diff mbox series

[v2,1/3] util/cutils: Introduce freq_to_str() to display Hertz units

Message ID 20201001164322.1585392-2-f4bug@amsat.org
State Superseded
Headers show
Series qdev-clock: Minor improvements to the Clock API | expand

Commit Message

Philippe Mathieu-Daudé Oct. 1, 2020, 4:43 p.m. UTC 
Introduce freq_to_str() to convert frequency values in human
friendly units using the SI units for Hertz.

Suggested-by: Luc Michel <luc@lmichel.fr>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 include/qemu/cutils.h | 12 ++++++++++++
 util/cutils.c         | 14 ++++++++++++++
 2 files changed, 26 insertions(+)

Comments

Alistair Francis Oct. 1, 2020, 4:55 p.m. UTC | #1 
On Thu, Oct 1, 2020 at 9:57 AM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>

> Introduce freq_to_str() to convert frequency values in human

> friendly units using the SI units for Hertz.

>

> Suggested-by: Luc Michel <luc@lmichel.fr>

> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>


Reviewed-by: Alistair Francis <alistair.francis@wdc.com>


Alistair

> ---

>  include/qemu/cutils.h | 12 ++++++++++++

>  util/cutils.c         | 14 ++++++++++++++

>  2 files changed, 26 insertions(+)

>

> diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h

> index 3a86ec0321..4bbf4834ea 100644

> --- a/include/qemu/cutils.h

> +++ b/include/qemu/cutils.h

> @@ -158,6 +158,18 @@ int qemu_strtosz_metric(const char *nptr, const char **end, uint64_t *result);

>

>  char *size_to_str(uint64_t val);

>

> +/**

> + * freq_to_str:

> + * @freq_hz: frequency to stringify

> + *

> + * Return human readable string for frequency @freq_hz.

> + * Use SI units like KHz, MHz, and so forth.

> + *

> + * The caller is responsible for releasing the value returned

> + * with g_free() after use.

> + */

> +char *freq_to_str(uint64_t freq_hz);

> +

>  /* used to print char* safely */

>  #define STR_OR_NULL(str) ((str) ? (str) : "null")

>

> diff --git a/util/cutils.c b/util/cutils.c

> index 8da34e04b0..be4e43a9ef 100644

> --- a/util/cutils.c

> +++ b/util/cutils.c

> @@ -885,6 +885,20 @@ char *size_to_str(uint64_t val)

>      return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);

>  }

>

> +char *freq_to_str(uint64_t freq_hz)

> +{

> +    static const char *const suffixes[] = { "", "K", "M", "G", "T", "P", "E" };

> +    double freq = freq_hz;

> +    size_t idx = 0;

> +

> +    while (freq >= 1000.0 && idx < ARRAY_SIZE(suffixes)) {

> +        freq /= 1000.0;

> +        idx++;

> +    }

> +

> +    return g_strdup_printf("%0.3g %sHz", freq, suffixes[idx]);

> +}

> +

>  int qemu_pstrcmp0(const char **str1, const char **str2)

>  {

>      return g_strcmp0(*str1, *str2);

> --

> 2.26.2

>

>
Eduardo Habkost Oct. 1, 2020, 6:42 p.m. UTC | #2 
On Thu, Oct 01, 2020 at 06:43:20PM +0200, Philippe Mathieu-Daudé wrote:
> Introduce freq_to_str() to convert frequency values in human
> friendly units using the SI units for Hertz.
> 
> Suggested-by: Luc Michel <luc@lmichel.fr>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  include/qemu/cutils.h | 12 ++++++++++++
>  util/cutils.c         | 14 ++++++++++++++
>  2 files changed, 26 insertions(+)
> 
> diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
> index 3a86ec0321..4bbf4834ea 100644
> --- a/include/qemu/cutils.h
> +++ b/include/qemu/cutils.h
> @@ -158,6 +158,18 @@ int qemu_strtosz_metric(const char *nptr, const char **end, uint64_t *result);
>  
>  char *size_to_str(uint64_t val);
>  
> +/**
> + * freq_to_str:
> + * @freq_hz: frequency to stringify
> + *
> + * Return human readable string for frequency @freq_hz.
> + * Use SI units like KHz, MHz, and so forth.
> + *
> + * The caller is responsible for releasing the value returned
> + * with g_free() after use.
> + */
> +char *freq_to_str(uint64_t freq_hz);
> +
>  /* used to print char* safely */
>  #define STR_OR_NULL(str) ((str) ? (str) : "null")
>  
> diff --git a/util/cutils.c b/util/cutils.c
> index 8da34e04b0..be4e43a9ef 100644
> --- a/util/cutils.c
> +++ b/util/cutils.c
> @@ -885,6 +885,20 @@ char *size_to_str(uint64_t val)
>      return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
>  }
>  
> +char *freq_to_str(uint64_t freq_hz)
> +{
> +    static const char *const suffixes[] = { "", "K", "M", "G", "T", "P", "E" };
> +    double freq = freq_hz;
> +    size_t idx = 0;
> +
> +    while (freq >= 1000.0 && idx < ARRAY_SIZE(suffixes)) {
> +        freq /= 1000.0;
> +        idx++;
> +    }
> +
> +    return g_strdup_printf("%0.3g %sHz", freq, suffixes[idx]);

