-memcached_fetch() is used to fetch an individual value from the server.
-memcached_mget() must always be called before using this method. You
-must pass in a key and its length to fetch the object. You must supply
-three pointer variables which will give you the state of the returned
-object. A uint32_t pointer to contain whatever flags you stored with the value,
-a size_t pointer which will be filled with size of of the object, and a
-memcached_return_t pointer to hold any error. The object will be returned
-upon success and NULL will be returned on failure. \fBMEMCACHD_END\fP is
-returned by the *error value when all objects that have been found are
-returned. The final value upon \fBMEMCACHED_END\fP is null. Values
-returned by memcached_fetch() must be freed by the caller. memcached_fetch()
-will be DEPRECATED in the near future, memcached_fetch_result() should be
-used instead.
-.sp
-memcached_fetch_result() is used to return a memcached_result_st(3) structure
-from a memcached server. The result object is forward compatible with changes
-to the server. For more information please refer to the memcached_result_st(3)
-help. This function will dynamically allocate a result structure for you
-if you do not pass one to the function.
-.sp
-memcached_fetch_execute() is a callback function for result sets. Instead
-of returning the results to you for processing, it passes each of the
-result sets to the list of functions you provide. It passes to the function
-a memcached_st that can be cloned for use in the called function (it can not
-be used directly). It also passes a result set which does not need to be freed.
-Finally it passes a "context". This is just a pointer to a memory reference
-you supply the calling function. Currently only one value is being passed
-to each function call. In the future there will be an option to allow this
-to be an array.
-.sp
-memcached_mget_execute() and memcached_mget_execute_by_key() is
-similar to memcached_mget(), but it may trigger the supplied callbacks
-with result sets while sending out the queries. If you try to perform
-a really large multiget with memcached_mget() you may encounter a
-deadlock in the OS kernel (it will fail to write data to the socket because
-the input buffer is full). memcached_mget_execute() solves this
-problem by processing some of the results before continuing sending
-out requests. Please note that this function is only available in the
-binary protocol.
-.sp
-memcached_get_by_key() and memcached_mget_by_key() behave in a similar nature
-as memcached_get() and memcached_mget(). The difference is that they take
-a master key that is used for determining which server an object was stored
-if key partitioning was used for storage.
-.sp
-All of the above functions are not tested when the \fBMEMCACHED_BEHAVIOR_USE_UDP\fPhas been set. Executing any of these functions with this behavior on will result in
-\fBMEMCACHED_NOT_SUPPORTED\fP being returned, or for those functions which do not return
-a \fBmemcached_return_t\fP, the error function parameter will be set to
-\fBMEMCACHED_NOT_SUPPORTED\fP.