2015-12-24 11:22:58

by Gujulan Elango, Hari Prasath (H.)

Subject: [PATCH] staging: most: replace multiple if..else with table lookup

From: Hari Prasath Gujulan Elango <[email protected]>

Replace multiple if..else if..statements with simple table lookup in two
functions.

Signed-off-by: Hari Prasath Gujulan Elango <[email protected]>
---
drivers/staging/most/mostcore/core.c | 39 ++++++++++++++++++++----------------
1 file changed, 22 insertions(+), 17 deletions(-)

diff --git a/drivers/staging/most/mostcore/core.c b/drivers/staging/most/mostcore/core.c
index ed1ed25..7b4636b 100644
--- a/drivers/staging/most/mostcore/core.c
+++ b/drivers/staging/most/mostcore/core.c
@@ -82,6 +82,14 @@ struct most_inst_obj {
struct list_head list;
};

+static const struct {
+ int most_ch_data_type;
+ char *name;
+} ch_data_type[] = { { MOST_CH_CONTROL, "control\n" },
+ { MOST_CH_ASYNC, "async\n" },
+ { MOST_CH_SYNC, "sync\n" },
+ { MOST_CH_ISOC_AVP, "isoc_avp\n"} };
+
#define to_inst_obj(d) container_of(d, struct most_inst_obj, kobj)

/**
@@ -414,14 +422,12 @@ static ssize_t show_set_datatype(struct most_c_obj *c,
struct most_c_attr *attr,
char *buf)
{
- if (c->cfg.data_type & MOST_CH_CONTROL)
- return snprintf(buf, PAGE_SIZE, "control\n");
- else if (c->cfg.data_type & MOST_CH_ASYNC)
- return snprintf(buf, PAGE_SIZE, "async\n");
- else if (c->cfg.data_type & MOST_CH_SYNC)
- return snprintf(buf, PAGE_SIZE, "sync\n");
- else if (c->cfg.data_type & MOST_CH_ISOC_AVP)
- return snprintf(buf, PAGE_SIZE, "isoc_avp\n");
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) {
+ if (c->cfg.data_type & ch_data_type[i].most_ch_data_type)
+ return snprintf(buf, PAGE_SIZE, ch_data_type[i].name);
+ }
return snprintf(buf, PAGE_SIZE, "unconfigured\n");
}

@@ -430,15 +436,14 @@ static ssize_t store_set_datatype(struct most_c_obj *c,
const char *buf,
size_t count)
{
- if (!strcmp(buf, "control\n")) {
- c->cfg.data_type = MOST_CH_CONTROL;
- } else if (!strcmp(buf, "async\n")) {
- c->cfg.data_type = MOST_CH_ASYNC;
- } else if (!strcmp(buf, "sync\n")) {
- c->cfg.data_type = MOST_CH_SYNC;
- } else if (!strcmp(buf, "isoc_avp\n")) {
- c->cfg.data_type = MOST_CH_ISOC_AVP;
- } else {
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) {
+ if (!strcmp(buf, ch_data_type[i].name))
+ c->cfg.data_type = ch_data_type[i].most_ch_data_type;
+ }
+
+ if (i == ARRAY_SIZE(ch_data_type)) {
pr_info("WARN: invalid attribute settings\n");
return -EINVAL;
}
--
1.9.1

2015-12-24 16:06:32

by Joe Perches

Subject: Re: [PATCH] staging: most: replace multiple if..else with table lookup

On Thu, 2015-12-24 at 10:49 +0000, Gujulan Elango, Hari Prasath (H.) wrote:
> From: Hari Prasath Gujulan Elango <[email protected]>
>
> Replace multiple if..else if..statements with simple table lookup in two
> functions.
>
> Signed-off-by: Hari Prasath Gujulan Elango <[email protected]>
> ---
> ?drivers/staging/most/mostcore/core.c | 39 ++++++++++++++++++++----------------
> ?1 file changed, 22 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/staging/most/mostcore/core.c b/drivers/staging/most/mostcore/core.c
> index ed1ed25..7b4636b 100644
> --- a/drivers/staging/most/mostcore/core.c
> +++ b/drivers/staging/most/mostcore/core.c
> @@ -82,6 +82,14 @@ struct most_inst_obj {
> ? struct list_head list;
> ?};
> ?
> +static const struct {
> + int most_ch_data_type;
> + char *name;
> +} ch_data_type[] = { { MOST_CH_CONTROL, "control\n" },
> + { MOST_CH_ASYNC, "async\n" },
> + { MOST_CH_SYNC, "sync\n" },
> + { MOST_CH_ISOC_AVP, "isoc_avp\n"} };
> +
> ?#define to_inst_obj(d) container_of(d, struct most_inst_obj, kobj)
> ?
> ?/**
> @@ -414,14 +422,12 @@ static ssize_t show_set_datatype(struct most_c_obj *c,
> ? ?struct most_c_attr *attr,
> ? ?char *buf)
> ?{
> - if (c->cfg.data_type & MOST_CH_CONTROL)
> - return snprintf(buf, PAGE_SIZE, "control\n");
> - else if (c->cfg.data_type & MOST_CH_ASYNC)
> - return snprintf(buf, PAGE_SIZE, "async\n");
> - else if (c->cfg.data_type & MOST_CH_SYNC)
> - return snprintf(buf, PAGE_SIZE, "sync\n");
> - else if (c->cfg.data_type & MOST_CH_ISOC_AVP)
> - return snprintf(buf, PAGE_SIZE, "isoc_avp\n");
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) {
> + if (c->cfg.data_type & ch_data_type[i].most_ch_data_type)
> + return snprintf(buf, PAGE_SIZE, ch_data_type[i].name);
> + }
> ? return snprintf(buf, PAGE_SIZE, "unconfigured\n");
> ?}
> ?
> @@ -430,15 +436,14 @@ static ssize_t store_set_datatype(struct most_c_obj *c,
> ? ??const char *buf,
> ? ??size_t count)
> ?{
> - if (!strcmp(buf, "control\n")) {
> - c->cfg.data_type = MOST_CH_CONTROL;
> - } else if (!strcmp(buf, "async\n")) {
> - c->cfg.data_type = MOST_CH_ASYNC;
> - } else if (!strcmp(buf, "sync\n")) {
> - c->cfg.data_type = MOST_CH_SYNC;
> - } else if (!strcmp(buf, "isoc_avp\n")) {
> - c->cfg.data_type = MOST_CH_ISOC_AVP;
> - } else {
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) {
> + if (!strcmp(buf, ch_data_type[i].name))
> + c->cfg.data_type = ch_data_type[i].most_ch_data_type;

