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StreamingCSVWriter

Struct StreamingCSVWriter 

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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()?;

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impl<W: Write> StreamingCSVWriter<W>

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pub fn new(output: W) -> Self

Create a new streaming CSV writer

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pub fn with_options(output: W, delimiter: u8, quote_style: QuoteStyle) -> Self

Create with custom CSV options

Trait Implementations§

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impl<W: Write + Send> StreamingWriter for StreamingCSVWriter<W>

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fn write_header(&mut self, metadata: &QueryMetadata) -> Result<(), OutputError>

Initialize writer with column metadata (write header if applicable) Read more
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fn write_chunk(&mut self, rows: &[QueryRow]) -> Result<usize, OutputError>

Write a chunk of rows (called multiple times during streaming) Read more
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fn finalize(&mut self) -> Result<(), OutputError>

Finalize output (flush buffers, write footer, close resources) Read more
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fn rows_written(&self) -> u64

Get count of rows written so far Read more
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fn bytes_written(&self) -> Option<u64>

Get bytes written so far (if trackable) Read more

Auto Trait Implementations§

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impl<W> Freeze for StreamingCSVWriter<W>
where W: Freeze,

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impl<W> RefUnwindSafe for StreamingCSVWriter<W>
where W: RefUnwindSafe,

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impl<W> Send for StreamingCSVWriter<W>
where W: Send,

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impl<W> Sync for StreamingCSVWriter<W>
where W: Sync,

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impl<W> Unpin for StreamingCSVWriter<W>
where W: Unpin,

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impl<W> UnsafeUnpin for StreamingCSVWriter<W>
where W: UnsafeUnpin,

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impl<W> UnwindSafe for StreamingCSVWriter<W>
where W: UnwindSafe,

Blanket Implementations§

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impl<T> Allocation for T
where T: RefUnwindSafe + Send + Sync,

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<ST, DT> CastableFrom<ST, Initialized, Initialized> for DT
where ST: ?Sized, DT: ?Sized,

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impl<ST, DT> CastableFrom<ST, Uninit, Uninit> for DT
where ST: ?Sized, DT: ?Sized,

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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoEither for T

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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 more
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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

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
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impl<T> Pointable for T

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const ALIGN: usize

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> Read<Exclusive, BecauseExclusive> for T
where T: ?Sized,

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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more