Implement lttng create --snapshot command

This is to ease the life of the user creating a session in snapshot
mode using the new API call.

Signed-off-by: David Goulet <dgoulet@efficios.com>

diff --git a/src/bin/lttng/commands/create.c b/src/bin/lttng/commands/create.c
index 72702d5a54743a1d91a652ebb6707ff428f156bd..d9880504f80c0adca416c9f7b5a1cc67b82d8a36 100644 (file)
--- a/src/bin/lttng/commands/create.c
+++ b/src/bin/lttng/commands/create.c
@@ -33,6 +33,7 @@
 #include <common/sessiond-comm/sessiond-comm.h>
 #include <common/uri.h>
 #include <common/utils.h>
+#include <lttng/snapshot.h>
 
 static char *opt_output_path;
 static char *opt_session_name;
@@ -41,6 +42,7 @@ static char *opt_ctrl_url;
 static char *opt_data_url;
 static int opt_no_consumer;
 static int opt_no_output;
+static int opt_snapshot;
 static int opt_disable_consumer;
 
 enum {
@@ -59,6 +61,7 @@ static struct poptOption long_options[] = {
        {"no-output",       0, POPT_ARG_VAL, &opt_no_output, 1, 0, 0},
        {"no-consumer",     0, POPT_ARG_VAL, &opt_no_consumer, 1, 0, 0},
        {"disable-consumer", 0, POPT_ARG_VAL, &opt_disable_consumer, 1, 0, 0},
+       {"snapshot",        0, POPT_ARG_VAL, &opt_snapshot, 1, 0, 0},
        {0, 0, 0, 0, 0, 0, 0}
 };
 
@@ -83,6 +86,11 @@ static void usage(FILE *ofp)
        fprintf(ofp, "      --list-options   Simple listing of options\n");
        fprintf(ofp, "  -o, --output PATH    Specify output path for traces\n");
        fprintf(ofp, "      --no-output      Traces will not be outputed\n");
+       fprintf(ofp, "      --snasphot       Set the session in snapshot mode.\n");
+       fprintf(ofp, "                       Created in no-output mode and uses the URL,\n");
+       fprintf(ofp, "                       if one, as the default snapshot output.\n");
+       fprintf(ofp, "                       Every channel will be set in overwrite mode\n");
+       fprintf(ofp, "                       and with mmap output (splice not supported).\n");
        fprintf(ofp, "\n");
        fprintf(ofp, "Extended Options:\n");
        fprintf(ofp, "\n");
@@ -170,6 +178,46 @@ error:
        return ret;
 }
 
+static int add_snapshot_output(const char *session_name, const char *ctrl_url,
+               const char *data_url)
+{
+       int ret;
+       struct lttng_snapshot_output *output = NULL;
+
+       assert(session_name);
+
+       output = lttng_snapshot_output_create();
+       if (!output) {
+               ret = CMD_FATAL;
+               goto error_create;
+       }
+
+       if (ctrl_url) {
+               ret = lttng_snapshot_output_set_ctrl_url(ctrl_url, output);
+               if (ret < 0) {
+                       goto error;
+               }
+       }
+
+       if (data_url) {
+               ret = lttng_snapshot_output_set_data_url(data_url, output);
+               if (ret < 0) {
+                       goto error;
+               }
+       }
+
+       /* This call, if successful, populates the id of the output object. */
+       ret = lttng_snapshot_add_output(session_name, output);
+       if (ret < 0) {
+               goto error;
+       }
+
+error:
+       lttng_snapshot_output_destroy(output);
+error_create:
+       return ret;
+}
+
 /*
  *  Create a tracing session.
  *  If no name is specified, a default name is generated.
@@ -276,7 +324,7 @@ static int create_session(void)
                        print_str_url = alloc_url + strlen("file://");
                }
        } else {
-               /* No output means --no-output. */
+               /* No output means --no-output or --snapshot mode. */
                url = NULL;
        }
 
@@ -286,7 +334,20 @@ static int create_session(void)
                goto error;
        }
 
-       ret = _lttng_create_session_ext(session_name, url, datetime);
+       if (opt_snapshot) {
+               /* No output by default. */
+               const char *snapshot_url = NULL;
+
+               if (opt_url) {
+                       snapshot_url = url;
+               } else if (!opt_data_url && !opt_ctrl_url) {
+                       /* This is the session path that we need to use as output. */
+                       snapshot_url = url;
+               }
+               ret = lttng_create_session_snapshot(session_name, snapshot_url);
+       } else {
+               ret = _lttng_create_session_ext(session_name, url, datetime);
+       }
        if (ret < 0) {
                /* Don't set ret so lttng can interpret the sessiond error. */
                switch (-ret) {
@@ -300,8 +361,13 @@ static int create_session(void)
        }
 
        if (opt_ctrl_url && opt_data_url) {
-               /* Setting up control URI (-C or/and -D opt) */
-               ret = set_consumer_url(session_name, opt_ctrl_url, opt_data_url);
+               if (opt_snapshot) {
+                       ret = add_snapshot_output(session_name, opt_ctrl_url,
+                                       opt_data_url);
+               } else {
+                       /* Setting up control URI (-C or/and -D opt) */
+                       ret = set_consumer_url(session_name, opt_ctrl_url, opt_data_url);
+               }
                if (ret < 0) {
                        /* Destroy created session because the URL are not valid. */
                        lttng_destroy_session(session_name);
@@ -310,8 +376,14 @@ static int create_session(void)
        }
 
        MSG("Session %s created.", session_name);
-       if (print_str_url) {
+       if (print_str_url && !opt_snapshot) {
                MSG("Traces will be written in %s", print_str_url);
+       } else if (opt_snapshot) {
+               if (print_str_url) {
+                       MSG("Default snapshot output set to: %s", print_str_url);
+               }
+               MSG("Snapshot mode set. Every channel enabled for that session will "
+                               "be set in overwrite mode and mmap output");
        }
 
        /* Init lttng session config */