Adding upstream version 16.2.upstream/16.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 191 insertions, 0 deletions

diff --git a/src/include/access/relscan.h b/src/include/access/relscan.h
new file mode 100644
index 0000000..d03360e
--- /dev/null
+++ b/src/include/access/relscan.h
@@ -0,0 +1,191 @@
+/*-------------------------------------------------------------------------
+ *
+ * relscan.h
+ *	  POSTGRES relation scan descriptor definitions.
+ *
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/relscan.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef RELSCAN_H
+#define RELSCAN_H
+
+#include "access/htup_details.h"
+#include "access/itup.h"
+#include "port/atomics.h"
+#include "storage/buf.h"
+#include "storage/spin.h"
+#include "utils/relcache.h"
+
+
+struct ParallelTableScanDescData;
+
+/*
+ * Generic descriptor for table scans. This is the base-class for table scans,
+ * which needs to be embedded in the scans of individual AMs.
+ */
+typedef struct TableScanDescData
+{
+	/* scan parameters */
+	Relation	rs_rd;			/* heap relation descriptor */
+	struct SnapshotData *rs_snapshot;	/* snapshot to see */
+	int			rs_nkeys;		/* number of scan keys */
+	struct ScanKeyData *rs_key; /* array of scan key descriptors */
+
+	/* Range of ItemPointers for table_scan_getnextslot_tidrange() to scan. */
+	ItemPointerData rs_mintid;
+	ItemPointerData rs_maxtid;
+
+	/*
+	 * Information about type and behaviour of the scan, a bitmask of members
+	 * of the ScanOptions enum (see tableam.h).
+	 */
+	uint32		rs_flags;
+
+	struct ParallelTableScanDescData *rs_parallel;	/* parallel scan
+													 * information */
+} TableScanDescData;
+typedef struct TableScanDescData *TableScanDesc;
+
+/*
+ * Shared state for parallel table scan.
+ *
+ * Each backend participating in a parallel table scan has its own
+ * TableScanDesc in backend-private memory, and those objects all contain a
+ * pointer to this structure.  The information here must be sufficient to
+ * properly initialize each new TableScanDesc as workers join the scan, and it
+ * must act as a information what to scan for those workers.
+ */
+typedef struct ParallelTableScanDescData
+{
+	Oid			phs_relid;		/* OID of relation to scan */
+	bool		phs_syncscan;	/* report location to syncscan logic? */
+	bool		phs_snapshot_any;	/* SnapshotAny, not phs_snapshot_data? */
+	Size		phs_snapshot_off;	/* data for snapshot */
+} ParallelTableScanDescData;
+typedef struct ParallelTableScanDescData *ParallelTableScanDesc;
+
+/*
+ * Shared state for parallel table scans, for block oriented storage.
+ */
+typedef struct ParallelBlockTableScanDescData
+{
+	ParallelTableScanDescData base;
+
+	BlockNumber phs_nblocks;	/* # blocks in relation at start of scan */
+	slock_t		phs_mutex;		/* mutual exclusion for setting startblock */
+	BlockNumber phs_startblock; /* starting block number */
+	pg_atomic_uint64 phs_nallocated;	/* number of blocks allocated to
+										 * workers so far. */
+}			ParallelBlockTableScanDescData;
+typedef struct ParallelBlockTableScanDescData *ParallelBlockTableScanDesc;
+
+/*
+ * Per backend state for parallel table scan, for block-oriented storage.
+ */
+typedef struct ParallelBlockTableScanWorkerData
+{
+	uint64		phsw_nallocated;	/* Current # of blocks into the scan */
+	uint32		phsw_chunk_remaining;	/* # blocks left in this chunk */
+	uint32		phsw_chunk_size;	/* The number of blocks to allocate in
+									 * each I/O chunk for the scan */
+} ParallelBlockTableScanWorkerData;
+typedef struct ParallelBlockTableScanWorkerData *ParallelBlockTableScanWorker;
+
+/*
+ * Base class for fetches from a table via an index. This is the base-class
+ * for such scans, which needs to be embedded in the respective struct for
+ * individual AMs.
