Struct ObjectBuilder

pub struct ObjectBuilder<'a> {
    parent_state: ParentState<'a>,
    fields: IndexMap<u32, usize>,
    parent_value_offset_base: usize,
    parent_metadata_offset_base: usize,
    has_been_finished: bool,
    validate_unique_fields: bool,
    duplicate_fields: HashSet<u32>,
}

A builder for creating Variant::Object values.

See the examples on VariantBuilder for usage.

Fields

parent_state: ParentState<'a>

fields: IndexMap<u32, usize>

parent_value_offset_base: usize

The starting offset in the parent’s buffer where this object starts

parent_metadata_offset_base: usize

The starting offset in the parent’s metadata buffer where this object starts used to truncate the written fields in drop if the current object has not been finished

has_been_finished: bool

Whether the object has been finished, the written content of the current object will be truncated in drop if has_been_finished is false

validate_unique_fields: bool

duplicate_fields: HashSet<u32>

Set of duplicate fields to report for errors

Implementations

impl<'a> ObjectBuilder<'a>

fn new(parent_state: ParentState<'a>, validate_unique_fields: bool) -> Self

pub fn insert<'m, 'd, T: Into<Variant<'m, 'd>>>(&mut self, key: &str, value: T)

Add a field with key and value to the object

See Also

• ObjectBuilder::try_insert for a fallible version.
• ObjectBuilder::with_field for a builder-style API.

Panics

This method will panic if the variant contains duplicate field names in objects when validation is enabled. For a fallible version, use ObjectBuilder::try_insert

pub fn try_insert<'m, 'd, T: Into<Variant<'m, 'd>>>( &mut self, key: &str, value: T, ) -> Result<(), ArrowError>

Add a field with key and value to the object

See Also

• ObjectBuilder::insert for a infallabel version
• ObjectBuilder::try_with_field for a builder-style API.

Note

When inserting duplicate keys, the new value overwrites the previous mapping, but the old value remains in the buffer, resulting in a larger variant

pub fn with_field<'m, 'd, T: Into<Variant<'m, 'd>>>( self, key: &str, value: T, ) -> Self

Builder style API for adding a field with key and value to the object

Same as ObjectBuilder::insert, but returns self for chaining.

pub fn try_with_field<'m, 'd, T: Into<Variant<'m, 'd>>>( self, key: &str, value: T, ) -> Result<Self, ArrowError>

Builder style API for adding a field with key and value to the object

Same as ObjectBuilder::try_insert, but returns self for chaining.

pub fn with_validate_unique_fields(self, validate_unique_fields: bool) -> Self

Enables validation for unique field keys when inserting into this object.

When this is enabled, calling ObjectBuilder::finish will return an error if any duplicate field keys were added using ObjectBuilder::insert.

fn parent_state<'b>(&'b mut self, key: &'b str) -> (ParentState<'b>, bool)

pub fn new_object<'b>(&'b mut self, key: &'b str) -> ObjectBuilder<'b>

Returns an object builder that can be used to append a new (nested) object to this object.

WARNING: The builder will have no effect unless/until ObjectBuilder::finish is called.

pub fn new_list<'b>(&'b mut self, key: &'b str) -> ListBuilder<'b>

Returns a list builder that can be used to append a new (nested) list to this object.

WARNING: The builder will have no effect unless/until ListBuilder::finish is called.

pub fn finish(self) -> Result<(), ArrowError>

Finalizes this object and appends it to its parent, which otherwise remains unmodified.

Trait Implementations

impl Drop for ObjectBuilder<'_>

Drop implementation for ObjectBuilder does nothing as the finish method must be called to finalize the object. This is to ensure that the object is always finalized before its parent builder is finalized.

fn drop(&mut self)

Executes the destructor for this type.