memcached_fetch(3) [centos man page]

MEMCACHED_FETCH(3)						   libmemcached 						MEMCACHED_FETCH(3)

NAME

       memcached_fetch - Retrieving data from the server

SYNOPSIS

       #include <libmemcached/memcached.h>

       char *memcached_fetch(memcached_st *ptr, char *key, size_t *key_length, size_t *value_length, uint32_t *flags, memcached_return_t *error)
	      Deprecated since version 0.50: Use memcached_fetch_result() instead.

       Compile and link with -lmemcached

DESCRIPTION

       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.  MEMCACHED_END	is  returned  by  the  *error  value when all objects that have been found are returned. The final value upon MEM-
       CACHED_END is null.

       Values returned by memcached_fetch() must be freed by the caller.

       All of the above functions are not tested when the MEMCACHED_BEHAVIOR_USE_UDP has been set. Executing any  of  these  functions	with  this
       behavior  on  will  result  in MEMCACHED_NOT_SUPPORTED being returned, or for those functions which do not return a memcached_return_t, the
       error function parameter will be set to MEMCACHED_NOT_SUPPORTED.

RETURN

       memcached_fetch() sets error to to MEMCACHED_END upon successful conclusion.  MEMCACHED_NOTFOUND will be return if  no  keys  at  all  were
       found.

       MEMCACHED_KEY_TOO_BIG  is set to error whenever memcached_fetch() was used and the key was set larger then MEMCACHED_MAX_KEY, which was the
       largest key allowed for the original memcached ascii server.

HOME

       To find out more information please check: http://libmemcached.org/

SEE ALSO

       memcached(1) libmemcached(3) memcached_strerror(3) memcached_fetch_result(3)

AUTHOR

       Brian Aker

COPYRIGHT

       2011-2013, Brian Aker DataDifferential, http://datadifferential.com/

1.0.16								 January 31, 2013						MEMCACHED_FETCH(3)

MEMCACHED_GET(3)						   libmemcached 						  MEMCACHED_GET(3)

NAME

       memcached_get - Retrieving data from the server

SYNOPSIS

       #include <libmemcached/memcached.h>

       memcached_result_st * memcached_fetch_result(memcached_st *ptr, memcached_result_st *result, memcached_return_t *error)

       char    *    memcached_get(memcached_st *ptr,	const	 char *key,   size_t key_length,   size_t *value_length,   uint32_t *flags,   mem-
       cached_return_t *error)

       memcached_return_t memcached_mget(memcached_st *ptr, const char * const *keys, const size_t *key_length, size_t number_of_keys)

       char  *	memcached_get_by_key(memcached_st *ptr,  const	char *group_key,  size_t group_key_length,  const  char *key,	size_t key_length,
       size_t *value_length, uint32_t *flags, memcached_return_t *error)

       memcached_return_t memcached_mget_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char * const *keys, const
       size_t *key_length, size_t number_of_keys)

       memcached_return_t memcached_fetch_execute(memcached_st *ptr, memcached_execute_fn *callback, void *context, uint32_t number_of_callbacks)

       memcached_return_t memcached_mget_execute(memcached_st *ptr, const char *  const *keys,	const  size_t *key_length,  size_t number_of_keys,
       memcached_execute_fn *callback, void *context, uint32_t number_of_callbacks)

       memcached_return_t   memcached_mget_execute_by_key(memcached_st *ptr,   const   char *group_key,   size_t group_key_length,  const  char  *
       const *keys, const size_t *key_length, size_t number_of_keys, memcached_execute_fn *callback, void *context, uint32_t number_of_callbacks)

       memcached_return_t (*memcached_execute_fn)(const memcached_st *ptr, memcached_result_st *result, void *context)

       Compile and link with -lmemcached

DESCRIPTION

       memcached_get() is used to fetch an individual value from the server.  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. Any object returned by memcached_get() must be
       released by the caller application.

       memcached_mget() is used to select multiple keys at once. For multiple key operations it is always faster to use this function. This  func-
       tion always works asynchronously.

       To  retrieve data after a successful execution of memcached_mget(), you will need to call memcached_fetch_result().  You should continue to
       call this function until it returns a NULL (i.e. no more values). If you need to quit in the middle of a  memcached_mget()  call,  you  can
       execute a memcached_quit(), those this is not required.

       memcached_fetch_result()  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. MEMCACHED_END is returned by the *error value when all objects that have been found are returned. The final value upon
       MEMCACHED_END is null.

       memcached_fetch_result() is used to return a memcached_result_st 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 help. This function will dynamically allocate a
       result structure for you if you do not pass one to the function.

       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.

       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.

       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.

       All  of	the  above  functions  are not tested when the MEMCACHED_BEHAVIOR_USE_UDP has been set. Executing any of these functions with this
       behavior on will result in MEMCACHED_NOT_SUPPORTED being returned, or for those functions which do not  return  a  memcached_return_t,  the
       error function parameter will be set to MEMCACHED_NOT_SUPPORTED.

RETURN

       All objects retrieved via memcached_get() or memcached_get_by_key() must be freed with free(3).

       memcached_get() will return NULL on error. You must look at the value of error to determine what the actual error was.

       memcached_fetch_execute()  return  MEMCACHED_SUCCESS  if all keys were successful. MEMCACHED_NOTFOUND will be return if no keys at all were
       found.

       memcached_fetch_result() sets error to MEMCACHED_END upon successful conclusion.  MEMCACHED_NOTFOUND will be return if no keys at all  were
       found.

HOME

       To find out more information please check: http://libmemcached.org/

SEE ALSO

       memcached(1) libmemcached(3) memcached_strerror(3)

AUTHOR

       Brian Aker

COPYRIGHT

       2011-2013, Brian Aker DataDifferential, http://datadifferential.com/

1.0.16								 January 31, 2013						  MEMCACHED_GET(3)