perf: Use boxed slice for archive comment, since it can't be concatenated

fuzz/fuzz_targets/fuzz_write.rs

@@ -21,8 +21,7 @@ pub enum BasicFileOperation<'k> {
     ShallowCopy(Box<FileOperation<'k>>),
     DeepCopy(Box<FileOperation<'k>>),
     MergeWithOtherFile {
-        first: Box<FileOperation<'k>>,
-        rest: Box<[FileOperation<'k>]>
+        operations: Box<[(FileOperation<'k>, bool)]>
     }
 }
 
@@ -43,8 +42,8 @@ pub struct FileOperation<'k> {
 
 #[derive(Arbitrary, Clone, Debug)]
 pub struct FuzzTestCase<'k> {
-    comment: Vec<u8>,
-    operations: Vec<(FileOperation<'k>, bool)>,
+    comment: Box<[u8]>,
+    operations: Box<[(FileOperation<'k>, bool)]>,
     flush_on_finish_file: bool,
 }
 
@@ -89,14 +88,13 @@ where
             do_operation(writer, &base, false, flush_on_finish_file)?;
             writer.deep_copy_file_from_path(&base.path, &path)?;
         }
-        BasicFileOperation::MergeWithOtherFile { first, rest } => {
+        BasicFileOperation::MergeWithOtherFile { operations } => {
             let mut other_writer = zip::ZipWriter::new(Cursor::new(Vec::new()));
-            let _ = do_operation(&mut other_writer, &first, false, flush_on_finish_file);
-            rest.iter().for_each(|operation| {
+            operations.iter().for_each(|(operation, abort)| {
                 let _ = do_operation(
                     &mut other_writer,
                     &operation,
-                    false,
+                    *abort,
                     false,
                 );
             });
@@ -133,11 +131,11 @@ fuzz_target!(|test_case: FuzzTestCase| {
             final_reopen = true;
         }
     }
-    for (operation, abort) in test_case.operations {
+    for (operation, abort) in test_case.operations.into_iter() {
         let _ = do_operation(
             &mut writer,
             &operation,
-            abort,
+            *abort,
             test_case.flush_on_finish_file,
         );
     }

src/read.rs

@@ -352,7 +352,7 @@ pub(crate) struct CentralDirectoryInfo {
 impl<R> ZipArchive<R> {
     pub(crate) fn from_finalized_writer(
         files: IndexMap<Box<str>, ZipFileData>,
-        comment: Vec<u8>,
+        comment: Box<[u8]>,
         reader: R,
         central_start: u64,
     ) -> ZipResult<Self> {
@@ -368,7 +368,7 @@ impl<R> ZipArchive<R> {
         Ok(Self {
             reader,
             shared,
-            comment: comment.into_boxed_slice().into(),
+            comment: comment.into(),
         })
     }
 

src/spec.rs

@@ -22,7 +22,7 @@ pub struct CentralDirectoryEnd {
     pub number_of_files: u16,
     pub central_directory_size: u32,
     pub central_directory_offset: u32,
-    pub zip_file_comment: Vec<u8>,
+    pub zip_file_comment: Box<[u8]>,
 }
 
 impl CentralDirectoryEnd {
@@ -38,7 +38,7 @@ impl CentralDirectoryEnd {
         let central_directory_size = reader.read_u32_le()?;
         let central_directory_offset = reader.read_u32_le()?;
         let zip_file_comment_length = reader.read_u16_le()? as usize;
-        let mut zip_file_comment = vec![0; zip_file_comment_length];
+        let mut zip_file_comment = vec![0; zip_file_comment_length].into_boxed_slice();
         reader.read_exact(&mut zip_file_comment)?;
 
         Ok(CentralDirectoryEnd {

src/write.rs

@@ -125,7 +125,7 @@ pub(crate) mod zip_writer {
         pub(super) stats: ZipWriterStats,
         pub(super) writing_to_file: bool,
         pub(super) writing_raw: bool,
-        pub(super) comment: Vec<u8>,
+        pub(super) comment: Box<[u8]>,
         pub(super) flush_on_finish_file: bool,
     }
 }
@@ -683,7 +683,7 @@ impl<W: Write + Seek> ZipWriter<W> {
             stats: Default::default(),
             writing_to_file: false,
             writing_raw: false,
-            comment: Vec::new(),
+            comment: Box::new([]),
             flush_on_finish_file: false,
         }
     }
@@ -696,16 +696,16 @@ impl<W: Write + Seek> ZipWriter<W> {
     /// Set ZIP archive comment.
     pub fn set_comment<S>(&mut self, comment: S)
     where
-        S: Into<String>,
+        S: Into<Box<str>>,
     {
-        self.set_raw_comment(comment.into().into())
+        self.set_raw_comment(comment.into().into_boxed_bytes())
     }
 
     /// Set ZIP archive comment.
     ///
     /// This sets the raw bytes of the comment. The comment
     /// is typically expected to be encoded in UTF-8
-    pub fn set_raw_comment(&mut self, comment: Vec<u8>) {
+    pub fn set_raw_comment(&mut self, comment: Box<[u8]>) {
         self.comment = comment;
     }
 
@@ -718,7 +718,7 @@ impl<W: Write + Seek> ZipWriter<W> {
     ///
     /// This returns the raw bytes of the comment. The comment
     /// is typically expected to be encoded in UTF-8
-    pub const fn get_raw_comment(&self) -> &Vec<u8> {
+    pub const fn get_raw_comment(&self) -> &[u8] {
         &self.comment
     }
 
@@ -2458,10 +2458,11 @@ mod test {
     #[test]
     fn test_crash_short_read() {
         let mut writer = ZipWriter::new(Cursor::new(Vec::new()));
-        let comment: Vec<u8> = vec![
+        let comment = vec![
             1, 80, 75, 5, 6, 237, 237, 237, 237, 237, 237, 237, 237, 44, 255, 191, 255, 255, 255,
             255, 255, 255, 255, 255, 16,
-        ];
+        ]
+        .into_boxed_slice();
         writer.set_raw_comment(comment);
         let options = SimpleFileOptions::default()
             .compression_method(Stored)