Moving the algorithm from print_type_size() into size_to_str() so that
other component can also leverage it. With that, refactor
print_type_size().

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 include/qemu-common.h        |  1 +
 qapi/string-output-visitor.c | 22 ++++++----------------
 util/cutils.c                | 23 +++++++++++++++++++++++
 3 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/include/qemu-common.h b/include/qemu-common.h
index d218821..d7d0448 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -145,6 +145,7 @@ void qemu_hexdump(const char *buf, FILE *fp, const char *prefix, size_t size);
 int parse_debug_env(const char *name, int max, int initial);
 
 const char *qemu_ether_ntoa(const MACAddr *mac);
+char *size_to_str(double val);
 void page_size_init(void);
 
 /* returns non-zero if dump is in progress, otherwise zero is
diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c
index 94ac821..53c2175 100644
--- a/qapi/string-output-visitor.c
+++ b/qapi/string-output-visitor.c
@@ -211,10 +211,8 @@ static void print_type_size(Visitor *v, const char *name, uint64_t *obj,
                             Error **errp)
 {
     StringOutputVisitor *sov = to_sov(v);
-    static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
-    uint64_t div, val;
-    char *out;
-    int i;
+    uint64_t val;
+    char *out, *psize;
 
     if (!sov->human) {
         out = g_strdup_printf("%"PRIu64, *obj);
@@ -223,19 +221,11 @@ static void print_type_size(Visitor *v, const char *name, uint64_t *obj,
     }
 
     val = *obj;
-
-    /* The exponent (returned in i) minus one gives us
-     * floor(log2(val * 1024 / 1000).  The correction makes us
-     * switch to the higher power when the integer part is >= 1000.
-     */
-    frexp(val / (1000.0 / 1024.0), &i);
-    i = (i - 1) / 10;
-    assert(i < ARRAY_SIZE(suffixes));
-    div = 1ULL << (i * 10);
-
-    out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
-                          (double)val/div, suffixes[i], i ? "iB" : "");
+    psize = size_to_str(val);
+    out = g_strdup_printf("%"PRIu64" (%s)", val, psize);
     string_output_set(sov, out);
+
+    g_free(psize);
 }
 
 static void print_type_bool(Visitor *v, const char *name, bool *obj,
diff --git a/util/cutils.c b/util/cutils.c
index 50ad179..c562d87 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -619,3 +619,26 @@ const char *qemu_ether_ntoa(const MACAddr *mac)
 
     return ret;
 }
+
+/*
+ * Please free the buffer after use.
+ */
+char *size_to_str(double val)
+{
+    static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" };
+    unsigned long div;
+    int i;
+
+    /*
+     * The exponent (returned in i) minus one gives us
+     * floor(log2(val * 1024 / 1000).  The correction makes us
+     * switch to the higher power when the integer part is >= 1000.
+     * (see e41b509d68afb1f for more info)
+     */
+    frexp(val / (1000.0 / 1024.0), &i);
+    i = (i - 1) / 10;
+    assert(i < ARRAY_SIZE(suffixes));
+    div = 1ULL << (i * 10);
+
+    return g_strdup_printf("%0.3g %sB", val / div, suffixes[i]);
+}
-- 
2.7.4

* Peter Xu (peterx@redhat.com) wrote:
> Moving the algorithm from print_type_size() into size_to_str() so that
> other component can also leverage it. With that, refactor
> print_type_size().
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  include/qemu-common.h        |  1 +
>  qapi/string-output-visitor.c | 22 ++++++----------------
>  util/cutils.c                | 23 +++++++++++++++++++++++
>  3 files changed, 30 insertions(+), 16 deletions(-)
> 
> diff --git a/include/qemu-common.h b/include/qemu-common.h
> index d218821..d7d0448 100644
> --- a/include/qemu-common.h
> +++ b/include/qemu-common.h
> @@ -145,6 +145,7 @@ void qemu_hexdump(const char *buf, FILE *fp, const char *prefix, size_t size);
>  int parse_debug_env(const char *name, int max, int initial);
>  
>  const char *qemu_ether_ntoa(const MACAddr *mac);
> +char *size_to_str(double val);
>  void page_size_init(void);
>  
>  /* returns non-zero if dump is in progress, otherwise zero is
> diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c
> index 94ac821..53c2175 100644
> --- a/qapi/string-output-visitor.c
> +++ b/qapi/string-output-visitor.c
> @@ -211,10 +211,8 @@ static void print_type_size(Visitor *v, const char *name, uint64_t *obj,
>                              Error **errp)
>  {
>      StringOutputVisitor *sov = to_sov(v);
> -    static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
> -    uint64_t div, val;
> -    char *out;
> -    int i;
> +    uint64_t val;
> +    char *out, *psize;
>  
>      if (!sov->human) {
>          out = g_strdup_printf("%"PRIu64, *obj);
> @@ -223,19 +221,11 @@ static void print_type_size(Visitor *v, const char *name, uint64_t *obj,
>      }
>  
>      val = *obj;
> -
> -    /* The exponent (returned in i) minus one gives us
> -     * floor(log2(val * 1024 / 1000).  The correction makes us
> -     * switch to the higher power when the integer part is >= 1000.
> -     */
> -    frexp(val / (1000.0 / 1024.0), &i);
> -    i = (i - 1) / 10;
> -    assert(i < ARRAY_SIZE(suffixes));
> -    div = 1ULL << (i * 10);
> -
> -    out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
> -                          (double)val/div, suffixes[i], i ? "iB" : "");
> +    psize = size_to_str(val);
> +    out = g_strdup_printf("%"PRIu64" (%s)", val, psize);
>      string_output_set(sov, out);
> +
> +    g_free(psize);
>  }
>  
>  static void print_type_bool(Visitor *v, const char *name, bool *obj,
> diff --git a/util/cutils.c b/util/cutils.c
> index 50ad179..c562d87 100644
> --- a/util/cutils.c
> +++ b/util/cutils.c
> @@ -619,3 +619,26 @@ const char *qemu_ether_ntoa(const MACAddr *mac)
>  
>      return ret;
>  }
> +
> +/*
> + * Please free the buffer after use.
> + */
> +char *size_to_str(double val)
> +{
> +    static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" };
> +    unsigned long div;
> +    int i;
> +
> +    /*
> +     * The exponent (returned in i) minus one gives us
> +     * floor(log2(val * 1024 / 1000).  The correction makes us
> +     * switch to the higher power when the integer part is >= 1000.
> +     * (see e41b509d68afb1f for more info)
> +     */
> +    frexp(val / (1000.0 / 1024.0), &i);
> +    i = (i - 1) / 10;
> +    assert(i < ARRAY_SIZE(suffixes));
> +    div = 1ULL << (i * 10);
> +
> +    return g_strdup_printf("%0.3g %sB", val / div, suffixes[i]);
> +}

Right, I think I'm happy with that;  Paolo, Markus - make sense to you?

Dave

> -- 
> 2.7.4
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK