pub struct StreamingCSVWriter<W: Write> { /* private fields */ }Expand description
Streaming CSV writer for memory-efficient export of large datasets
Unlike the batch CSVWriter, this writer processes data incrementally,
allowing export of arbitrarily large result sets within memory constraints.
§Example
ⓘ
let file = File::create("output.csv")?;
let mut writer = StreamingCSVWriter::new(file);
writer.write_header(&metadata)?;
for chunk in result_iterator.chunks(10_000) {
writer.write_chunk(&chunk)?;
}
writer.finalize()?;Implementations§
Source§impl<W: Write> StreamingCSVWriter<W>
impl<W: Write> StreamingCSVWriter<W>
Sourcepub fn with_options(output: W, delimiter: u8, quote_style: QuoteStyle) -> Self
pub fn with_options(output: W, delimiter: u8, quote_style: QuoteStyle) -> Self
Create with custom CSV options
Trait Implementations§
Source§impl<W: Write + Send> StreamingWriter for StreamingCSVWriter<W>
impl<W: Write + Send> StreamingWriter for StreamingCSVWriter<W>
Source§fn write_header(&mut self, metadata: &QueryMetadata) -> Result<(), OutputError>
fn write_header(&mut self, metadata: &QueryMetadata) -> Result<(), OutputError>
Initialize writer with column metadata (write header if applicable) Read more
Source§fn write_chunk(&mut self, rows: &[QueryRow]) -> Result<usize, OutputError>
fn write_chunk(&mut self, rows: &[QueryRow]) -> Result<usize, OutputError>
Write a chunk of rows (called multiple times during streaming) Read more
Source§fn finalize(&mut self) -> Result<(), OutputError>
fn finalize(&mut self) -> Result<(), OutputError>
Finalize output (flush buffers, write footer, close resources) Read more
Source§fn rows_written(&self) -> u64
fn rows_written(&self) -> u64
Get count of rows written so far Read more
Auto Trait Implementations§
impl<W> Freeze for StreamingCSVWriter<W>where
W: Freeze,
impl<W> RefUnwindSafe for StreamingCSVWriter<W>where
W: RefUnwindSafe,
impl<W> Send for StreamingCSVWriter<W>where
W: Send,
impl<W> Sync for StreamingCSVWriter<W>where
W: Sync,
impl<W> Unpin for StreamingCSVWriter<W>where
W: Unpin,
impl<W> UnsafeUnpin for StreamingCSVWriter<W>where
W: UnsafeUnpin,
impl<W> UnwindSafe for StreamingCSVWriter<W>where
W: UnwindSafe,
Blanket Implementations§
impl<T> Allocation for T
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<ST, DT> CastableFrom<ST, Initialized, Initialized> for DT
impl<ST, DT> CastableFrom<ST, Uninit, Uninit> for DT
Source§impl<T> Instrument for T
impl<T> Instrument for T
Source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
Source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
Converts
self into a Left variant of Either<Self, Self>
if into_left is true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
Converts
self into a Left variant of Either<Self, Self>
if into_left(&self) returns true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read more