1
/*-------------------------------------------------------------------------
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* Primary include file for PostgreSQL server .c files
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* This should be the first file included by PostgreSQL backend modules.
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* Client-side code should include postgres_fe.h instead.
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* Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
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* Portions Copyright (c) 1995, Regents of the University of California
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* src/include/postgres.h
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*-------------------------------------------------------------------------
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*----------------------------------------------------------------
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* When adding stuff to this file, please try to put stuff
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* into the relevant section, or add new sections as appropriate.
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* ------- ------------------------------------------------
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* 1) variable-length datatypes (TOAST support)
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* 2) datum type + support macros
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* 3) exception handling definitions
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* In general, this file should contain declarations that are widely needed
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* in the backend environment, but are of no interest outside the backend.
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* Simple type definitions live in c.h, where they are shared with
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* postgres_fe.h. We do that since those type definitions are needed by
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* frontend modules that want to deal with binary data transmission to or
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* from the backend. Type definitions in this file should be for
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* representations that never escape the backend, such as Datum or
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* TOASTed varlena objects.
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*----------------------------------------------------------------
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#include "utils/elog.h"
49
#include "utils/palloc.h"
51
/* ----------------------------------------------------------------
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* Section 1: variable-length datatypes (TOAST support)
53
* ----------------------------------------------------------------
57
* struct varatt_external is a "TOAST pointer", that is, the information
58
* needed to fetch a stored-out-of-line Datum. The data is compressed
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* if and only if va_extsize < va_rawsize - VARHDRSZ. This struct must not
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* contain any padding, because we sometimes compare pointers using memcmp.
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* Note that this information is stored unaligned within actual tuples, so
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* you need to memcpy from the tuple into a local struct variable before
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* you can look at these fields! (The reason we use memcmp is to avoid
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* having to do that just to detect equality of two TOAST pointers...)
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struct varatt_external
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int32 va_rawsize; /* Original data size (includes header) */
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int32 va_extsize; /* External saved size (doesn't) */
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Oid va_valueid; /* Unique ID of value within TOAST table */
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Oid va_toastrelid; /* RelID of TOAST table containing it */
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* These structs describe the header of a varlena object that may have been
77
* TOASTed. Generally, don't reference these structs directly, but use the
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* We use separate structs for the aligned and unaligned cases because the
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* compiler might otherwise think it could generate code that assumes
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* alignment while touching fields of a 1-byte-header varlena.
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struct /* Normal varlena (4-byte length) */
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struct /* Compressed-in-line format */
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uint32 va_rawsize; /* Original data size (excludes header) */
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char va_data[1]; /* Compressed data */
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char va_data[1]; /* Data begins here */
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uint8 va_header; /* Always 0x80 or 0x01 */
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uint8 va_len_1be; /* Physical length of datum */
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char va_data[1]; /* Data (for now always a TOAST pointer) */
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* Bit layouts for varlena headers on big-endian machines:
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* 00xxxxxx 4-byte length word, aligned, uncompressed data (up to 1G)
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* 01xxxxxx 4-byte length word, aligned, *compressed* data (up to 1G)
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* 10000000 1-byte length word, unaligned, TOAST pointer
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* 1xxxxxxx 1-byte length word, unaligned, uncompressed data (up to 126b)
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* Bit layouts for varlena headers on little-endian machines:
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* xxxxxx00 4-byte length word, aligned, uncompressed data (up to 1G)
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* xxxxxx10 4-byte length word, aligned, *compressed* data (up to 1G)
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* 00000001 1-byte length word, unaligned, TOAST pointer
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* xxxxxxx1 1-byte length word, unaligned, uncompressed data (up to 126b)
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* The "xxx" bits are the length field (which includes itself in all cases).
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* In the big-endian case we mask to extract the length, in the little-endian
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* case we shift. Note that in both cases the flag bits are in the physically
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* first byte. Also, it is not possible for a 1-byte length word to be zero;
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* this lets us disambiguate alignment padding bytes from the start of an
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* unaligned datum. (We now *require* pad bytes to be filled with zero!)
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* Endian-dependent macros. These are considered internal --- use the
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* external macros below instead of using these directly.
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* Note: IS_1B is true for external toast records but VARSIZE_1B will return 0
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* for such records. Hence you should usually check for IS_EXTERNAL before
141
* checking for IS_1B.
