Announcing 2.0.0 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

New Features

• Add support for BSON Binary Vector.

Changes

• BSON_ERROR_BUFFER_SIZE is reduced from 504 to 503 to reserve the final byte for internal use.
  • The data layout of bson_error_t remains otherwise unchanged: the size is still 512 bytes and the offset of the .code, .domain, and .message data members remain unchanged.
• The pkg-config files libbson-1.0 and libbson-static-1.0 have been renamed to bson2, and bson2-static, respectively.

CMake Packages and Imported Targets

The bson-1.0 CMake package has been removed. Instead, use or bson, and
specify a version or version range to be imported:

find_package(bson 1.30...2.0)

The new package imports different target names:

• mongo::bson_static → bson::static
• mongo::bson_shared → bson::shared
• The target bson::bson is a shim target that points to either the shared library or the static library.

Removals

• bson_as_json and bson_array_as_json are removed due to producing non-portable Legacy Extended JSON. Prefer Canonical Extended JSON or Relaxed Extended JSON for portability. To continue using Legacy Extended JSON, use bson_as_legacy_extended_json and bson_array_as_legacy_extended_json.
• Compiling with BSON_MEMCHECK defined now has no effect.
• Remove deprecated integral comparison interfaces: bson_in_range_* and bson_cmp_*.
• Remove deprecated atomic and threading interfaces: bson_atomic_* and bson_thrd_yield.
• The deprecated ENABLE_EXTRA_ALIGNMENT CMake option is removed.
  • bson_t and bson_iter_t are now aligned to the size of a pointer instead of 128.
  • bson_error_t, bson_value_t, and bson_visitor_t are now aligned to the size of a pointer instead of 8.
  • BSON_ALIGNED_BEGIN and BSON_ALIGNED_END now unconditionally apply their requested alignment.
• Remove deprecated bson_copy_to_excluding. Use bson_copy_to_excluding_noinit instead.

libmongoc

New Features

• Support aggregate operations with $lookup stage for In-Use Encryption.

Notes

• In a future minor release the minimum supported MongoDB Server version will be raised from 4.0 to 4.2. This is in accordance with MongoDB Software Lifecycle Schedules.
• Raise required version of libmongocrypt to 1.13.0 to support In-Use Encryption (corresponds to the CMake option: ENABLE_CLIENT_SIDE_ENCRYPTION).

Changes

• Passing batchSize:0 as an option to mongoc_client_watch, mongoc_database_watch, or mongoc_collection_watch
  now applies batchSize:0 to the aggregate command. Useful to request an immediate cursor. Previously the value
  was ignored.
• bson_oid_init_sequence is removed. Use bson_oid_init instead.
• mongoc_server_description_host changes the return type from mongoc_host_list_t * to const mongoc_host_list_t *.
• URI authentication credentials validation (only applicable during creation of a new mongoc_uri_t object from a connection string):
  • The requirement that a username is non-empty when specified is now enforced regardless of authentication mechanism.
  • Username and password specification requirements are now validated and returns a client error for the specified authentication mechanism.
    • e.g. it is a client error to not specify a username or a password for SCRAM-SHA-1, SCRAM-SHA-256, and PLAIN.
    • e.g. it is a client error to specify a password for MONGODB-X509.
    • e.g. it is a client error to specify a username or a password without the other for MONGODB-AWS.
  • authSource is now correctly defaulted to "$external" for MONGODB-AWS (instead of the database name or "admin").
  • authMechanism is now validated and returns a client error for invalid or unsupported values.
  • authMechanismProperties is now validated and returns a client error for invalid or unsupported properties for the specified authentication mechanism.
  • authMechanismProperties now correctly supports ':' within property values.
    • Old behavior: authMechanismProperties=A:B,C:D:E,F:G is parsed as {'A': 'B', 'C': 'D:E,F:G'}.
    • New behavior: authMechanismProperties=A:B,C:D:E,F:G is parsed as {'A': 'B': 'C': 'D:E', 'F': 'G'}.
• Calling mongoc_bulk_operation_execute on the same mongoc_bulk_operation_t repeatedly is an error. Previously this was only discouraged in documentation.
• Consistently apply __cdecl calling convention to function declarations in public API. Intended to support consumers building their code using a different default calling convention with MSVC. The mongoc and bson libraries only support being built with the __cdecl default calling convention.
• mongoc_client_set_ssl_opts now ignores a pooled mongoc_client_t and logs an error. Use mongoc_client_pool_set_ssl_opts to set TLS options on a mongoc_client_pool_t before popping any clients.
• mongoc_client_set_ssl_stream_initiator now ignores a pooled mongoc_client_t and logs an error.
• The pkg-config files libmongoc-1.0, libmongoc-static-1.0, libbson-1.0, and libbson-static-1.0 have been renamed to mongoc2, mongoc2-static, bson2, and bson2-static, respectively.

