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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:15:05 +0000
commit46651ce6fe013220ed397add242004d764fc0153 (patch)
tree6e5299f990f88e60174a1d3ae6e48eedd2688b2b /src/include/access/brin_tuple.h
parentInitial commit. (diff)
downloadpostgresql-14-46651ce6fe013220ed397add242004d764fc0153.tar.xz
postgresql-14-46651ce6fe013220ed397add242004d764fc0153.zip
Adding upstream version 14.5.upstream/14.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/include/access/brin_tuple.h')
-rw-r--r--src/include/access/brin_tuple.h110
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diff --git a/src/include/access/brin_tuple.h b/src/include/access/brin_tuple.h
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+/*
+ * brin_tuple.h
+ * Declarations for dealing with BRIN-specific tuples.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/include/access/brin_tuple.h
+ */
+#ifndef BRIN_TUPLE_H
+#define BRIN_TUPLE_H
+
+#include "access/brin_internal.h"
+#include "access/tupdesc.h"
+
+/*
+ * The BRIN opclasses may register serialization callback, in case the on-disk
+ * and in-memory representations differ (e.g. for performance reasons).
+ */
+typedef void (*brin_serialize_callback_type) (BrinDesc *bdesc, Datum src, Datum *dst);
+
+/*
+ * A BRIN index stores one index tuple per page range. Each index tuple
+ * has one BrinValues struct for each indexed column; in turn, each BrinValues
+ * has (besides the null flags) an array of Datum whose size is determined by
+ * the opclass.
+ */
+typedef struct BrinValues
+{
+ AttrNumber bv_attno; /* index attribute number */
+ bool bv_hasnulls; /* are there any nulls in the page range? */
+ bool bv_allnulls; /* are all values nulls in the page range? */
+ Datum *bv_values; /* current accumulated values */
+ Datum bv_mem_value; /* expanded accumulated values */
+ MemoryContext bv_context;
+ brin_serialize_callback_type bv_serialize;
+} BrinValues;
+
+/*
+ * This struct is used to represent an in-memory index tuple. The values can
+ * only be meaningfully decoded with an appropriate BrinDesc.
+ */
+typedef struct BrinMemTuple
+{
+ bool bt_placeholder; /* this is a placeholder tuple */
+ BlockNumber bt_blkno; /* heap blkno that the tuple is for */
+ MemoryContext bt_context; /* memcxt holding the bt_columns values */
+ /* output arrays for brin_deform_tuple: */
+ Datum *bt_values; /* values array */
+ bool *bt_allnulls; /* allnulls array */
+ bool *bt_hasnulls; /* hasnulls array */
+ /* not an output array, but must be last */
+ BrinValues bt_columns[FLEXIBLE_ARRAY_MEMBER];
+} BrinMemTuple;
+
+/*
+ * An on-disk BRIN tuple. This is possibly followed by a nulls bitmask, with
+ * room for 2 null bits (two bits for each indexed column); an opclass-defined
+ * number of Datum values for each column follow.
+ */
+typedef struct BrinTuple
+{
+ /* heap block number that the tuple is for */
+ BlockNumber bt_blkno;
+
+ /* ---------------
+ * bt_info is laid out in the following fashion:
+ *
+ * 7th (high) bit: has nulls
+ * 6th bit: is placeholder tuple
+ * 5th bit: unused
+ * 4-0 bit: offset of data
+ * ---------------
+ */
+ uint8 bt_info;
+} BrinTuple;
+
+#define SizeOfBrinTuple (offsetof(BrinTuple, bt_info) + sizeof(uint8))
+
+/*
+ * bt_info manipulation macros
+ */
+#define BRIN_OFFSET_MASK 0x1F
+/* bit 0x20 is not used at present */
+#define BRIN_PLACEHOLDER_MASK 0x40
+#define BRIN_NULLS_MASK 0x80
+
+#define BrinTupleDataOffset(tup) ((Size) (((BrinTuple *) (tup))->bt_info & BRIN_OFFSET_MASK))
+#define BrinTupleHasNulls(tup) (((((BrinTuple *) (tup))->bt_info & BRIN_NULLS_MASK)) != 0)
+#define BrinTupleIsPlaceholder(tup) (((((BrinTuple *) (tup))->bt_info & BRIN_PLACEHOLDER_MASK)) != 0)
+
+
+extern BrinTuple *brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno,
+ BrinMemTuple *tuple, Size *size);
+extern BrinTuple *brin_form_placeholder_tuple(BrinDesc *brdesc,
+ BlockNumber blkno, Size *size);
+extern void brin_free_tuple(BrinTuple *tuple);
+extern BrinTuple *brin_copy_tuple(BrinTuple *tuple, Size len,
+ BrinTuple *dest, Size *destsz);
+extern bool brin_tuples_equal(const BrinTuple *a, Size alen,
+ const BrinTuple *b, Size blen);
+
+extern BrinMemTuple *brin_new_memtuple(BrinDesc *brdesc);
+extern BrinMemTuple *brin_memtuple_initialize(BrinMemTuple *dtuple,
+ BrinDesc *brdesc);
+extern BrinMemTuple *brin_deform_tuple(BrinDesc *brdesc,
+ BrinTuple *tuple, BrinMemTuple *dMemtuple);
+
+#endif /* BRIN_TUPLE_H */