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Detailed Description

Retrieve a document from the cluster

Function Documentation

lcb_cmdget_on_behalf_of()

lcb_STATUS lcb_cmdget_on_behalf_of	(	lcb_CMDGET *	cmd,
		const char *	data,
		size_t	data_len )

Stability

Internal

Internal: This should never be used and is not supported.

lcb_cmdget_on_behalf_of_extra_privilege()

lcb_STATUS lcb_cmdget_on_behalf_of_extra_privilege	(	lcb_CMDGET *	cmd,
		const char *	privilege,
		size_t	privilege_len )

Stability

Internal

Internal: This should never be used and is not supported.

Typedef Documentation

lcb_RESPGET

typedef struct lcb_RESPGET_ lcb_RESPGET

Command for retrieving a single item.

See also

lcb_get()

lcb_RESPGET

Use of the exptime field

• Get And Touch:

  It is possible to retrieve an item and concurrently modify its expiration time (thus keeping it "alive"). The item's expiry time can be set by calling lcb_cmdget_expiry.

• Lock Calling lcb_cmdget_locktime will set the time the lock should be held for

Stability

Committed

Spool a single get operation

Parameters

instance	the handle
cookie	a pointer to be associated with the command
cmd	the command structure

Returns

LCB_SUCCESS if successful, an error code otherwise

Request

lcb_CMDGET* cmd;
lcb_cmdget_create(&cmd);
lcb_cmdget_key(cmd, "Hello", 5);
lcb_get(instance, cookie, cmd);

Response

lcb_install_callback(instance, LCB_CALLBACK_GET, get_callback);
static void get_callback(lcb_INSTANCE *instance, int cbtype, const lcb_RESPBASE *rb) {
    const lcb_RESPGET *resp = (const lcb_RESPGET*)rb;
    char* key;
    char* value;
    size_t key_len;
    size_t value_len;
    uint64_t cas;
    uint32_t flags;
    lcb_respget_key(resp, &key, &key_len);
    printf("Got response for key: %.*s\n", key_len, key);
 
 
    lcb_STATUS rc = lcb_respget_status(resp);
    if (rc != LCB_SUCCESS) {
        printf("Couldn't get item: %s\n", lcb_strerror_short(rc));
    } else {
        lcb_respget_cas(resp, &cas);
        lcb_respget_value(resp, &value, &value_len);
        lcb_respget_flags(resp, &flags);
        printf("Got value: %.*s\n", value_len, value);
        printf("Got CAS: 0x%llx\n", cas);
        printf("Got item/formatting flags: 0x%x\n", flags);
    }
}

Errors

• ::LCB_ERR_DOCUMENT_NOT_FOUND if the item does not exist in the cluster
• ::LCB_ERR_TEMPORARY_FAILURE if the lcb_cmdget_locktime was set but the item was already locked. Note that this error may also be returned (as a generic error) if there is a resource constraint within the server itself.