CMake Packages and Imported Targets

The mongoc-1.0 (and bson-1.0) CMake packages have been removed. Instead, use
mongoc or bson, and specify a version or version range to be imported:

find_package(mongoc 1.30...2.0)

The new packages import different target names:

• mongo::mongoc_static → mongoc::static
• mongo::mongoc_shared → mongoc::shared
• The target mongoc::mongoc is a shim target that points to either the shared library or the static library.

The BSON library has had similar name changes.

Removals

• The bson_md5_t struct and associated API is removed.
• The client side matching feature, mongoc_matcher_t and related functions are removed.
• mongoc_server_description_ismaster is removed. Use the equivalent mongoc_server_description_hello instead.
• MONGOC_QUERY_SLAVE_OK is removed. Use the equivalent MONGOC_QUERY_SECONDARY_OK instead.
• MONGOC_URI_SLAVEOK is removed. It was unused.
• mongoc_client_command, mongoc_database_command, and mongoc_collection_command are removed. Use mongoc_client_command_simple, mongoc_database_command_simple, and mongoc_collection_command_simple instead.
• MONGOC_URI_MAXIDLETIMEMS and MONGOC_URI_WAITQUEUEMULTIPLE are removed. They were unused.
• bson_string_t and associated functions are removed.
• Support for ENABLE_SASL=CYRUS on Windows is removed. Use ENABLE_SASL=SSPI or ENABLE_SASL=OFF instead.
  • The associated Windows-only option CYRUS_PLUGIN_PATH_PREFIX is removed.
• Support for the deprecated minPoolSize URI option is removed along with associated API: MONGOC_URI_MINPOOLSIZE and mongoc_client_pool_min_size.
• Support for LibreSSL (the CMake option ENABLE_SSL=LIBRESSL) is removed. Associated API is removed (MONGOC_ENABLE_SSL_LIBRESSL and mongoc_stream_tls_libressl_new).
• MONGOC_WRITE_CONCERN_W_ERRORS_IGNORED (value -1) is removed. Use MONGOC_WRITE_CONCERN_W_UNACKNOWLEDGED (value 0) which is handled equivalently. If specified in a URI, replace: mongodb://host/?w=-1 with mongodb://host/?w=0.
• The deprecated CMake option ENABLE_AUTOMATIC_INIT_AND_CLEANUP is removed. See Initialization and cleanup for expected use of mongoc_init() and mongoc_cleanup().
• mongoc_client_get_database_names is removed. Use mongoc_client_get_database_names_with_opts instead.
• mongoc_client_find_databases is removed. Use mongoc_client_find_databases_with_opts instead.
• mongoc_client_get_max_message_size is removed.
• mongoc_client_get_max_bson_size is removed.
• Deprecated mongoc_apm_command_*_get_server_connection_id functions are removed. Use mongoc_apm_command_*_get_server_connection_id_int64 instead.
• Deprecated index management API is removed:
  • mongoc_collection_create_index_with_opts, mongoc_collection_create_index, and mongoc_collection_ensure_index are removed. Use mongoc_collection_create_indexes_with_opts instead.
  • mongoc_index_opt_t, mongoc_index_opt_geo_t mongoc_index_opt_wt_t are removed. Pass options using bson_t to mongoc_collection_create_indexes_with_opts instead.
  • mongoc_collection_find_indexes is removed. Use mongoc_collection_find_indexes_with_opts instead.
  • See MongoDB documentation for working with indexes.
• Deprecated cursor API is removed:
  • mongoc_cursor_is_alive is removed. Use the equivalent mongoc_cursor_more instead.
  • mongoc_cursor_set_hint is removed. Use the equivalent mongoc_cursor_set_server_id instead.
  • mongoc_cursor_get_hint is removed. Use the equivalent mongoc_cursor_get_server_id instead.
  • mongoc_cursor_new_from_command_reply is removed. Use mongoc_cursor_new_from_command_reply_with_opts instead.
• Deprecated CRUD API is removed:
  • mongoc_collection_save is removed. Use mongoc_collection_insert_one or mongoc_collection_replace_one instead.
  • mongoc_collection_delete is removed. Use mongoc_collection_delete_one or mongoc_collection_delete_many instead.
  • mongoc_delete_flags_t and mongoc_reply_flags_t are removed.
  • mongoc_collection_find is removed. Use mongoc_collection_find_with_opts instead.
  • mongoc_collection_insert_bulk is removed. Use mongoc_collection_insert_many instead.
  • mongoc_collection_create_bulk_operation is removed. Use mongoc_collection_create_bulk_operation_with_opts instead.
  • mongoc_collection_get_last_error is removed. To get results from write operations, instead use:
    • mongoc_collection_update_one
    • mongoc_collection_update_many
    • mongoc_collection_replace_one
    • mongoc_collection_delete_one
    • mongoc_collection_delete_many
    • mongoc_collection_insert_one
    • mongoc_collection_insert_many
    • mongoc_bulkwrite_t
    • mongoc_bulk_operation_t
  • mongoc_bulk_operation_delete is removed. Use mongoc_bulk_operation_remove() instead.
  • mongoc_bulk_operation_delete_one is removed. Use mongoc_bulk_operation_remove_one instead.
  • mongoc_bulk_operation_get_hint is removed. Use mongoc_bulk_operation_get_server_id instead.
  • mongoc_bulk_operation_set_hint is removed. Use mongoc_bulk_operation_set_server_id instead.
  • mongoc_collection_count and mongoc_collection_count_with_opts are removed. Use mongoc_collection_count_documents or mongoc_collection_estimated_document_count instead.
• mongoc_collection_stats is removed. Use the $collStats aggregation pipeline stage with mongoc_collection_aggregate instead.
• mongoc_collection_validate is removed. Run the validate command directly with mongoc_client_read_command_with_opts instead.
• Deprecated API for mongoc_database_t is removed:
  • mongoc_database_find_collections is removed. Use mongoc_database_find_collections_with_opts instead.
  • mongoc_database_get_collection_names is removed. Use mongoc_database_get_collection_names_with_opts instead.
• Deprecated GridFS API has been removed:
  • mongoc_gridfs_find is removed. Use mongoc_gridfs_find_with_opts instead.
  • mongoc_gridfs_find_one is removed. Use mongoc_gridfs_find_one_with_opts instead.
• Deprecated TLS stream API is removed:
  • mongoc_stream_tls_do_handshake is removed. Use mongoc_stream_tls_handshake instead.
  • mongoc_stream_tls_check_cert is removed. Use mongoc_stream_tls_handshake instead.
  • mongoc_stream_tls_new is removed. Use mongoc_stream_tls_new_with_hostname instead.
• Deprecated URI API has been removed:
  • mongoc_uri_get_service is removed. Use mongoc_uri_get_srv_hostname instead.
  • mongoc_uri_get_read_prefs is removed. Use mongoc_uri_get_read_prefs_t instead.
  • mongoc_uri_get_ssl is removed. Use mongoc_uri_get_tls instead.
• Deprecated write concern API is removed:
  • mongoc_write_concern_get_fsync is removed. Use mongoc_write_concern_get_journal instead.
  • mongoc_write_concern_set_fsync is removed. Use mongoc_write_concern_set_journal instead.
• The libmongoc-ssl-1.0 pkg-config file has been removed.

