init
This commit is contained in:
blue-lemon0104
808
db_include/postgres.h
Executable file
808
db_include/postgres.h
Executable file
@@ -0,0 +1,808 @@
|
||||
/*-------------------------------------------------------------------------
|
||||
*
|
||||
* postgres.h
|
||||
* Primary include file for PostgreSQL server .c files
|
||||
*
|
||||
* This should be the first file included by PostgreSQL backend modules.
|
||||
* Client-side code should include postgres_fe.h instead.
|
||||
*
|
||||
*
|
||||
* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1995, Regents of the University of California
|
||||
*
|
||||
* src/include/postgres.h
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
/*
|
||||
*----------------------------------------------------------------
|
||||
* TABLE OF CONTENTS
|
||||
*
|
||||
* When adding stuff to this file, please try to put stuff
|
||||
* into the relevant section, or add new sections as appropriate.
|
||||
*
|
||||
* section description
|
||||
* ------- ------------------------------------------------
|
||||
* 1) variable-length datatypes (TOAST support)
|
||||
* 2) Datum type + support macros
|
||||
*
|
||||
* NOTES
|
||||
*
|
||||
* In general, this file should contain declarations that are widely needed
|
||||
* in the backend environment, but are of no interest outside the backend.
|
||||
*
|
||||
* Simple type definitions live in c.h, where they are shared with
|
||||
* postgres_fe.h. We do that since those type definitions are needed by
|
||||
* frontend modules that want to deal with binary data transmission to or
|
||||
* from the backend. Type definitions in this file should be for
|
||||
* representations that never escape the backend, such as Datum or
|
||||
* TOASTed varlena objects.
|
||||
*
|
||||
*----------------------------------------------------------------
|
||||
*/
|
||||
#ifndef POSTGRES_H
|
||||
#define POSTGRES_H
|
||||
|
||||
#include "c.h"
|
||||
#include "utils/elog.h"
|
||||
#include "utils/palloc.h"
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* Section 1: variable-length datatypes (TOAST support)
|
||||
* ----------------------------------------------------------------
|
||||
*/
|
||||
|
||||
/*
|
||||
* struct varatt_external is a traditional "TOAST pointer", that is, the
|
||||
* information needed to fetch a Datum stored out-of-line in a TOAST table.
|
||||
* The data is compressed if and only if the external size stored in
|
||||
* va_extinfo is less than va_rawsize - VARHDRSZ.
|
||||
*
|
||||
* This struct must not contain any padding, because we sometimes compare
|
||||
* these pointers using memcmp.
|
||||
*
|
||||
* Note that this information is stored unaligned within actual tuples, so
|
||||
* you need to memcpy from the tuple into a local struct variable before
|
||||
* you can look at these fields! (The reason we use memcmp is to avoid
|
||||
* having to do that just to detect equality of two TOAST pointers...)
|
||||
*/
|
||||
typedef struct varatt_external
|
||||
{
|
||||
int32 va_rawsize; /* Original data size (includes header) */
|
||||
uint32 va_extinfo; /* External saved size (without header) and
|
||||
* compression method */
|
||||
Oid va_valueid; /* Unique ID of value within TOAST table */
|
||||
Oid va_toastrelid; /* RelID of TOAST table containing it */
|
||||
} varatt_external;
|
||||
|
||||
/*
|
||||
* These macros define the "saved size" portion of va_extinfo. Its remaining
|
||||
* two high-order bits identify the compression method.
|
||||
*/
|
||||
#define VARLENA_EXTSIZE_BITS 30
|
||||
#define VARLENA_EXTSIZE_MASK ((1U << VARLENA_EXTSIZE_BITS) - 1)
|
||||
|
||||
/*
|
||||
* struct varatt_indirect is a "TOAST pointer" representing an out-of-line
|
||||
* Datum that's stored in memory, not in an external toast relation.
|
||||
* The creator of such a Datum is entirely responsible that the referenced
|
||||
* storage survives for as long as referencing pointer Datums can exist.
|
||||
*
|
||||
* Note that just as for struct varatt_external, this struct is stored
|
||||
* unaligned within any containing tuple.
|
||||
*/
|
||||
typedef struct varatt_indirect
|
||||
{
|
||||
struct varlena *pointer; /* Pointer to in-memory varlena */
|
||||
} varatt_indirect;
|
||||
|
||||
/*
|
||||
* struct varatt_expanded is a "TOAST pointer" representing an out-of-line
|
||||
* Datum that is stored in memory, in some type-specific, not necessarily
|
||||
* physically contiguous format that is convenient for computation not
|
||||
* storage. APIs for this, in particular the definition of struct
|
||||
* ExpandedObjectHeader, are in src/include/utils/expandeddatum.h.
