80d71121b7
Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20201211171152.146877-9-armbru@redhat.com>
72 lines
1.9 KiB
C
72 lines
1.9 KiB
C
/*
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* QNum Module
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*
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* Copyright (C) 2009 Red Hat Inc.
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*
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* Authors:
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* Luiz Capitulino <lcapitulino@redhat.com>
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* Anthony Liguori <aliguori@us.ibm.com>
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* Marc-André Lureau <marcandre.lureau@redhat.com>
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*
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* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
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* See the COPYING.LIB file in the top-level directory.
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*/
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#ifndef QNUM_H
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#define QNUM_H
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#include "qapi/qmp/qobject.h"
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typedef enum {
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QNUM_I64,
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QNUM_U64,
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QNUM_DOUBLE
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} QNumKind;
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/*
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* QNum encapsulates how our dialect of JSON fills in the blanks left
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* by the JSON specification (RFC 8259) regarding numbers.
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*
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* Conceptually, we treat number as an abstract type with three
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* concrete subtypes: floating-point, signed integer, unsigned
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* integer. QNum implements this as a discriminated union of double,
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* int64_t, uint64_t.
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*
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* The JSON parser picks the subtype as follows. If the number has a
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* decimal point or an exponent, it is floating-point. Else if it
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* fits into int64_t, it's signed integer. Else if it fits into
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* uint64_t, it's unsigned integer. Else it's floating-point.
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*
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* Any number can serve as double: qnum_get_double() converts under
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* the hood.
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*
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* An integer can serve as signed / unsigned integer as long as it is
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* in range: qnum_get_try_int() / qnum_get_try_uint() check range and
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* convert under the hood.
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*/
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struct QNum {
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struct QObjectBase_ base;
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QNumKind kind;
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union {
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int64_t i64;
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uint64_t u64;
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double dbl;
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} u;
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};
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QNum *qnum_from_int(int64_t value);
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QNum *qnum_from_uint(uint64_t value);
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QNum *qnum_from_double(double value);
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bool qnum_get_try_int(const QNum *qn, int64_t *val);
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int64_t qnum_get_int(const QNum *qn);
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bool qnum_get_try_uint(const QNum *qn, uint64_t *val);
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uint64_t qnum_get_uint(const QNum *qn);
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double qnum_get_double(QNum *qn);
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char *qnum_to_string(QNum *qn);
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#endif /* QNUM_H */
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