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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:15:05 +0000 |
commit | 46651ce6fe013220ed397add242004d764fc0153 (patch) | |
tree | 6e5299f990f88e60174a1d3ae6e48eedd2688b2b /src/include/utils/varbit.h | |
parent | Initial commit. (diff) | |
download | postgresql-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/utils/varbit.h')
-rw-r--r-- | src/include/utils/varbit.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/src/include/utils/varbit.h b/src/include/utils/varbit.h new file mode 100644 index 0000000..2fcbb5d --- /dev/null +++ b/src/include/utils/varbit.h @@ -0,0 +1,74 @@ +/*------------------------------------------------------------------------- + * + * varbit.h + * Functions for the SQL datatypes BIT() and BIT VARYING(). + * + * Code originally contributed by Adriaan Joubert. + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/utils/varbit.h + * + *------------------------------------------------------------------------- + */ +#ifndef VARBIT_H +#define VARBIT_H + +#include <limits.h> + +#include "fmgr.h" + +/* + * Modeled on struct varlena from postgres.h, but data type is bits8. + * + * Caution: if bit_len is not a multiple of BITS_PER_BYTE, the low-order + * bits of the last byte of bit_dat[] are unused and MUST be zeroes. + * (This allows bit_cmp() to not bother masking the last byte.) + * Also, there should not be any excess bytes counted in the header length. + */ +typedef struct +{ + int32 vl_len_; /* varlena header (do not touch directly!) */ + int32 bit_len; /* number of valid bits */ + bits8 bit_dat[FLEXIBLE_ARRAY_MEMBER]; /* bit string, most sig. byte + * first */ +} VarBit; + +/* + * fmgr interface macros + * + * BIT and BIT VARYING are toastable varlena types. They are the same + * as far as representation goes, so we just have one set of macros. + */ +#define DatumGetVarBitP(X) ((VarBit *) PG_DETOAST_DATUM(X)) +#define DatumGetVarBitPCopy(X) ((VarBit *) PG_DETOAST_DATUM_COPY(X)) +#define VarBitPGetDatum(X) PointerGetDatum(X) +#define PG_GETARG_VARBIT_P(n) DatumGetVarBitP(PG_GETARG_DATUM(n)) +#define PG_GETARG_VARBIT_P_COPY(n) DatumGetVarBitPCopy(PG_GETARG_DATUM(n)) +#define PG_RETURN_VARBIT_P(x) return VarBitPGetDatum(x) + +/* Header overhead *in addition to* VARHDRSZ */ +#define VARBITHDRSZ sizeof(int32) +/* Number of bits in this bit string */ +#define VARBITLEN(PTR) (((VarBit *) (PTR))->bit_len) +/* Pointer to the first byte containing bit string data */ +#define VARBITS(PTR) (((VarBit *) (PTR))->bit_dat) +/* Number of bytes in the data section of a bit string */ +#define VARBITBYTES(PTR) (VARSIZE(PTR) - VARHDRSZ - VARBITHDRSZ) +/* Padding of the bit string at the end (in bits) */ +#define VARBITPAD(PTR) (VARBITBYTES(PTR)*BITS_PER_BYTE - VARBITLEN(PTR)) +/* Number of bytes needed to store a bit string of a given length */ +#define VARBITTOTALLEN(BITLEN) (((BITLEN) + BITS_PER_BYTE-1)/BITS_PER_BYTE + \ + VARHDRSZ + VARBITHDRSZ) +/* + * Maximum number of bits. Several code sites assume no overflow from + * computing bitlen + X; VARBITTOTALLEN() has the largest such X. + */ +#define VARBITMAXLEN (INT_MAX - BITS_PER_BYTE + 1) +/* pointer beyond the end of the bit string (like end() in STL containers) */ +#define VARBITEND(PTR) (((bits8 *) (PTR)) + VARSIZE(PTR)) +/* Mask that will cover exactly one byte, i.e. BITS_PER_BYTE bits */ +#define BITMASK 0xFF + +#endif |