|
||||
*
|
||||
* Note that just as for struct varatt_external, this struct is stored
|
||||
* unaligned within any containing tuple.
|
||||
*/
|
||||
typedef struct ExpandedObjectHeader ExpandedObjectHeader;
|
||||
|
||||
typedef struct varatt_expanded
|
||||
{
|
||||
ExpandedObjectHeader *eohptr;
|
||||
} varatt_expanded;
|
||||
|
||||
/*
|
||||
* Type tag for the various sorts of "TOAST pointer" datums. The peculiar
|
||||
* value for VARTAG_ONDISK comes from a requirement for on-disk compatibility
|
||||
* with a previous notion that the tag field was the pointer datum's length.
|
||||
*/
|
||||
typedef enum vartag_external
|
||||
{
|
||||
VARTAG_INDIRECT = 1,
|
||||
VARTAG_EXPANDED_RO = 2,
|
||||
VARTAG_EXPANDED_RW = 3,
|
||||
VARTAG_ONDISK = 18
|
||||
} vartag_external;
|
||||
|
||||
/* this test relies on the specific tag values above */
|
||||
#define VARTAG_IS_EXPANDED(tag) \
|
||||
(((tag) & ~1) == VARTAG_EXPANDED_RO)
|
||||
|
||||
#define VARTAG_SIZE(tag) \
|
||||
((tag) == VARTAG_INDIRECT ? sizeof(varatt_indirect) : \
|
||||
VARTAG_IS_EXPANDED(tag) ? sizeof(varatt_expanded) : \
|
||||
(tag) == VARTAG_ONDISK ? sizeof(varatt_external) : \
|
||||
TrapMacro(true, "unrecognized TOAST vartag"))
|
||||
|
||||
/*
|
||||
* These structs describe the header of a varlena object that may have been
|
||||
* TOASTed. Generally, don't reference these structs directly, but use the
|
||||
* macros below.
|
||||
*
|
||||
* We use separate structs for the aligned and unaligned cases because the
|
||||
* compiler might otherwise think it could generate code that assumes
|
||||
* alignment while touching fields of a 1-byte-header varlena.
|
||||
*/
|
||||
typedef union
|
||||
{
|
||||
struct /* Normal varlena (4-byte length) */
|
||||
{
|
||||
uint32 va_header;
|
||||
char va_data[FLEXIBLE_ARRAY_MEMBER];
|
||||
} va_4byte;
|
||||
struct /* Compressed-in-line format */
|
||||
{
|
||||
uint32 va_header;
|
||||
uint32 va_tcinfo; /* Original data size (excludes header) and
|
||||
* compression method; see va_extinfo */
|
||||
char va_data[FLEXIBLE_ARRAY_MEMBER]; /* Compressed data */
|
||||
} va_compressed;
|
||||
} varattrib_4b;
|
||||
|
||||
typedef struct
|
||||
{
|
||||
uint8 va_header;
|
||||
char va_data[FLEXIBLE_ARRAY_MEMBER]; /* Data begins here */
|
||||
} varattrib_1b;
|
||||
|
||||
/* TOAST pointers are a subset of varattrib_1b with an identifying tag byte */
|
||||
typedef struct
|
||||
{
|
||||
uint8 va_header; /* Always 0x80 or 0x01 */
|
||||
uint8 va_tag; /* Type of datum */
|
||||
char va_data[FLEXIBLE_ARRAY_MEMBER]; /* Type-specific data */
|
||||
} varattrib_1b_e;
|
||||
|
||||
/*
|
||||
* Bit layouts for varlena headers on big-endian machines:
|
||||
*
|
||||
* 00xxxxxx 4-byte length word, aligned, uncompressed data (up to 1G)
|
||||
* 01xxxxxx 4-byte length word, aligned, *compressed* data (up to 1G)
|
||||
* 10000000 1-byte length word, unaligned, TOAST pointer
|
||||
* 1xxxxxxx 1-byte length word, unaligned, uncompressed data (up to 126b)
|
||||
*
|
||||
* Bit layouts for varlena headers on little-endian machines:
|
||||
*
|
||||
* xxxxxx00 4-byte length word, aligned, uncompressed data (up to 1G)
|
||||
* xxxxxx10 4-byte length word, aligned, *compressed* data (up to 1G)
|
||||
* 00000001 1-byte length word, unaligned, TOAST pointer
|
||||
* xxxxxxx1 1-byte length word, unaligned, uncompressed data (up to 126b)
|
||||
*
|
||||
* The "xxx" bits are the length field (which includes itself in all cases).