Forwarding headers (#include <bson.h> and #include <mongoc.h>)

The compatibility "forwarding" headers have been removed (previously added in 1.13.0). This means it is no longer valid to include the literal header names mongoc.h or bson.h directly:

#include <bson.h> // No longer provided!
#include <mongoc.h> // No longer provided!

Instead, the names must be prefixed with the parent directory: mongoc/mongoc.h and bson/bson.h:

#include <bson/bson.h>
#include <mongoc/mongoc.h>

mongoc_client_kill_cursor

mongoc_client_kill_cursor is removed. It did not accept a server identifier. It was only reliable when connected to a single server.

Sending killCursors is not typically needed. mongoc_cursor_t manages the cursor lifetime. If needed, use a generic command helper to manually send a killCursors command:

bson_t *cmd = BCON_NEW ("killCursors", "coll", "cursors", "[", BCON_INT64 (cursor_id), "]");
bool ok = mongoc_client_command_simple_with_server_id (client, "db", cmd, NULL, server_id, NULL, &error);
if (!ok) {
  printf ("Failed to send 'killCursors': %s\n", error.message);
}
bson_destroy (cmd);

mongoc_client_get_server_status

mongoc_client_get_server_status is removed. Use a command helper to run the "serverStatus" command instead:

bson_t *cmd = BCON_NEW("serverStatus", BCON_INT32(1));
if (!mongoc_client_command_simple(client, "db", cmd, NULL, &reply, &error)) {
    printf("Failed to send 'serverStatus': %s\n", error.message);
} else {
  // TODO: use `reply`
}
bson_destroy(&reply);
bson_destroy(cmd);

Links

• All the issues resolved in 2.0.0
• Documentation

Contributors

Thanks to everyone who contributed to this release.

• Kevin Albertson
• Ezra Chung
• Colby Pike
• Micah Scott
• Jeroen Ooms
• Lin Raymond