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/error.h>
  21 #include <assert.h>
  22
  23 LTTNG_HIDDEN
  24 struct lttng_buffer_view lttng_buffer_view_init(
  25                 const char *src, size_t offset, ptrdiff_t len)
  26 {
  27         struct lttng_buffer_view view = { .data = src + offset, .size = len };
  28         return view;
  29 }
  30
  31 LTTNG_HIDDEN
  32 struct lttng_buffer_view lttng_buffer_view_from_view(
  33                 const struct lttng_buffer_view *src, size_t offset,
  34                 ptrdiff_t len)
  35 {
  36         struct lttng_buffer_view view = { .data = NULL, .size = 0 };
  37
  38         assert(src);
  39
  40         if (offset > src->size) {
  41                 ERR("Attempt to create buffer view with invalid offset");
  42                 goto end;
  43         }
  44
  45         if (len != -1 && len > (src->size - offset)) {
  46                 ERR("Attempt to create buffer view with invalid length");
  47                 goto end;
  48         }
  49
  50         view.data = src->data + offset;
  51         view.size = len == -1 ? (src->size - offset) : len;
  52 end:
  53         return view;
  54 }
  55
  56 LTTNG_HIDDEN
  57 struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer(
  58                 const struct lttng_dynamic_buffer *src, size_t offset,
  59                 ptrdiff_t len)
  60 {
  61         struct lttng_buffer_view view = { .data = NULL, .size = 0 };
  62
  63         assert(src);
  64
  65         if (offset > src->size) {
  66                 ERR("Attempt to create buffer view with invalid offset");
  67                 goto end;
  68         }
  69
  70         if (len != -1 && len > (src->size - offset)) {
  71                 ERR("Attempt to create buffer view with invalid length");
  72                 goto end;
  73         }
  74
  75         view.data = src->data + offset;
  76         view.size = len == -1 ? (src->size - offset) : len;
  77 end:
  78         return view;
  79 }