On 07/26/2013 10:57 PM, Jonathan Nieder wrote:
> Hi,
>
> Stefan Beller wrote:
>
>> --- a/git.c
>> +++ b/git.c
>> @@ -309,9 +309,18 @@ static int run_builtin(struct cmd_struct *p, int argc,
>> const char **argv)
>> return 0;
>> }
>>
>> +static int compare_internal_command(const void *a, const void *b) {
>> + /* The first parameter is of type char* describing the name,
>> + the second is a struct cmd_struct */
>
> Style:
>
> /*
> * Multi-line comments in git look like this, with an initial
> * "/*" line, a leading "*" on each line with text, and a line
> * with '*' '/' at the end.
> */
>
> [...]
Thanks for noting, however as Eric points out, that comment was not
enlightening, so I removed it.
>> @@ -447,12 +456,12 @@ static void handle_internal_command(int argc, const
>> char **argv)
>> argv[0] = cmd = "help";
>> }
>>
>> - for (i = 0; i < ARRAY_SIZE(commands); i++) {
>> - struct cmd_struct *p = commands+i;
>> - if (strcmp(p->cmd, cmd))
>> - continue;
>> + struct cmd_struct *p = (struct cmd_struct *)bsearch(cmd, commands,
>> + ARRAY_SIZE(commands), sizeof(struct cmd_struct),
>> + compare_internal_command);
>
> No need to cast --- this is C.
Also removed.
>
> Fun. Does this result in a measurable speedup, or is it just for more
> pleasant reading?
>
> Thanks and hope that helps,
> Jonathan
>
premature optimization is the root of all evil....
I tried hard to come up with a benchmark, but this is lost in the
noise. I could not figure out a way to reproducably make sure this
patch is really faster.
So I tried to `time git add COPYING` to show it's not getting slower
for the first entries in the list as well as `git fast-external-command`
whereas the fast-external-command is just an int main() {return 0; }
to check if the external commands, which are executed after searching
through all the internals come up faster.
However I could not find a speedup.
So if the patch is accepted, it would only be for readability.
I was fiddling around with make now to include the suggestion of Eric to
check the arguments for being sorted in make. However I do not
seem to fully understand the syntax yet.
My approach would have been:
sorted_internal_cmds: git.c
{ awk '/cmd_struct commands/,/};/ { if (match($2,/"/)) print $2 }'
<git.c >builtin.actual && \
sort <builtin.actual >builtin.expect && \
cmp -s builtin.expect builtin.actual && \
rm builtin.expect builtin.actual \
}
all:: sorted_internal_cmds
But then there is
$ make
...
}
/bin/sh: 5: Syntax error: end of file unexpected (expecting "}")
So I suspect the { within the shell code inside the awk parameter is messing up?
Thanks,
Stefan
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