Type Alias GenericStringBuilder

pub type GenericStringBuilder<O> = GenericByteBuilder<GenericStringType<O>>;

Array builder for GenericStringArray

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

This builder also implements std::fmt::Write with any written data included in the next appended value. This allows using std::fmt::Display with standard Rust idioms like write! and writeln! to write data directly to the builder without intermediate allocations.

Example writing strings with append_value

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

// Write one string value
builder.append_value("foobarbaz");

// Write a second string
builder.append_value("v2");

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

Example incrementally writing strings with std::fmt::Write

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

// Write data in multiple `write!` 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");
assert_eq!(array.value(1), "v2");

Aliased Type

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

Implementations

impl<T: ByteArrayType> GenericByteBuilder<T>

pub fn new() -> Self

Creates a new GenericByteBuilder.

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).

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.

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

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.

pub fn append_null(&mut self)

Append a null value into the builder.

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

Builds the GenericByteArray and reset this builder.

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

Builds the GenericByteArray without resetting the builder.

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

Returns the current values buffer as a slice

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

Returns the current offsets buffer as a slice

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

Returns the current null buffer as a slice

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

Returns the current null buffer as a mutable slice

Trait Implementations

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

fn write_str(&mut self, s: &str) -> Result

Writes a string slice into this writer, returning whether the write succeeded.

fn write_char(&mut self, c: char) -> Result<(), Error>

Writes a char into this writer, returning whether the write succeeded.

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

Glue for usage of the write! macro with implementors of this trait.

impl<T: ByteArrayType> ArrayBuilder for GenericByteBuilder<T>

fn len(&self) -> usize

Returns the number of binary slots in the builder

fn finish(&mut self) -> ArrayRef

Builds the array and reset this builder.

fn finish_cloned(&self) -> ArrayRef

Builds the array without resetting the builder.

fn as_any(&self) -> &dyn Any

Returns the builder as a non-mutable Any reference.

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

Returns the builder as a mutable Any reference.

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

Returns the boxed builder as a box of Any.

fn is_empty(&self) -> bool

Returns whether number of array slots is zero

impl<T: ByteArrayType> Debug for GenericByteBuilder<T>

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

Formats the value using the given formatter.

impl<T: ByteArrayType> Default for GenericByteBuilder<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: ByteArrayType, V: AsRef<T::Native>> Extend<Option<V>> for GenericByteBuilder<T>

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

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

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.