qapi/string-output-visitor.c

   1 /*
   2  * String printing Visitor
   3  *
   4  * Copyright Red Hat, Inc. 2012
   5  *
   6  * Author: Paolo Bonzini <pbonzini@redhat.com>
   7  *
   8  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
   9  * See the COPYING.LIB file in the top-level directory.
  10  *
  11  */
  12
  13 #include "qemu-common.h"
  14 #include "qapi/string-output-visitor.h"
  15 #include "qapi/visitor-impl.h"
  16 #include "qapi/qmp/qerror.h"
  17 #include "qemu/host-utils.h"
  18 #include <math.h>
  19
  20 struct StringOutputVisitor
  21 {
  22     Visitor visitor;
  23     bool human;
  24     char *string;
  25 };
  26
  27 static void string_output_set(StringOutputVisitor *sov, char *string)
  28 {
  29     g_free(sov->string);
  30     sov->string = string;
  31 }
  32
  33 static void print_type_int(Visitor *v, int64_t *obj, const char *name,
  34                            Error **errp)
  35 {
  36     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
  37     char *out;
  38
  39     if (sov->human) {
  40         out = g_strdup_printf("%lld (%#llx)", (long long) *obj, (long long) *obj);
  41     } else {
  42         out = g_strdup_printf("%lld", (long long) *obj);
  43     }
  44     string_output_set(sov, out);
  45 }
  46
  47 static void print_type_size(Visitor *v, uint64_t *obj, const char *name,
  48                            Error **errp)
  49 {
  50     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
  51     static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
  52     uint64_t div, val;
  53     char *out;
  54     int i;
  55
  56     if (!sov->human) {
  57         out = g_strdup_printf("%"PRIu64, *obj);
  58         string_output_set(sov, out);
  59         return;
  60     }
  61
  62     val = *obj;
  63
  64     /* The exponent (returned in i) minus one gives us
  65      * floor(log2(val * 1024 / 1000).  The correction makes us
  66      * switch to the higher power when the integer part is >= 1000.
  67      */
  68     frexp(val / (1000.0 / 1024.0), &i);
  69     i = (i - 1) / 10;
  70     assert(i < ARRAY_SIZE(suffixes));
  71     div = 1ULL << (i * 10);
  72
  73     out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
  74                           (double)val/div, suffixes[i], i ? "iB" : "");
  75     string_output_set(sov, out);
  76 }
  77
  78 static void print_type_bool(Visitor *v, bool *obj, const char *name,
  79                             Error **errp)
  80 {
  81     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
  82     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
  83 }
  84
  85 static void print_type_str(Visitor *v, char **obj, const char *name,
  86                            Error **errp)
  87 {
  88     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
  89     char *out;
  90
  91     if (sov->human) {
  92         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
  93     } else {
  94         out = g_strdup(*obj ? *obj : "");
  95     }
  96     string_output_set(sov, out);
  97 }
  98
  99 static void print_type_number(Visitor *v, double *obj, const char *name,
 100                               Error **errp)
 101 {
 102     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
 103     string_output_set(sov, g_strdup_printf("%f", *obj));
 104 }
 105
 106 char *string_output_get_string(StringOutputVisitor *sov)
 107 {
 108     char *string = sov->string;
 109     sov->string = NULL;
 110     return string;
 111 }
 112
 113 Visitor *string_output_get_visitor(StringOutputVisitor *sov)
 114 {
 115     return &sov->visitor;
 116 }
 117
 118 void string_output_visitor_cleanup(StringOutputVisitor *sov)
 119 {
 120     g_free(sov->string);
 121     g_free(sov);
 122 }
 123
 124 StringOutputVisitor *string_output_visitor_new(bool human)
 125 {
 126     StringOutputVisitor *v;
 127
 128     v = g_malloc0(sizeof(*v));
 129
 130     v->human = human;
 131     v->visitor.type_enum = output_type_enum;
 132     v->visitor.type_int = print_type_int;
 133     v->visitor.type_size = print_type_size;
 134     v->visitor.type_bool = print_type_bool;
 135     v->visitor.type_str = print_type_str;
 136     v->visitor.type_number = print_type_number;
 137
 138     return v;
 139 }