|
||||
* In the big-endian case we mask to extract the length, in the little-endian
|
||||
* case we shift. Note that in both cases the flag bits are in the physically
|
||||
* first byte. Also, it is not possible for a 1-byte length word to be zero;
|
||||
* this lets us disambiguate alignment padding bytes from the start of an
|
||||
* unaligned datum. (We now *require* pad bytes to be filled with zero!)
|
||||
*
|
||||
* In TOAST pointers the va_tag field (see varattrib_1b_e) is used to discern
|
||||
* the specific type and length of the pointer datum.
|
||||
*/
|
||||
|
||||
/*
|
||||
* Endian-dependent macros. These are considered internal --- use the
|
||||
* external macros below instead of using these directly.
|
||||
*
|
||||
* Note: IS_1B is true for external toast records but VARSIZE_1B will return 0
|
||||
* for such records. Hence you should usually check for IS_EXTERNAL before
|
||||
* checking for IS_1B.
|
||||
*/
|
||||
|
||||
#ifdef WORDS_BIGENDIAN
|
||||
|
||||
#define VARATT_IS_4B(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header & 0x80) == 0x00)
|
||||
#define VARATT_IS_4B_U(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header & 0xC0) == 0x00)
|
||||
#define VARATT_IS_4B_C(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header & 0xC0) == 0x40)
|
||||
#define VARATT_IS_1B(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header & 0x80) == 0x80)
|
||||
#define VARATT_IS_1B_E(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header) == 0x80)
|
||||
#define VARATT_NOT_PAD_BYTE(PTR) \
|
||||
(*((uint8 *) (PTR)) != 0)
|
||||
|
||||
/* VARSIZE_4B() should only be used on known-aligned data */
|
||||
#define VARSIZE_4B(PTR) \
|
||||
(((varattrib_4b *) (PTR))->va_4byte.va_header & 0x3FFFFFFF)
|
||||
#define VARSIZE_1B(PTR) \
|
||||
(((varattrib_1b *) (PTR))->va_header & 0x7F)
|
||||
#define VARTAG_1B_E(PTR) \
|
||||
(((varattrib_1b_e *) (PTR))->va_tag)
|
||||
|
||||
#define SET_VARSIZE_4B(PTR,len) \
|
||||
(((varattrib_4b *) (PTR))->va_4byte.va_header = (len) & 0x3FFFFFFF)
|
||||
#define SET_VARSIZE_4B_C(PTR,len) \
|
||||
(((varattrib_4b *) (PTR))->va_4byte.va_header = ((len) & 0x3FFFFFFF) | 0x40000000)
|
||||
#define SET_VARSIZE_1B(PTR,len) \
|
||||
(((varattrib_1b *) (PTR))->va_header = (len) | 0x80)
|
||||
#define SET_VARTAG_1B_E(PTR,tag) \
|
||||
(((varattrib_1b_e *) (PTR))->va_header = 0x80, \
|
||||
((varattrib_1b_e *) (PTR))->va_tag = (tag))
|
||||
|
||||
#else /* !WORDS_BIGENDIAN */
|
||||
|
||||
#define VARATT_IS_4B(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header & 0x01) == 0x00)
|
||||
#define VARATT_IS_4B_U(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header & 0x03) == 0x00)
|
||||
#define VARATT_IS_4B_C(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header & 0x03) == 0x02)
|
||||
