qemu-e2k/qapi/string-output-visitor.c
Michael Roth 173bbb754f qapi: String visitor, use %f representation for floats
Currently string-output-visitor formats floats as %g, which is nice in
that trailing 0's are automatically truncated, but otherwise this causes
some issues:

 - it uses 6 significant figures instead of 6 decimal places, which
   means something like 155777.5 (which even has an exact floating point
   representation) will be rounded to 155778 when converted to a string.

 - output will be presented in scientific notation when the normalized
   form requires a 10^x multiplier. Not a huge deal, but arguably less
   readable for command-line arguments.

 - due to using scientific notation for numbers requiring more than 6
   significant figures, instead of hard-defined decimal places, it
   fails a lot of the test-visitor-serialization unit tests for floats.

Instead, let's just use %f, which is what the QJSON and the QMP visitors
use.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2012-06-08 16:11:14 +02:00

90 lines
2.2 KiB
C

/*
* String printing Visitor
*
* Copyright Red Hat, Inc. 2012
*
* Author: Paolo Bonzini <pbonzini@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-common.h"
#include "string-output-visitor.h"
#include "qapi/qapi-visit-impl.h"
#include "qerror.h"
struct StringOutputVisitor
{
Visitor visitor;
char *string;
};
static void string_output_set(StringOutputVisitor *sov, char *string)
{
g_free(sov->string);
sov->string = string;
}
static void print_type_int(Visitor *v, int64_t *obj, const char *name,
Error **errp)
{
StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
string_output_set(sov, g_strdup_printf("%lld", (long long) *obj));
}
static void print_type_bool(Visitor *v, bool *obj, const char *name,
Error **errp)
{
StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
string_output_set(sov, g_strdup(*obj ? "true" : "false"));
}
static void print_type_str(Visitor *v, char **obj, const char *name,
Error **errp)
{
StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
string_output_set(sov, g_strdup(*obj ? *obj : ""));
}
static void print_type_number(Visitor *v, double *obj, const char *name,
Error **errp)
{
StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
string_output_set(sov, g_strdup_printf("%f", *obj));
}
char *string_output_get_string(StringOutputVisitor *sov)
{
char *string = sov->string;
sov->string = NULL;
return string;
}
Visitor *string_output_get_visitor(StringOutputVisitor *sov)
{
return &sov->visitor;
}
void string_output_visitor_cleanup(StringOutputVisitor *sov)
{
g_free(sov->string);
g_free(sov);
}
StringOutputVisitor *string_output_visitor_new(void)
{
StringOutputVisitor *v;
v = g_malloc0(sizeof(*v));
v->visitor.type_enum = output_type_enum;
v->visitor.type_int = print_type_int;
v->visitor.type_bool = print_type_bool;
v->visitor.type_str = print_type_str;
v->visitor.type_number = print_type_number;
return v;
}