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