On Tue, 14 Aug 2018 21:03:48 +0300
"Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx> wrote:
> This patch introduces a basic example, showing how to use the
> C API of KernelShark to import/export configuration data.
>
Maybe this is a good way for me to describe what I'm trying to get at.
> Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@xxxxxxxxx>
> ---
> kernel-shark-qt/examples/CMakeLists.txt | 4 ++
> kernel-shark-qt/examples/configio.c | 67 +++++++++++++++++++++++++
> 2 files changed, 71 insertions(+)
> create mode 100644 kernel-shark-qt/examples/configio.c
>
> diff --git a/kernel-shark-qt/examples/CMakeLists.txt b/kernel-shark-qt/examples/CMakeLists.txt
> index 6906eba..a3745fa 100644
> --- a/kernel-shark-qt/examples/CMakeLists.txt
> +++ b/kernel-shark-qt/examples/CMakeLists.txt
> @@ -11,3 +11,7 @@ target_link_libraries(dfilter kshark)
> message(STATUS "datahisto")
> add_executable(dhisto datahisto.c)
> target_link_libraries(dhisto kshark)
> +
> +message(STATUS "confogio")
> +add_executable(confio configio.c)
> +target_link_libraries(confio kshark)
> diff --git a/kernel-shark-qt/examples/configio.c b/kernel-shark-qt/examples/configio.c
> new file mode 100644
> index 0000000..b7efad1
> --- /dev/null
> +++ b/kernel-shark-qt/examples/configio.c
> @@ -0,0 +1,67 @@
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +#include "libkshark.h"
> +
> +int main(int argc, char **argv)
> +{
> + struct kshark_config_doc *conf, *filter, *hello;
> + struct kshark_context *kshark_ctx;
> + int *ids, i;
> +
> + /* Create a new kshark session. */
> + kshark_ctx = NULL;
> + if (!kshark_instance(&kshark_ctx))
> + return 1;
> +
> + if (argc == 1) {
> + tracecmd_filter_id_add(kshark_ctx->show_task_filter, 314);
> + tracecmd_filter_id_add(kshark_ctx->show_task_filter, 42);
> +
> + /* Create a new Confog. doc. */
> + conf = kshark_config_new("foo.bar.config", KS_JSON_CONFIG);
> +
> + /* Add filter's info. */
> + filter = kshark_export_all_filters(kshark_ctx);
> + kshark_config_doc_add(conf, "Filters" ,filter);
> +
> + /* Add "Hello Kernel" message. */
> + hello = kshark_string_config_alloc();
> + hello->conf_doc = "Hello Kernel";
> + kshark_config_doc_add(conf, "Message" ,hello);
What I meant by having the API at too low of a level, is that instead
of having to do:
hello = kshark_string_config_alloc();
hello->conf_doc = "Hello Kernel";
kshark_config_doc_add(conf, "Message", hello);
We should have:
kshark_config_doc_add_message(conf, "Hello Kernel");
And that be something that does everything we need.
> +
> + /* Save to file. */
> + kshark_save_config_file("conf.json", conf);
> + } else {
> + /* Open a Config. file. */
> + conf = kshark_open_config_file(argv[1], "foo.bar.config");
> +
> + /* Retriever the filter's info. */
> + filter = kshark_config_alloc(KS_JSON_CONFIG);
> + if (!kshark_config_doc_get(conf, "Filters" ,filter))
> + return 1;
> +
> + kshark_import_all_filters(kshark_ctx, filter);
> +
> + /* Get the array of Ids to be fitered. */
> + ids = tracecmd_filter_ids(kshark_ctx->show_task_filter);
Instead of having to do:
filter = kshark_config_alloc(KS_JSON_CONFIG);
kshark_config_doc_get(conf, "Filters", filter);
kshark_import_all_filters(kshark_ctx, filter);
ids = tracecmd_filter_ids(...);
We should have:
ids = kshark_doc_get_all_filters(kshark_ctx, conf);
See what I'm trying to get at. Think higher level. The API should be
the functionality we want, not the implementation level. Abstract that
part out.
Make sense?
-- Steve
> + for (i = 0; i < kshark_ctx->show_task_filter->count; ++i)
> + printf("pid: %i\n", ids[i]);
> +
> + /* Retriever the message. */
> + hello = kshark_string_config_alloc();
> + kshark_config_doc_get(conf, "Message" ,hello);
> +
> + puts((char *) hello->conf_doc);
> +
> + free(filter);
> + free(hello);
> + free(ids);
> + }
> +
> + kshark_free_config_doc(conf);
> +
> + kshark_free(kshark_ctx);
> +
> + return 0;
> +}
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