#define VARATT_IS_1B(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header & 0x01) == 0x01)
|
||||
#define VARATT_IS_1B_E(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header) == 0x01)
|
||||
#define VARATT_NOT_PAD_BYTE(PTR) \
|
||||
(*((uint8 *) (PTR)) != 0)
|
||||
|
||||
/* VARSIZE_4B() should only be used on known-aligned data */
|
||||
#define VARSIZE_4B(PTR) \
|
||||
((((varattrib_4b *) (PTR))->va_4byte.va_header >> 2) & 0x3FFFFFFF)
|
||||
#define VARSIZE_1B(PTR) \
|
||||
((((varattrib_1b *) (PTR))->va_header >> 1) & 0x7F)
|
||||
#define VARTAG_1B_E(PTR) \
|
||||
(((varattrib_1b_e *) (PTR))->va_tag)
|
||||
|
||||
#define SET_VARSIZE_4B(PTR,len) \
|
||||
(((varattrib_4b *) (PTR))->va_4byte.va_header = (((uint32) (len)) << 2))
|
||||
#define SET_VARSIZE_4B_C(PTR,len) \
|
||||
(((varattrib_4b *) (PTR))->va_4byte.va_header = (((uint32) (len)) << 2) | 0x02)
|
||||
#define SET_VARSIZE_1B(PTR,len) \
|
||||
(((varattrib_1b *) (PTR))->va_header = (((uint8) (len)) << 1) | 0x01)
|
||||
#define SET_VARTAG_1B_E(PTR,tag) \
|
||||
(((varattrib_1b_e *) (PTR))->va_header = 0x01, \
|
||||
((varattrib_1b_e *) (PTR))->va_tag = (tag))
|
||||
|
||||
#endif /* WORDS_BIGENDIAN */
|
||||
|
||||
#define VARDATA_4B(PTR) (((varattrib_4b *) (PTR))->va_4byte.va_data)
|
||||
#define VARDATA_4B_C(PTR) (((varattrib_4b *) (PTR))->va_compressed.va_data)
|
||||
#define VARDATA_1B(PTR) (((varattrib_1b *) (PTR))->va_data)
|
||||
#define VARDATA_1B_E(PTR) (((varattrib_1b_e *) (PTR))->va_data)
|
||||
|
||||
/*
|
||||
* Externally visible TOAST macros begin here.
|
||||
*/
|
||||
|
||||
#define VARHDRSZ_EXTERNAL offsetof(varattrib_1b_e, va_data)
|
||||
#define VARHDRSZ_COMPRESSED offsetof(varattrib_4b, va_compressed.va_data)
|
||||
#define VARHDRSZ_SHORT offsetof(varattrib_1b, va_data)
|
||||
|
||||
#define VARATT_SHORT_MAX 0x7F
|
||||
#define VARATT_CAN_MAKE_SHORT(PTR) \
|
||||
(VARATT_IS_4B_U(PTR) && \
|
||||
(VARSIZE(PTR) - VARHDRSZ + VARHDRSZ_SHORT) <= VARATT_SHORT_MAX)
|
||||
#define VARATT_CONVERTED_SHORT_SIZE(PTR) \
|
||||
(VARSIZE(PTR) - VARHDRSZ + VARHDRSZ_SHORT)
|
||||
|
||||
/*
|
||||
* In consumers oblivious to data alignment, call PG_DETOAST_DATUM_PACKED(),
|
||||
* VARDATA_ANY(), VARSIZE_ANY() and VARSIZE_ANY_EXHDR(). Elsewhere, call
|
||||
* PG_DETOAST_DATUM(), VARDATA() and VARSIZE(). Directly fetching an int16,
|
||||
* int32 or wider field in the struct representing the datum layout requires
|
||||
* aligned data. memcpy() is alignment-oblivious, as are most operations on
|
||||
* datatypes, such as text, whose layout struct contains only char fields.
|
||||
*
|
||||
* Code assembling a new datum should call VARDATA() and SET_VARSIZE().
|
||||
* (Datums begin life untoasted.)
|
||||
*
|
||||
* Other macros here should usually be used only by tuple assembly/disassembly
|
||||
* code and code that specifically wants to work with still-toasted Datums.
