NAME¶
mongoc_client_t - MongoDB Connection Abstraction
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 node, 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
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.
LIFECYCLE¶
It is an error to call mongoc_client_destroy on a client that has
operations pending. It is required that you release mongoc_collection_t
and mongoc_database_t structures before calling
mongoc_client_destroy
EXAMPLE¶
/* gcc example.c ‐o example $(pkg‐config ‐‐cflags ‐‐libs libmongoc‐1.0) */
/* ./example‐client [CONNECTION_STRING [COLLECTION_NAME]] */
#include <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 *uristr = "mongodb://127.0.0.1/";
const char *collection_name = "test";
bson_t query;
char *str;
mongoc_init ();
if (argc > 1) {
uristr = argv [1];
}
if (argc > 2) {
collection_name = argv [2];
}
client = mongoc_client_new (uristr);
if (!client) {
fprintf (stderr, "Failed to parse URI.\n");
return EXIT_FAILURE;
}
mongoc_client_set_error_api (client, 2);
bson_init (&query);
#if 0
bson_append_utf8 (&query, "hello", ‐1, "world", ‐1);
#endif
collection = mongoc_client_get_collection (client, "test", collection_name);
cursor = mongoc_collection_find (collection,
MONGOC_QUERY_NONE,
0,
0,
0,
&query,
NULL, /* Fields, NULL for all. */
NULL); /* Read Prefs, NULL for default */
while (mongoc_cursor_next (cursor, &doc)) {
str = bson_as_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_client_destroy (client);
mongoc_cleanup ();
return EXIT_SUCCESS;
}
