src/common/payload-view.c

   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 LTTNG_HIDDEN
  15 bool lttng_payload_view_is_valid(const struct lttng_payload_view *view)
  16 {
  17         return view && lttng_buffer_view_is_valid(&view->buffer);
  18 }
  19
  20 LTTNG_HIDDEN
  21 struct lttng_payload_view lttng_payload_view_from_payload(
  22                 const struct lttng_payload *payload, size_t offset,
  23                 ptrdiff_t len)
  24 {
  25         return payload ? (struct lttng_payload_view) {
  26                 .buffer = lttng_buffer_view_from_dynamic_buffer(
  27                         &payload->buffer, offset, len),
  28                 ._fd_handles = payload->_fd_handles,
  29                 } : (struct lttng_payload_view) {};
  30 }
  31
  32 LTTNG_HIDDEN
  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.p_fd_handles_position = view->_iterator.p_fd_handles_position ?:
  42                                 &view->_iterator.fd_handles_position,
  43                 } : (struct lttng_payload_view) {};
  44 }
  45
  46 LTTNG_HIDDEN
  47 struct lttng_payload_view lttng_payload_view_from_dynamic_buffer(
  48                 const struct lttng_dynamic_buffer *buffer, size_t offset,
  49                 ptrdiff_t len)
  50 {
  51         return buffer ? (struct lttng_payload_view) {
  52                 .buffer = lttng_buffer_view_from_dynamic_buffer(
  53                         buffer, offset, len)
  54                 } : (struct lttng_payload_view) {};
  55 }
  56
  57 LTTNG_HIDDEN
  58 struct lttng_payload_view lttng_payload_view_from_buffer_view(
  59                 const struct lttng_buffer_view *view, size_t offset,
  60                 ptrdiff_t len)
  61 {
  62         return view ? (struct lttng_payload_view) {
  63                 .buffer = lttng_buffer_view_from_view(
  64                         view, offset, len)
  65                 } : (struct lttng_payload_view) {};
  66 }
  67
  68 LTTNG_HIDDEN
  69 struct lttng_payload_view lttng_payload_view_init_from_buffer(
  70         const char *src, size_t offset, ptrdiff_t len)
  71 {
  72         return (struct lttng_payload_view) {
  73                 .buffer = lttng_buffer_view_init(
  74                         src, offset, len)
  75         };
  76 }
  77
  78 LTTNG_HIDDEN
  79 int lttng_payload_view_get_fd_handle_count(
  80                 const struct lttng_payload_view *payload_view)
  81 {
  82         int ret;
  83         size_t position;
  84
  85         if (!payload_view) {
  86                 ret = -1;
  87                 goto end;
  88         }
  89
  90         ret = lttng_dynamic_pointer_array_get_count(&payload_view->_fd_handles);
  91         if (ret < 0) {
  92                 goto end;
  93         }
  94
  95         position = payload_view->_iterator.p_fd_handles_position ?
  96                         *payload_view->_iterator.p_fd_handles_position :
  97                         payload_view->_iterator.fd_handles_position;
  98         ret = ret - (int) position;
  99 end:
 100         return ret;
 101 }
 102
 103 LTTNG_HIDDEN
 104 struct fd_handle *lttng_payload_view_pop_fd_handle(
 105                 struct lttng_payload_view *view)
 106 {
 107         struct fd_handle *handle = NULL;
 108         size_t fd_handle_count;
 109         size_t *pos;
 110
 111         if (!view) {
 112                 goto end;
 113         }
 114
 115         fd_handle_count = lttng_payload_view_get_fd_handle_count(view);
 116         if (fd_handle_count == 0) {
 117                 goto end;
 118         }
 119
 120         pos = view->_iterator.p_fd_handles_position ?
 121                         view->_iterator.p_fd_handles_position :
 122                         &view->_iterator.fd_handles_position;
 123         handle = lttng_dynamic_pointer_array_get_pointer(&view->_fd_handles,
 124                         *pos);
 125         (*pos)++;
 126         fd_handle_get(handle);
 127 end:
 128         return handle;
 129 }