v1::read_concern (CXX-3237, CXX-3238) (#1503)

Author: eramongodb

src/mongocxx/include/mongocxx/v1/read_concern.hpp

@@ -190,6 +190,11 @@ class read_concern {
     }
     /// @}
     ///
+
+    class internal;
+
+   private:
+    /* explicit(false) */ read_concern(void* impl);
 };
 
 } // namespace v1

src/mongocxx/include/mongocxx/v_noabi/mongocxx/read_concern-fwd.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <mongocxx/v1/read_concern-fwd.hpp>
+
 #include <mongocxx/config/prelude.hpp>
 
 namespace mongocxx {
@@ -26,7 +28,7 @@ class read_concern;
 
 namespace mongocxx {
 
-using ::mongocxx::v_noabi::read_concern;
+using v_noabi::read_concern;
 
 } // namespace mongocxx
 
@@ -36,3 +38,6 @@ using ::mongocxx::v_noabi::read_concern;
 /// @file
 /// Declares @ref mongocxx::v_noabi::read_concern.
 ///
+/// @par Includes
+/// - @ref mongocxx/v1/read_concern-fwd.hpp
+///

src/mongocxx/include/mongocxx/v_noabi/mongocxx/read_concern.hpp

@@ -14,20 +14,26 @@
 
 #pragma once
 
-#include <memory>
-
-#include <mongocxx/client-fwd.hpp>
-#include <mongocxx/collection-fwd.hpp>
-#include <mongocxx/database-fwd.hpp>
-#include <mongocxx/options/transaction-fwd.hpp>
 #include <mongocxx/read_concern-fwd.hpp> // IWYU pragma: export
-#include <mongocxx/uri-fwd.hpp>
+
+//
+
+#include <mongocxx/v1/read_concern.hpp> // IWYU pragma: export
+
+#include <memory> // IWYU pragma: keep: backward compatibility, to be removed.
+#include <utility>
+
+#include <mongocxx/client-fwd.hpp>              // IWYU pragma: keep: backward compatibility, to be removed.
+#include <mongocxx/collection-fwd.hpp>          // IWYU pragma: keep: backward compatibility, to be removed.
+#include <mongocxx/database-fwd.hpp>            // IWYU pragma: keep: backward compatibility, to be removed.
+#include <mongocxx/options/transaction-fwd.hpp> // IWYU pragma: keep: backward compatibility, to be removed.
+#include <mongocxx/uri-fwd.hpp>                 // IWYU pragma: keep: backward compatibility, to be removed.
 
 #include <bsoncxx/document/value.hpp>
 #include <bsoncxx/stdx/optional.hpp> // IWYU pragma: keep: backward compatibility, to be removed.
 #include <bsoncxx/stdx/string_view.hpp>
 
-#include <mongocxx/options/transaction.hpp>
+#include <mongocxx/options/transaction.hpp> // IWYU pragma: keep: backward compatibility, to be removed.
 
 #include <mongocxx/config/prelude.hpp>
 
@@ -46,6 +52,9 @@ namespace v_noabi {
 /// - [Read Concern (MongoDB Manual)](https://www.mongodb.com/docs/manual/reference/read-concern/)
 ///
 class read_concern {
+   private:
+    v1::read_concern _rc;
+
    public:
     ///
     /// A class to represent the read concern level for read operations.
@@ -71,32 +80,31 @@ class read_concern {
     /// run with this read_concern will use the server's default read_concern instead of
     /// specifying one.
     ///
-    MONGOCXX_ABI_EXPORT_CDECL() read_concern();
-
-    ///
-    /// Copy constructs a read_concern.
-    ///
-    MONGOCXX_ABI_EXPORT_CDECL() read_concern(read_concern const&);
+    read_concern() = default;
 
     ///
-    /// Copy assigns a read_concern.
+    /// Construct with the @ref mongocxx::v1 equivalent.
     ///
-    MONGOCXX_ABI_EXPORT_CDECL(read_concern&) operator=(read_concern const&);
+    /* explicit(false) */ read_concern(v1::read_concern rc) : _rc{std::move(rc)} {}
 
     ///
-    /// Move constructs a read_concern.
+    /// Convert to the @ref mongocxx::v1 equivalent.
     ///
-    MONGOCXX_ABI_EXPORT_CDECL() read_concern(read_concern&&) noexcept;
-
+    /// @par Postconditions:
+    /// - `other` is in an assign-or-destroy-only state.
     ///
-    /// Move assigns a read_concern.
+    /// @warning Invalidates all associated iterators and views.
     ///
-    MONGOCXX_ABI_EXPORT_CDECL(read_concern&) operator=(read_concern&&) noexcept;
+    explicit operator v1::read_concern() && {
+        return std::move(_rc);
+    }
 
     ///
-    /// Destroys a read_concern.
+    /// Convert to the @ref mongocxx::v1 equivalent.
     ///
-    MONGOCXX_ABI_EXPORT_CDECL() ~read_concern();
+    explicit operator v1::read_concern() const& {
+        return _rc;
+    }
 
