diff options
Diffstat (limited to 'qobject/qnum.c')
-rw-r--r-- | qobject/qnum.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/qobject/qnum.c b/qobject/qnum.c new file mode 100644 index 0000000000..7bb9006763 --- /dev/null +++ b/qobject/qnum.c @@ -0,0 +1,159 @@ +/* + * QNum Module + * + * Copyright (C) 2009 Red Hat Inc. + * + * Authors: + * Luiz Capitulino <lcapitulino@redhat.com> + * Anthony Liguori <aliguori@us.ibm.com> + * Marc-André Lureau <marcandre.lureau@redhat.com> + * + * This work is licensed under the terms of the GNU LGPL, version 2.1 or later. + * See the COPYING.LIB file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "qapi/qmp/qnum.h" +#include "qapi/qmp/qobject.h" +#include "qemu-common.h" + +/** + * qnum_from_int(): Create a new QNum from an int64_t + * + * Return strong reference. + */ +QNum *qnum_from_int(int64_t value) +{ + QNum *qn = g_new(QNum, 1); + + qobject_init(QOBJECT(qn), QTYPE_QNUM); + qn->kind = QNUM_I64; + qn->u.i64 = value; + + return qn; +} + +/** + * qnum_from_double(): Create a new QNum from a double + * + * Return strong reference. + */ +QNum *qnum_from_double(double value) +{ + QNum *qn = g_new(QNum, 1); + + qobject_init(QOBJECT(qn), QTYPE_QNUM); + qn->kind = QNUM_DOUBLE; + qn->u.dbl = value; + + return qn; +} + +/** + * qnum_get_try_int(): Get an integer representation of the number + * + * Return true on success. + */ +bool qnum_get_try_int(const QNum *qn, int64_t *val) +{ + switch (qn->kind) { + case QNUM_I64: + *val = qn->u.i64; + return true; + case QNUM_DOUBLE: + return false; + } + + assert(0); + return false; +} + +/** + * qnum_get_int(): Get an integer representation of the number + * + * assert() on failure. + */ +int64_t qnum_get_int(const QNum *qn) +{ + int64_t val; + bool success = qnum_get_try_int(qn, &val); + assert(success); + return val; +} + +/** + * qnum_get_double(): Get a float representation of the number + * + * qnum_get_double() loses precision for integers beyond 53 bits. + */ +double qnum_get_double(QNum *qn) +{ + switch (qn->kind) { + case QNUM_I64: + return qn->u.i64; + case QNUM_DOUBLE: + return qn->u.dbl; + } + + assert(0); + return 0.0; +} + +char *qnum_to_string(QNum *qn) +{ + char *buffer; + int len; + + switch (qn->kind) { + case QNUM_I64: + return g_strdup_printf("%" PRId64, qn->u.i64); + case QNUM_DOUBLE: + /* FIXME: snprintf() is locale dependent; but JSON requires + * numbers to be formatted as if in the C locale. Dependence + * on C locale is a pervasive issue in QEMU. */ + /* FIXME: This risks printing Inf or NaN, which are not valid + * JSON values. */ + /* FIXME: the default precision of 6 for %f often causes + * rounding errors; we should be using DBL_DECIMAL_DIG (17), + * and only rounding to a shorter number if the result would + * still produce the same floating point value. */ + buffer = g_strdup_printf("%f" , qn->u.dbl); + len = strlen(buffer); + while (len > 0 && buffer[len - 1] == '0') { + len--; + } + + if (len && buffer[len - 1] == '.') { + buffer[len - 1] = 0; + } else { + buffer[len] = 0; + } + + return buffer; + } + + assert(0); + return NULL; +} + +/** + * qobject_to_qnum(): Convert a QObject into a QNum + */ +QNum *qobject_to_qnum(const QObject *obj) +{ + if (!obj || qobject_type(obj) != QTYPE_QNUM) { + return NULL; + } + return container_of(obj, QNum, base); +} + +/** + * qnum_destroy_obj(): Free all memory allocated by a + * QNum object + */ +void qnum_destroy_obj(QObject *obj) +{ + assert(obj != NULL); + g_free(qobject_to_qnum(obj)); +} |