|
||||
*/
|
||||
#define VARDATA(PTR) VARDATA_4B(PTR)
|
||||
#define VARSIZE(PTR) VARSIZE_4B(PTR)
|
||||
|
||||
#define VARSIZE_SHORT(PTR) VARSIZE_1B(PTR)
|
||||
#define VARDATA_SHORT(PTR) VARDATA_1B(PTR)
|
||||
|
||||
#define VARTAG_EXTERNAL(PTR) VARTAG_1B_E(PTR)
|
||||
#define VARSIZE_EXTERNAL(PTR) (VARHDRSZ_EXTERNAL + VARTAG_SIZE(VARTAG_EXTERNAL(PTR)))
|
||||
#define VARDATA_EXTERNAL(PTR) VARDATA_1B_E(PTR)
|
||||
|
||||
#define VARATT_IS_COMPRESSED(PTR) VARATT_IS_4B_C(PTR)
|
||||
#define VARATT_IS_EXTERNAL(PTR) VARATT_IS_1B_E(PTR)
|
||||
#define VARATT_IS_EXTERNAL_ONDISK(PTR) \
|
||||
(VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_ONDISK)
|
||||
#define VARATT_IS_EXTERNAL_INDIRECT(PTR) \
|
||||
(VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_INDIRECT)
|
||||
#define VARATT_IS_EXTERNAL_EXPANDED_RO(PTR) \
|
||||
(VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_EXPANDED_RO)
|
||||
#define VARATT_IS_EXTERNAL_EXPANDED_RW(PTR) \
|
||||
(VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_EXPANDED_RW)
|
||||
#define VARATT_IS_EXTERNAL_EXPANDED(PTR) \
|
||||
(VARATT_IS_EXTERNAL(PTR) && VARTAG_IS_EXPANDED(VARTAG_EXTERNAL(PTR)))
|
||||
#define VARATT_IS_EXTERNAL_NON_EXPANDED(PTR) \
|
||||
(VARATT_IS_EXTERNAL(PTR) && !VARTAG_IS_EXPANDED(VARTAG_EXTERNAL(PTR)))
|
||||
#define VARATT_IS_SHORT(PTR) VARATT_IS_1B(PTR)
|
||||
#define VARATT_IS_EXTENDED(PTR) (!VARATT_IS_4B_U(PTR))
|
||||
|
||||
#define SET_VARSIZE(PTR, len) SET_VARSIZE_4B(PTR, len)
|
||||
#define SET_VARSIZE_SHORT(PTR, len) SET_VARSIZE_1B(PTR, len)
|
||||
#define SET_VARSIZE_COMPRESSED(PTR, len) SET_VARSIZE_4B_C(PTR, len)
|
||||
|
||||
#define SET_VARTAG_EXTERNAL(PTR, tag) SET_VARTAG_1B_E(PTR, tag)
|
||||
|
||||
#define VARSIZE_ANY(PTR) \
|
||||
(VARATT_IS_1B_E(PTR) ? VARSIZE_EXTERNAL(PTR) : \
|
||||
(VARATT_IS_1B(PTR) ? VARSIZE_1B(PTR) : \
|
||||
VARSIZE_4B(PTR)))
|
||||
|
||||
/* Size of a varlena data, excluding header */
|
||||
#define VARSIZE_ANY_EXHDR(PTR) \
|
||||
(VARATT_IS_1B_E(PTR) ? VARSIZE_EXTERNAL(PTR)-VARHDRSZ_EXTERNAL : \
|
||||
(VARATT_IS_1B(PTR) ? VARSIZE_1B(PTR)-VARHDRSZ_SHORT : \
|
||||
VARSIZE_4B(PTR)-VARHDRSZ))
|
||||
|
||||
/* caution: this will not work on an external or compressed-in-line Datum */
|
||||
/* caution: this will return a possibly unaligned pointer */
|
||||
#define VARDATA_ANY(PTR) \
|
||||
(VARATT_IS_1B(PTR) ? VARDATA_1B(PTR) : VARDATA_4B(PTR))
|
||||
|
||||
/* Decompressed size and compression method of a compressed-in-line Datum */
|
||||
#define VARDATA_COMPRESSED_GET_EXTSIZE(PTR) \
|
||||
(((varattrib_4b *) (PTR))->va_compressed.va_tcinfo & VARLENA_EXTSIZE_MASK)
|
||||
#define VARDATA_COMPRESSED_GET_COMPRESS_METHOD(PTR) \
|
||||
(((varattrib_4b *) (PTR))->va_compressed.va_tcinfo >> VARLENA_EXTSIZE_BITS)
|
||||
|
||||
/* Same for external Datums; but note argument is a struct varatt_external */
|
||||
#define VARATT_EXTERNAL_GET_EXTSIZE(toast_pointer) \
|
||||
((toast_pointer).va_extinfo & VARLENA_EXTSIZE_MASK)
|
||||
#define VARATT_EXTERNAL_GET_COMPRESS_METHOD(toast_pointer) \
|
||||
((toast_pointer).va_extinfo >> VARLENA_EXTSIZE_BITS)
|
||||
|
||||
#define VARATT_EXTERNAL_SET_SIZE_AND_COMPRESS_METHOD(toast_pointer, len, cm) \
|
||||
do { \
|
||||
Assert((cm) == TOAST_PGLZ_COMPRESSION_ID || \
|
||||
(cm) == TOAST_LZ4_COMPRESSION_ID); \
|
||||
((toast_pointer).va_extinfo = \
|
||||
(len) | ((uint32) (cm) << VARLENA_EXTSIZE_BITS)); \
|
||||
} while (0)
|
||||
|
||||
/*
|
||||
* Testing whether an externally-stored value is compressed now requires
|
||||
* comparing size stored in va_extinfo (the actual length of the external data)
|
||||
* to rawsize (the original uncompressed datum's size). The latter includes
|
||||
* VARHDRSZ overhead, the former doesn't. We never use compression unless it
|
||||
* actually saves space, so we expect either equality or less-than.
