Replace AtomicU64 with OnceLock

.github/workflows/ci.yaml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macOS-latest, windows-latest]
-        rust: [stable, 1.67.0, nightly]
+        rust: [stable, 1.70, nightly]
 
     steps:
     - uses: actions/checkout@master

Cargo.toml

@@ -7,7 +7,7 @@ license = "MIT"
 repository = "https://github.com/Pr0methean/zip-next.git"
 keywords = ["zip", "archive"]
 description = """
-rust-version = "1.67.0"
+rust-version = "1.70.0"
 Library to support the reading and writing of zip files.
 """
 edition = "2021"

README.md

@@ -64,7 +64,7 @@ By default `aes-crypto`, `deflate`, `deflate-zlib-ng`, `deflate-zopfli`, `bzip2`
 MSRV
 ----
 
-Our current Minimum Supported Rust Version is **1.67.0**. When adding features,
+Our current Minimum Supported Rust Version is **1.70**. When adding features,
 we will follow these guidelines:
 
 - We will always support the latest four minor Rust versions. This gives you a 6

src/read.rs

@@ -8,14 +8,14 @@ use crate::crc32::Crc32Reader;
 use crate::read::zip_archive::Shared;
 use crate::result::{ZipError, ZipResult};
 use crate::spec;
-use crate::types::{AesMode, AesVendorVersion, AtomicU64, DateTime, System, ZipFileData};
+use crate::types::{AesMode, AesVendorVersion, DateTime, System, ZipFileData};
 use crate::zipcrypto::{ZipCryptoReader, ZipCryptoReaderValid, ZipCryptoValidator};
 use byteorder::{LittleEndian, ReadBytesExt};
 use std::borrow::{Borrow, Cow};
 use std::collections::HashMap;
 use std::io::{self, prelude::*};
 use std::path::{Path, PathBuf};
-use std::sync::Arc;
+use std::sync::{Arc, OnceLock};
 
 #[cfg(any(
     feature = "deflate",
@@ -227,14 +227,19 @@ pub(crate) fn find_content<'a>(
     if signature != spec::LOCAL_FILE_HEADER_SIGNATURE {
         return Err(ZipError::InvalidArchive("Invalid local file header"));
     }
-
-    reader.seek(io::SeekFrom::Current(22))?;
-    let file_name_length = reader.read_u16::<LittleEndian>()? as u64;
-    let extra_field_length = reader.read_u16::<LittleEndian>()? as u64;
-    let magic_and_header = 4 + 22 + 2 + 2;
-    let data_start = data.header_start + magic_and_header + file_name_length + extra_field_length;
-    data.data_start.store(data_start);
-
+    let data_start = match data.data_start.get() {
+        None => {
+            reader.seek(io::SeekFrom::Current(22))?;
+            let file_name_length = reader.read_u16::<LittleEndian>()? as u64;
+            let extra_field_length = reader.read_u16::<LittleEndian>()? as u64;
+            let magic_and_header = 4 + 22 + 2 + 2;
+            let data_start = data.header_start + magic_and_header + file_name_length + extra_field_length;
+            data.data_start.get_or_init(|| data_start);
+            data_start
+        }
+        Some(start) => *start
+    };
+    
     reader.seek(io::SeekFrom::Start(data_start))?;
     Ok((reader as &mut dyn Read).take(data.compressed_size))
 }
@@ -827,7 +832,7 @@ fn central_header_to_zip_file_inner<R: Read>(
         file_comment,
         header_start: offset,
         central_header_start,
-        data_start: AtomicU64::new(0),
+        data_start: OnceLock::new(),
         external_attributes: external_file_attributes,
         large_file: false,
         aes_mode: None,
@@ -1068,7 +1073,7 @@ impl<'a> ZipFile<'a> {
 
     /// Get the starting offset of the data of the compressed file
     pub fn data_start(&self) -> u64 {
-        self.data.data_start.load()
+        *self.data.data_start.get().unwrap_or(&0)
     }
 
     /// Get the starting offset of the zip header for this file
@@ -1188,7 +1193,7 @@ pub fn read_zipfile_from_stream<'a, R: Read>(reader: &'a mut R) -> ZipResult<Opt
         // header_start and data start are not available, but also don't matter, since seeking is
         // not available.
         header_start: 0,
-        data_start: AtomicU64::new(0),
+        data_start: OnceLock::new(),
         central_header_start: 0,
         // The external_attributes field is only available in the central directory.
         // We set this to zero, which should be valid as the docs state 'If input came

src/read/stream.rs

@@ -200,7 +200,7 @@ impl ZipStreamFileMetadata {
 
     /// Get the starting offset of the data of the compressed file
     pub fn data_start(&self) -> u64 {
-        self.0.data_start.load()
+        *self.0.data_start.get().unwrap_or(&0)
     }
 
     /// Get unix mode for the file

src/types.rs

@@ -1,16 +1,10 @@
 //! Types that specify what is contained in a ZIP.
 use path::{Component, Path, PathBuf};
 use std::path;
-use std::sync::Arc;
+use std::sync::{Arc, OnceLock};
 
