lttng-view: clean-up: move `--viewer` code to specific file
authorFrancis Deslauriers <francis.deslauriers@efficios.com>
Fri, 3 Apr 2020 18:21:25 +0000 (14:21 -0400)
committerJérémie Galarneau <jeremie.galarneau@efficios.com>
Fri, 3 Apr 2020 22:33:12 +0000 (18:33 -0400)
This code will be reuse by the lttng-crash utility.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: Ide72ad08577d55bbf2f7833d46e734b8a680c9d2
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
src/bin/lttng/commands/view.c
src/common/Makefile.am
src/common/spawn-viewer.c [new file with mode: 0644]
src/common/spawn-viewer.h [new file with mode: 0644]

index 3ba5766ea00c0e45dd332126956434d579bdf7d9..d7632b62bd722259c9b2c23f5c01bf2e0028dc9c 100644 (file)
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <common/spawn-viewer.h>
 #include "../command.h"
 
 static char *opt_session_name;
 static char *opt_viewer;
 static char *opt_trace_path;
-static const char *babeltrace_bin = CONFIG_BABELTRACE_BIN;
-static const char *babeltrace2_bin = CONFIG_BABELTRACE2_BIN;
 
 #ifdef LTTNG_EMBED_HELP
 static const char help_msg[] =
@@ -42,232 +41,9 @@ static struct poptOption long_options[] = {
        {0, 0, 0, 0, 0, 0, 0}
 };
 
-/*
- * This is needed for each viewer since we are using execvp().
- */
-static const char *babeltrace_opts[] = { "babeltrace" };
-static const char *babeltrace2_opts[] = { "babeltrace2" };
-
-/*
- * Type is also use as the index in the viewers array. So please, make sure
- * your enum value is in the right order in the array below.
- */
-enum viewer_type {
-       VIEWER_BABELTRACE    = 0,
-       VIEWER_BABELTRACE2   = 1,
-       VIEWER_USER_DEFINED  = 2,
-};
-
-static const struct viewer {
-       const char *exec_name;
-       enum viewer_type type;
-} viewers[] = {
-       { "babeltrace", VIEWER_BABELTRACE },
-       { "babeltrace2", VIEWER_BABELTRACE2 },
-       { NULL, VIEWER_USER_DEFINED },
-};
-
 /* Is the session we are trying to view is in live mode. */
 static int session_live_mode;
 
