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");