Struct BinaryCopyWriter 

#[non_exhaustive]
pub struct BinaryCopyWriter { /* private fields */ }

Writer for PostgreSQL binary COPY format.

This struct helps encode the binary COPY protocol header, individual rows, and the terminating trailer. Each call to write_row appends to an internal buffer and returns a slice of the newly added bytes.

Implementations

impl BinaryCopyWriter

pub fn new(column_count: i16) -> Self

Create a new binary COPY writer for the given number of columns.

pub fn column_count(&self) -> i16

Returns the number of columns this writer expects.

pub fn header(&mut self) -> &[u8]

Generate and return the binary COPY file header.

This should be called once at the start of the COPY stream and the returned bytes sent to the server before any row data.

The header consists of:

• 15-byte magic signature: PGCOPY\n\xff\r\n\0
• 4-byte flags (0)
• 4-byte header extension length (0)

pub fn write_row(&mut self, values: &[Option<&[u8]>]) -> &[u8]

Encode a single row and return the bytes.

values must have exactly column_count elements. None represents a NULL field.

Panics

Panics if values.len() != column_count.

pub fn trailer(&mut self) -> &[u8]

Generate the binary COPY trailer (field_count = -1).

This should be sent after all row data to signal the end of the COPY stream.

pub fn into_inner(self) -> Vec<u8>

Consume the writer and return the complete buffer.

pub fn buffer(&self) -> &[u8]

Return a reference to the accumulated buffer.

pub fn clear(&mut self)

Clear the internal buffer, keeping the allocation.

Trait Implementations

impl Clone for BinaryCopyWriter

fn clone(&self) -> BinaryCopyWriter

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BinaryCopyWriter

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

Formats the value using the given formatter.