 e41b509d68
			
		
	
	
		e41b509d68
		
	
	
	
	
		
			
			This fixes several bugs or shortcomings of the previous pretty-printer. In particular: * use PRIu64 instead of casting to long long * the exact value is included too * the correct unit of measure (MiB, GiB, etc.) is used. PiB and EiB are added too. * due to an off-by-one error, 512*2^30 was printed as 0.500MiB rather than 512MiB. floor(log2(val)) is equal to 63 - clz(val), while the code used 64. * The desired specification is %g rather than %f, which always uses three decimals in the current code. However %g would switch to scientific notation when the integer part is >= 1000 (e.g. 1000*2^30). To keep the code simple, switch to the higher power when the integer part is >= 1000; overflow is avoided by using frexp instead of clz. Suggested-by: Eric Blake <eblake@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andreas Färber <afaerber@suse.de>
		
			
				
	
	
		
			140 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			140 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * String printing Visitor
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|  *
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|  * Copyright Red Hat, Inc. 2012
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|  *
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|  * Author: Paolo Bonzini <pbonzini@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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|  */
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| 
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| #include "qemu-common.h"
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| #include "qapi/string-output-visitor.h"
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| #include "qapi/visitor-impl.h"
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| #include "qapi/qmp/qerror.h"
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| #include "qemu/host-utils.h"
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| #include <math.h>
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| 
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| struct StringOutputVisitor
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| {
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|     Visitor visitor;
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|     bool human;
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|     char *string;
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| };
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| 
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| static void string_output_set(StringOutputVisitor *sov, char *string)
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| {
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|     g_free(sov->string);
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|     sov->string = string;
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| }
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| 
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| static void print_type_int(Visitor *v, int64_t *obj, const char *name,
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|                            Error **errp)
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| {
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|     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
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|     char *out;
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| 
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|     if (sov->human) {
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|         out = g_strdup_printf("%lld (%#llx)", (long long) *obj, (long long) *obj);
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|     } else {
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|         out = g_strdup_printf("%lld", (long long) *obj);
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|     }
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|     string_output_set(sov, out);
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| }
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| 
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| static void print_type_size(Visitor *v, uint64_t *obj, const char *name,
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|                            Error **errp)
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| {
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|     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
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|     static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
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|     uint64_t div, val;
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|     char *out;
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|     int i;
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| 
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|     if (!sov->human) {
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|         out = g_strdup_printf("%"PRIu64, *obj);
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|         string_output_set(sov, out);
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|         return;
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|     }
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| 
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|     val = *obj;
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| 
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|     /* The exponent (returned in i) minus one gives us
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|      * floor(log2(val * 1024 / 1000).  The correction makes us
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|      * switch to the higher power when the integer part is >= 1000.
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|      */
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|     frexp(val / (1000.0 / 1024.0), &i);
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|     i = (i - 1) / 10;
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|     assert(i < ARRAY_SIZE(suffixes));
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|     div = 1ULL << (i * 10);
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| 
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|     out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
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|                           (double)val/div, suffixes[i], i ? "iB" : "");
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|     string_output_set(sov, out);
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| }
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| 
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| static void print_type_bool(Visitor *v, bool *obj, const char *name,
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|                             Error **errp)
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| {
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|     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
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|     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
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| }
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| 
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| static void print_type_str(Visitor *v, char **obj, const char *name,
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|                            Error **errp)
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| {
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|     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
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|     char *out;
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| 
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|     if (sov->human) {
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|         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
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|     } else {
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|         out = g_strdup(*obj ? *obj : "");
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|     }
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|     string_output_set(sov, out);
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| }
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| 
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| static void print_type_number(Visitor *v, double *obj, const char *name,
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|                               Error **errp)
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| {
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|     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
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|     string_output_set(sov, g_strdup_printf("%f", *obj));
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| }
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| 
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| char *string_output_get_string(StringOutputVisitor *sov)
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| {
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|     char *string = sov->string;
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|     sov->string = NULL;
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|     return string;
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| }
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| 
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| Visitor *string_output_get_visitor(StringOutputVisitor *sov)
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| {
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|     return &sov->visitor;
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| }
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| 
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| void string_output_visitor_cleanup(StringOutputVisitor *sov)
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| {
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|     g_free(sov->string);
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|     g_free(sov);
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| }
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| 
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| StringOutputVisitor *string_output_visitor_new(bool human)
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| {
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|     StringOutputVisitor *v;
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| 
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|     v = g_malloc0(sizeof(*v));
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| 
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|     v->human = human;
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|     v->visitor.type_enum = output_type_enum;
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|     v->visitor.type_int = print_type_int;
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|     v->visitor.type_size = print_type_size;
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|     v->visitor.type_bool = print_type_bool;
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|     v->visitor.type_str = print_type_str;
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|     v->visitor.type_number = print_type_number;
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| 
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|     return v;
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| }
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