MONGOC_CLIENT_T(3)

💅 MONGOC_CLIENT_T(3) 💅

hiii bestie, welcome to libmongoc section 3 — this page is all about mongoc_client_t, and it's literally a single-threaded MongoDB connection. See Connection Pooling for the pool bestie situation. 🦋

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✨ 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);

okay so mongoc_client_t is an opaque type that gives you access to a MongoDB server, replica set, or sharded cluster. It keeps up with management of underlying sockets and routing to individual nodes based on mongoc_read_prefs_t or mongoc_write_concern_t. periodt. 👑

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🌊 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(). slay. 🧚

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🧵 THREAD SAFETY 🧵

big warning bestie: mongoc_client_t is NOT thread-safe, and it should only be used from one thread at a time. when you're 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. no cap. 💀

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🍴 FORK SAFETY 🍴

a mongoc_client_t is only usable in the parent process after a fork. the child process must call mongoc_client_reset(). that's the rule, okay? 🙈

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🌟 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\n"
              "error message: %s\n",
              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;
}

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👑 AUTHOR 👑

MongoDB, Inc

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📜 COPYRIGHT 📜

2009-present, MongoDB, Inc.

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okay bye bestie 💖 this was MONGOC_CLIENT_T(3) from source libmongoc, version 2.5.6, dated Oct 09, 2026. mwah 💋✨