-static const struct viewer *parse_viewer_option(void)
-{
-       if (opt_viewer == NULL) {
-               /* Default is babeltrace2 */
-               return &(viewers[VIEWER_BABELTRACE2]);
-       }
-
-       return &(viewers[VIEWER_USER_DEFINED]);
-}
-
-/*
- * Alloc an array of string pointer from a simple string having all options
- * seperated by spaces. Also adds the trace path to the arguments.
- *
- * The returning pointer is ready to be passed to execvp().
- */
-static char **alloc_argv_from_user_opts(char *opts, const char *trace_path)
-{
-       int i = 0, ignore_space = 0;
-       unsigned int num_opts = 1;
-       char **argv, *token = opts;
-
-       /* Count number of arguments. */
-       do {
-               if (*token == ' ') {
-                       /* Use to ignore consecutive spaces */
-                       if (!ignore_space) {
-                               num_opts++;
-                       }
-                       ignore_space = 1;
-               } else {
-                       ignore_space = 0;
-               }
-               token++;
-       } while (*token != '\0');
-
-       /* Add two here for the NULL terminating element and trace path */
-       argv = zmalloc(sizeof(char *) * (num_opts + 2));
-       if (argv == NULL) {
-               goto error;
-       }
-
-       token = strtok(opts, " ");
-       while (token != NULL) {
-               argv[i] = strdup(token);
-               if (argv[i] == NULL) {
-                       goto error;
-               }
-               token = strtok(NULL, " ");
-               i++;
-       }
-
-       argv[num_opts] = (char *) trace_path;
-       argv[num_opts + 1] = NULL;
-
-       return argv;
-
-error:
-       if (argv) {
-               for (i = 0; i < num_opts + 2; i++) {
-                       free(argv[i]);
-               }
-               free(argv);
-       }
-
-       return NULL;
-}
-
-/*
- * Alloc an array of string pointer from an array of strings. It also adds
- * the trace path to the argv.
- *
- * The returning pointer is ready to be passed to execvp().
- */
-static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len,
-               const char *trace_path)
-{
-       char **argv;
-       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 *) * mem_len;
-
-       /* Add two here for the trace_path and the NULL terminating element. */
-       argv = zmalloc(size);
-       if (argv == NULL) {
-               goto error;
-       }
-
-       memcpy(argv, opts, sizeof(char *) * opts_len);
-
-       if (session_live_mode) {
-               argv[opts_len] = (char *) "-i";
-               argv[opts_len + 1] = (char *) "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;
-}
-
-/*
- * Spawn viewer with the trace directory path.
- */
-static int spawn_viewer(const char *trace_path)
-{
-       int ret = 0;
-       struct stat status;
-       const char *viewer_bin = NULL;
-       const struct viewer *viewer;
-       char **argv = NULL;
-
-       /* Check for --viewer option. */
-       viewer = parse_viewer_option();
-       if (viewer == NULL) {
-               ret = CMD_ERROR;
-               goto error;
-       }
-
-retry_viewer:
-       switch (viewer->type) {
-       case VIEWER_BABELTRACE2:
-               if (stat(babeltrace2_bin, &status) == 0) {
-                       viewer_bin = babeltrace2_bin;
-               } else {
-                       viewer_bin = viewer->exec_name;
-               }
-               argv = alloc_argv_from_local_opts(babeltrace2_opts,
-                               ARRAY_SIZE(babeltrace2_opts), trace_path);
-               break;
-       case VIEWER_BABELTRACE:
-               if (stat(babeltrace_bin, &status) == 0) {
-                       viewer_bin = babeltrace_bin;
-               } else {
-                       viewer_bin = viewer->exec_name;
-               }
-               argv = alloc_argv_from_local_opts(babeltrace_opts,
-                               ARRAY_SIZE(babeltrace_opts), trace_path);
-               break;
-       case VIEWER_USER_DEFINED:
-               argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
-               if (argv) {
-                       viewer_bin = argv[0];
-               }
-               break;
-       default:
-               viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
-               argv = alloc_argv_from_local_opts(babeltrace_opts,
-                               ARRAY_SIZE(babeltrace_opts), trace_path);
-               break;
-       }
-
-       if (argv == NULL || !viewer_bin) {
-               ret = CMD_FATAL;
-               goto error;
-       }
-
-       DBG("Using %s viewer", viewer_bin);
-
-       ret = execvp(viewer_bin, argv);
-       if (ret) {
-               if (errno == ENOENT && viewer->exec_name) {
-                       if (viewer->type == VIEWER_BABELTRACE2) {
-                               /* Fallback to legacy babeltrace. */
-                               DBG("babeltrace2 not installed on the system, falling back to babeltrace 1.x");
-                               viewer = &viewers[VIEWER_BABELTRACE];
-                               free(argv);
-                               argv = NULL;
-                               goto retry_viewer;
-                       } else {
-                               ERR("Viewer \"%s\" not found on the system",
-                                               viewer_bin);
-                       }
-               } else {
-                       PERROR("Failed to launch \"%s\" viewer", viewer_bin);
-               }
-               ret = CMD_FATAL;
-               goto error;
-       }
-
-error:
-       free(argv);
-       return ret;
-}
-
 /*
  * Build the live path we need for the lttng live view.
  */
@@ -391,7 +167,7 @@ static int view_trace(void)
 
        MSG("Trace directory: %s\n", trace_path);
 
