src/bin/lttng/commands/metadata.c

   1 /*
   2  * Copyright (C) 2015 - Julien Desfossez <jdesfossez@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  19 #include <assert.h>
  20 #include <ctype.h>
  21 #include <popt.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 #include <common/mi-lttng.h>
  28
  29 #include "../command.h"
  30
  31 static char *opt_session_name;
  32 static char *session_name = NULL;
  33
  34 static int metadata_regenerate(int argc, const char **argv);
  35
  36 enum {
  37         OPT_HELP = 1,
  38         OPT_LIST_OPTIONS,
  39         OPT_LIST_COMMANDS,
  40 };
  41
  42 static struct mi_writer *writer;
  43
  44 static struct poptOption long_options[] = {
  45         /* { longName, shortName, argInfo, argPtr, value, descrip, argDesc, } */
  46         { "help",               'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0, },
  47         { "session",            's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  48         { "list-options",       0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, 0, 0, },
  49         { "list-commands",      0, POPT_ARG_NONE, NULL, OPT_LIST_COMMANDS},
  50         { 0, 0, 0, 0, 0, 0, 0, },
  51 };
  52
  53 static struct cmd_struct actions[] = {
  54         { "regenerate", metadata_regenerate },
  55         { NULL, NULL }  /* Array closure */
  56 };
  57
  58 /*
  59  * usage
  60  */
  61 static void usage(FILE *ofp)
  62 {
  63         fprintf(ofp, "usage: lttng metadata [OPTION] ACTION\n");
  64         fprintf(ofp, "\n");
  65         fprintf(ofp, "Actions:\n");
  66         fprintf(ofp, "   regenerate\n");
  67         fprintf(ofp, "      Regenerate and overwrite the metadata of the session.\n");
  68         fprintf(ofp, "Options:\n");
  69         fprintf(ofp, "  -h, --help               Show this help.\n");
  70         fprintf(ofp, "      --list-options       Simple listing of options.\n");
  71         fprintf(ofp, "  -s, --session NAME       Apply to session name.\n");
  72         fprintf(ofp, "\n");
  73 }
  74
  75 /*
  76  * Count and return the number of arguments in argv.
  77  */
  78 static int count_arguments(const char **argv)
  79 {
  80         int i = 0;
  81
  82         assert(argv);
  83
  84         while (argv[i] != NULL) {
  85                 i++;
  86         }
  87
  88         return i;
  89 }
  90
  91 static int metadata_regenerate(int argc, const char **argv)
  92 {
  93         int ret;
  94
  95         ret = lttng_metadata_regenerate(session_name);
  96         if (ret == 0) {
  97                 MSG("Metadata successfully regenerated for session %s", session_name);
  98         }
  99         return ret;
 100 }
 101
 102 static int handle_command(const char **argv)
 103 {
 104         struct cmd_struct *cmd;
 105         int ret = CMD_SUCCESS, i = 0, argc, command_ret = CMD_SUCCESS;
 106
 107         if (argv == NULL) {
 108                 usage(stderr);
 109                 command_ret = CMD_ERROR;
 110                 goto end;
 111         }
 112
 113         argc = count_arguments(argv);
 114
 115         cmd = &actions[i];
 116         while (cmd->func != NULL) {
 117                 /* Find command */
 118                 if (strcmp(argv[0], cmd->name) == 0) {
 119                         if (lttng_opt_mi) {
 120                                 /* Action element */
 121                                 ret = mi_lttng_writer_open_element(writer,
 122                                                 mi_lttng_element_command_metadata_action);
 123                                 if (ret) {
 124                                         ret = CMD_ERROR;
 125                                         goto end;
 126                                 }
 127
 128                                 /* Name of the action */
 129                                 ret = mi_lttng_writer_write_element_string(writer,
 130                                                 config_element_name, argv[0]);
 131                                 if (ret) {
 132                                         ret = CMD_ERROR;
 133                                         goto end;
 134                                 }
 135                         }
 136                         command_ret = cmd->func(argc, argv);
 137                         if (lttng_opt_mi) {
 138                                 /* Close output and action element */
 139                                 ret = mi_lttng_writer_close_element(writer);
 140                                 if (ret) {
 141                                         ret = CMD_ERROR;
 142                                         goto end;
 143                                 }
 144                         }
 145                         goto end;
 146                 }
 147
 148                 cmd = &actions[i++];
 149         }
 150
 151         ret = CMD_UNDEFINED;
 152
 153 end:
 154         /* Overwrite ret if an error occurred in cmd->func() */
 155         ret = command_ret ? command_ret : ret;
 156         return ret;
 157 }
 158
 159 /*
 160  * Metadata command handling.