     ///
     /// Sets the read concern level.
@@ -118,7 +126,9 @@ class read_concern {
     ///
     /// @return The read concern level.
     ///
-    MONGOCXX_ABI_EXPORT_CDECL(level) acknowledge_level() const;
+    level acknowledge_level() const {
+        return static_cast<level>(_rc.acknowledge_level());
+    }
 
     ///
     /// Sets the read concern string. Any valid read concern string (e.g. "local",
@@ -129,8 +139,9 @@ class read_concern {
     /// @param rc_string
     ///   The read concern string.
     ///
-    MONGOCXX_ABI_EXPORT_CDECL(void)
-    acknowledge_string(bsoncxx::v_noabi::stdx::string_view rc_string);
+    void acknowledge_string(bsoncxx::v1::stdx::string_view rc_string) {
+        _rc.acknowledge_string(rc_string);
+    }
 
     ///
     /// Gets the current read concern string.
@@ -140,40 +151,56 @@ class read_concern {
     ///
     /// @return The read concern string.
     ///
-    MONGOCXX_ABI_EXPORT_CDECL(bsoncxx::v_noabi::stdx::string_view) acknowledge_string() const;
+    bsoncxx::v1::stdx::string_view acknowledge_string() const {
+        auto ret = _rc.acknowledge_string();
+        if (ret.empty()) {
+            ret = "";
+        }
+        return ret;
+    }
 
     ///
     /// Gets the document form of this read_concern.
     ///
     /// @return
     ///   Document representation of this read_concern.
     ///
-    MONGOCXX_ABI_EXPORT_CDECL(bsoncxx::v_noabi::document::value) to_document() const;
+    bsoncxx::v_noabi::document::value to_document() const {
+        return bsoncxx::v_noabi::from_v1(_rc.to_document());
+    }
 
     ///
     /// @relates mongocxx::v_noabi::read_concern
     ///
     /// Compares two read_concern objects for (in)-equality.
     ///
     /// @{
-    friend MONGOCXX_ABI_EXPORT_CDECL(bool) operator==(read_concern const&, read_concern const&);
-    friend MONGOCXX_ABI_EXPORT_CDECL(bool) operator!=(read_concern const&, read_concern const&);
+    friend bool operator==(read_concern const& lhs, read_concern const& rhs) {
+        return lhs.acknowledge_level() == rhs.acknowledge_level();
+    }
+
+    friend bool operator!=(read_concern const& lhs, read_concern const& rhs) {
+        return !(lhs == rhs);
+    }
     /// @}
     ///
 
-   private:
-    friend ::mongocxx::v_noabi::client;
-    friend ::mongocxx::v_noabi::collection;
-    friend ::mongocxx::v_noabi::database;
-    friend ::mongocxx::v_noabi::options::transaction;
-    friend ::mongocxx::v_noabi::uri;
-
-    class impl;
+    class internal;
+};
 
-    read_concern(std::unique_ptr<impl>&& implementation);
+///
+/// Convert to the @ref mongocxx::v_noabi equivalent of `v`.
+///
+inline v_noabi::read_concern from_v1(v1::read_concern v) {
+    return {std::move(v)};
+}
 
-    std::unique_ptr<impl> _impl;
-};
+///
+/// Convert to the @ref mongocxx::v1 equivalent of `v`.
+///
+inline v1::read_concern to_v1(v_noabi::read_concern v) {
+    return v1::read_concern{std::move(v)};
+}
 
 } // namespace v_noabi
 } // namespace mongocxx
@@ -184,3 +211,6 @@ class read_concern {
 /// @file
 /// Provides @ref mongocxx::v_noabi::read_concern.
 ///
+/// @par Includes
+/// - @ref mongocxx/v1/read_concern.hpp
+///

