From 6457f8e488a84e2da71fe57f362adefc393a480b Mon Sep 17 00:00:00 2001 From: Francis Deslauriers Date: Fri, 3 Apr 2020 14:21:25 -0400 Subject: [PATCH] lttng-view: clean-up: move `--viewer` code to specific file MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This code will be reuse by the lttng-crash utility. Signed-off-by: Francis Deslauriers Change-Id: Ide72ad08577d55bbf2f7833d46e734b8a680c9d2 Signed-off-by: Jérémie Galarneau --- src/bin/lttng/commands/view.c | 228 +----------------------------- src/common/Makefile.am | 1 + src/common/spawn-viewer.c | 256 ++++++++++++++++++++++++++++++++++ src/common/spawn-viewer.h | 22 +++ 4 files changed, 281 insertions(+), 226 deletions(-) create mode 100644 src/common/spawn-viewer.c create mode 100644 src/common/spawn-viewer.h diff --git a/src/bin/lttng/commands/view.c b/src/bin/lttng/commands/view.c index 3ba5766ea..d7632b62b 100644 --- a/src/bin/lttng/commands/view.c +++ b/src/bin/lttng/commands/view.c @@ -14,13 +14,12 @@ #include #include +#include #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; diff --git a/src/common/Makefile.am b/src/common/Makefile.am index 1c9c8e4f0..cca159e56 100644 --- a/src/common/Makefile.am +++ b/src/common/Makefile.am @@ -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 index 000000000..26fe9199f --- /dev/null +++ b/src/common/spawn-viewer.c @@ -0,0 +1,256 @@ +/* + * Copyright (C) 2011 David Goulet + * Copyright (C) 2014 Mathieu Desnoyers + * Copyright (C) 2020 Francis Deslauriers + * + * SPDX-License-Identifier: GPL-2.0-only + * + */ + +#include +#include +#include +#include +#include +#include + +#include + +#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 index 000000000..578924682 --- /dev/null +++ b/src/common/spawn-viewer.h @@ -0,0 +1,22 @@ +#ifndef LTTNG_SPAWN_VIEWER_H +#define LTTNG_SPAWN_VIEWER_H + +/* + * Copyright (C) 2020 Francis Deslauriers + * + * SPDX-License-Identifier: GPL-2.0-only + * + */ + +#include + +/* + * 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 */ -- 2.34.1