Missing braces and break;

> + }
> +
> + if (i == ARRAY_SIZE(ch_data_type)) {
> ? pr_info("WARN: invalid attribute settings\n");
> ? return -EINVAL;
> ? }

This seems like a lot of code for a simple test.

2015-12-30 10:45:04

by Gujulan Elango, Hari Prasath (H.)

Subject: Re: [PATCH] staging: most: replace multiple if..else with table lookup

On Thu, Dec 24, 2015 at 08:06:26AM -0800, Joe Perches wrote:
> On Thu, 2015-12-24 at 10:49 +0000, Gujulan Elango, Hari Prasath (H.) wrote:
> > From: Hari Prasath Gujulan Elango <[email protected]>
> >
> > Replace multiple if..else if..statements with simple table lookup in two
> > functions.
> >
> > Signed-off-by: Hari Prasath Gujulan Elango <[email protected]>
> > ---
> > ?drivers/staging/most/mostcore/core.c | 39 ++++++++++++++++++++----------------
> > ?1 file changed, 22 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/staging/most/mostcore/core.c b/drivers/staging/most/mostcore/core.c
> > index ed1ed25..7b4636b 100644
> > --- a/drivers/staging/most/mostcore/core.c
> > +++ b/drivers/staging/most/mostcore/core.c
> > @@ -82,6 +82,14 @@ struct most_inst_obj {
> > ? struct list_head list;
> > ?};
> > ?
> > +static const struct {
> > + int most_ch_data_type;
> > + char *name;
> > +} ch_data_type[] = { { MOST_CH_CONTROL, "control\n" },
> > + { MOST_CH_ASYNC, "async\n" },
> > + { MOST_CH_SYNC, "sync\n" },
> > + { MOST_CH_ISOC_AVP, "isoc_avp\n"} };
> > +
> > ?#define to_inst_obj(d) container_of(d, struct most_inst_obj, kobj)
> > ?
> > ?/**
> > @@ -414,14 +422,12 @@ static ssize_t show_set_datatype(struct most_c_obj *c,
> > ? ?struct most_c_attr *attr,
> > ? ?char *buf)
> > ?{
> > - if (c->cfg.data_type & MOST_CH_CONTROL)
> > - return snprintf(buf, PAGE_SIZE, "control\n");
> > - else if (c->cfg.data_type & MOST_CH_ASYNC)
> > - return snprintf(buf, PAGE_SIZE, "async\n");
> > - else if (c->cfg.data_type & MOST_CH_SYNC)
> > - return snprintf(buf, PAGE_SIZE, "sync\n");
> > - else if (c->cfg.data_type & MOST_CH_ISOC_AVP)
> > - return snprintf(buf, PAGE_SIZE, "isoc_avp\n");
> > + int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) {
> > + if (c->cfg.data_type & ch_data_type[i].most_ch_data_type)
> > + return snprintf(buf, PAGE_SIZE, ch_data_type[i].name);
> > + }
> > ? return snprintf(buf, PAGE_SIZE, "unconfigured\n");
> > ?}
> > ?
> > @@ -430,15 +436,14 @@ static ssize_t store_set_datatype(struct most_c_obj *c,
> > ? ??const char *buf,
> > ? ??size_t count)
> > ?{
> > - if (!strcmp(buf, "control\n")) {
> > - c->cfg.data_type = MOST_CH_CONTROL;
> > - } else if (!strcmp(buf, "async\n")) {
> > - c->cfg.data_type = MOST_CH_ASYNC;
> > - } else if (!strcmp(buf, "sync\n")) {
> > - c->cfg.data_type = MOST_CH_SYNC;
> > - } else if (!strcmp(buf, "isoc_avp\n")) {
> > - c->cfg.data_type = MOST_CH_ISOC_AVP;
> > - } else {
> > + int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(ch_data_type); i++) {
> > + if (!strcmp(buf, ch_data_type[i].name))
> > + c->cfg.data_type = ch_data_type[i].most_ch_data_type;
>
> Missing braces and break;
>
> > + }
> > +
> > + if (i == ARRAY_SIZE(ch_data_type)) {
> > ? pr_info("WARN: invalid attribute settings\n");
> > ? return -EINVAL;
> > ? }
>
> This seems like a lot of code for a simple test.
>
Hello Joe,
I have sent a v2 for this patch with corrections made.

Regards,
Hari Prasath-