Remove backup and check options (#546)

Tidy up the API by removing a couple of options we don't really need.
Backup was discussed in #542
Check was discussed in  #439

@shssoichiro Just say if you prefer to keep either of these 🙂

src/lib.rs

@@ -34,7 +34,7 @@ use log::{debug, info, trace, warn};
 use rayon::prelude::*;
 use std::borrow::Cow;
 use std::fmt;
-use std::fs::{copy, File, Metadata};
+use std::fs::{File, Metadata};
 use std::io::{stdin, stdout, BufWriter, Read, Write};
 use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicBool, Ordering};
@@ -147,18 +147,10 @@ pub type PngResult<T> = Result<T, PngError>;
 #[derive(Clone, Debug)]
 /// Options controlling the output of the `optimize` function
 pub struct Options {
- /// Whether the input file should be backed up before writing the output.
- ///
- /// Default: `false`
- pub backup: bool,
  /// Attempt to fix errors when decoding the input file rather than returning an `Err`.
  ///
  /// Default: `false`
  pub fix_errors: bool,
- /// Don't actually run any optimizations, just parse the PNG file.
- ///
- /// Default: `false`
- pub check: bool,
  /// Write to output even if there was no improvement in compression.
  ///
  /// Default: `false`
@@ -307,8 +299,6 @@ impl Default for Options {
  fn default() -> Options {
  // Default settings based on -o 2 from the CLI interface
  Options {
- backup: false,
- check: false,
  fix_errors: false,
  force: false,
  filter: indexset! {RowFilter::None, RowFilter::Sub, RowFilter::Entropy, RowFilter::Bigrams},
@@ -462,11 +452,6 @@ pub fn optimize(input: &InFile, output: &OutFile, opts: &Options) -> PngResult<(
 
  let mut png = PngData::from_slice(&in_data, opts)?;
 
- if opts.check {
- info!("Running in check mode, not optimizing");
- return Ok(());
- }
-
  // Run the optimizer on the decoded PNG.
  let mut optimized_output = optimize_png(&mut png, &in_data, opts, deadline)?;
 
@@ -516,9 +501,6 @@ pub fn optimize(input: &InFile, output: &OutFile, opts: &Options) -> PngResult<(
  .as_ref()
  .map(|p| p.as_path())
  .unwrap_or_else(|| input.path().unwrap());
- if opts.backup {
- perform_backup(output_path)?;
- }
  let out_file = File::create(output_path).map_err(|err| {
  PngError::new(&format!(
  "Unable to write to file {}: {}",
@@ -998,19 +980,6 @@ fn is_fully_optimized(original_size: usize, optimized_size: usize, opts: &Option
  original_size <= optimized_size && !opts.force
 }
 
-fn perform_backup(input_path: &Path) -> PngResult<()> {
- let backup_file = input_path.with_extension(format!(
- "bak.{}",
- input_path.extension().unwrap().to_str().unwrap()
- ));
- copy(input_path, &backup_file).map(|_| ()).map_err(|_| {
- PngError::new(&format!(
- "Unable to write to backup file at {}",
- backup_file.display()
- ))
- })
-}
-
 #[cfg(not(unix))]
 fn copy_permissions(metadata_input: &Metadata, out_file: &File) -> PngResult<()> {
  let readonly_input = metadata_input.permissions().readonly();

src/main.rs

@@ -61,6 +61,7 @@ fn main() {
  .help("Back up modified files")
  .short('b')
  .long("backup")
+ .hide(true)
  .action(ArgAction::SetTrue),
  )
  .arg(
@@ -103,13 +104,6 @@ fn main() {
  .long("preserve")
  .action(ArgAction::SetTrue),
  )
- .arg(
- Arg::new("check")
- .help("Do not run any optimization passes")
- .short('c')
- .long("check")
- .action(ArgAction::SetTrue),
- )
  .arg(
  Arg::new("pretend")
  .help("Do not write any files, only calculate compression gains")
@@ -299,6 +293,11 @@ Heuristic filter selection strategies:
  )
  .get_matches_from(std::env::args());
 
+ if matches.get_flag("backup") {
+ eprintln!("The --backup flag is no longer supported. Please use --out or --dir to preserve your existing files.");
+ exit(1)
+ }
+
  let (out_file, out_dir, opts) = match parse_opts_into_struct(&matches) {
  Ok(x) => x,
  Err(x) => {
@@ -492,14 +491,10 @@ fn parse_opts_into_struct(
  opts.fast_evaluation = matches.get_flag("fast");
  }
 
- opts.backup = matches.get_flag("backup");
-
  opts.force = matches.get_flag("force");
 
  opts.fix_errors = matches.get_flag("fix");
 
- opts.check = matches.get_flag("check");
-
  opts.bit_depth_reduction = !matches.get_flag("no-bit-reduction");
 
  opts.color_type_reduction = !matches.get_flag("no-color-reduction");