 161  */
 162 int cmd_metadata(int argc, const char **argv)
 163 {
 164         int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 165         static poptContext pc;
 166
 167         if (argc < 1) {
 168                 usage(stderr);
 169                 ret = CMD_ERROR;
 170                 goto end;
 171         }
 172
 173         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 174         poptReadDefaultConfig(pc, 0);
 175
 176         if (lttng_opt_mi) {
 177                 writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
 178                 if (!writer) {
 179                         ret = -LTTNG_ERR_NOMEM;
 180                         goto end;
 181                 }
 182                 /* Open command element */
 183                 ret = mi_lttng_writer_command_open(writer,
 184                                 mi_lttng_element_command_metadata);
 185                 if (ret) {
 186                         ret = CMD_ERROR;
 187                         goto end;
 188                 }
 189
 190                 /* Open output element */
 191                 ret = mi_lttng_writer_open_element(writer,
 192                                 mi_lttng_element_command_output);
 193                 if (ret) {
 194                         ret = CMD_ERROR;
 195                         goto end;
 196                 }
 197         }
 198
 199         while ((opt = poptGetNextOpt(pc)) != -1) {
 200                 switch (opt) {
 201                 case OPT_HELP:
 202                         usage(stdout);
 203                         goto end;
 204                 case OPT_LIST_OPTIONS:
 205                         list_cmd_options(stdout, long_options);
 206                         goto end;
 207                 case OPT_LIST_COMMANDS:
 208                         list_commands(actions, stdout);
 209                         goto end;
 210                 default:
 211                         usage(stderr);
 212                         ret = CMD_UNDEFINED;
 213                         goto end;
 214                 }
 215         }
 216
 217         if (!opt_session_name) {
 218                 session_name = get_session_name();
 219                 if (session_name == NULL) {
 220                         ret = CMD_ERROR;
 221                         goto end;
 222                 }
 223         } else {
 224                 session_name = opt_session_name;
 225         }
 226
 227         command_ret = handle_command(poptGetArgs(pc));
 228         if (command_ret) {
 229                 switch (-command_ret) {
 230                 default:
 231                         ERR("%s", lttng_strerror(command_ret));
 232                         success = 0;
 233                         break;
 234                 }
 235         }
 236
 237         if (lttng_opt_mi) {
 238                 /* Close output element */
 239                 ret = mi_lttng_writer_close_element(writer);
 240                 if (ret) {
 241                         ret = CMD_ERROR;
 242                         goto end;
 243                 }
 244
 245                 /* Success ? */
 246                 ret = mi_lttng_writer_write_element_bool(writer,
 247                                 mi_lttng_element_command_success, success);
 248                 if (ret) {
 249                         ret = CMD_ERROR;
 250                         goto end;
 251                 }
 252
 253                 /* Command element close */
 254                 ret = mi_lttng_writer_command_close(writer);
 255                 if (ret) {
 256                         ret = CMD_ERROR;
 257                         goto end;
 258                 }
 259         }
 260
 261 end:
 262         /* Mi clean-up */
 263         if (writer && mi_lttng_writer_destroy(writer)) {
 264                 /* Preserve original error code */
 265                 ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
 266         }
 267
 268         if (!opt_session_name) {
 269                 free(session_name);
 270         }
 271
 272         /* Overwrite ret if an error occurred during handle_command() */
 273         ret = command_ret ? command_ret : ret;
 274
 275         poptFreeContext(pc);
 276         return ret;
 277 }