gpcontrib/pxf_fdw/pxf_fragment.h

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 */

#ifndef GPDB_PXFFRAGMENT_H
#define GPDB_PXFFRAGMENT_H

#include "libchurl.h"
#include "pxf_header.h"

#include "lib/stringinfo.h"
#include "utils/rel.h"

#define PXF_SEGMENT_ID                 GpIdentity.segindex
#define PXF_SEGMENT_COUNT              getgpsegmentCount()

/*
 * Context for the Fragmenter
 */
typedef struct sClientContext
{
	CHURL_HEADERS http_headers;
	CHURL_HANDLE handle;
	/* part of the HTTP response - received	*/
	/* from one call to churl_read 			*/
	/* contains the complete HTTP response 	*/
	StringInfoData the_rest_buf;
}			ClientContext;

/*
 * FragmentData - describes a single Hadoop file split / HBase table region
 * in means of location (ip, port), the source name of the specific file/table that is being accessed,
 * and the index of a of list of fragments (splits/regions) for that source name.
 * The index refers to the list of the fragments of that source name.
 * user_data is optional.
 */
typedef struct FragmentData
{
	char	   *authority;
	char	   *index;
	char	   *source_name;
	char	   *fragment_md;
	char	   *user_data;
	char	   *profile;
	int			fragment_idx;
} FragmentData;

/*
 * One debug level for all log messages from the data allocation algorithm
 */
#define FRAGDEBUG DEBUG2

/*
 * Gets the fragments for the given uri location
 */
extern List *GetFragmentList(PxfOptions *options,
							 Relation relation,
							 char *filter_string,
							 List *retrieved_attrs);

/*
 * Takes a list of fragments and determines which ones need to be processed
 * by the given segment based on MOD function. Removes the elements which will
 * not be processed from the list and frees up their memory.
 * Returns the resulting list, or NIL if no elements satisfy the condition.
 */
extern List *FilterFragmentsForSegment(List *list);

/*
 * Serializes a List of FragmentData such that it can be transmitted
 * via the interconnect, and the list can be passed from master to
 * segments
 */
extern List * SerializeFragmentList(List *fragments);

/*
 * Deserializes a List of FragmentData received from the interconnect
 */
extern List * DeserializeFragmentList(List *serializedFragmentList);

/*
 * Assign PXF Host for each Data Fragment
 * Will use the same host as the existing segment as the PXF host.
 */
extern void AssignPxfLocationToFragments(PxfOptions *options, List *fragments);

/*
 * Frees the given fragment
 */
extern void FreeFragment(FragmentData *data);

#endif							/* GPDB_PXFFRAGMENT_H */