Allow sorting files in torrents

The order in which files appear in torrents can now be controlled
with the `--order` flag:

    imdl torrent create --input foo --order alphabetical-asc

See `--help` documentation for possible values.

type: added

src/common.rs

@@ -2,7 +2,7 @@
 pub(crate) use std::{
   borrow::Cow,
   char,
-  cmp::Reverse,
+  cmp::{Ordering, Reverse},
   collections::{BTreeMap, BTreeSet, HashMap, HashSet},
   convert::{Infallible, TryInto},
   env,
@@ -59,14 +59,15 @@ pub(crate) use crate::{
 // structs and enums
 pub(crate) use crate::{
   arguments::Arguments, bytes::Bytes, env::Env, error::Error, file_error::FileError,
-  file_info::FileInfo, file_path::FilePath, file_status::FileStatus, files::Files, hasher::Hasher,
-  host_port::HostPort, host_port_parse_error::HostPortParseError, info::Info, infohash::Infohash,
-  input::Input, input_target::InputTarget, lint::Lint, linter::Linter, magnet_link::MagnetLink,
-  md5_digest::Md5Digest, metainfo::Metainfo, metainfo_error::MetainfoError, mode::Mode,
-  options::Options, output_stream::OutputStream, output_target::OutputTarget,
-  piece_length_picker::PieceLengthPicker, piece_list::PieceList, platform::Platform,
-  sha1_digest::Sha1Digest, status::Status, style::Style, subcommand::Subcommand, table::Table,
-  torrent_summary::TorrentSummary, use_color::UseColor, verifier::Verifier, walker::Walker,
+  file_info::FileInfo, file_order::FileOrder, file_path::FilePath, file_status::FileStatus,
+  files::Files, hasher::Hasher, host_port::HostPort, host_port_parse_error::HostPortParseError,
+  info::Info, infohash::Infohash, input::Input, input_target::InputTarget, lint::Lint,
+  linter::Linter, magnet_link::MagnetLink, md5_digest::Md5Digest, metainfo::Metainfo,
+  metainfo_error::MetainfoError, mode::Mode, options::Options, output_stream::OutputStream,
+  output_target::OutputTarget, piece_length_picker::PieceLengthPicker, piece_list::PieceList,
+  platform::Platform, sha1_digest::Sha1Digest, status::Status, style::Style,
+  subcommand::Subcommand, table::Table, torrent_summary::TorrentSummary, use_color::UseColor,
+  verifier::Verifier, walker::Walker,
 };
 
 // type aliases

src/error.rs

@@ -24,6 +24,8 @@ pub(crate) enum Error {
   FilenameDecode { filename: PathBuf },
   #[snafu(display("Path had no file name: {}", path.display()))]
   FilenameExtract { path: PathBuf },
+  #[snafu(display("Unknown file ordering: {}", text))]
+  FileOrderUnknown { text: String },
   #[snafu(display("I/O error at `{}`: {}", path.display(), source))]
   Filesystem { source: io::Error, path: PathBuf },
   #[snafu(display("Invalid glob: {}", source))]