|
||||
*/
|
||||
#define VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer) \
|
||||
(VARATT_EXTERNAL_GET_EXTSIZE(toast_pointer) < \
|
||||
(toast_pointer).va_rawsize - VARHDRSZ)
|
||||
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* Section 2: Datum type + support macros
|
||||
* ----------------------------------------------------------------
|
||||
*/
|
||||
|
||||
/*
|
||||
* A Datum contains either a value of a pass-by-value type or a pointer to a
|
||||
* value of a pass-by-reference type. Therefore, we require:
|
||||
*
|
||||
* sizeof(Datum) == sizeof(void *) == 4 or 8
|
||||
*
|
||||
* The macros below and the analogous macros for other types should be used to
|
||||
* convert between a Datum and the appropriate C type.
|
||||
*/
|
||||
|
||||
typedef uintptr_t Datum;
|
||||
|
||||
/*
|
||||
* A NullableDatum is used in places where both a Datum and its nullness needs
|
||||
* to be stored. This can be more efficient than storing datums and nullness
|
||||
* in separate arrays, due to better spatial locality, even if more space may
|
||||
* be wasted due to padding.
|
||||
*/
|
||||
typedef struct NullableDatum
|
||||
{
|
||||
#define FIELDNO_NULLABLE_DATUM_DATUM 0
|
||||
Datum value;
|
||||
#define FIELDNO_NULLABLE_DATUM_ISNULL 1
|
||||
bool isnull;
|
||||
/* due to alignment padding this could be used for flags for free */
|
||||
} NullableDatum;
|
||||
|
||||
#define SIZEOF_DATUM SIZEOF_VOID_P
|
||||
|
||||
/*
|
||||
* DatumGetBool
|
||||
* Returns boolean value of a datum.
|
||||
*
|
||||
* Note: any nonzero value will be considered true.
|
||||
*/
|
||||
|
||||
#define DatumGetBool(X) ((bool) ((X) != 0))
|
||||
|
||||
/*
|
||||
* BoolGetDatum
|
||||
* Returns datum representation for a boolean.
|
||||
*
|
||||
* Note: any nonzero value will be considered true.
|
||||
*/
|
||||
|
||||
#define BoolGetDatum(X) ((Datum) ((X) ? 1 : 0))
|
||||
|
||||
/*
|
||||
* DatumGetChar
|
||||
* Returns character value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetChar(X) ((char) (X))
|
||||
|
||||
/*
|
||||
* CharGetDatum
|
||||
* Returns datum representation for a character.
|
||||
*/
|
||||
|
||||
#define CharGetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* Int8GetDatum
|
||||
* Returns datum representation for an 8-bit integer.
|
||||
*/
|
||||
|
||||
#define Int8GetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetUInt8
|
||||
* Returns 8-bit unsigned integer value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetUInt8(X) ((uint8) (X))
|
||||
|
||||
/*
|
||||
* UInt8GetDatum
|
||||
* Returns datum representation for an 8-bit unsigned integer.
|
||||
*/
|
||||
|
||||
#define UInt8GetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetInt16
|
||||
* Returns 16-bit integer value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetInt16(X) ((int16) (X))
|
||||
|
||||
/*
|
||||
* Int16GetDatum
|
||||
* Returns datum representation for a 16-bit integer.
|
||||
*/
|
||||
|
||||
#define Int16GetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetUInt16
|
||||
* Returns 16-bit unsigned integer value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetUInt16(X) ((uint16) (X))
|
||||
|
||||
/*
|
||||
* UInt16GetDatum
|
||||
* Returns datum representation for a 16-bit unsigned integer.
|
||||
*/
|
||||
|
||||
#define UInt16GetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetInt32
|
||||
* Returns 32-bit integer value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetInt32(X) ((int32) (X))
|
||||
|
||||
/*
|
||||
* Int32GetDatum
|
||||
* Returns datum representation for a 32-bit integer.
|
||||
*/
|
||||
|
||||
#define Int32GetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetUInt32
|
||||
* Returns 32-bit unsigned integer value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetUInt32(X) ((uint32) (X))
|
||||
|
||||
/*
|
||||
* UInt32GetDatum
|
||||
* Returns datum representation for a 32-bit unsigned integer.