144
#ifdef WORDS_BIGENDIAN
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#define VARATT_IS_4B(PTR) \
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((((varattrib_1b *) (PTR))->va_header & 0x80) == 0x00)
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#define VARATT_IS_4B_U(PTR) \
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((((varattrib_1b *) (PTR))->va_header & 0xC0) == 0x00)
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#define VARATT_IS_4B_C(PTR) \
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((((varattrib_1b *) (PTR))->va_header & 0xC0) == 0x40)
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#define VARATT_IS_1B(PTR) \
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((((varattrib_1b *) (PTR))->va_header & 0x80) == 0x80)
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#define VARATT_IS_1B_E(PTR) \
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((((varattrib_1b *) (PTR))->va_header) == 0x80)
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#define VARATT_NOT_PAD_BYTE(PTR) \
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(*((uint8 *) (PTR)) != 0)
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/* VARSIZE_4B() should only be used on known-aligned data */
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#define VARSIZE_4B(PTR) \
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(((varattrib_4b *) (PTR))->va_4byte.va_header & 0x3FFFFFFF)
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#define VARSIZE_1B(PTR) \
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(((varattrib_1b *) (PTR))->va_header & 0x7F)
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#define VARSIZE_1B_E(PTR) \
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(((varattrib_1b_e *) (PTR))->va_len_1be)
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#define SET_VARSIZE_4B(PTR,len) \
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(((varattrib_4b *) (PTR))->va_4byte.va_header = (len) & 0x3FFFFFFF)
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#define SET_VARSIZE_4B_C(PTR,len) \
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(((varattrib_4b *) (PTR))->va_4byte.va_header = ((len) & 0x3FFFFFFF) | 0x40000000)
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#define SET_VARSIZE_1B(PTR,len) \
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(((varattrib_1b *) (PTR))->va_header = (len) | 0x80)
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#define SET_VARSIZE_1B_E(PTR,len) \
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(((varattrib_1b_e *) (PTR))->va_header = 0x80, \
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((varattrib_1b_e *) (PTR))->va_len_1be = (len))
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#else /* !WORDS_BIGENDIAN */
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#define VARATT_IS_4B(PTR) \
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((((varattrib_1b *) (PTR))->va_header & 0x01) == 0x00)
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#define VARATT_IS_4B_U(PTR) \
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((((varattrib_1b *) (PTR))->va_header & 0x03) == 0x00)
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#define VARATT_IS_4B_C(PTR) \
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((((varattrib_1b *) (PTR))->va_header & 0x03) == 0x02)
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#define VARATT_IS_1B(PTR) \
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((((varattrib_1b *) (PTR))->va_header & 0x01) == 0x01)
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#define VARATT_IS_1B_E(PTR) \
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((((varattrib_1b *) (PTR))->va_header) == 0x01)
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#define VARATT_NOT_PAD_BYTE(PTR) \
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(*((uint8 *) (PTR)) != 0)
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/* VARSIZE_4B() should only be used on known-aligned data */
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#define VARSIZE_4B(PTR) \
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((((varattrib_4b *) (PTR))->va_4byte.va_header >> 2) & 0x3FFFFFFF)
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#define VARSIZE_1B(PTR) \
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((((varattrib_1b *) (PTR))->va_header >> 1) & 0x7F)
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#define VARSIZE_1B_E(PTR) \
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(((varattrib_1b_e *) (PTR))->va_len_1be)
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#define SET_VARSIZE_4B(PTR,len) \
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(((varattrib_4b *) (PTR))->va_4byte.va_header = (((uint32) (len)) << 2))
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#define SET_VARSIZE_4B_C(PTR,len) \
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(((varattrib_4b *) (PTR))->va_4byte.va_header = (((uint32) (len)) << 2) | 0x02)
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#define SET_VARSIZE_1B(PTR,len) \
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(((varattrib_1b *) (PTR))->va_header = (((uint8) (len)) << 1) | 0x01)
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#define SET_VARSIZE_1B_E(PTR,len) \
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(((varattrib_1b_e *) (PTR))->va_header = 0x01, \
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((varattrib_1b_e *) (PTR))->va_len_1be = (len))
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#endif /* WORDS_BIGENDIAN */
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#define VARHDRSZ_SHORT 1
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#define VARATT_SHORT_MAX 0x7F
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#define VARATT_CAN_MAKE_SHORT(PTR) \
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(VARATT_IS_4B_U(PTR) && \
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(VARSIZE(PTR) - VARHDRSZ + VARHDRSZ_SHORT) <= VARATT_SHORT_MAX)
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#define VARATT_CONVERTED_SHORT_SIZE(PTR) \
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(VARSIZE(PTR) - VARHDRSZ + VARHDRSZ_SHORT)
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#define VARHDRSZ_EXTERNAL 2
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#define VARDATA_4B(PTR) (((varattrib_4b *) (PTR))->va_4byte.va_data)
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#define VARDATA_4B_C(PTR) (((varattrib_4b *) (PTR))->va_compressed.va_data)
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#define VARDATA_1B(PTR) (((varattrib_1b *) (PTR))->va_data)
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#define VARDATA_1B_E(PTR) (((varattrib_1b_e *) (PTR))->va_data)
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#define VARRAWSIZE_4B_C(PTR) \
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(((varattrib_4b *) (PTR))->va_compressed.va_rawsize)
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/* Externally visible macros */
231
* VARDATA, VARSIZE, and SET_VARSIZE are the recommended API for most code
232
* for varlena datatypes. Note that they only work on untoasted,
233
* 4-byte-header Datums!
