Fix: improve lttng with live by spawning relayd

[lttng-tools.git] / src / bin / lttng / commands / view.c

diff --git a/src/bin/lttng/commands/view.c b/src/bin/lttng/commands/view.c
index d339282e61e7513b3559643d646f5d847a20bf24..adedf298966c0c7fad786f13bb34a66f4698a6de 100644 (file)
--- a/src/bin/lttng/commands/view.c
+++ b/src/bin/lttng/commands/view.c
@@ -76,6 +76,9 @@ static struct viewers {
        { NULL, VIEWER_USER_DEFINED },
 };
 
+/* Is the session we are trying to view is in live mode. */
+static int session_live_mode;
+
 /*
  * usage
  */
@@ -179,20 +182,38 @@ static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len,
                const char *trace_path)
 {
        char **argv;
-       size_t size;
+       size_t size, mem_len;
+
+
+       /* Add one for the NULL terminating element. */
+       mem_len = opts_len + 1;
+       if (session_live_mode) {
+               /* Add 3 option for the live mode being "-i lttng-live URL". */
+               mem_len += 3;
+       } else {
+               /* Add option for the trace path. */
+               mem_len += 1;
+       }
 
-       size = sizeof(char *) * opts_len;
+       size = sizeof(char *) * mem_len;
 
        /* Add two here for the trace_path and the NULL terminating element. */
-       argv = malloc(size + 2);
+       argv = malloc(size);
        if (argv == NULL) {
                goto error;
        }
 
        memcpy(argv, opts, size);
 
-       argv[opts_len] = (char *)trace_path;
-       argv[opts_len + 1] = NULL;
+       if (session_live_mode) {
+               argv[opts_len] = "-i";
+               argv[opts_len + 1] = "lttng-live";
+               argv[opts_len + 2] = (char *) trace_path;
+               argv[opts_len + 3] = NULL;
+       } else {
+               argv[opts_len] = (char *) trace_path;
+               argv[opts_len + 1] = NULL;
+       }
 
 error:
        return argv;
@@ -273,13 +294,39 @@ error:
        return ret;
 }
 
+/*
+ * Build the live path we need for the lttng live view.
+ */
+static char *build_live_path(char *session_name)
+{
+       int ret;
+       char *path = NULL;
+       char hostname[HOST_NAME_MAX];
+
+       ret = gethostname(hostname, sizeof(hostname));
+       if (ret < 0) {
+               perror("gethostname");
+               goto error;
+       }
+
+       ret = asprintf(&path, "net://localhost/host/%s/%s", hostname,
+                       session_name);
+       if (ret < 0) {
+               perror("asprintf live path");
+               goto error;
+       }
+
+error:
+       return path;
+}
+
 /*
  * Exec viewer if found and use session name path.
  */
 static int view_trace(void)
 {
        int ret;
-       char *session_name, *trace_path;
+       char *session_name, *trace_path = NULL;
        struct lttng_session *sessions = NULL;
 
        /*
@@ -340,14 +387,28 @@ static int view_trace(void)
                        goto free_sessions;
                }
 
-               trace_path = sessions[i].path;
+               session_live_mode = sessions[i].live_timer_interval;
+
+               DBG("Session live mode set to %d", session_live_mode);
 
-               if (sessions[i].enabled) {
+               if (sessions[i].enabled && !session_live_mode) {
                        WARN("Session %s is running. Please stop it before reading it.",
                                        session_name);
                        ret = CMD_ERROR;
                        goto free_sessions;
                }
+
+               /* If the timer interval is set we are in live mode. */
+               if (session_live_mode) {
+                       trace_path = build_live_path(session_name);
+                       if (!trace_path) {
+                               ret = CMD_ERROR;
+                               goto free_sessions;
+                       }
+               } else {
+                       /* Get file system session path. */
+                       trace_path = sessions[i].path;
+               }
        } else {
                trace_path = opt_trace_path;
        }
@@ -361,6 +422,9 @@ static int view_trace(void)
        }
 
 free_sessions:
+       if (session_live_mode) {
+               free(trace_path);
+       }
        free(sessions);
 free_error:
        if (opt_session_name == NULL) {