|
||||
*/
|
||||
|
||||
#define UInt32GetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetObjectId
|
||||
* Returns object identifier value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetObjectId(X) ((Oid) (X))
|
||||
|
||||
/*
|
||||
* ObjectIdGetDatum
|
||||
* Returns datum representation for an object identifier.
|
||||
*/
|
||||
|
||||
#define ObjectIdGetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetTransactionId
|
||||
* Returns transaction identifier value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetTransactionId(X) ((TransactionId) (X))
|
||||
|
||||
/*
|
||||
* TransactionIdGetDatum
|
||||
* Returns datum representation for a transaction identifier.
|
||||
*/
|
||||
|
||||
#define TransactionIdGetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* MultiXactIdGetDatum
|
||||
* Returns datum representation for a multixact identifier.
|
||||
*/
|
||||
|
||||
#define MultiXactIdGetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetCommandId
|
||||
* Returns command identifier value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetCommandId(X) ((CommandId) (X))
|
||||
|
||||
/*
|
||||
* CommandIdGetDatum
|
||||
* Returns datum representation for a command identifier.
|
||||
*/
|
||||
|
||||
#define CommandIdGetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetPointer
|
||||
* Returns pointer value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetPointer(X) ((Pointer) (X))
|
||||
|
||||
/*
|
||||
* PointerGetDatum
|
||||
* Returns datum representation for a pointer.
|
||||
*/
|
||||
|
||||
#define PointerGetDatum(X) ((Datum) (X))
|
||||
|
||||
/*
|
||||
* DatumGetCString
|
||||
* Returns C string (null-terminated string) value of a datum.
|
||||
*
|
||||
* Note: C string is not a full-fledged Postgres type at present,
|
||||
* but type input functions use this conversion for their inputs.
|
||||
*/
|
||||
|
||||
#define DatumGetCString(X) ((char *) DatumGetPointer(X))
|
||||
|
||||
/*
|
||||
* CStringGetDatum
|
||||
* Returns datum representation for a C string (null-terminated string).
|
||||
*
|
||||
* Note: C string is not a full-fledged Postgres type at present,
|
||||
* but type output functions use this conversion for their outputs.
|
||||
* Note: CString is pass-by-reference; caller must ensure the pointed-to
|
||||
* value has adequate lifetime.
|
||||
*/
|
||||
|
||||
#define CStringGetDatum(X) PointerGetDatum(X)
|
||||
|
||||
/*
|
||||
* DatumGetName
|
||||
* Returns name value of a datum.
|
||||
*/
|
||||
|
||||
#define DatumGetName(X) ((Name) DatumGetPointer(X))
|
||||
|
||||
/*
|
||||
* NameGetDatum
|
||||
* Returns datum representation for a name.
|
||||
*
|
||||
* Note: Name is pass-by-reference; caller must ensure the pointed-to
|
||||
* value has adequate lifetime.
|
||||
*/
|
||||
|
||||
#define NameGetDatum(X) CStringGetDatum(NameStr(*(X)))
|
||||
|
||||
/*
|
||||
* DatumGetInt64
|
||||
* Returns 64-bit integer value of a datum.
|
||||
*
|
||||
* Note: this macro hides whether int64 is pass by value or by reference.
|
||||
*/
|
||||
|
||||
#ifdef USE_FLOAT8_BYVAL
|
||||
#define DatumGetInt64(X) ((int64) (X))
|
||||
#else
|
||||
#define DatumGetInt64(X) (* ((int64 *) DatumGetPointer(X)))
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Int64GetDatum
|
||||
* Returns datum representation for a 64-bit integer.
|
||||
*
|
||||
* Note: if int64 is pass by reference, this function returns a reference
|
||||
* to palloc'd space.
|
||||
*/
|
||||
|
||||
#ifdef USE_FLOAT8_BYVAL
|
||||
#define Int64GetDatum(X) ((Datum) (X))
|
||||
#else
|
||||
extern Datum Int64GetDatum(int64 X);
|
||||
#endif
|
||||
|
||||
/*
|
||||
* DatumGetUInt64
|
||||
* Returns 64-bit unsigned integer value of a datum.
|
||||
*
|
||||
* Note: this macro hides whether int64 is pass by value or by reference.
|
||||
*/
|
||||
|
||||
#ifdef USE_FLOAT8_BYVAL
|
||||
#define DatumGetUInt64(X) ((uint64) (X))
|
||||
#else
|
||||
#define DatumGetUInt64(X) (* ((uint64 *) DatumGetPointer(X)))
|
||||
#endif
|
||||
|
||||
/*
|
||||
* UInt64GetDatum
|
||||
* Returns datum representation for a 64-bit unsigned integer.
