64 lines
1.8 KiB
C
64 lines
1.8 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) 1998-2014, PostgreSQL Global Development Group
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*
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* src/include/utils/numeric.h
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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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/* The actual contents of Numeric are private to numeric.c */
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struct NumericData;
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typedef struct NumericData *Numeric;
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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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/*
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* Utility functions in numeric.c
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*/
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extern bool numeric_is_nan(Numeric num);
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int32 numeric_maximum_size(int32 typmod);
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extern char *numeric_out_sci(Numeric num, int scale);
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extern char *numeric_normalize(Numeric num);
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#endif /* _PG_NUMERIC_H_ */
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