Struct AtomicWriter 

pub struct AtomicWriter { /* private fields */ }

流式原子写入器。

适用于加密大文件——载荷逐块产生，不必先在内存里拼出完整文件。 未调用 AtomicWriter::commit 就 drop 时，临时文件会被自动删除。

示例

use omy_core::fsatomic::AtomicWriter;
let mut w = AtomicWriter::create(std::path::Path::new("out.omy"))?;
w.write_all(b"header")?;
w.write_all(b"chunk-0")?;
w.commit()?;   // 不调用 commit 则临时文件被丢弃

Implementations

impl AtomicWriter

pub fn create(target: &Path) -> Result<Self>

创建临时文件并准备写入。

临时文件名为 <target>.<pid>.<nonce><TMP_SUFFIX>，与目标同目录—— 这是 rename 原子性的前提（跨文件系统的 rename 不是原子操作，且多数平台 直接失败）。

名字必须每个实例唯一，不能固定为 <target>.tmp：两个并发写入者（例如 两个 Tauri 命令线程同时保存同一配置）会共用同一个 tmp 文件，先提交者 的 rename 会把 tmp 移走，后提交者的 rename 报 ENOENT——并发保存因此 偶发失败。唯一的 tmp 让各写入者互不干扰，最终语义仍是「最后一次提交 胜出」。

Errors

创建目录或临时文件失败时返回 Error::Io。

pub fn write_all(&mut self, buf: &[u8]) -> Result<()>

追加写入一段数据。

Errors

写入失败或写入器已关闭时返回 Error::Io。

pub const fn written(&self) -> u64

已写入的字节数。

pub fn target(&self) -> &Path

目标路径。

pub fn commit(self) -> Result<()>

提交：fsync → fsync 父目录 → rename → fsync 父目录。

Errors

任一步失败时返回 Error::Io；此时会尽力删除临时文件，目标保持原样。

pub fn abort(self)

主动放弃写入并删除临时文件。

Trait Implementations

impl Debug for AtomicWriter

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for AtomicWriter

fn drop(&mut self)

未提交即析构 → 丢弃临时文件，避免留下垃圾。

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl Seek for AtomicWriter

标准 Seek：流式加密写完载荷后要回到开头填写头部。

注意 written 统计的是写入调用累计的字节数，seek 回去覆写头部会让它 大于文件长度；需要文件长度时以 stream_position / 元数据为准。

fn seek(&mut self, pos: SeekFrom) -> Result<u64>

Seek to an offset, in bytes, in a stream.

fn rewind(&mut self) -> Result<(), Error>

Rewind to the beginning of a stream.

fn stream_len(&mut self) -> Result<u64, Error>

🔬This is a nightly-only experimental API. (seek_stream_len)

Returns the length of this stream (in bytes).

fn stream_position(&mut self) -> Result<u64, Error>

Returns the current seek position from the start of the stream.

fn seek_relative(&mut self, offset: i64) -> Result<(), Error>

Seeks relative to the current position.

impl Write for AtomicWriter

标准 Write：让流式加密直接写进临时文件，提交前目标位置不受影响。

fn write(&mut self, buf: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.