Struct Deserializer

pub struct Deserializer<'de>(/* private fields */);

A structure to deserialize Arrow arrays into Rust objects

It can be constructed via

• Deserializer::from_record_batch
• Deserializer::from_arrow
• Deserializer::from_arrow2

Implementations

impl<'de> Deserializer<'de>

pub fn from_arrow<A>(fields: &[FieldRef], arrays: &'de [A]) -> Result<Self>

where A: AsRef<dyn Array>,

Construct a new deserializer from arrow arrays (requires one of the arrow-* features)

Usage

use arrow::datatypes::FieldRef;
use serde::{Deserialize, Serialize};
use serde_arrow::{Deserializer, schema::{SchemaLike, TracingOptions}};

#[derive(Deserialize, Serialize)]
struct Record {
    a: Option<f32>,
    b: u64,
}

let fields = Vec::<FieldRef>::from_type::<Record>(TracingOptions::default())?;

let deserializer = Deserializer::from_arrow(&fields, &arrays)?;
let items = Vec::<Record>::deserialize(deserializer)?;

pub fn from_record_batch(record_batch: &'de RecordBatch) -> Result<Self>

Construct a new deserializer from a record batch (requires one of the arrow-* features)

Usage:

use serde::Deserialize;
use serde_arrow::Deserializer;

#[derive(Deserialize)]
struct Record {
    a: Option<f32>,
    b: u64,
}

let deserializer = Deserializer::from_record_batch(&record_batch)?;
let items = Vec::<Record>::deserialize(deserializer)?;

impl<'de> Deserializer<'de>

pub fn from_arrow2<A>(fields: &[ArrowField], arrays: &'de [A]) -> Result<Self>

where A: AsRef<dyn Array>,

Build a deserializer from arrow2 arrays (requires one of the arrow2-* features)

Usage:

use arrow2::datatypes::Field;
use serde::{Deserialize, Serialize};
use serde_arrow::{Deserializer, schema::{SchemaLike, TracingOptions}};

#[derive(Deserialize, Serialize)]
struct Record {
    a: Option<f32>,
    b: u64,
}

let fields = Vec::<Field>::from_type::<Record>(TracingOptions::default())?;

let deserializer = Deserializer::from_arrow2(&fields, &arrays)?;
let items = Vec::<Record>::deserialize(deserializer)?;

Trait Implementations

impl<'de> Deserializer<'de> for Deserializer<'de>

type Error = Error

The error type that can be returned if some error occurs during deserialization.

fn deserialize_any<V: Visitor<'de>>(self, visitor: V) -> Result<V::Value>

Require the Deserializer to figure out how to drive the visitor based on what data type is in the input.

fn deserialize_ignored_any<V: Visitor<'de>>( self, visitor: V, ) -> Result<V::Value>

Hint that the Deserialize type needs to deserialize a value whose type doesn’t matter because it is ignored.

fn deserialize_seq<V: Visitor<'de>>(self, visitor: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a sequence of values.

fn deserialize_tuple<V: Visitor<'de>>( self, _len: usize, visitor: V, ) -> Result<V::Value>

Hint that the Deserialize type is expecting a sequence of values and knows how many values there are without looking at the serialized data.

fn deserialize_tuple_struct<V: Visitor<'de>>( self, _name: &'static str, _len: usize, visitor: V, ) -> Result<V::Value>

Hint that the Deserialize type is expecting a tuple struct with a particular name and number of fields.

fn deserialize_newtype_struct<V: Visitor<'de>>( self, _: &'static str, visitor: V, ) -> Result<V::Value>

Hint that the Deserialize type is expecting a newtype struct with a particular name.

fn deserialize_bool<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a bool value.

fn deserialize_byte_buf<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a byte array and would benefit from taking ownership of buffered data owned by the Deserializer.

fn deserialize_bytes<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a byte array and does not benefit from taking ownership of buffered data owned by the Deserializer.

fn deserialize_char<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a char value.

fn deserialize_enum<V: Visitor<'de>>( self, _: &'static str, _: &'static [&'static str], _: V, ) -> Result<V::Value>

Hint that the Deserialize type is expecting an enum value with a particular name and possible variants.

fn deserialize_f32<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a f32 value.

fn deserialize_f64<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a f64 value.

fn deserialize_i128<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting an i128 value.

fn deserialize_i16<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting an i16 value.

fn deserialize_i32<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting an i32 value.

fn deserialize_i64<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting an i64 value.

fn deserialize_i8<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting an i8 value.

fn deserialize_identifier<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting the name of a struct field or the discriminant of an enum variant.

fn deserialize_map<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a map of key-value pairs.

fn deserialize_option<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting an optional value.

fn deserialize_str<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a string value and does not benefit from taking ownership of buffered data owned by the Deserializer.

fn deserialize_string<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a string value and would benefit from taking ownership of buffered data owned by the Deserializer.

fn deserialize_struct<V: Visitor<'de>>( self, _: &'static str, _: &'static [&'static str], _: V, ) -> Result<V::Value>

Hint that the Deserialize type is expecting a struct with a particular name and fields.

fn deserialize_u128<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting an u128 value.

fn deserialize_u16<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a u16 value.

fn deserialize_u32<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a u32 value.

fn deserialize_u64<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a u64 value.

fn deserialize_u8<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a u8 value.

fn deserialize_unit<V: Visitor<'de>>(self, _: V) -> Result<V::Value>

Hint that the Deserialize type is expecting a unit value.

fn deserialize_unit_struct<V: Visitor<'de>>( self, _: &'static str, _: V, ) -> Result<V::Value>

Hint that the Deserialize type is expecting a unit struct with a particular name.

fn is_human_readable(&self) -> bool

Determine whether Deserialize implementations should expect to deserialize their human-readable form.