The only thing protecting this from out of bounds array access is
the fact that UINT64_MAX is smaller than 1000E.  I wonder if this
causes a Coverity warning.

> +}
> +
>  int qemu_pstrcmp0(const char **str1, const char **str2)
>  {
>      return g_strcmp0(*str1, *str2);
> -- 
> 2.26.2
>
Luc Michel Oct. 2, 2020, 7:09 a.m. UTC | #3 
On 18:43 Thu 01 Oct     , Philippe Mathieu-Daudé wrote:
> Introduce freq_to_str() to convert frequency values in human
> friendly units using the SI units for Hertz.
> 
> Suggested-by: Luc Michel <luc@lmichel.fr>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Reviewed-by: Luc Michel <luc@lmichel.fr>

> ---
>  include/qemu/cutils.h | 12 ++++++++++++
>  util/cutils.c         | 14 ++++++++++++++
>  2 files changed, 26 insertions(+)
> 
> diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
> index 3a86ec0321..4bbf4834ea 100644
> --- a/include/qemu/cutils.h
> +++ b/include/qemu/cutils.h
> @@ -158,6 +158,18 @@ int qemu_strtosz_metric(const char *nptr, const char **end, uint64_t *result);
>  
>  char *size_to_str(uint64_t val);
>  
> +/**
> + * freq_to_str:
> + * @freq_hz: frequency to stringify
> + *
> + * Return human readable string for frequency @freq_hz.
> + * Use SI units like KHz, MHz, and so forth.
> + *
> + * The caller is responsible for releasing the value returned
> + * with g_free() after use.
> + */
> +char *freq_to_str(uint64_t freq_hz);
> +
>  /* used to print char* safely */
>  #define STR_OR_NULL(str) ((str) ? (str) : "null")
>  
> diff --git a/util/cutils.c b/util/cutils.c
> index 8da34e04b0..be4e43a9ef 100644
> --- a/util/cutils.c
> +++ b/util/cutils.c
> @@ -885,6 +885,20 @@ char *size_to_str(uint64_t val)
>      return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
>  }
>  
> +char *freq_to_str(uint64_t freq_hz)
> +{
> +    static const char *const suffixes[] = { "", "K", "M", "G", "T", "P", "E" };
> +    double freq = freq_hz;
> +    size_t idx = 0;
> +
> +    while (freq >= 1000.0 && idx < ARRAY_SIZE(suffixes)) {
> +        freq /= 1000.0;
> +        idx++;
> +    }
> +
> +    return g_strdup_printf("%0.3g %sHz", freq, suffixes[idx]);
> +}
> +
>  int qemu_pstrcmp0(const char **str1, const char **str2)
>  {
>      return g_strcmp0(*str1, *str2);
> -- 
> 2.26.2
> 