-       ret = spawn_viewer(trace_path);
+       ret = spawn_viewer(trace_path, opt_viewer, session_live_mode);
        if (ret < 0) {
                /* Don't set ret so lttng can interpret the sessiond error. */
                goto free_sessions;
index 1c9c8e4f04ecfc3d677182cfe5674e0ed4308dc6..cca159e564b53ba6b7f74d303d3e30af17fa4013 100644 (file)
@@ -55,6 +55,7 @@ libcommon_la_SOURCES = \
        session-consumed-size.c \
        session-descriptor.c \
        session-rotation.c \
+       spawn-viewer.c spawn-viewer.h \
        time.c \
        trace-chunk.c trace-chunk.h \
        trace-chunk-registry.h \
diff --git a/src/common/spawn-viewer.c b/src/common/spawn-viewer.c
new file mode 100644 (file)
index 0000000..26fe919
--- /dev/null
@@ -0,0 +1,256 @@
+/*
+ * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include <assert.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <lttng/constant.h>
+
+#include "error.h"
+#include "macros.h"
+#include "spawn-viewer.h"
+
+
+static const char *babeltrace_bin = CONFIG_BABELTRACE_BIN;
+static const char *babeltrace2_bin = CONFIG_BABELTRACE2_BIN;
+
+/*
+ * This is needed for each viewer since we are using execvp().
+ */
+static const char *babeltrace_opts[] = { "babeltrace" };
+static const char *babeltrace2_opts[] = { "babeltrace2" };
+
+/*
+ * Type is also use as the index in the viewers array. So please, make sure
+ * your enum value is in the right order in the array below.
+ */
+enum viewer_type {
+       VIEWER_BABELTRACE    = 0,
+       VIEWER_BABELTRACE2   = 1,
+       VIEWER_USER_DEFINED  = 2,
+};
+
+static const struct viewer {
+       const char *exec_name;
+       enum viewer_type type;
+} viewers[] = {
+       { "babeltrace", VIEWER_BABELTRACE },
+       { "babeltrace2", VIEWER_BABELTRACE2 },
+       { NULL, VIEWER_USER_DEFINED },
+};
+
+static const struct viewer *parse_viewer_option(const char *opt_viewer)
+{
+       if (opt_viewer == NULL) {
+               /* Default is babeltrace2 */
+               return &(viewers[VIEWER_BABELTRACE2]);
+       }
+
+       return &(viewers[VIEWER_USER_DEFINED]);
+}
+
+/*
+ * Alloc an array of string pointer from a simple string having all options
+ * seperated by spaces. Also adds the trace path to the arguments.
+ *
+ * The returning pointer is ready to be passed to execvp().
+ */
+static char **alloc_argv_from_user_opts(char *opts, const char *trace_path)
+{
+       int i = 0, ignore_space = 0;
+       unsigned int num_opts = 1;
+       char **argv, *token = opts;
+
+       /* Count number of arguments. */
+       do {
+               if (*token == ' ') {
+                       /* Use to ignore consecutive spaces */
+                       if (!ignore_space) {
+                               num_opts++;
+                       }
+                       ignore_space = 1;
+               } else {
+                       ignore_space = 0;
+               }
+               token++;
+       } while (*token != '\0');
+
+       /* Add two here for the NULL terminating element and trace path */
+       argv = zmalloc(sizeof(char *) * (num_opts + 2));
+       if (argv == NULL) {
+               goto error;
+       }
+
+       token = strtok(opts, " ");
+       while (token != NULL) {
+               argv[i] = strdup(token);
+               if (argv[i] == NULL) {
+                       goto error;
+               }
+               token = strtok(NULL, " ");
+               i++;
+       }
+
+       argv[num_opts] = (char *) trace_path;
+       argv[num_opts + 1] = NULL;
+
+       return argv;
+
+error:
+       if (argv) {
+               for (i = 0; i < num_opts + 2; i++) {
+                       free(argv[i]);
+               }
+               free(argv);
+       }
+
+       return NULL;
+}
+
+/*
+ * Alloc an array of string pointer from an array of strings. It also adds
+ * the trace path to the argv.
+ *
+ * The returning pointer is ready to be passed to execvp().
+ */
+static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len,
+               const char *trace_path, bool opt_live_mode)
+{
+       char **argv;
+       size_t size, mem_len;
+
+       /* Add one for the NULL terminating element. */
+       mem_len = opts_len + 1;
+       if (opt_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 *) * mem_len;
+
+       /* Add two here for the trace_path and the NULL terminating element. */
+       argv = zmalloc(size);
+       if (argv == NULL) {
