Struct AsyncCopyInWriter 

pub struct AsyncCopyInWriter<'a> { /* private fields */ }

Async COPY IN writer for bulk data insertion.

Drop Safety

If this writer is dropped without calling finish() or cancel(), it will attempt a best-effort synchronous cancel by queuing a CopyFail message in the connection’s write buffer. The next async operation on the connection will flush and drain the cancel response, restoring the connection to a usable state.

Implementations

impl<'a> AsyncCopyInWriter<'a>

pub async fn send(&mut self, data: &[u8]) -> Result<()>

Sends data to the server.

Errors

Currently infallible — frame construction is pure. The Result return type is preserved for forward compatibility.

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

Flushes any buffered data to the server.

Errors

Returns Error (I/O) if flushing the async transport fails.

pub async fn send_direct(&mut self, data: &[u8]) -> Result<()>

Sends COPY data directly to the stream without internal buffering.

This writes data directly to the TCP stream, letting the kernel handle buffering. More efficient for streaming large amounts of data. Call flush_stream() periodically to ensure data is sent.

Errors

• Returns Error (protocol) if data.len() + 4 exceeds u32::MAX.
• Returns Error (I/O) on transport write failure.

pub async fn flush_stream(&mut self) -> Result<()>

Flushes the TCP stream.

Use with send_direct() to periodically ensure data reaches the server.

Errors

Returns Error (I/O) if flushing the async transport fails.

pub async fn finish(self) -> Result<u64>

Finishes the COPY operation and returns the number of rows inserted.

Errors

Returns Error (server) if the server reports an ErrorResponse, or Error (I/O) / Error (closed) on transport failure.

pub async fn cancel(self, reason: &str) -> Result<()>

Cancels the COPY operation.

Errors

Returns Error (I/O) on transport write failure, or Error (closed) if the server drops the connection before acknowledging the cancel.

Trait Implementations

impl<'a> Debug for AsyncCopyInWriter<'a>

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

Formats the value using the given formatter.

impl Drop for AsyncCopyInWriter<'_>

fn drop(&mut self)

Executes the destructor for this type.

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.