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