135                     fs::rename(filename, bk_name)?;
 136                     fs::rename(tmp_name, filename)?;
 137                 }
 138             }
 139         }
 140         WriteMode::Overwrite => {
 141             // Write text directly over original file if there is a diff.
 142             let (source, formatted) = source_and_formatted_text(text, filename, config)?;
 143             if source != formatted {
 144                 let file = File::create(filename)?;
 145                 write_system_newlines(file, text, config)?;
 146             }
 147         }
 148         WriteMode::Plain => {
 149             write_system_newlines(out, text, config)?;
 150         }
 151         WriteMode::Display | WriteMode::Coverage => {
 152             println!("{}:\n", filename);
 153             write_system_newlines(out, text, config)?;
 154         }
 155         WriteMode::Diff => {
 156             if let Ok((ori, fmt)) = source_and_formatted_text(text, filename, config) {
 157                 let mismatch = make_diff(&ori, &fmt, 3);
 158                 let has_diff = !mismatch.is_empty();
 159                 print_diff(
 160                     mismatch,
 161                     |line_num| format!("Diff in {} at line {}:", filename, line_num),
 162                     config.color(),
 163                 );
 164                 return Ok(has_diff);
 165             }
 166         }
 167         WriteMode::Checkstyle => {
 168             let diff = create_diff(filename, text, config)?;
 169             output_checkstyle_file(out, filename, diff)?;
 170         }
 171     }
 172
 173     // when we are not in diff mode, don't indicate differing files
 174     Ok(false)
 175 }