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.h>
   9 #include <common/buffer-view.h>
  10 #include "payload-view.h"
  11 #include "payload.h"
  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         } : (struct lttng_payload_view) {
  28                 .buffer = {},
  29                 ._fd_handles = {}
  30         };
  31 }
  32
  33 struct lttng_payload_view lttng_payload_view_from_view(
  34                 struct lttng_payload_view *view, size_t offset,
  35                 ptrdiff_t len)
  36 {
  37         return view ? (struct lttng_payload_view) {
  38                 .buffer = lttng_buffer_view_from_view(
  39                                 &view->buffer, offset, len),
  40                 ._fd_handles = view->_fd_handles,
  41                 ._iterator = {
  42                         .p_fd_handles_position = view->_iterator.p_fd_handles_position ?:
  43                                 &view->_iterator.fd_handles_position,
  44                 }
  45         } : (struct lttng_payload_view) {
  46                 .buffer = {},
  47                 ._fd_handles = {}
  48         };
  49 }
  50
  51 struct lttng_payload_view lttng_payload_view_from_dynamic_buffer(
  52                 const struct lttng_dynamic_buffer *buffer, size_t offset,
  53                 ptrdiff_t len)
  54 {
  55         return buffer ? (struct lttng_payload_view) {
  56                 .buffer = lttng_buffer_view_from_dynamic_buffer(
  57                         buffer, offset, len),
  58                 ._fd_handles = {}
  59         } : (struct lttng_payload_view) {
  60                 .buffer = {},
  61                 ._fd_handles = {}
  62         };
  63 }
  64
  65 struct lttng_payload_view lttng_payload_view_from_buffer_view(
  66                 const struct lttng_buffer_view *view, size_t offset,
  67                 ptrdiff_t len)
  68 {
  69         return view ? (struct lttng_payload_view) {
  70                 .buffer = lttng_buffer_view_from_view(
  71                         view, offset, len),
  72                 ._fd_handles = {}
  73         } : (struct lttng_payload_view) {
  74                 .buffer = {},
  75                 ._fd_handles = {}
  76         };
  77 }
  78
  79 struct lttng_payload_view lttng_payload_view_init_from_buffer(
  80         const char *src, size_t offset, ptrdiff_t len)
  81 {
  82         return (struct lttng_payload_view) {
  83                 .buffer = lttng_buffer_view_init(
  84                         src, offset, len),
  85                 ._fd_handles = {}
  86         };
  87 }
  88
  89 int lttng_payload_view_get_fd_handle_count(
  90                 const struct lttng_payload_view *payload_view)
  91 {
  92         int ret;
  93         size_t position;
  94
  95         if (!payload_view) {
  96                 ret = -1;
  97                 goto end;
  98         }
  99
 100         ret = lttng_dynamic_pointer_array_get_count(&payload_view->_fd_handles);
 101         if (ret < 0) {
 102                 goto end;
 103         }
 104
 105         position = payload_view->_iterator.p_fd_handles_position ?
 106                         *payload_view->_iterator.p_fd_handles_position :
 107                         payload_view->_iterator.fd_handles_position;
 108         ret = ret - (int) position;
 109 end:
 110         return ret;
 111 }
 112
 113 struct fd_handle *lttng_payload_view_pop_fd_handle(
 114                 struct lttng_payload_view *view)
 115 {
 116         struct fd_handle *handle = NULL;
 117         size_t fd_handle_count;
 118         size_t *pos;
 119
 120         if (!view) {
 121                 goto end;
 122         }
 123
 124         fd_handle_count = lttng_payload_view_get_fd_handle_count(view);
 125         if (fd_handle_count == 0) {
 126                 goto end;
 127         }
 128
 129         pos = view->_iterator.p_fd_handles_position ?
 130                         view->_iterator.p_fd_handles_position :
 131                         &view->_iterator.fd_handles_position;
 132         handle = (fd_handle *) lttng_dynamic_pointer_array_get_pointer(&view->_fd_handles,
 133                         *pos);
 134         (*pos)++;
 135         fd_handle_get(handle);
 136 end:
 137         return handle;
 138 }