src/common/payload-view.cpp

   1 /*
   2  * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #include <common/dynamic-array.hpp>
   9 #include <common/buffer-view.hpp>
  10 #include "payload-view.hpp"
  11 #include "payload.hpp"
  12 #include <stddef.h>
  13
  14 bool lttng_payload_view_is_valid(const struct lttng_payload_view *view)
  15 {
  16         return view && lttng_buffer_view_is_valid(&view->buffer);
  17 }
  18
  19 struct lttng_payload_view lttng_payload_view_from_payload(
  20                 const struct lttng_payload *payload, size_t offset,
  21                 ptrdiff_t len)
  22 {
  23         return payload ? (struct lttng_payload_view) {
  24                 .buffer = lttng_buffer_view_from_dynamic_buffer(
  25                         &payload->buffer, offset, len),
  26                 ._fd_handles = payload->_fd_handles,
  27                 ._iterator = {},
  28         } : (struct lttng_payload_view) {
  29                 .buffer = {},
  30                 ._fd_handles = {},
  31                 ._iterator = {},
  32         };
  33 }
  34
  35 struct lttng_payload_view lttng_payload_view_from_view(
  36                 struct lttng_payload_view *view, size_t offset,
  37                 ptrdiff_t len)
  38 {
  39         return view ? (struct lttng_payload_view) {
  40                 .buffer = lttng_buffer_view_from_view(
  41                                 &view->buffer, offset, len),
  42                 ._fd_handles = view->_fd_handles,
  43                 ._iterator = {
  44                         .p_fd_handles_position = view->_iterator.p_fd_handles_position ?:
  45                                 &view->_iterator.fd_handles_position,
  46                         .fd_handles_position = 0,
  47                 }
  48         } : (struct lttng_payload_view) {
  49                 .buffer = {},
  50                 ._fd_handles = {},
  51                 ._iterator = {},
  52         };
  53 }
  54
  55 struct lttng_payload_view lttng_payload_view_from_dynamic_buffer(
  56                 const struct lttng_dynamic_buffer *buffer, size_t offset,
  57                 ptrdiff_t len)
  58 {
  59         return buffer ? (struct lttng_payload_view) {
  60                 .buffer = lttng_buffer_view_from_dynamic_buffer(
  61                         buffer, offset, len),
  62                 ._fd_handles = {},
  63                 ._iterator = {},
  64         } : (struct lttng_payload_view) {
  65                 .buffer = {},
  66                 ._fd_handles = {},
  67                 ._iterator = {},
  68         };
  69 }
  70
  71 struct lttng_payload_view lttng_payload_view_from_buffer_view(
  72                 const struct lttng_buffer_view *view, size_t offset,
  73                 ptrdiff_t len)
  74 {
  75         return view ? (struct lttng_payload_view) {
  76                 .buffer = lttng_buffer_view_from_view(
  77                         view, offset, len),
  78                 ._fd_handles = {},
  79                 ._iterator = {},
  80         } : (struct lttng_payload_view) {
  81                 .buffer = {},
  82                 ._fd_handles = {},
  83                 ._iterator = {},
  84         };
  85 }
  86
  87 struct lttng_payload_view lttng_payload_view_init_from_buffer(
  88         const char *src, size_t offset, ptrdiff_t len)
  89 {
  90         return (struct lttng_payload_view) {
  91                 .buffer = lttng_buffer_view_init(
  92                         src, offset, len),
  93                 ._fd_handles = {},
  94                 ._iterator = {},
  95         };
  96 }
  97
  98 int lttng_payload_view_get_fd_handle_count(
  99                 const struct lttng_payload_view *payload_view)
 100 {
 101         int ret;
 102         size_t position;
 103
 104         if (!payload_view) {
 105                 ret = -1;
 106                 goto end;
 107         }
 108
 109         ret = lttng_dynamic_pointer_array_get_count(&payload_view->_fd_handles);
 110         if (ret < 0) {
 111                 goto end;
 112         }
 113
 114         position = payload_view->_iterator.p_fd_handles_position ?
 115                         *payload_view->_iterator.p_fd_handles_position :
 116                         payload_view->_iterator.fd_handles_position;
 117         ret = ret - (int) position;
 118 end:
 119         return ret;
 120 }
 121
 122 struct fd_handle *lttng_payload_view_pop_fd_handle(
 123                 struct lttng_payload_view *view)
 124 {
 125         struct fd_handle *handle = NULL;
 126         size_t fd_handle_count;
 127         size_t *pos;
 128
 129         if (!view) {
 130                 goto end;
 131         }
 132
 133         fd_handle_count = lttng_payload_view_get_fd_handle_count(view);
 134         if (fd_handle_count == 0) {
 135                 goto end;
 136         }
 137
 138         pos = view->_iterator.p_fd_handles_position ?
 139                         view->_iterator.p_fd_handles_position :
 140                         &view->_iterator.fd_handles_position;
 141         handle = (fd_handle *) lttng_dynamic_pointer_array_get_pointer(&view->_fd_handles,
 142                         *pos);
 143         (*pos)++;
 144         fd_handle_get(handle);
 145 end:
 146         return handle;
 147 }