src/file_order.rs

@@ -0,0 +1,110 @@
+use crate::common::*;
+
+#[derive(Eq, PartialEq, Debug, Copy, Clone, Ord, PartialOrd)]
+pub(crate) enum FileOrder {
+  AlphabeticalDesc,
+  AlphabeticalAsc,
+  SizeDesc,
+  SizeAsc,
+}
+
+impl FileOrder {
+  pub(crate) const ALPHABETICAL_ASC: &'static str = "alphabetical-asc";
+  pub(crate) const ALPHABETICAL_DESC: &'static str = "alphabetical-desc";
+  pub(crate) const SIZE_ASC: &'static str = "size-asc";
+  pub(crate) const SIZE_DESC: &'static str = "size-desc";
+  pub(crate) const VALUES: &'static [&'static str] = &[
+    Self::ALPHABETICAL_DESC,
+    Self::ALPHABETICAL_ASC,
+    Self::SIZE_DESC,
+    Self::SIZE_ASC,
+  ];
+
+  pub(crate) fn name(self) -> &'static str {
+    match self {
+      Self::AlphabeticalDesc => Self::ALPHABETICAL_DESC,
+      Self::AlphabeticalAsc => Self::ALPHABETICAL_ASC,
+      Self::SizeDesc => Self::SIZE_DESC,
+      Self::SizeAsc => Self::SIZE_ASC,
+    }
+  }
+
+  pub(crate) fn compare_file_info(self, a: &FileInfo, b: &FileInfo) -> Ordering {
+    match self {
+      Self::AlphabeticalAsc => a.path.cmp(&b.path),
+      Self::AlphabeticalDesc => a.path.cmp(&b.path).reverse(),
+      Self::SizeAsc => a.length.cmp(&b.length).then_with(|| a.path.cmp(&b.path)),
+      Self::SizeDesc => a
+        .length
+        .cmp(&b.length)
+        .reverse()
+        .then_with(|| a.path.cmp(&b.path)),
+    }
+  }
+}
+
+impl FromStr for FileOrder {
+  type Err = Error;
+
+  fn from_str(text: &str) -> Result<Self, Self::Err> {
+    match text.replace('_', "-").to_lowercase().as_str() {
+      Self::ALPHABETICAL_DESC => Ok(Self::AlphabeticalDesc),
+      Self::ALPHABETICAL_ASC => Ok(Self::AlphabeticalAsc),
+      Self::SIZE_DESC => Ok(Self::SizeDesc),
+      Self::SIZE_ASC => Ok(Self::SizeAsc),
+      _ => Err(Error::FileOrderUnknown {
+        text: text.to_string(),
+      }),
+    }
+  }
+}
+
+impl Display for FileOrder {
+  fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    write!(f, "{}", self.name())
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn from_str_ok() {
+    assert_eq!(
+      FileOrder::AlphabeticalDesc,
+      "alphabetical_desc".parse().unwrap()
+    );
+
+    assert_eq!(
+      FileOrder::AlphabeticalDesc,
+      "alphabetical-desc".parse().unwrap()
+    );
+
+    assert_eq!(
+      FileOrder::AlphabeticalDesc,
+      "ALPHABETICAL-desc".parse().unwrap()
+    );
+  }
+
+  #[test]
+  fn convert() {
+    fn case(text: &str, value: FileOrder) {
+      assert_eq!(value, text.parse().unwrap());
+      assert_eq!(value.name(), text);
+    }
+
+    case("alphabetical-desc", FileOrder::AlphabeticalDesc);
+    case("alphabetical-asc", FileOrder::AlphabeticalAsc);
+    case("size-desc", FileOrder::SizeDesc);
+    case("size-asc", FileOrder::SizeAsc);
+  }
+
+  #[test]
+  fn from_str_err() {
+    assert_matches!(
+      "foo".parse::<FileOrder>(),
+      Err(Error::FileOrderUnknown { text }) if text == "foo"
+    );
+  }
+}

src/main.rs

@@ -56,6 +56,7 @@ mod env;
 mod error;
 mod file_error;
 mod file_info;
+mod file_order;
 mod file_path;
 mod file_status;
 mod files;

src/metainfo.rs

@@ -79,6 +79,18 @@ impl Metainfo {
     Self::deserialize(&InputTarget::File("<TEST>".into()), bytes).unwrap()
   }
 
+  #[cfg(test)]
+  pub(crate) fn file_paths(&self) -> Vec<String> {
+    let files = match &self.info.mode {
+      Mode::Single { .. } => panic!(),
+      Mode::Multiple { files } => files,
+    };
+
+    let paths: Vec<String> = files.iter().map(|f| f.path.to_string()).collect();
+
+    paths
+  }
+
   pub(crate) fn verify(&self, base: &Path, progress_bar: Option<ProgressBar>) -> Result<Status> {
     Verifier::verify(self, base, progress_bar)
   }

