MongoDB C++ Driver  mongocxx-3.10.2
pool.hpp
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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
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8 //
9 // Unless required by applicable law or agreed to in writing, software
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12 // See the License for the specific language governing permissions and
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14 
15 #pragma once
16 
17 #include <functional>
18 #include <memory>
19 
20 #include <mongocxx/client-fwd.hpp>
21 #include <mongocxx/options/auto_encryption-fwd.hpp>
22 #include <mongocxx/pool-fwd.hpp>
23 
24 #include <bsoncxx/stdx/optional.hpp>
25 #include <mongocxx/options/pool.hpp>
26 #include <mongocxx/stdx.hpp>
27 #include <mongocxx/uri.hpp>
28 
29 #include <mongocxx/config/prelude.hpp>
30 
31 namespace mongocxx {
32 namespace v_noabi {
33 
49 class pool {
50  public:
62  explicit pool(const uri& mongodb_uri = mongocxx::v_noabi::uri(),
63  const options::pool& options = options::pool());
64 
68  ~pool();
69 
77  class MONGOCXX_API entry {
78  public:
80  client* operator->() const& noexcept;
81  client* operator->() && = delete;
82 
84  client& operator*() const& noexcept;
85  client& operator*() && = delete;
86 
88  entry& operator=(std::nullptr_t) noexcept;
89 
91  explicit operator bool() const noexcept;
92 
93  private:
94  friend ::mongocxx::v_noabi::pool;
95 
96  using unique_client = std::unique_ptr<client, std::function<void MONGOCXX_CALL(client*)>>;
97 
98  MONGOCXX_PRIVATE explicit entry(unique_client);
99 
100  unique_client _client;
101  };
102 
108 
113  stdx::optional<entry> try_acquire();
114 
115  private:
116  friend ::mongocxx::v_noabi::options::auto_encryption;
117 
118  MONGOCXX_PRIVATE void _release(client* client);
119 
120  class MONGOCXX_PRIVATE impl;
121  const std::unique_ptr<impl> _impl;
122 };
123 
124 } // namespace v_noabi
125 } // namespace mongocxx
126 
127 #include <mongocxx/config/postlude.hpp>
Class representing a client connection to MongoDB.
Definition: client.hpp:61
Class representing the optional arguments to a MongoDB driver pool object.
Definition: pool.hpp:31
An entry is a handle on a client object acquired via the pool.
Definition: pool.hpp:77
client * operator->() const &noexcept
Access a member of the client instance.
A pool of client objects associated with a MongoDB deployment.
Definition: pool.hpp:49
pool(const uri &mongodb_uri=mongocxx::v_noabi::uri(), const options::pool &options=options::pool())
Creates a pool associated with a connection string.
stdx::optional< entry > try_acquire()
Acquires a client from the pool.
entry acquire()
Acquires a client from the pool.
~pool()
Destroys a pool.
Class representing a MongoDB connection string URI.
Definition: uri.hpp:47
The top-level namespace for mongocxx library entities.
Definition: bulk_write-fwd.hpp:19