Re: [PATCH v2 20/20] kernel-shark: Integrate streams with libkshark-configio

["Yordan Karadzhov (VMware)" <y.karadz@gmail.com>]

On 5.11.20 г. 21:22 ч., Steven Rostedt wrote:
> On Mon, 12 Oct 2020 16:35:23 +0300
> "Yordan Karadzhov (VMware)" <y.karadz@gmail.com> wrote:
> 
>> +int kshark_import_trace_file(struct kshark_context *kshark_ctx,
>> +			     struct kshark_config_doc *conf)
>>   {
>> -	const char *file = NULL;
>> +	const char *file = NULL, *name = NULL;
>> +	int sd = -1;
>> +
>>   	switch (conf->format) {
>>   	case KS_CONFIG_JSON:
>> -		if (kshark_trace_file_from_json(&file, conf->conf_doc))
>> -			kshark_open(kshark_ctx, file);
>> +		if (kshark_trace_file_from_json(&file, &name, "data",
>> +						conf->conf_doc)) {
>> +			if (strcmp(name, "top") == 0) {
> 
> Is "top" something that could be named by a user? That is, we could have a
> conflict if a buffer is called "top"?
> 
> If this is a special meaning, then we should probably make this something A
> user can not do, or even better, unlikely to have. And we shouldn't have it
> hardcoded as "top" anyway, it should be a macro.
> 
> 
> #define KERNEL_SHARK_TOP_STREAM		"/ / / __Top__ / / /"
> 
> Then everywhere use that.
> 
> Like in kshark_tep_init_input():
> 
> 	stream->name = strdup(KERNEL_SHARK_TOP_STREAM);
> 
> And also replace "top" in this code with that macro as well.

Hi Steven,

In the review of patch 13/20 you already suggested to replace the name 
"top" with a non-printable character:

const char top_name[] = { 0x1b, 0x00 }; // Non printable character
#define TOP_NAME	(char *)&top_name

This change will be included in v3.

Thanks!
Yordan


> 
> -- Steve
> 
> 
>> +				sd = kshark_open(kshark_ctx, file);
>> +			} else {
>> +				int sd_top;
>> +
>> +				sd_top = kshark_tep_find_top_stream(kshark_ctx,
>> +								    file);
>> +				if (sd_top < 0) {
>> +					/*
>> +					 * The "top" steam (buffer) has to be
>> +					 * initialized first.
>> +					 */
>> +					sd_top = kshark_open(kshark_ctx, file);
>> +				}
>> +
>> +				if (sd_top >= 0)
>> +					sd = kshark_tep_open_buffer(kshark_ctx,
>> +								    sd_top,
>> +								    name);
>> +
>> +				if (sd >= 0)
>> +				kshark_tep_handle_plugins(kshark_ctx, sd);
>> +			}
>> +		}
>> +
>> +		break;
>>   
>> +	default:
>> +		fprintf(stderr, "Document format %d not supported\n",
>> +			conf->format);
>>   		break;
>> +	}
>> +
>> +	return sd;
>> +}