|
||||
*
|
||||
* Note: if int64 is pass by reference, this function returns a reference
|
||||
* to palloc'd space.
|
||||
*/
|
||||
|
||||
#ifdef USE_FLOAT8_BYVAL
|
||||
#define UInt64GetDatum(X) ((Datum) (X))
|
||||
#else
|
||||
#define UInt64GetDatum(X) Int64GetDatum((int64) (X))
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Float <-> Datum conversions
|
||||
*
|
||||
* These have to be implemented as inline functions rather than macros, when
|
||||
* passing by value, because many machines pass int and float function
|
||||
* parameters/results differently; so we need to play weird games with unions.
|
||||
*/
|
||||
|
||||
/*
|
||||
* DatumGetFloat4
|
||||
* Returns 4-byte floating point value of a datum.
|
||||
*/
|
||||
static inline float4
|
||||
DatumGetFloat4(Datum X)
|
||||
{
|
||||
union
|
||||
{
|
||||
int32 value;
|
||||
float4 retval;
|
||||
} myunion;
|
||||
|
||||
myunion.value = DatumGetInt32(X);
|
||||
return myunion.retval;
|
||||
}
|
||||
|
||||
/*
|
||||
* Float4GetDatum
|
||||
* Returns datum representation for a 4-byte floating point number.
|
||||
*/
|
||||
static inline Datum
|
||||
Float4GetDatum(float4 X)
|
||||
{
|
||||
union
|
||||
{
|
||||
float4 value;
|
||||
int32 retval;
|
||||
} myunion;
|
||||
|
||||
myunion.value = X;
|
||||
return Int32GetDatum(myunion.retval);
|
||||
}
|
||||
|
||||
/*
|
||||
* DatumGetFloat8
|
||||
* Returns 8-byte floating point value of a datum.
|
||||
*
|
||||
* Note: this macro hides whether float8 is pass by value or by reference.
|
||||
*/
|
||||
|
||||
#ifdef USE_FLOAT8_BYVAL
|
||||
static inline float8
|
||||
DatumGetFloat8(Datum X)
|
||||
{
|
||||
union
|
||||
{
|
||||
int64 value;
|
||||
float8 retval;
|
||||
} myunion;
|
||||
|
||||
myunion.value = DatumGetInt64(X);
|
||||
return myunion.retval;
|
||||
}
|
||||
#else
|
||||
#define DatumGetFloat8(X) (* ((float8 *) DatumGetPointer(X)))
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Float8GetDatum
|
||||
* Returns datum representation for an 8-byte floating point number.
|
||||
*
|
||||
* Note: if float8 is pass by reference, this function returns a reference
|
||||
* to palloc'd space.
|
||||
*/
|
||||
|
||||
#ifdef USE_FLOAT8_BYVAL
|
||||
static inline Datum
|
||||
Float8GetDatum(float8 X)
|
||||
{
|
||||
union
|
||||
{
|
||||
float8 value;
|
||||
int64 retval;
|
||||
} myunion;
|
||||
|
||||
myunion.value = X;
|
||||
return Int64GetDatum(myunion.retval);
|
||||
}
|
||||
#else
|
||||
extern Datum Float8GetDatum(float8 X);
|
||||
#endif
|
||||
|
||||
|
||||
/*
|
||||
* Int64GetDatumFast
|
||||
* Float8GetDatumFast
|
||||
*
|
||||
* These macros are intended to allow writing code that does not depend on
|
||||
* whether int64 and float8 are pass-by-reference types, while not
|
||||
* sacrificing performance when they are. The argument must be a variable
|
||||
* that will exist and have the same value for as long as the Datum is needed.
|
||||
* In the pass-by-ref case, the address of the variable is taken to use as
|
||||
* the Datum. In the pass-by-val case, these will be the same as the non-Fast
|
||||
* macros.
|
||||
*/
|
||||
|
||||
#ifdef USE_FLOAT8_BYVAL
|
||||
#define Int64GetDatumFast(X) Int64GetDatum(X)
|
||||
#define Float8GetDatumFast(X) Float8GetDatum(X)
|
||||
#else
|
||||
#define Int64GetDatumFast(X) PointerGetDatum(&(X))
|
||||
#define Float8GetDatumFast(X) PointerGetDatum(&(X))
|
||||
#endif
|
||||
|
||||
#endif /* POSTGRES_H */
|
||||
Reference in New Issue
Block a user