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