src/cpp-common/bt2/message-iterator.hpp

   1 /*
   2  * Copyright (c) 2023 Philippe Proulx <pproulx@efficios.com>
   3  *
   4  * SPDX-License-Identifier: MIT
   5  */
   6
   7 #ifndef BABELTRACE_CPP_COMMON_BT2_MESSAGE_ITERATOR_HPP
   8 #define BABELTRACE_CPP_COMMON_BT2_MESSAGE_ITERATOR_HPP
   9
  10 #include <babeltrace2/babeltrace.h>
  11
  12 #include "common/common.h"
  13 #include "cpp-common/bt2s/optional.hpp"
  14
  15 #include "component-port.hpp"
  16 #include "exc.hpp"
  17 #include "message-array.hpp"
  18 #include "shared-object.hpp"
  19
  20 namespace bt2 {
  21 namespace internal {
  22
  23 struct MessageIteratorRefFuncs final
  24 {
  25     static void get(const bt_message_iterator * const libObjPtr) noexcept
  26     {
  27         bt_message_iterator_get_ref(libObjPtr);
  28     }
  29
  30     static void put(const bt_message_iterator * const libObjPtr) noexcept
  31     {
  32         bt_message_iterator_put_ref(libObjPtr);
  33     }
  34 };
  35
  36 } /* namespace internal */
  37
  38 class MessageIterator final : public BorrowedObject<bt_message_iterator>
  39 {
  40 public:
  41     using Shared =
  42         SharedObject<MessageIterator, bt_message_iterator, internal::MessageIteratorRefFuncs>;
  43
  44     explicit MessageIterator(const LibObjPtr libObjPtr) noexcept : _ThisBorrowedObject {libObjPtr}
  45     {
  46     }
  47
  48     ConstComponent component() const noexcept
  49     {
  50         return ConstComponent {bt_message_iterator_borrow_component(this->libObjPtr())};
  51     }
  52
  53     bt2s::optional<ConstMessageArray> next() const
  54     {
  55         bt_message_array_const libMsgsPtr;
  56         std::uint64_t count;
  57         const auto status = bt_message_iterator_next(this->libObjPtr(), &libMsgsPtr, &count);
  58
  59         switch (status) {
  60         case BT_MESSAGE_ITERATOR_NEXT_STATUS_OK:
  61             /* Caller becomes the owner of the contained messages */
  62             return ConstMessageArray::wrapExisting(libMsgsPtr, count);
  63         case BT_MESSAGE_ITERATOR_NEXT_STATUS_END:
  64             return bt2s::nullopt;
  65         case BT_MESSAGE_ITERATOR_NEXT_STATUS_AGAIN:
  66             throw TryAgain {};
  67         case BT_MESSAGE_ITERATOR_NEXT_STATUS_MEMORY_ERROR:
  68             throw MemoryError {};
  69         case BT_MESSAGE_ITERATOR_NEXT_STATUS_ERROR:
  70             throw Error {};
  71         default:
  72             bt_common_abort();
  73         }
  74     }
  75
  76     bool canSeekBeginning() const
  77     {
  78         bt_bool canSeek;
  79
  80         const auto status = bt_message_iterator_can_seek_beginning(this->libObjPtr(), &canSeek);
  81
  82         switch (status) {
  83         case BT_MESSAGE_ITERATOR_CAN_SEEK_BEGINNING_STATUS_OK:
  84             return static_cast<bool>(canSeek);
  85         case BT_MESSAGE_ITERATOR_CAN_SEEK_BEGINNING_STATUS_AGAIN:
  86             throw TryAgain {};
  87         case BT_MESSAGE_ITERATOR_CAN_SEEK_BEGINNING_STATUS_MEMORY_ERROR:
  88             throw MemoryError {};
  89         case BT_MESSAGE_ITERATOR_CAN_SEEK_BEGINNING_STATUS_ERROR:
  90             throw Error {};
  91         default:
  92             bt_common_abort();
  93         }
  94     }
  95
  96     void seekBeginning() const
  97     {
  98         const auto status = bt_message_iterator_seek_beginning(this->libObjPtr());
  99
 100         switch (status) {
 101         case BT_MESSAGE_ITERATOR_SEEK_BEGINNING_STATUS_OK:
 102             return;
 103         case BT_MESSAGE_ITERATOR_SEEK_BEGINNING_STATUS_AGAIN:
 104             throw TryAgain {};
 105         case BT_MESSAGE_ITERATOR_SEEK_BEGINNING_STATUS_MEMORY_ERROR:
 106             throw MemoryError {};
 107         case BT_MESSAGE_ITERATOR_SEEK_BEGINNING_STATUS_ERROR:
 108             throw Error {};
 109         default:
 110             bt_common_abort();
 111         }
 112     }
 113
 114     bool canSeekNsFromOrigin(const std::int64_t nsFromOrigin) const
 115     {
 116         bt_bool canSeek;
 117
 118         const auto status =
 119             bt_message_iterator_can_seek_ns_from_origin(this->libObjPtr(), nsFromOrigin, &canSeek);
 120
 121         switch (status) {
 122         case BT_MESSAGE_ITERATOR_CAN_SEEK_NS_FROM_ORIGIN_STATUS_OK:
 123             return static_cast<bool>(canSeek);
 124         case BT_MESSAGE_ITERATOR_CAN_SEEK_NS_FROM_ORIGIN_STATUS_AGAIN:
 125             throw TryAgain {};
 126         case BT_MESSAGE_ITERATOR_CAN_SEEK_NS_FROM_ORIGIN_STATUS_MEMORY_ERROR:
 127             throw MemoryError {};
 128         case BT_MESSAGE_ITERATOR_CAN_SEEK_NS_FROM_ORIGIN_STATUS_ERROR:
 129             throw Error {};
 130         default:
 131             bt_common_abort();
 132         }
 133     }
 134
 135     void seekNsFromOrigin(const std::int64_t nsFromOrigin) const
 136     {
 137         const auto status =
 138             bt_message_iterator_seek_ns_from_origin(this->libObjPtr(), nsFromOrigin);
 139
 140         switch (status) {
 141         case BT_MESSAGE_ITERATOR_SEEK_NS_FROM_ORIGIN_STATUS_OK:
 142             return;
 143         case BT_MESSAGE_ITERATOR_SEEK_NS_FROM_ORIGIN_STATUS_AGAIN:
 144             throw TryAgain {};
 145         case BT_MESSAGE_ITERATOR_SEEK_NS_FROM_ORIGIN_STATUS_MEMORY_ERROR:
 146             throw MemoryError {};
 147         case BT_MESSAGE_ITERATOR_SEEK_NS_FROM_ORIGIN_STATUS_ERROR:
 148             throw Error {};
 149         default:
 150             bt_common_abort();
 151         }
 152     }
 153
 154     bool canSeekForward() const noexcept
 155     {
 156         return static_cast<bool>(bt_message_iterator_can_seek_forward(this->libObjPtr()));
 157     }
 158
 159     Shared shared() const noexcept
 160     {
 161         return Shared::createWithRef(*this);
 162     }
 163 };
 164
 165 } /* namespace bt2 */
 166
 167 #endif /* BABELTRACE_CPP_COMMON_BT2_MESSAGE_ITERATOR_HPP */