枚举 Decoder 

enum Decoder {
    Null(usize),
    Boolean(BooleanBufferBuilder),
    Int32(Vec<i32>),
    Int64(Vec<i64>),
    DurationSecond(Vec<i64>),
    DurationMillisecond(Vec<i64>),
    DurationMicrosecond(Vec<i64>),
    DurationNanosecond(Vec<i64>),
    Float32(Vec<f32>),
    Float64(Vec<f64>),
    Date32(Vec<i32>),
    TimeMillis(Vec<i32>),
    TimeMicros(Vec<i64>),
    TimestampMillis(bool, Vec<i64>),
    TimestampMicros(bool, Vec<i64>),
    TimestampNanos(bool, Vec<i64>),
    Int32ToInt64(Vec<i64>),
    Int32ToFloat32(Vec<f32>),
    Int32ToFloat64(Vec<f64>),
    Int64ToFloat32(Vec<f32>),
    Int64ToFloat64(Vec<f64>),
    Float32ToFloat64(Vec<f64>),
    BytesToString(OffsetBufferBuilder<i32>, Vec<u8>),
    StringToBytes(OffsetBufferBuilder<i32>, Vec<u8>),
    Binary(OffsetBufferBuilder<i32>, Vec<u8>),
    String(OffsetBufferBuilder<i32>, Vec<u8>),
    StringView(OffsetBufferBuilder<i32>, Vec<u8>),
    Array(FieldRef, OffsetBufferBuilder<i32>, Box<Decoder>),
    Record(Fields, Vec<Decoder>, Option<Projector>),
    Map(FieldRef, OffsetBufferBuilder<i32>, OffsetBufferBuilder<i32>, Vec<u8>, Box<Decoder>),
    Fixed(i32, Vec<u8>),
    Enum(Vec<i32>, Arc<[String]>, Option<EnumResolution>),
    Duration(IntervalMonthDayNanoBuilder),
    Uuid(Vec<u8>),
    Decimal32(usize, Option<usize>, Option<usize>, Decimal32Builder),
    Decimal64(usize, Option<usize>, Option<usize>, Decimal64Builder),
    Decimal128(usize, Option<usize>, Option<usize>, Decimal128Builder),
    Decimal256(usize, Option<usize>, Option<usize>, Decimal256Builder),
    RunEndEncoded(u8, usize, Box<Decoder>),
    Union(UnionDecoder),
    Nullable(Nullability, NullBufferBuilder, Box<Decoder>, NullablePlan),
}

变体

Null(usize)

Boolean(BooleanBufferBuilder)

Int32(Vec<i32>)

Int64(Vec<i64>)

DurationSecond(Vec<i64>)

DurationMillisecond(Vec<i64>)

DurationMicrosecond(Vec<i64>)

DurationNanosecond(Vec<i64>)

Float32(Vec<f32>)

Float64(Vec<f64>)

Date32(Vec<i32>)

TimeMillis(Vec<i32>)

TimeMicros(Vec<i64>)

TimestampMillis(bool, Vec<i64>)

TimestampMicros(bool, Vec<i64>)

TimestampNanos(bool, Vec<i64>)

Int32ToInt64(Vec<i64>)

Int32ToFloat32(Vec<f32>)

Int32ToFloat64(Vec<f64>)

Int64ToFloat32(Vec<f32>)

Int64ToFloat64(Vec<f64>)

Float32ToFloat64(Vec<f64>)

BytesToString(OffsetBufferBuilder<i32>, Vec<u8>)

StringToBytes(OffsetBufferBuilder<i32>, Vec<u8>)

Binary(OffsetBufferBuilder<i32>, Vec<u8>)

String(OffsetBufferBuilder<i32>, Vec<u8>)

字符串数据以 UTF-8 字节编码，映射到 Arrow 的 StringArray

StringView(OffsetBufferBuilder<i32>, Vec<u8>)

字符串数据以 UTF-8 字节编码，但映射到 Arrow 的 StringViewArray

Array(FieldRef, OffsetBufferBuilder<i32>, Box<Decoder>)

Record(Fields, Vec<Decoder>, Option<Projector>)

Map(FieldRef, OffsetBufferBuilder<i32>, OffsetBufferBuilder<i32>, Vec<u8>, Box<Decoder>)

Fixed(i32, Vec<u8>)

Enum(Vec<i32>, Arc<[String]>, Option<EnumResolution>)

Duration(IntervalMonthDayNanoBuilder)

Uuid(Vec<u8>)

Decimal32(usize, Option<usize>, Option<usize>, Decimal32Builder)

Decimal64(usize, Option<usize>, Option<usize>, Decimal64Builder)

Decimal128(usize, Option<usize>, Option<usize>, Decimal128Builder)

Decimal256(usize, Option<usize>, Option<usize>, Decimal256Builder)

RunEndEncoded(u8, usize, Box<Decoder>)

Union(UnionDecoder)

Nullable(Nullability, NullBufferBuilder, Box<Decoder>, NullablePlan)

实现

impl Decoder

fn try_new(data_type: &AvroDataType) -> Result<Self, ArrowError>

fn try_new_internal(data_type: &AvroDataType) -> Result<Self, ArrowError>

fn append_null(&mut self) -> Result<(), ArrowError>

附加一个空记录

fn append_default(&mut self, lit: &AvroLiteral) -> Result<(), ArrowError>

将单个默认字面量附加到解码器的缓冲区中

fn decode(&mut self, buf: &mut AvroCursor<'_>) -> Result<(), ArrowError>

从 buf 解码单个记录

fn decode_with_promotion( &mut self, buf: &mut AvroCursor<'_>, promotion: Promotion, ) -> Result<(), ArrowError>

fn flush(&mut self, nulls: Option<NullBuffer>) -> Result<ArrayRef, ArrowError>

将解码的记录刷出到一个 [ArrayRef]

Trait 实现

impl AsRef<str> for Decoder

fn as_ref(&self) -> &str

将此类型转换为（通常是推断出的）输入类型的共享引用。

impl Debug for Decoder

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

使用给定的格式化程序格式化值。 阅读更多