+               goto error;
+       }
+
+       memcpy(argv, opts, sizeof(char *) * opts_len);
+
+       if (opt_live_mode) {
+               argv[opts_len] = (char *) "-i";
+               argv[opts_len + 1] = (char *) "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;
+}
+
+
+/*
+ * Spawn viewer with the trace directory path.
+ */
+int spawn_viewer(const char *trace_path, char *opt_viewer, bool opt_live_mode)
+{
+       int ret = 0;
+       struct stat status;
+       const char *viewer_bin = NULL;
+       const struct viewer *viewer;
+       char **argv = NULL;
+
+       /* Check for --viewer option. */
+       viewer = parse_viewer_option(opt_viewer);
+       if (viewer == NULL) {
+               ret = -1;
+               goto error;
+       }
+
+retry_viewer:
+       switch (viewer->type) {
+       case VIEWER_BABELTRACE2:
+               if (stat(babeltrace2_bin, &status) == 0) {
+                       viewer_bin = babeltrace2_bin;
+               } else {
+                       viewer_bin = viewer->exec_name;
+               }
+               argv = alloc_argv_from_local_opts(babeltrace2_opts,
+                               ARRAY_SIZE(babeltrace2_opts), trace_path,
+                               opt_live_mode);
+               break;
+       case VIEWER_BABELTRACE:
+               if (stat(babeltrace_bin, &status) == 0) {
+                       viewer_bin = babeltrace_bin;
+               } else {
+                       viewer_bin = viewer->exec_name;
+               }
+               argv = alloc_argv_from_local_opts(babeltrace_opts,
+                               ARRAY_SIZE(babeltrace_opts), trace_path,
+                               opt_live_mode);
+               break;
+       case VIEWER_USER_DEFINED:
+               argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
+               if (argv) {
+                       viewer_bin = argv[0];
+               }
+               break;
+       default:
+               abort();
+       }
+
+       if (argv == NULL || !viewer_bin) {
+               ret = -1;
+               goto error;
+       }
+
+       DBG("Using %s viewer", viewer_bin);
+
+       ret = execvp(viewer_bin, argv);
+       if (ret) {
+               if (errno == ENOENT && viewer->exec_name) {
+                       if (viewer->type == VIEWER_BABELTRACE2) {
+                               /* Fallback to legacy babeltrace. */
+                               DBG("Default viewer \"%s\" not installed on the system, falling back to \"%s\"",
+                                               viewers[VIEWER_BABELTRACE2].exec_name,
+                                               viewers[VIEWER_BABELTRACE].exec_name);
+                               viewer = &viewers[VIEWER_BABELTRACE];
+                               free(argv);
+                               argv = NULL;
+                               goto retry_viewer;
+                       } else {
+                               ERR("Default viewer \"%s\" (and fallback \"%s\") not found on the system",
+                                               viewers[VIEWER_BABELTRACE2].exec_name,
+                                               viewers[VIEWER_BABELTRACE].exec_name);
+                       }
+               } else {
+                       PERROR("Failed to launch \"%s\" viewer", viewer_bin);
+               }
+               ret = -1;
+               goto error;
+       }
+
+       /*
+        * This function should never return if successfull because `execvp(3)`
+        * onle returns if an error has occurred.
+        */
+       assert(ret != 0);
+error:
+       free(argv);
+       return ret;
+}
diff --git a/src/common/spawn-viewer.h b/src/common/spawn-viewer.h
new file mode 100644 (file)
index 0000000..5789246
--- /dev/null
@@ -0,0 +1,22 @@
+#ifndef LTTNG_SPAWN_VIEWER_H
+#define LTTNG_SPAWN_VIEWER_H
+
+/*
+ * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include <stdbool.h>
+
+/*
+ * Read the trace by `exec()ing` the provided viewer program if any. If
+ * `opt_viewer` is NULL, try to read the trace with the default trace reader.
+ * On success, this function doesn't return.
+ * Returns -1 if the `opt_viewer` string or the default trace viewer can't be
+ * `exec()`.
+ */
+int spawn_viewer(const char *trace_path, char *opt_viewer, bool opt_live_mode);
+
+#endif /* ifndef LTTNG_SPAWN_VIEWER_H */
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