MongoDB C++ Driver mongocxx-3.6.7
change_stream.hpp
1// Copyright 2018-present MongoDB Inc.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15#pragma once
16
17#include <memory>
18
19#include <bsoncxx/document/view.hpp>
20#include <bsoncxx/stdx/optional.hpp>
21
22#include <mongocxx/config/prelude.hpp>
23
24namespace mongocxx {
25MONGOCXX_INLINE_NAMESPACE_BEGIN
26
27class client;
28class collection;
29class database;
30
31class MONGOCXX_API change_stream {
32 public:
33 class MONGOCXX_API iterator;
34
38 change_stream(change_stream&& other) noexcept;
39
44
49
70 iterator begin() const;
71
79 iterator end() const;
80
104 bsoncxx::stdx::optional<bsoncxx::document::view> get_resume_token() const;
105
106 private:
107 friend class client;
108 friend class collection;
109 friend class database;
110 friend class change_stream::iterator;
111
112 MONGOCXX_PRIVATE change_stream(void* change_stream_ptr);
113
114 class MONGOCXX_PRIVATE impl;
115 std::unique_ptr<impl> _impl;
116};
117
118class MONGOCXX_API change_stream::iterator {
119 public:
120 // Support input-iterator (caveat of post-increment returning void)
121 using difference_type = std::int64_t;
123 using pointer = std::add_pointer<value_type>::type;
124 using reference = std::add_lvalue_reference<value_type>::type;
125 using iterator_category = std::input_iterator_tag;
126
133
138
143
155
166 void operator++(int);
167
168 private:
169 friend class change_stream;
170 enum class iter_type { k_tracking, k_default_constructed, k_end };
171
172 MONGOCXX_PRIVATE explicit iterator(iter_type type, const change_stream* change_stream);
173
182 friend MONGOCXX_API bool MONGOCXX_CALL operator==(const change_stream::iterator&,
183 const change_stream::iterator&) noexcept;
184
185 friend MONGOCXX_API bool MONGOCXX_CALL operator!=(const change_stream::iterator&,
186 const change_stream::iterator&) noexcept;
190
191 MONGOCXX_PRIVATE bool is_exhausted() const;
192
193 // iter_type==k_default_constructed is equivalent to _change_stream==nullptr
194 iter_type _type;
195 const change_stream* _change_stream;
196};
197
198MONGOCXX_INLINE_NAMESPACE_END
199} // namespace mongocxx
200
201#include <mongocxx/config/postlude.hpp>
A read-only, non-owning view of a BSON document.
Definition: view.hpp:33
Definition: change_stream.hpp:118
friend bool operator==(const change_stream::iterator &, const change_stream::iterator &) noexcept
Compare two iterators for (in)-equality.
const bsoncxx::document::view * operator->() const
Accesses a member of the dereferenced document currently being pointed to.
const bsoncxx::document::view & operator*() const
Dereferences the view for the document currently being pointed to.
iterator & operator++()
Pre-increments the iterator to move to the next document.
iterator()
Default-construct an iterator.
void operator++(int)
Post-increments the iterator to move to the next document.
friend bool operator!=(const change_stream::iterator &, const change_stream::iterator &) noexcept
Compare two iterators for (in)-equality.
Definition: change_stream.hpp:31
~change_stream()
Destroys a change_stream.
iterator begin() const
A change_stream::iterator points to the beginning of any available notifications.
iterator end() const
A change_stream::iterator indicating stream exhaustion, meaning that no notifications are available f...
bsoncxx::stdx::optional< bsoncxx::document::view > get_resume_token() const
Returns a resume token for this change stream.
change_stream(change_stream &&other) noexcept
Move constructs a change_stream.
change_stream & operator=(change_stream &&other) noexcept
Move assigns a change_stream.
Class representing a client connection to MongoDB.
Definition: client.hpp:58
Class representing server side document groupings within a MongoDB database.
Definition: collection.hpp:81
Class representing a MongoDB database.
Definition: database.hpp:43
Top level namespace for the MongoDB C++ driver.
Definition: bulk_write.hpp:24