235
* Code that wants to use 1-byte-header values without detoasting should
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* use VARSIZE_ANY/VARSIZE_ANY_EXHDR/VARDATA_ANY. The other macros here
237
* should usually be used only by tuple assembly/disassembly code and
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* code that specifically wants to work with still-toasted Datums.
240
* WARNING: It is only safe to use VARDATA_ANY() -- typically with
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* PG_DETOAST_DATUM_PACKED() -- if you really don't care about the alignment.
242
* Either because you're working with something like text where the alignment
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* doesn't matter or because you're not going to access its constituent parts
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* and just use things like memcpy on it anyways.
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#define VARDATA(PTR) VARDATA_4B(PTR)
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#define VARSIZE(PTR) VARSIZE_4B(PTR)
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#define VARSIZE_SHORT(PTR) VARSIZE_1B(PTR)
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#define VARDATA_SHORT(PTR) VARDATA_1B(PTR)
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#define VARSIZE_EXTERNAL(PTR) VARSIZE_1B_E(PTR)
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#define VARDATA_EXTERNAL(PTR) VARDATA_1B_E(PTR)
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#define VARATT_IS_COMPRESSED(PTR) VARATT_IS_4B_C(PTR)
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#define VARATT_IS_EXTERNAL(PTR) VARATT_IS_1B_E(PTR)
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#define VARATT_IS_SHORT(PTR) VARATT_IS_1B(PTR)
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#define VARATT_IS_EXTENDED(PTR) (!VARATT_IS_4B_U(PTR))
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#define SET_VARSIZE(PTR, len) SET_VARSIZE_4B(PTR, len)
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#define SET_VARSIZE_SHORT(PTR, len) SET_VARSIZE_1B(PTR, len)
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#define SET_VARSIZE_COMPRESSED(PTR, len) SET_VARSIZE_4B_C(PTR, len)
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#define SET_VARSIZE_EXTERNAL(PTR, len) SET_VARSIZE_1B_E(PTR, len)
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#define VARSIZE_ANY(PTR) \
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(VARATT_IS_1B_E(PTR) ? VARSIZE_1B_E(PTR) : \
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(VARATT_IS_1B(PTR) ? VARSIZE_1B(PTR) : \
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#define VARSIZE_ANY_EXHDR(PTR) \
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(VARATT_IS_1B_E(PTR) ? VARSIZE_1B_E(PTR)-VARHDRSZ_EXTERNAL : \
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(VARATT_IS_1B(PTR) ? VARSIZE_1B(PTR)-VARHDRSZ_SHORT : \
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VARSIZE_4B(PTR)-VARHDRSZ))
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/* caution: this will not work on an external or compressed-in-line Datum */
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/* caution: this will return a possibly unaligned pointer */
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#define VARDATA_ANY(PTR) \
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(VARATT_IS_1B(PTR) ? VARDATA_1B(PTR) : VARDATA_4B(PTR))
281
/* ----------------------------------------------------------------
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* Section 2: datum type + support macros
283
* ----------------------------------------------------------------
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* Postgres makes the following assumptions about datatype sizes:
290
* sizeof(Datum) == sizeof(void *) == 4 or 8
294
* When a type narrower than Datum is stored in a Datum, we place it in the
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* low-order bits and are careful that the DatumGetXXX macro for it discards
296
* the unused high-order bits (as opposed to, say, assuming they are zero).
297
* This is needed to support old-style user-defined functions, since depending
298
* on architecture and compiler, the return value of a function returning char
299
* or short may contain garbage when called as if it returned Datum.