 #[cfg(feature = "chrono")]
 use chrono::{Datelike, NaiveDate, NaiveDateTime, NaiveTime, Timelike};
-#[cfg(not(any(
-    all(target_arch = "arm", target_pointer_width = "32"),
-    target_arch = "mips",
-    target_arch = "powerpc"
-)))]
-use std::sync::atomic;
 #[cfg(doc)]
 use {crate::read::ZipFile, crate::write::FileOptions};
 
@@ -330,37 +324,6 @@ impl TryFrom<OffsetDateTime> for DateTime {
 
 pub const DEFAULT_VERSION: u8 = 46;
 
-/// A type like `AtomicU64` except it implements `Clone` and has predefined
-/// ordering.
-///
-/// It uses `Relaxed` ordering because it is not used for synchronisation.
-#[derive(Debug)]
-pub struct AtomicU64(atomic::AtomicU64);
-
-impl AtomicU64 {
-    pub const fn new(v: u64) -> Self {
-        Self(atomic::AtomicU64::new(v))
-    }
-
-    pub fn load(&self) -> u64 {
-        self.0.load(atomic::Ordering::Relaxed)
-    }
-
-    pub fn store(&self, val: u64) {
-        self.0.store(val, atomic::Ordering::Relaxed)
-    }
-
-    pub fn get_mut(&mut self) -> &mut u64 {
-        self.0.get_mut()
-    }
-}
-
-impl Clone for AtomicU64 {
-    fn clone(&self) -> Self {
-        Self(atomic::AtomicU64::new(self.load()))
-    }
-}
-
 /// Structure representing a ZIP file.
 #[derive(Debug, Clone)]
 pub struct ZipFileData {
@@ -401,7 +364,7 @@ pub struct ZipFileData {
     /// Note that when this is not known, it is set to 0
     pub central_header_start: u64,
     /// Specifies where the compressed data of the file starts
-    pub data_start: AtomicU64,
+    pub data_start: OnceLock<u64>,
     /// External file attributes
     pub external_attributes: u32,
     /// Reserve local ZIP64 extra field
@@ -562,7 +525,7 @@ mod test {
             central_extra_field: Arc::new(vec![]),
             file_comment: String::with_capacity(0).into_boxed_str(),
             header_start: 0,
-            data_start: AtomicU64::new(0),
+            data_start: OnceLock::new(),
             central_header_start: 0,
             external_attributes: 0,
             large_file: false,

src/write.rs

@@ -4,7 +4,7 @@ use crate::compression::CompressionMethod;
 use crate::read::{find_content, ZipArchive, ZipFile, ZipFileReader};
 use crate::result::{ZipError, ZipResult};
 use crate::spec;
-use crate::types::{ffi, AtomicU64, DateTime, System, ZipFileData, DEFAULT_VERSION};
+use crate::types::{ffi, DateTime, System, ZipFileData, DEFAULT_VERSION};
 use byteorder::{LittleEndian, WriteBytesExt};
 #[cfg(any(
     feature = "deflate",
@@ -24,7 +24,7 @@ use std::io::prelude::*;
 use std::io::{BufReader, SeekFrom};
 use std::mem;
 use std::str::{from_utf8, Utf8Error};
-use std::sync::Arc;
+use std::sync::{Arc, OnceLock};
 
 #[cfg(any(
     feature = "deflate",
@@ -477,7 +477,7 @@ impl<A: Read + Write + Seek> ZipWriter<A> {
         let write_position = self.inner.get_plain().stream_position()?;
         let src_index = self.index_by_name(src_name)?;
         let src_data = &self.files[src_index];
-        let data_start = src_data.data_start.load();
+        let data_start = *src_data.data_start.get().unwrap_or(&0);
         let compressed_size = src_data.compressed_size;
         debug_assert!(compressed_size <= write_position - data_start);
         let uncompressed_size = src_data.uncompressed_size;
@@ -616,7 +616,7 @@ impl<W: Write + Seek> ZipWriter<W> {
                 central_extra_field: options.central_extra_data,
                 file_comment: String::with_capacity(0).into_boxed_str(),
                 header_start,
-                data_start: AtomicU64::new(0),
+                data_start: OnceLock::new(),
                 central_header_start: 0,
                 external_attributes: permissions << 16,
                 large_file: options.large_file,
@@ -710,7 +710,8 @@ impl<W: Write + Seek> ZipWriter<W> {
                 self.inner = Storer(MaybeEncrypted::Encrypted(zipwriter));
             }
             self.stats.start = header_end;
-            *file.data_start.get_mut() = header_end;
+            debug_assert!(file.data_start.get().is_none());
+            file.data_start.get_or_init(|| header_end);
             self.writing_to_file = true;
             self.stats.bytes_written = 0;
             self.stats.hasher = Hasher::new();
@@ -800,10 +801,12 @@ impl<W: Write + Seek> ZipWriter<W> {
         self.switch_to_non_encrypting_writer()?;
         // Make sure this is the last file, and that no shallow copies of it remain; otherwise we'd
         // overwrite a valid file and corrupt the archive
+        let last_file_start = last_file.data_start.get().unwrap();
         if self
             .files
             .iter()
-            .all(|file| file.data_start.load() < last_file.data_start.load())
+            .flat_map(|file| file.data_start.get())
+            .all(|start| start < last_file_start)
         {
             self.inner
                 .get_plain()