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234a02b2a8
Get rid of VARATT_SIZE and VARATT_DATA, which were simply redundant with VARSIZE and VARDATA, and as a consequence almost no code was using the longer names. Rename the length fields of struct varlena and various derived structures to catch anyplace that was accessing them directly; and clean up various places so caught. In itself this patch doesn't change any behavior at all, but it is necessary infrastructure if we hope to play any games with the representation of varlena headers. Greg Stark and Tom Lane
88 lines
2.7 KiB
C
88 lines
2.7 KiB
C
/*-------------------------------------------------------------------------
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*
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* numeric.h
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* Definitions for the exact numeric data type of Postgres
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*
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* Original coding 1998, Jan Wieck. Heavily revised 2003, Tom Lane.
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*
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* Copyright (c) 1998-2007, PostgreSQL Global Development Group
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*
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* $PostgreSQL: pgsql/src/include/utils/numeric.h,v 1.24 2007/02/27 23:48:10 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef _PG_NUMERIC_H_
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#define _PG_NUMERIC_H_
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#include "fmgr.h"
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/*
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* Hardcoded precision limit - arbitrary, but must be small enough that
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* dscale values will fit in 14 bits.
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*/
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#define NUMERIC_MAX_PRECISION 1000
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/*
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* Internal limits on the scales chosen for calculation results
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*/
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#define NUMERIC_MAX_DISPLAY_SCALE NUMERIC_MAX_PRECISION
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#define NUMERIC_MIN_DISPLAY_SCALE 0
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#define NUMERIC_MAX_RESULT_SCALE (NUMERIC_MAX_PRECISION * 2)
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/*
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* For inherently inexact calculations such as division and square root,
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* we try to get at least this many significant digits; the idea is to
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* deliver a result no worse than float8 would.
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*/
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#define NUMERIC_MIN_SIG_DIGITS 16
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/*
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* Sign values and macros to deal with packing/unpacking n_sign_dscale
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*/
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#define NUMERIC_SIGN_MASK 0xC000
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#define NUMERIC_POS 0x0000
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#define NUMERIC_NEG 0x4000
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#define NUMERIC_NAN 0xC000
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#define NUMERIC_DSCALE_MASK 0x3FFF
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#define NUMERIC_SIGN(n) ((n)->n_sign_dscale & NUMERIC_SIGN_MASK)
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#define NUMERIC_DSCALE(n) ((n)->n_sign_dscale & NUMERIC_DSCALE_MASK)
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#define NUMERIC_IS_NAN(n) (NUMERIC_SIGN(n) != NUMERIC_POS && \
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NUMERIC_SIGN(n) != NUMERIC_NEG)
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/*
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* The Numeric data type stored in the database
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*
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* NOTE: by convention, values in the packed form have been stripped of
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* all leading and trailing zero digits (where a "digit" is of base NBASE).
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* In particular, if the value is zero, there will be no digits at all!
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* The weight is arbitrary in that case, but we normally set it to zero.
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*/
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typedef struct NumericData
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{
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int32 vl_len_; /* varlena header (do not touch directly!) */
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int16 n_weight; /* Weight of 1st digit */
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uint16 n_sign_dscale; /* Sign + display scale */
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char n_data[1]; /* Digits (really array of NumericDigit) */
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} NumericData;
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typedef NumericData *Numeric;
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#define NUMERIC_HDRSZ (VARHDRSZ + sizeof(int16) + sizeof(uint16))
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/*
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* fmgr interface macros
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*/
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#define DatumGetNumeric(X) ((Numeric) PG_DETOAST_DATUM(X))
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#define DatumGetNumericCopy(X) ((Numeric) PG_DETOAST_DATUM_COPY(X))
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#define NumericGetDatum(X) PointerGetDatum(X)
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#define PG_GETARG_NUMERIC(n) DatumGetNumeric(PG_GETARG_DATUM(n))
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#define PG_GETARG_NUMERIC_COPY(n) DatumGetNumericCopy(PG_GETARG_DATUM(n))
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#define PG_RETURN_NUMERIC(x) return NumericGetDatum(x)
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#endif /* _PG_NUMERIC_H_ */
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