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