Struct MergeRecordDecoder 

pub struct MergeRecordDecoder<D> { /* private fields */ }

Merges the record decoding streams from one or more other decoders, performing a k-merge based on Record::index_ts().

Implementations

impl<D> RecordDecoder<D>

where D: DecodeRecordRef,

pub fn new(decoders: Vec<D>) -> Result<Self>

Creates a new record-stream merging decoder.

Errors

This function returns an error if decoders is empty. It will also return an error if one of the inner decoders returns an error while decoding the first record. A decoder returning Ok(None) does not result in a failure.

pub fn with_hints(decoders: Vec<D>, start_ts_hints: Vec<u64>) -> Result<Self>

Creates a new record-stream merging decoder with a hint for the start time for each decoder. This can assist the merger to avoid reading from a decoder before necessary.

The hint timestamp must be <= raw_index_ts() of the first record in the file. Metadata::start is an example source of for hint.

Errors

This function returns an error if decoders is empty or decoders and start_ts_hints are of different lengths. It will also return an error if one of the inner decoders returns an error while decoding the first record. A decoder returning Ok(None) does not result in a failure.

Trait Implementations

impl<D> DecodeRecord for RecordDecoder<D>

where D: LastRecord + DecodeRecordRef,

fn decode_record<T: HasRType>(&mut self) -> Result<Option<&T>>

Tries to decode a reference to a single record of type T. Returns Ok(None) if the input has been exhausted.

fn decode_records<T: HasRType + Clone>(self) -> Result<Vec<T>>

where Self: Sized,

Tries to decode all records into a Vec. This eagerly decodes the data.

impl<D> DecodeRecordRef for RecordDecoder<D>

where D: LastRecord + DecodeRecordRef,

fn decode_record_ref(&mut self) -> Result<Option<RecordRef<'_>>>

Tries to decode a generic reference a record. Returns Ok(None) if input has been exhausted.

fn decode_buf_iter(&mut self) -> impl Iterator<Item = Result<RecordBuf>> + '_

Returns an Iterator of owned RecordBufs decoded from this reader.

impl<D> DecodeStream for RecordDecoder<D>

where D: LastRecord + DecodeRecordRef,

fn decode_stream<T: HasRType>(self) -> StreamIterDecoder<Self, T>

where Self: Sized,

Converts the decoder into a streaming iterator of records of type T. This lazily decodes the data.