302
typedef uintptr_t Datum;
304
#define SIZEOF_DATUM SIZEOF_VOID_P
306
typedef Datum *DatumPtr;
308
#define GET_1_BYTE(datum) (((Datum) (datum)) & 0x000000ff)
309
#define GET_2_BYTES(datum) (((Datum) (datum)) & 0x0000ffff)
310
#define GET_4_BYTES(datum) (((Datum) (datum)) & 0xffffffff)
311
#if SIZEOF_DATUM == 8
312
#define GET_8_BYTES(datum) ((Datum) (datum))
314
#define SET_1_BYTE(value) (((Datum) (value)) & 0x000000ff)
315
#define SET_2_BYTES(value) (((Datum) (value)) & 0x0000ffff)
316
#define SET_4_BYTES(value) (((Datum) (value)) & 0xffffffff)
317
#if SIZEOF_DATUM == 8
318
#define SET_8_BYTES(value) ((Datum) (value))
323
* Returns boolean value of a datum.
325
* Note: any nonzero value will be considered TRUE, but we ignore bits to
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* the left of the width of bool, per comment above.
329
#define DatumGetBool(X) ((bool) (((bool) (X)) != 0))
333
* Returns datum representation for a boolean.
335
* Note: any nonzero value will be considered TRUE.
338
#define BoolGetDatum(X) ((Datum) ((X) ? 1 : 0))
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* Returns character value of a datum.
345
#define DatumGetChar(X) ((char) GET_1_BYTE(X))
349
* Returns datum representation for a character.
352
#define CharGetDatum(X) ((Datum) SET_1_BYTE(X))
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* Returns datum representation for an 8-bit integer.
359
#define Int8GetDatum(X) ((Datum) SET_1_BYTE(X))
363
* Returns 8-bit unsigned integer value of a datum.
366
#define DatumGetUInt8(X) ((uint8) GET_1_BYTE(X))
370
* Returns datum representation for an 8-bit unsigned integer.
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#define UInt8GetDatum(X) ((Datum) SET_1_BYTE(X))
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* Returns 16-bit integer value of a datum.
380
#define DatumGetInt16(X) ((int16) GET_2_BYTES(X))
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* Returns datum representation for a 16-bit integer.
387
#define Int16GetDatum(X) ((Datum) SET_2_BYTES(X))
391
* Returns 16-bit unsigned integer value of a datum.
394
#define DatumGetUInt16(X) ((uint16) GET_2_BYTES(X))
398
* Returns datum representation for a 16-bit unsigned integer.
401
#define UInt16GetDatum(X) ((Datum) SET_2_BYTES(X))
405
* Returns 32-bit integer value of a datum.
408
#define DatumGetInt32(X) ((int32) GET_4_BYTES(X))
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* Returns datum representation for a 32-bit integer.
415
#define Int32GetDatum(X) ((Datum) SET_4_BYTES(X))
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* Returns 32-bit unsigned integer value of a datum.
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#define DatumGetUInt32(X) ((uint32) GET_4_BYTES(X))
426
* Returns datum representation for a 32-bit unsigned integer.
429
#define UInt32GetDatum(X) ((Datum) SET_4_BYTES(X))
433
* Returns object identifier value of a datum.
436
#define DatumGetObjectId(X) ((Oid) GET_4_BYTES(X))
440
* Returns datum representation for an object identifier.
443
#define ObjectIdGetDatum(X) ((Datum) SET_4_BYTES(X))
446
* DatumGetTransactionId
447
* Returns transaction identifier value of a datum.
450
#define DatumGetTransactionId(X) ((TransactionId) GET_4_BYTES(X))
453
* TransactionIdGetDatum
454
* Returns datum representation for a transaction identifier.
457
#define TransactionIdGetDatum(X) ((Datum) SET_4_BYTES((X)))
461
* Returns command identifier value of a datum.
464
#define DatumGetCommandId(X) ((CommandId) GET_4_BYTES(X))
468
* Returns datum representation for a command identifier.
471
#define CommandIdGetDatum(X) ((Datum) SET_4_BYTES(X))
475
* Returns pointer value of a datum.
478
#define DatumGetPointer(X) ((Pointer) (X))
482
* Returns datum representation for a pointer.
485
#define PointerGetDatum(X) ((Datum) (X))
489
* Returns C string (null-terminated string) value of a datum.
491
* Note: C string is not a full-fledged Postgres type at present,
492
* but type input functions use this conversion for their inputs.
495
#define DatumGetCString(X) ((char *) DatumGetPointer(X))
499
* Returns datum representation for a C string (null-terminated string).
501
* Note: C string is not a full-fledged Postgres type at present,
502
* but type output functions use this conversion for their outputs.
503
* Note: CString is pass-by-reference; caller must ensure the pointed-to
504
* value has adequate lifetime.
507
#define CStringGetDatum(X) PointerGetDatum(X)
511
* Returns name value of a datum.
514
#define DatumGetName(X) ((Name) DatumGetPointer(X))
518
* Returns datum representation for a name.
