arrow_array::builder

Type Alias GenericBinaryBuilder

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pub type GenericBinaryBuilder<O> = GenericByteBuilder<GenericBinaryType<O>>;
Expand description

Array builder for GenericBinaryArray

Values can be appended using GenericByteBuilder::append_value, and nulls with GenericByteBuilder::append_null.

§Example

let mut builder = GenericBinaryBuilder::<i32>::new();

// Write data
builder.append_value("foo");

// Write second value
builder.append_value(&[0,1,2]);

let array = builder.finish();
// binary values
assert_eq!(array.value(0), b"foo");
assert_eq!(array.value(1), b"\x00\x01\x02");

§Example incrementally writing bytes with write_bytes

let mut builder = GenericBinaryBuilder::<i32>::new();

// Write data in multiple `write_bytes` calls
write!(builder, "foo").unwrap();
write!(builder, "bar").unwrap();
// The next call to append_value finishes the current string
// including all previously written strings.
builder.append_value("baz");

// Write second value with a single write call
write!(builder, "v2").unwrap();
// finish the value by calling append_value with an empty string
builder.append_value("");

let array = builder.finish();
assert_eq!(array.value(0), "foobarbaz".as_bytes());
assert_eq!(array.value(1), "v2".as_bytes());

Aliased Type§

struct GenericBinaryBuilder<O> { /* private fields */ }

Implementations

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impl<T: ByteArrayType> GenericByteBuilder<T>

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pub fn new() -> Self

Creates a new GenericByteBuilder.

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pub fn with_capacity(item_capacity: usize, data_capacity: usize) -> Self

Creates a new GenericByteBuilder.

  • item_capacity is the number of items to pre-allocate. The size of the preallocated buffer of offsets is the number of items plus one.
  • data_capacity is the total number of bytes of data to pre-allocate (for all items, not per item).
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pub unsafe fn new_from_buffer( offsets_buffer: MutableBuffer, value_buffer: MutableBuffer, null_buffer: Option<MutableBuffer>, ) -> Self

Creates a new GenericByteBuilder from buffers.

§Safety

This doesn’t verify buffer contents as it assumes the buffers are from existing and valid GenericByteArray.

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pub fn append_value(&mut self, value: impl AsRef<T::Native>)

Appends a value into the builder.

See the GenericStringBuilder documentation for examples of incrementally building string values with multiple write! calls.

§Panics

Panics if the resulting length of Self::values_slice would exceed T::Offset::MAX bytes.

For example, this can happen with StringArray or BinaryArray where the total length of all values exceeds 2GB

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pub fn append_option(&mut self, value: Option<impl AsRef<T::Native>>)

Append an Option value into the builder.

  • A None value will append a null value.
  • A Some value will append the value.

See Self::append_value for more panic information.

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pub fn append_null(&mut self)

Append a null value into the builder.

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pub fn finish(&mut self) -> GenericByteArray<T>

Builds the GenericByteArray and reset this builder.

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pub fn finish_cloned(&self) -> GenericByteArray<T>

Builds the GenericByteArray without resetting the builder.

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

Returns the current values buffer as a slice

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pub fn offsets_slice(&self) -> &[T::Offset]

Returns the current offsets buffer as a slice

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pub fn validity_slice(&self) -> Option<&[u8]>

Returns the current null buffer as a slice

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pub fn validity_slice_mut(&mut self) -> Option<&mut [u8]>

Returns the current null buffer as a mutable slice

Trait Implementations§

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impl<O: OffsetSizeTrait> Write for GenericBinaryBuilder<O>

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fn write(&mut self, bs: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written. Read more
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fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
1.36.0 · Source§

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers. Read more
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fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)
Determines if this Writer has an efficient write_vectored implementation. Read more
1.0.0 · Source§

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer. Read more
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fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)
Attempts to write multiple buffers into this writer. Read more
1.0.0 · Source§

fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered. Read more
1.0.0 · Source§

fn by_ref(&mut self) -> &mut Self
where Self: Sized,

Creates a “by reference” adapter for this instance of Write. Read more
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impl<T: ByteArrayType> ArrayBuilder for GenericByteBuilder<T>

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fn len(&self) -> usize

Returns the number of binary slots in the builder

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fn finish(&mut self) -> ArrayRef

Builds the array and reset this builder.

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fn finish_cloned(&self) -> ArrayRef

Builds the array without resetting the builder.

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fn as_any(&self) -> &dyn Any

Returns the builder as a non-mutable Any reference.

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fn as_any_mut(&mut self) -> &mut dyn Any

Returns the builder as a mutable Any reference.

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fn into_box_any(self: Box<Self>) -> Box<dyn Any>

Returns the boxed builder as a box of Any.

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fn is_empty(&self) -> bool

Returns whether number of array slots is zero
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impl<T: ByteArrayType> Debug for GenericByteBuilder<T>

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

Formats the value using the given formatter. Read more
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impl<T: ByteArrayType> Default for GenericByteBuilder<T>

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fn default() -> Self

Returns the “default value” for a type. Read more
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impl<T: ByteArrayType, V: AsRef<T::Native>> Extend<Option<V>> for GenericByteBuilder<T>

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fn extend<I: IntoIterator<Item = Option<V>>>(&mut self, iter: I)

Extends a collection with the contents of an iterator. Read more
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fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)
Extends a collection with exactly one element.
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fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)
Reserves capacity in a collection for the given number of additional elements. Read more