+ */
+typedef struct IndexFetchTableData
+{
+	Relation	rel;
+} IndexFetchTableData;
+
+/*
+ * We use the same IndexScanDescData structure for both amgettuple-based
+ * and amgetbitmap-based index scans.  Some fields are only relevant in
+ * amgettuple-based scans.
+ */
+typedef struct IndexScanDescData
+{
+	/* scan parameters */
+	Relation	heapRelation;	/* heap relation descriptor, or NULL */
+	Relation	indexRelation;	/* index relation descriptor */
+	struct SnapshotData *xs_snapshot;	/* snapshot to see */
+	int			numberOfKeys;	/* number of index qualifier conditions */
+	int			numberOfOrderBys;	/* number of ordering operators */
+	struct ScanKeyData *keyData;	/* array of index qualifier descriptors */
+	struct ScanKeyData *orderByData;	/* array of ordering op descriptors */
+	bool		xs_want_itup;	/* caller requests index tuples */
+	bool		xs_temp_snap;	/* unregister snapshot at scan end? */
+
+	/* signaling to index AM about killing index tuples */
+	bool		kill_prior_tuple;	/* last-returned tuple is dead */
+	bool		ignore_killed_tuples;	/* do not return killed entries */
+	bool		xactStartedInRecovery;	/* prevents killing/seeing killed
+										 * tuples */
+
+	/* index access method's private state */
+	void	   *opaque;			/* access-method-specific info */
+
+	/*
+	 * In an index-only scan, a successful amgettuple call must fill either
+	 * xs_itup (and xs_itupdesc) or xs_hitup (and xs_hitupdesc) to provide the
+	 * data returned by the scan.  It can fill both, in which case the heap
+	 * format will be used.
+	 */
+	IndexTuple	xs_itup;		/* index tuple returned by AM */
+	struct TupleDescData *xs_itupdesc;	/* rowtype descriptor of xs_itup */
+	HeapTuple	xs_hitup;		/* index data returned by AM, as HeapTuple */
+	struct TupleDescData *xs_hitupdesc; /* rowtype descriptor of xs_hitup */
+
+	ItemPointerData xs_heaptid; /* result */
+	bool		xs_heap_continue;	/* T if must keep walking, potential
+									 * further results */
+	IndexFetchTableData *xs_heapfetch;
+
+	bool		xs_recheck;		/* T means scan keys must be rechecked */
+
+	/*
+	 * When fetching with an ordering operator, the values of the ORDER BY
+	 * expressions of the last returned tuple, according to the index.  If
+	 * xs_recheckorderby is true, these need to be rechecked just like the
+	 * scan keys, and the values returned here are a lower-bound on the actual
+	 * values.
+	 */
+	Datum	   *xs_orderbyvals;
+	bool	   *xs_orderbynulls;
+	bool		xs_recheckorderby;
+
+	/* parallel index scan information, in shared memory */
+	struct ParallelIndexScanDescData *parallel_scan;
+}			IndexScanDescData;
+
+/* Generic structure for parallel scans */
+typedef struct ParallelIndexScanDescData
+{
+	Oid			ps_relid;
+	Oid			ps_indexid;
+	Size		ps_offset;		/* Offset in bytes of am specific structure */
+	char		ps_snapshot_data[FLEXIBLE_ARRAY_MEMBER];
+}			ParallelIndexScanDescData;
+
+struct TupleTableSlot;
+
+/* Struct for storage-or-index scans of system tables */
+typedef struct SysScanDescData
+{
+	Relation	heap_rel;		/* catalog being scanned */
+	Relation	irel;			/* NULL if doing heap scan */
+	struct TableScanDescData *scan; /* only valid in storage-scan case */
+	struct IndexScanDescData *iscan;	/* only valid in index-scan case */
+	struct SnapshotData *snapshot;	/* snapshot to unregister at end of scan */
+	struct TupleTableSlot *slot;
+}			SysScanDescData;
+
+#endif							/* RELSCAN_H */