Re: [PATCH V3 4/6] perf tools: add perf_data_file__open_tmp

[Jiri Olsa]

On Fri, Oct 20, 2017 at 01:05:32PM -0700, kan.liang@xxxxxxxxx wrote:
> From: Kan Liang <Kan.liang@xxxxxxxxx>
> 
> And an interface for perf_data_file to open tmp file.
> Automatically generate the tmp file name if it's not assigned. The name
> cannot be const char. Introduce char *tmp_path for it.
> The tmp file will be deleted after close.
> 
> It will be used as per-thread file to temporarily store event synthesizd
> result in the following patch.
> 
> Signed-off-by: Kan Liang <Kan.liang@xxxxxxxxx>
> ---
>  tools/perf/util/data.c | 26 ++++++++++++++++++++++++++
>  tools/perf/util/data.h |  2 ++
>  2 files changed, 28 insertions(+)
> 
> diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c
> index 1123b30..cd6fdf9 100644
> --- a/tools/perf/util/data.c
> +++ b/tools/perf/util/data.c
> @@ -139,9 +139,35 @@ int perf_data_file__open(struct perf_data_file *file)
>  	return open_file(file);
>  }
>  
> +int perf_data_file__open_tmp(struct perf_data_file *file)
> +{
> +	int fd;
> +
> +	if (!file->tmp_path &&
> +	    (asprintf(&file->tmp_path, "perf.tmp.XXXXXX") < 0))
> +		goto err;
> +
> +	fd = mkstemp(file->tmp_path);
> +	if (fd < 0) {
> +		free(file->tmp_path);
> +		goto err;
> +	}
> +
> +	file->fd = fd;
> +	return 0;
> +err:
> +	file->tmp_path = NULL;
> +	return -1;
> +}
> +
>  void perf_data_file__close(struct perf_data_file *file)
>  {
>  	close(file->fd);
> +	if (file->tmp_path) {
> +		unlink(file->tmp_path);
> +		free(file->tmp_path);
> +		file->tmp_path = NULL;
> +	}
>  }
>  
>  ssize_t perf_data_file__write(struct perf_data_file *file,
> diff --git a/tools/perf/util/data.h b/tools/perf/util/data.h
> index ae510ce..892b3d5 100644
> --- a/tools/perf/util/data.h
> +++ b/tools/perf/util/data.h
> @@ -10,6 +10,7 @@ enum perf_data_mode {
>  
>  struct perf_data_file {
>  	const char		*path;
> +	char			*tmp_path;

could we add is_tmp instead of new path pointer
and keep the path for the name..?

thanks,
jirka