src/common/buffer-view.c

   1 /*
   2  * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this program; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 #include <common/buffer-view.h>
  19 #include <common/dynamic-buffer.h>
  20 #include <common/macros.h>
  21 #include <common/error.h>
  22 #include <assert.h>
  23
  24 struct lttng_buffer_view lttng_buffer_view_from_view(
  25                 const struct lttng_buffer_view *src, size_t offset,
  26                 ptrdiff_t len)
  27 {
  28         struct lttng_buffer_view view = { .data = NULL, .size = 0 };
  29
  30         assert(src);
  31
  32         if (offset > src->size) {
  33                 ERR("Attempt to create buffer view with invalid offset");
  34                 goto end;
  35         }
  36
  37         if (len != -1 && len > (src->size - offset)) {
  38                 ERR("Attempt to create buffer view with invalid length");
  39                 goto end;
  40         }
  41
  42         view.data = src->data + offset;
  43         view.size = len == -1 ? (src->size - offset) : len;
  44 end:
  45         return view;
  46 }
  47
  48 struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer(
  49                 const struct lttng_dynamic_buffer *src, size_t offset,
  50                 ptrdiff_t len)
  51 {
  52         struct lttng_buffer_view view = { .data = NULL, .size = 0 };
  53
  54         assert(src);
  55
  56         if (offset > src->size) {
  57                 ERR("Attempt to create buffer view with invalid offset");
  58                 goto end;
  59         }
  60
  61         if (len != -1 && len > (src->size - offset)) {
  62                 ERR("Attempt to create buffer view with invalid length");
  63                 goto end;
  64         }
  65
  66         view.data = src->data + offset;
  67         view.size = len == -1 ? (src->size - offset) : len;
  68 end:
  69         return view;
  70 }