src/subcommand/torrent/create.rs

@@ -153,6 +153,15 @@ pub(crate) struct Create {
             Linux; `open` on macOS; and `cmd /C start` on Windows"
   )]
   open: bool,
+  #[structopt(
+    long = "order",
+    value_name = "ORDER",
+    possible_values = FileOrder::VALUES,
+    set(ArgSettings::CaseInsensitive),
+    help = "Specify the file order within the torrent. \
+            Defaults to ascending alphabetical order."
+  )]
+  order: Option<FileOrder>,
   #[structopt(
     long = "output",
     short = "o",
@@ -246,6 +255,7 @@ impl Create {
       .include_junk(self.include_junk)
       .include_hidden(self.include_hidden)
       .follow_symlinks(self.follow_symlinks)
+      .file_order(self.order.unwrap_or(FileOrder::AlphabeticalAsc))
       .globs(&self.globs)?
       .spinner(spinner)
       .files()?;
@@ -2385,4 +2395,147 @@ Content Size  9 bytes
     let err = fs::read(torrent).unwrap_err();
     assert_eq!(err.kind(), io::ErrorKind::NotFound);
   }
+
+  #[test]
+  fn file_ordering_by_default() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+      ],
+      tree: {
+        foo: {
+          a: "aa",
+          b: "b",
+          c: "ccc",
+          d: {
+            e: "eeee",
+          },
+        },
+      }
+    };
+
+    assert_matches!(env.run(), Ok(()));
+
+    let torrent = env.load_metainfo("foo.torrent");
+    assert_eq!(torrent.file_paths(), &["a", "b", "c", "d/e"]);
+  }
+
+  #[test]
+  fn file_ordering_by_alpha_asc() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+        "--order",
+        "alphabetical-asc",
+      ],
+      tree: {
+        foo: {
+          a: "aa",
+          b: "b",
+          c: "ccc",
+          d: {
+            e: "eeee",
+          },
+        },
+      }
+    };
+
+    assert_matches!(env.run(), Ok(()));
+
+    let torrent = env.load_metainfo("foo.torrent");
+    assert_eq!(torrent.file_paths(), &["a", "b", "c", "d/e"]);
+  }
+
+  #[test]
+  fn file_ordering_by_alpha_desc() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+        "--order",
+        "alphabetical-desc",
+      ],
+      tree: {
+        foo: {
+          a: "aa",
+          b: "b",
+          c: "ccc",
+          d: {
+            a: "aaaa",
+          },
+        },
+      }
+    };
+
+    assert_matches!(env.run(), Ok(()));
+
+    let torrent = env.load_metainfo("foo.torrent");
+    assert_eq!(torrent.file_paths(), &["d/a", "c", "b", "a"]);
+  }
+
+  #[test]
+  fn file_ordering_by_size_asc() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+        "--order",
+        "size-asc",
+      ],
+      tree: {
+        foo: {
+          a: "aa",
+          b: "b",
+          c: "ccc",
+          d: {
+            e: "e",
+          },
+        },
+      }
+    };
+
+    assert_matches!(env.run(), Ok(()));
+
+    let torrent = env.load_metainfo("foo.torrent");
+    assert_eq!(torrent.file_paths(), &["b", "d/e", "a", "c"]);
+  }
+
+  #[test]
+  fn file_ordering_by_size_desc() {
+    let mut env = test_env! {
+      args: [
+        "torrent",
+        "create",
+        "--input",
+        "foo",
+        "--order",
+        "size-desc",
+      ],
+      tree: {
+        foo: {
+          a: "aa",
+          b: "b",
+          c: "ccc",
+          d: {
+            e: "e",
+          },
+        },
+      }
+    };
+
+    assert_matches!(env.run(), Ok(()));
+
+    let torrent = env.load_metainfo("foo.torrent");
+    assert_eq!(torrent.file_paths(), &["c", "a", "b", "d/e"]);
+  }
 }

src/walker.rs

@@ -12,6 +12,7 @@ pub(crate) struct Walker {
   follow_symlinks: bool,
   include_hidden: bool,
   include_junk: bool,
+  file_order: FileOrder,
   patterns: Vec<Pattern>,
   root: PathBuf,
   spinner: Option<ProgressBar>,
@@ -23,6 +24,7 @@ impl Walker {
       follow_symlinks: false,
       include_hidden: false,
       include_junk: false,
+      file_order: FileOrder::AlphabeticalAsc,
       patterns: Vec::new(),
       root: root.to_owned(),
       spinner: None,
@@ -43,6 +45,10 @@ impl Walker {
     }
   }
 
+  pub(crate) fn file_order(self, file_order: FileOrder) -> Self {
+    Self { file_order, ..self }
+  }
+
   pub(crate) fn globs(mut self, globs: &[String]) -> Result<Self, Error> {
     for glob in globs {
       let exclude = glob.starts_with('!');
@@ -112,11 +118,10 @@ impl Walker {
       true
     };
 
-    let mut paths = Vec::new();
+    let mut file_infos = Vec::new();
     let mut total_size = 0;
     for result in WalkDir::new(&self.root)
       .follow_links(self.follow_symlinks)
-      .sort_by(|a, b| a.file_name().cmp(b.file_name()))
       .into_iter()
       .filter_entry(filter)
     {
@@ -154,12 +159,26 @@ impl Walker {
         continue;
       }
 
-      total_size += metadata.len();
+      let len = metadata.len();
+      total_size += len;
 
-      paths.push(file_path);
+      file_infos.push(FileInfo {
+        path: file_path,
+        length: Bytes(len),
+        md5sum: None,
+      });
     }
 
-    Ok(Files::dir(self.root, Bytes::from(total_size), paths))
+    file_infos.sort_by(|a, b| self.file_order.compare_file_info(a, b));
+
+    Ok(Files::dir(
+      self.root,
+      Bytes::from(total_size),
+      file_infos
+        .into_iter()
+        .map(|file_info| file_info.path)
+        .collect(),
+    ))
   }
 
   fn pattern_filter(&self, relative: &Path) -> bool {