/* ------------------------------------------------------------------------
 *
 * partition_filter.h
 *		Select partition for INSERT operation
 *
 * Copyright (c) 2016, Postgres Professional
 *
 * ------------------------------------------------------------------------
 */

#ifndef RUNTIME_INSERT_H
#define RUNTIME_INSERT_H

#include "relation_info.h"
#include "utils.h"

#include "postgres.h"
#include "commands/explain.h"
#include "optimizer/planner.h"

#if PG_VERSION_NUM >= 90600
#include "nodes/extensible.h"
#endif


#define ERR_PART_ATTR_NULL		"partitioned column's value should not be NULL"
#define ERR_PART_ATTR_NO_PART	"no suitable partition for key '%s'"
#define ERR_PART_ATTR_MULTIPLE	"PartitionFilter selected more than one partition"


/*
 * Single element of 'result_rels_table'.
 */
typedef struct
{
	Oid					partid;					/* partition's relid */
	ResultRelInfo	   *result_rel_info;		/* cached ResultRelInfo */
} ResultRelInfoHolder;

/*
 * Callback to be fired at rri_holder creation.
 */
typedef void (*on_new_rri_holder)(EState *estate,
								  ResultRelInfoHolder *rri_holder,
								  void *arg);

/*
 * Cached ResultRelInfos of partitions.
 */
typedef struct
{
	ResultRelInfo	   *saved_rel_info;			/* original ResultRelInfo (parent) */
	HTAB			   *result_rels_table;
	HASHCTL				result_rels_table_config;

	bool				speculative_inserts;	/* for ExecOpenIndices() */

	on_new_rri_holder	on_new_rri_holder_callback;
	void			   *callback_arg;

	EState			   *estate;					/* pointer to executor's state */

	CmdType				command_type;			/* currenly we only allow INSERT */
	LOCKMODE			head_open_lock_mode;
	LOCKMODE			heap_close_lock_mode;
} ResultPartsStorage;

/*
 * Standard size of ResultPartsStorage entry.
 */
#define ResultPartsStorageStandard	0

typedef struct
{
	CustomScanState		css;

	Oid					partitioned_table;
	OnConflictAction	on_conflict_action;

	Plan			   *subplan;				/* proxy variable to store subplan */
	ResultPartsStorage	result_parts;			/* partition ResultRelInfo cache */

	bool				warning_triggered;		/* warning message counter */
} PartitionFilterState;


extern bool					pg_pathman_enable_partition_filter;
extern int					pg_pathman_insert_into_fdw;

extern CustomScanMethods	partition_filter_plan_methods;
extern CustomExecMethods	partition_filter_exec_methods;


void init_partition_filter_static_data(void);

void add_partition_filters(List *rtable, Plan *plan);

/* ResultPartsStorage init\fini\scan function */
void init_result_parts_storage(ResultPartsStorage *parts_storage,
							   EState *estate,
							   bool speculative_inserts,
							   Size table_entry_size,
							   on_new_rri_holder on_new_rri_holder_cb,
							   void *on_new_rri_holder_cb_arg);
void fini_result_parts_storage(ResultPartsStorage *parts_storage,
							   bool close_rels);
ResultRelInfoHolder * scan_result_parts_storage(Oid partid,
												ResultPartsStorage *storage);

/* Find suitable partition using 'value' */
Oid *find_partitions_for_value(Datum value, const PartRelationInfo *prel,
							   ExprContext *econtext, int *nparts);

Plan * make_partition_filter(Plan *subplan,
							 Oid partitioned_table,
							 OnConflictAction conflict_action);

Node * partition_filter_create_scan_state(CustomScan *node);

void partition_filter_begin(CustomScanState *node,
							EState *estate,
							int eflags);

TupleTableSlot * partition_filter_exec(CustomScanState *node);

void partition_filter_end(CustomScanState *node);

void partition_filter_rescan(CustomScanState *node);

void partition_filter_explain(CustomScanState *node,
							  List *ancestors,
							  ExplainState *es);

ResultRelInfoHolder * select_partition_for_insert(const PartRelationInfo *prel,
												  ResultPartsStorage *parts_storage,
												  Datum value, EState *estate,
												  bool spawn_partitions);

#endif