520
* Note: Name is pass-by-reference; caller must ensure the pointed-to
521
* value has adequate lifetime.
524
#define NameGetDatum(X) PointerGetDatum(X)
528
* Returns 64-bit integer value of a datum.
530
* Note: this macro hides whether int64 is pass by value or by reference.
533
#ifdef USE_FLOAT8_BYVAL
534
#define DatumGetInt64(X) ((int64) GET_8_BYTES(X))
536
#define DatumGetInt64(X) (* ((int64 *) DatumGetPointer(X)))
541
* Returns datum representation for a 64-bit integer.
543
* Note: if int64 is pass by reference, this function returns a reference
547
#ifdef USE_FLOAT8_BYVAL
548
#define Int64GetDatum(X) ((Datum) SET_8_BYTES(X))
550
extern Datum Int64GetDatum(int64 X);
555
* Returns 4-byte floating point value of a datum.
557
* Note: this macro hides whether float4 is pass by value or by reference.
560
#ifdef USE_FLOAT4_BYVAL
561
extern float4 DatumGetFloat4(Datum X);
563
#define DatumGetFloat4(X) (* ((float4 *) DatumGetPointer(X)))
568
* Returns datum representation for a 4-byte floating point number.
570
* Note: if float4 is pass by reference, this function returns a reference
574
extern Datum Float4GetDatum(float4 X);
578
* Returns 8-byte floating point value of a datum.
580
* Note: this macro hides whether float8 is pass by value or by reference.
583
#ifdef USE_FLOAT8_BYVAL
584
extern float8 DatumGetFloat8(Datum X);
586
#define DatumGetFloat8(X) (* ((float8 *) DatumGetPointer(X)))
591
* Returns datum representation for an 8-byte floating point number.
593
* Note: if float8 is pass by reference, this function returns a reference
597
extern Datum Float8GetDatum(float8 X);
605
* These macros are intended to allow writing code that does not depend on
606
* whether int64, float8, float4 are pass-by-reference types, while not
607
* sacrificing performance when they are. The argument must be a variable
608
* that will exist and have the same value for as long as the Datum is needed.
609
* In the pass-by-ref case, the address of the variable is taken to use as
610
* the Datum. In the pass-by-val case, these will be the same as the non-Fast
614
#ifdef USE_FLOAT8_BYVAL
615
#define Int64GetDatumFast(X) Int64GetDatum(X)
616
#define Float8GetDatumFast(X) Float8GetDatum(X)
618
#define Int64GetDatumFast(X) PointerGetDatum(&(X))
619
#define Float8GetDatumFast(X) PointerGetDatum(&(X))
622
#ifdef USE_FLOAT4_BYVAL
623
#define Float4GetDatumFast(X) Float4GetDatum(X)
625
#define Float4GetDatumFast(X) PointerGetDatum(&(X))
629
/* ----------------------------------------------------------------
630
* Section 3: exception handling definitions
631
* Assert, Trap, etc macros
632
* ----------------------------------------------------------------
635
extern PGDLLIMPORT bool assert_enabled;
638
* USE_ASSERT_CHECKING, if defined, turns on all the assertions.
641
* It should _NOT_ be defined in releases or in benchmark copies
646
* Generates an exception if the given condition is true.
648
#define Trap(condition, errorType) \
650
if ((assert_enabled) && (condition)) \
651
ExceptionalCondition(CppAsString(condition), (errorType), \
652
__FILE__, __LINE__); \
656
* TrapMacro is the same as Trap but it's intended for use in macros:
658
* #define foo(x) (AssertMacro(x != 0) && bar(x))
662
#define TrapMacro(condition, errorType) \
663
((bool) ((! assert_enabled) || ! (condition) || \
664
(ExceptionalCondition(CppAsString(condition), (errorType), \
665
__FILE__, __LINE__))))
667
#ifndef USE_ASSERT_CHECKING
668
#define Assert(condition)
669
#define AssertMacro(condition) ((void)true)
670
#define AssertArg(condition)
671
#define AssertState(condition)
673
#define Assert(condition) \
674
Trap(!(condition), "FailedAssertion")
676
#define AssertMacro(condition) \
677
((void) TrapMacro(!(condition), "FailedAssertion"))
679
#define AssertArg(condition) \
680
Trap(!(condition), "BadArgument")
682
#define AssertState(condition) \
683
Trap(!(condition), "BadState")
684
#endif /* USE_ASSERT_CHECKING */
686
extern int ExceptionalCondition(const char *conditionName,
687
const char *errorType,
688
const char *fileName, int lineNumber);
690
#endif /* POSTGRES_H */
added
removed
src/include/postgres.h