src/mongocxx/lib/mongocxx/v1/read_concern.cpp

@@ -12,4 +12,159 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <mongocxx/v1/read_concern.hpp>
+#include <mongocxx/v1/read_concern.hh>
+
+//
+
+#include <bsoncxx/v1/document/value.hpp>
+#include <bsoncxx/v1/stdx/string_view.hpp>
+
+#include <cstring>
+#include <string>
+#include <unordered_map>
+
+#include <bsoncxx/private/bson.hh>
+
+#include <mongocxx/private/mongoc.hh>
+#include <mongocxx/private/scoped_bson.hh>
+#include <mongocxx/private/utility.hh>
+
+namespace mongocxx {
+namespace v1 {
+
+namespace {
+
+mongoc_read_concern_t* to_mongoc(void* ptr) {
+    return static_cast<mongoc_read_concern_t*>(ptr);
+}
+
+} // namespace
+
+read_concern::~read_concern() {
+    libmongoc::read_concern_destroy(to_mongoc(_impl));
+}
+
+read_concern::read_concern(read_concern&& other) noexcept : _impl{exchange(other._impl, nullptr)} {}
+
+read_concern& read_concern::operator=(read_concern&& other) noexcept {
+    if (this != &other) {
+        libmongoc::read_concern_destroy(to_mongoc(exchange(_impl, exchange(other._impl, nullptr))));
+    }
+    return *this;
+}
+
+read_concern::read_concern(read_concern const& other) : _impl{libmongoc::read_concern_copy(to_mongoc(other._impl))} {}
+
+read_concern& read_concern::operator=(read_concern const& other) {
+    if (this != &other) {
+        libmongoc::read_concern_destroy(
+            to_mongoc(exchange(_impl, libmongoc::read_concern_copy(to_mongoc(other._impl)))));
+    }
+    return *this;
+}
+
+read_concern::read_concern() : _impl{libmongoc::read_concern_new()} {}
+
+read_concern& read_concern::acknowledge_level(level v) {
+    // Return value is always true: no input validation by mongoc.
+    switch (v) {
+        case level::k_local:
+            (void)libmongoc::read_concern_set_level(to_mongoc(_impl), MONGOC_READ_CONCERN_LEVEL_LOCAL);
+            break;
+        case level::k_majority:
+            (void)libmongoc::read_concern_set_level(to_mongoc(_impl), MONGOC_READ_CONCERN_LEVEL_MAJORITY);
+            break;
+        case level::k_linearizable:
+            (void)libmongoc::read_concern_set_level(to_mongoc(_impl), MONGOC_READ_CONCERN_LEVEL_LINEARIZABLE);
+            break;
+
+        case level::k_server_default:
+            (void)libmongoc::read_concern_set_level(to_mongoc(_impl), nullptr);
+            break;
+
+        case level::k_available:
+            (void)libmongoc::read_concern_set_level(to_mongoc(_impl), MONGOC_READ_CONCERN_LEVEL_AVAILABLE);
+            break;
+        case level::k_snapshot:
+            (void)libmongoc::read_concern_set_level(to_mongoc(_impl), MONGOC_READ_CONCERN_LEVEL_SNAPSHOT);
+            break;
+
+        default:
+        case level::k_unknown:
+            // Precondition violation: undocumented but well-defined behavior.
+            (void)libmongoc::read_concern_set_level(to_mongoc(_impl), nullptr);
+            break;
+    }
+
+    return *this;
+}
+
+read_concern::level read_concern::acknowledge_level() const {
+    auto const level_cstr = libmongoc::read_concern_get_level(to_mongoc(_impl));
+
+    if (!level_cstr) {
+        return level::k_server_default;
+    }
+
+    std::unordered_map<bsoncxx::v1::stdx::string_view, level> const map = {
+        {MONGOC_READ_CONCERN_LEVEL_LOCAL, level::k_local},
+        {MONGOC_READ_CONCERN_LEVEL_MAJORITY, level::k_majority},
+        {MONGOC_READ_CONCERN_LEVEL_LINEARIZABLE, level::k_linearizable},
+        {MONGOC_READ_CONCERN_LEVEL_AVAILABLE, level::k_available},
+        {MONGOC_READ_CONCERN_LEVEL_SNAPSHOT, level::k_snapshot},
+    };
+
+    auto const iter = map.find(level_cstr);
+
+    return iter != map.end() ? iter->second : level::k_unknown;
+}
+
+read_concern& read_concern::acknowledge_string(bsoncxx::v1::stdx::string_view v) {
+    // Return value is always true: no input validation by mongoc.
+    (void)libmongoc::read_concern_set_level(to_mongoc(_impl), v.empty() ? nullptr : std::string{v}.c_str());
+    return *this;
+}
+
+bsoncxx::v1::stdx::string_view read_concern::acknowledge_string() const {
+    bsoncxx::v1::stdx::string_view ret;
+
+    if (auto const level_cstr = libmongoc::read_concern_get_level(to_mongoc(_impl))) {
+        ret = bsoncxx::v1::stdx::string_view{level_cstr};
+    }
+
+    return ret;
+}
+
+bsoncxx::v1::document::value read_concern::to_document() const {
+    scoped_bson doc;
+
+    if (auto const level_cstr = libmongoc::read_concern_get_level(to_mongoc(_impl))) {
+        doc += scoped_bson{BCON_NEW("level", BCON_UTF8(level_cstr))};
+    }
+
+    return std::move(doc).value();
+}
+
+bool operator==(read_concern const& lhs, read_concern const& rhs) {
+    auto const lhs_cstr = libmongoc::read_concern_get_level(to_mongoc(lhs._impl));
+    auto const rhs_cstr = libmongoc::read_concern_get_level(to_mongoc(rhs._impl));
+
+    if (!lhs_cstr != !rhs_cstr) {
+        return false;
+    }
+
+    return !lhs_cstr || std::strcmp(lhs_cstr, rhs_cstr) == 0;
+}
+
+read_concern::read_concern(void* impl) : _impl{impl} {}
+
+read_concern read_concern::internal::make(mongoc_read_concern_t* rc) {
+    return {rc};
+}
+
+mongoc_read_concern_t const* read_concern::internal::as_mongoc(read_concern const& self) {
+    return to_mongoc(self._impl);
+}
+
+} // namespace v1
+} // namespace mongocxx