src/common/index/index.c

   1 /*
   2  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   3  *                      David Goulet <dgoulet@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License, version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 51
  16  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <assert.h>
  21
  22 #include <common/common.h>
  23 #include <common/defaults.h>
  24 #include <common/utils.h>
  25
  26 #include "index.h"
  27
  28 /*
  29  * Create the index file associated with a trace file.
  30  *
  31  * Return fd on success, a negative value on error.
  32  */
  33 int index_create_file(char *path_name, char *stream_name, int uid, int gid,
  34                 uint64_t size, uint64_t count)
  35 {
  36         int ret, fd = -1;
  37         struct lttng_packet_index_file_hdr hdr;
  38
  39         ret = utils_create_stream_file(path_name, stream_name, size, count, uid,
  40                         gid, DEFAULT_INDEX_FILE_SUFFIX);
  41         if (ret < 0) {
  42                 goto error;
  43         }
  44         fd = ret;
  45
  46         memcpy(hdr.magic, INDEX_MAGIC, sizeof(hdr.magic));
  47         hdr.index_major = htobe32(INDEX_MAJOR);
  48         hdr.index_minor = htobe32(INDEX_MINOR);
  49
  50         do {
  51                 ret = write(fd, &hdr, sizeof(hdr));
  52         } while (ret < 0 && errno == EINTR);
  53         if (ret < 0) {
  54                 PERROR("write index header");
  55                 goto error;
  56         }
  57
  58         return fd;
  59
  60 error:
  61         if (fd >= 0) {
  62                 int close_ret;
  63
  64                 close_ret = close(fd);
  65                 if (close_ret < 0) {
  66                         PERROR("close index fd");
  67                 }
  68         }
  69         return ret;
  70 }
  71
  72 /*
  73  * Write index values to the given fd of size len.
  74  *
  75  * Return 0 on success or else a negative value on error.
  76  */
  77 int index_write(int fd, struct lttng_packet_index *index, size_t len)
  78 {
  79         int ret;
  80
  81         assert(fd >= 0);
  82         assert(index);
  83
  84         do {
  85                 ret = write(fd, index, len);
  86         } while (ret < 0 && errno == EINTR);
  87         if (ret < 0) {
  88                 PERROR("writing index file");
  89         }
  90
  91         return ret;
  92 }