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MONGOC_CLIENT_T(3) libmongoc MONGOC_CLIENT_T(3)

NAME

mongoc_client_t - mongoc_client_t

A single-threaded MongoDB connection. See Connection Pooling.

SYNOPSIS

typedef struct _mongoc_client_t mongoc_client_t;
typedef mongoc_stream_t *(*mongoc_stream_initiator_t) (

const mongoc_uri_t *uri,
const mongoc_host_list_t *host,
void *user_data,
bson_error_t *error);


mongoc_client_t is an opaque type that provides access to a MongoDB server, replica set, or sharded cluster. It maintains management of underlying sockets and routing to individual nodes based on mongoc_read_prefs_t or mongoc_write_concern_t.

STREAMS

The underlying transport for a given client can be customized, wrapped or replaced by any implementation that fulfills mongoc_stream_t. A custom transport can be set with mongoc_client_set_stream_initiator().

THREAD SAFETY

mongoc_client_t is NOT thread-safe and should only be used from one thread at a time. When used in multi-threaded scenarios, it is recommended that you use the thread-safe mongoc_client_pool_t to retrieve a mongoc_client_t for your thread.

EXAMPLE

example-client.c

/* gcc example-client.c -o example-client $(pkg-config --cflags --libs

* libmongoc-1.0) */ /* ./example-client [CONNECTION_STRING [COLLECTION_NAME]] */ #include <mongoc/mongoc.h> #include <stdio.h> #include <stdlib.h> int main (int argc, char *argv[]) {
mongoc_client_t *client;
mongoc_collection_t *collection;
mongoc_cursor_t *cursor;
bson_error_t error;
const bson_t *doc;
const char *collection_name = "test";
bson_t query;
char *str;
const char *uri_string = "mongodb://127.0.0.1/?appname=client-example";
mongoc_uri_t *uri;
mongoc_init ();
if (argc > 1) {
uri_string = argv[1];
}
if (argc > 2) {
collection_name = argv[2];
}
uri = mongoc_uri_new_with_error (uri_string, &error);
if (!uri) {
fprintf (stderr,
"failed to parse URI: %s\n"
"error message: %s\n",
uri_string,
error.message);
return EXIT_FAILURE;
}
client = mongoc_client_new_from_uri (uri);
if (!client) {
return EXIT_FAILURE;
}
mongoc_client_set_error_api (client, 2);
bson_init (&query);
collection = mongoc_client_get_collection (client, "test", collection_name);
cursor = mongoc_collection_find_with_opts (
collection,
&query,
NULL, /* additional options */
NULL); /* read prefs, NULL for default */
while (mongoc_cursor_next (cursor, &doc)) {
str = bson_as_canonical_extended_json (doc, NULL);
fprintf (stdout, "%s\n", str);
bson_free (str);
}
if (mongoc_cursor_error (cursor, &error)) {
fprintf (stderr, "Cursor Failure: %s\n", error.message);
return EXIT_FAILURE;
}
bson_destroy (&query);
mongoc_cursor_destroy (cursor);
mongoc_collection_destroy (collection);
mongoc_uri_destroy (uri);
mongoc_client_destroy (client);
mongoc_cleanup ();
return EXIT_SUCCESS; }


AUTHOR

MongoDB, Inc

COPYRIGHT

2017-present, MongoDB, Inc

October 20, 2022 1.23.1