Struct mz_avro::Writer

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pub struct Writer<W> { /* private fields */ }
Expand description

Main interface for writing Avro Object Container Files.

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impl<W: Write> Writer<W>

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pub fn new(schema: Schema, writer: W) -> Writer<W>

Creates a Writer for the Schema and something implementing the std::io::Write trait to write to.

This uses the no-compression Codec::Null when appending records.

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pub fn with_codec(schema: Schema, writer: W, codec: Codec) -> Writer<W>

Creates a Writer given a Schema and a specific compression Codec

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pub fn with_codec_opt( schema: Schema, writer: W, codec: Option<Codec> ) -> Writer<W>

Create a Writer with the given parameters.

All parameters have the same meaning as with_codec, but if codec is None then no compression will be used and the avro.codec field in the header will be omitted.

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pub fn append_to(file: W) -> Result<Writer<W>, Error>
where W: AvroRead + Seek + Unpin + Send,

Creates a Writer that appends to an existing OCF file.

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pub fn schema(&self) -> &Schema

Get a reference to the Schema associated to a Writer.

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pub fn append<T: ToAvro>(&mut self, value: T) -> Result<usize, Error>

Append a compatible value (implementing the ToAvro trait) to a Writer, also performing schema validation.

Return the number of bytes written (it might be 0, see below).

NOTE This function is not guaranteed to perform any actual write, since it relies on internal buffering for performance reasons. If you want to be sure the value has been written, then call flush.

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pub fn append_value_ref(&mut self, value: &Value) -> Result<usize, Error>

Append a compatible value to a Writer, also performing schema validation.

Return the number of bytes written (it might be 0, see below).

NOTE This function is not guaranteed to perform any actual write, since it relies on internal buffering for performance reasons. If you want to be sure the value has been written, then call flush.

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pub fn extend<I, T: ToAvro>(&mut self, values: I) -> Result<usize, Error>
where I: IntoIterator<Item = T>,

Extend a Writer with an Iterator of compatible values (implementing the ToAvro trait), also performing schema validation.

Return the number of bytes written.

NOTE This function forces the written data to be flushed (an implicit call to flush is performed).

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pub fn extend_from_slice(&mut self, values: &[Value]) -> Result<usize, Error>

Extend a Writer by appending each Value from a slice, while also performing schema validation on each value appended.

Return the number of bytes written.

NOTE This function forces the written data to be flushed (an implicit call to flush is performed).

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pub fn flush(&mut self) -> Result<usize, Error>

Flush the content appended to a Writer. Call this function to make sure all the content has been written before releasing the Writer.

Return the number of bytes written.

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pub fn into_inner(self) -> W

Return what the Writer is writing to, consuming the Writer itself.

NOTE This function doesn’t guarantee that everything gets written before consuming the buffer. Please call flush before.

Auto Trait Implementations§

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

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

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

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

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

Blanket Implementations§

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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<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> Same for T

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type Output = T

Should always be Self
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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<V, T> VZip<V> for T
where V: MultiLane<T>,

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fn vzip(self) -> V

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