org.apache.parquet.hadoop

Interface IndexCache

public interface IndexCache

A cache for caching indexes(including: ColumnIndex, OffsetIndex and BloomFilter)

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	IndexCache.CacheStrategy

Method Summary

Modifier and Type	Method and Description
void	clean() Clean the cache
static IndexCache	create(ParquetFileReader fileReader, Set<ColumnPath> columns, IndexCache.CacheStrategy cacheStrategy, boolean freeCacheAfterGet) Create an index cache for the given file reader
BloomFilter	getBloomFilter(ColumnChunkMetaData chunk) Get the BloomFilter for the given column in the set row group.
ColumnIndex	getColumnIndex(ColumnChunkMetaData chunk) Get the ColumnIndex for the given column in the set row group.
OffsetIndex	getOffsetIndex(ColumnChunkMetaData chunk) Get the OffsetIndex for the given column in the set row group.
void	setBlockMetadata(BlockMetaData currentBlockMetadata) Set the current BlockMetadata

Method Detail

create

static IndexCache create(ParquetFileReader fileReader,
                         Set<ColumnPath> columns,
                         IndexCache.CacheStrategy cacheStrategy,
                         boolean freeCacheAfterGet)

Create an index cache for the given file reader

Parameters:

fileReader - the file reader

columns - the columns that need to do cache

cacheStrategy - the cache strategy, supports NONE and PREFETCH_BLOCK

freeCacheAfterGet - whether free the given index cache after calling the given get method

Returns:

the index cache

setBlockMetadata

void setBlockMetadata(BlockMetaData currentBlockMetadata)
               throws IOException

Set the current BlockMetadata

Throws:

IOException

getColumnIndex

ColumnIndex getColumnIndex(ColumnChunkMetaData chunk)
                    throws IOException

Get the ColumnIndex for the given column in the set row group.

Parameters:

chunk - the given column chunk

Returns:

the ColumnIndex for the given column

Throws:

IOException - if any I/O error occurs during get the ColumnIndex

getOffsetIndex

OffsetIndex getOffsetIndex(ColumnChunkMetaData chunk)
                    throws IOException

Get the OffsetIndex for the given column in the set row group.

Parameters:

chunk - the given column chunk

Returns:

the OffsetIndex for the given column

Throws:

IOException - if any I/O error occurs during get the OffsetIndex

getBloomFilter

BloomFilter getBloomFilter(ColumnChunkMetaData chunk)
                    throws IOException

Get the BloomFilter for the given column in the set row group.

Parameters:

chunk - the given column chunk

Returns:

the BloomFilter for the given column

Throws:

IOException - if any I/O error occurs during get the BloomFilter

clean

void clean()

Clean the cache