Package com.databricks.jdbc.api.impl.arrow

Class ThriftChunkLinkFetcher

java.lang.Object

com.databricks.jdbc.api.impl.arrow.ThriftChunkLinkFetcher

All Implemented Interfaces:

ChunkLinkFetcher

public class ThriftChunkLinkFetcher
extends Object
implements ChunkLinkFetcher

ChunkLinkFetcher implementation for the Thrift client.

Thrift provides chunk links via the getResultChunks API, which returns links with nextChunkIndex to indicate continuation. When nextChunkIndex is null, it indicates no more chunks.

Constructor Summary

Constructors

Constructor	Description
ThriftChunkLinkFetcher(IDatabricksSession session, StatementId statementId)

Method Summary

Modifier and Type	Method	Description
void	close()	Closes any resources held by the fetcher.
ChunkLinkFetchResult	fetchLinks(long startChunkIndex, long startRowOffset)	Fetches the next batch of chunk links starting from the given position.
ExternalLink	refetchLink(long chunkIndex, long rowOffset)	Refetches a specific chunk link that may have expired.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ThriftChunkLinkFetcher

public ThriftChunkLinkFetcher(IDatabricksSession session,
                              StatementId statementId)

Method Detail

fetchLinks

public ChunkLinkFetchResult fetchLinks(long startChunkIndex,
                                       long startRowOffset)
                                throws SQLException

Description copied from interface: ChunkLinkFetcher

Fetches the next batch of chunk links starting from the given position.

The implementation may return one or more links in a single call. The returned ChunkLinkFetchResult indicates whether more chunks are available.

SEA implementations use startChunkIndex while Thrift implementations use startRowOffset. Each implementation uses the parameter relevant to its protocol and ignores the other.

Specified by:

fetchLinks in interface ChunkLinkFetcher

Parameters:

startChunkIndex - The chunk index to start fetching from (used by SEA)

startRowOffset - The row offset to start fetching from (used by Thrift with FETCH_ABSOLUTE)

Returns:

ChunkLinkFetchResult containing the fetched links and continuation information

Throws:

SQLException - if the fetch operation fails

refetchLink

public ExternalLink refetchLink(long chunkIndex,
                                long rowOffset)
                         throws SQLException

Description copied from interface: ChunkLinkFetcher

Refetches a specific chunk link that may have expired.

This is used when a previously fetched link has expired before the chunk could be downloaded. Both SEA and Thrift clients support this via the getResultChunks API.

SEA uses chunkIndex while Thrift uses rowOffset to identify the chunk to refetch.

Specified by:

refetchLink in interface ChunkLinkFetcher

Parameters:

chunkIndex - The specific chunk index to refetch (used by SEA)

rowOffset - The row offset of the chunk to refetch (used by Thrift)

Returns:

The refreshed ExternalLink with a new expiration time

Throws:

SQLException - if the refetch operation fails

close

public void close()

Description copied from interface: ChunkLinkFetcher

Closes any resources held by the fetcher.

Specified by:

close in interface ChunkLinkFetcher