--
Philippe Mathieu-Daudé Oct. 10, 2020, 4:31 p.m. UTC | #4 
On 10/1/20 8:42 PM, Eduardo Habkost wrote:
> On Thu, Oct 01, 2020 at 06:43:20PM +0200, Philippe Mathieu-Daudé wrote:
>> Introduce freq_to_str() to convert frequency values in human
>> friendly units using the SI units for Hertz.
>>
>> Suggested-by: Luc Michel <luc@lmichel.fr>
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>>   include/qemu/cutils.h | 12 ++++++++++++
>>   util/cutils.c         | 14 ++++++++++++++
>>   2 files changed, 26 insertions(+)
>>
>> diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
>> index 3a86ec0321..4bbf4834ea 100644
>> --- a/include/qemu/cutils.h
>> +++ b/include/qemu/cutils.h
>> @@ -158,6 +158,18 @@ int qemu_strtosz_metric(const char *nptr, const char **end, uint64_t *result);
>>   
>>   char *size_to_str(uint64_t val);
>>   
>> +/**
>> + * freq_to_str:
>> + * @freq_hz: frequency to stringify
>> + *
>> + * Return human readable string for frequency @freq_hz.
>> + * Use SI units like KHz, MHz, and so forth.
>> + *
>> + * The caller is responsible for releasing the value returned
>> + * with g_free() after use.
>> + */
>> +char *freq_to_str(uint64_t freq_hz);
>> +
>>   /* used to print char* safely */
>>   #define STR_OR_NULL(str) ((str) ? (str) : "null")
>>   
>> diff --git a/util/cutils.c b/util/cutils.c
>> index 8da34e04b0..be4e43a9ef 100644
>> --- a/util/cutils.c
>> +++ b/util/cutils.c
>> @@ -885,6 +885,20 @@ char *size_to_str(uint64_t val)
>>       return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
>>   }
>>   
>> +char *freq_to_str(uint64_t freq_hz)
>> +{
>> +    static const char *const suffixes[] = { "", "K", "M", "G", "T", "P", "E" };
>> +    double freq = freq_hz;
>> +    size_t idx = 0;
>> +
>> +    while (freq >= 1000.0 && idx < ARRAY_SIZE(suffixes)) {
>> +        freq /= 1000.0;
>> +        idx++;
>> +    }
>> +
>> +    return g_strdup_printf("%0.3g %sHz", freq, suffixes[idx]);
> 
> The only thing protecting this from out of bounds array access is
> the fact that UINT64_MAX is smaller than 1000E.  I wonder if this
> causes a Coverity warning.

Aren't we protected by the "idx < ARRAY_SIZE(suffixes)" check?

> 
>> +}
>> +
>>   int qemu_pstrcmp0(const char **str1, const char **str2)
>>   {
>>       return g_strcmp0(*str1, *str2);
>> -- 
>> 2.26.2
>>
>
diff mbox series

Patch

diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
index 3a86ec0321..4bbf4834ea 100644
--- a/include/qemu/cutils.h
+++ b/include/qemu/cutils.h
@@ -158,6 +158,18 @@  int qemu_strtosz_metric(const char *nptr, const char **end, uint64_t *result);
 
 char *size_to_str(uint64_t val);
 
+/**
+ * freq_to_str:
+ * @freq_hz: frequency to stringify
+ *
+ * Return human readable string for frequency @freq_hz.
+ * Use SI units like KHz, MHz, and so forth.
+ *
+ * The caller is responsible for releasing the value returned
+ * with g_free() after use.
+ */
+char *freq_to_str(uint64_t freq_hz);
+
 /* used to print char* safely */
 #define STR_OR_NULL(str) ((str) ? (str) : "null")
 
diff --git a/util/cutils.c b/util/cutils.c
index 8da34e04b0..be4e43a9ef 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -885,6 +885,20 @@  char *size_to_str(uint64_t val)
     return g_strdup_printf("%0.3g %sB", (double)val / div, suffixes[i]);
 }
 
+char *freq_to_str(uint64_t freq_hz)
+{
+    static const char *const suffixes[] = { "", "K", "M", "G", "T", "P", "E" };
+    double freq = freq_hz;
+    size_t idx = 0;
+
+    while (freq >= 1000.0 && idx < ARRAY_SIZE(suffixes)) {
+        freq /= 1000.0;
+        idx++;
+    }
+
+    return g_strdup_printf("%0.3g %sHz", freq, suffixes[idx]);
+}
+
 int qemu_pstrcmp0(const char **str1, const char **str2)
 {
     return g_strcmp0(*str1, *str2);