=head1 NAME
-memcached_get, memcached_mget, memcached_fetch
+memcached_get, memcached_mget, memcached_fetch, memcached_mget_execute,
+memcached_mget_execute_by_key - Get a value
=head1 LIBRARY
=head1 SYNOPSIS
-#include <memcached.h>
-char *memcached_get(memcached_st *ptr, char *key, size_t key_length,
- size_t *value_length,
- uint16_t *flags,
- memcached_return *error);
-memcached_return memcached_mget(memcached_st *ptr,
- char **keys, size_t *key_length,
- unsigned int number_of_keys);
-char *memcached_fetch(memcached_st *ptr, char *key, size_t *key_length,
- size_t *value_length, uint16_t *flags,
- memcached_return *error);
+ #include <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,
+ memcached_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 *master_key, size_t master_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 *master_key, size_t master_key_length,
+ const char * const *keys,
+ const size_t *key_length,
+ size_t number_of_keys);
+
+ char *
+ memcached_fetch (memcached_st *ptr,
+ char *key, size_t *key_length,
+ size_t *value_length,
+ uint32_t *flags,
+ memcached_return_t *error);
+
+ 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 *master_key,
+ size_t master_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);
-=head1 DESCRIPTION
+=head1 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 uint16_t pointer to contain whatever flags you stored with the value,
+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 pointer to hold any error. The object will be returned
-upon success and NULL will be returned on failure.
+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 function always
-works asyncronously. memcached_fetch() is then used to retrieve any keys
-found. No error is given on keys that are not found.
-
-memcached_fetch() is used to fetch an individual value from the server.
+works asynchronously. memcached_fetch() is then used to retrieve any keys
+found. No error is given on keys that are not found. You must call either
+memcached_fetch() or memcached_fetch_result() after a successful call to
+memcached_mget(). You should continue to call these functions until they
+return NULL (aka no more values). If you need to quit in the middle of a
+memcached_get() call, execute a memcached_quit(). After you do this, you can
+issue new queries against the server.
+
+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 uint16_t pointer to contain whatever flags you stored with the value,
+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 pointer to hold any error. The object will be returned
-upon success and NULL will be returned on failure.
+memcached_return_t pointer to hold any error. The object will be returned
+upon success and NULL will be returned on failure. MEMCACHD_END is returned
+by the *error value when all objects that have been found are returned.
+The final value upon MEMCACHED_END is null. Values returned by
+memcached_fetch() musted be free'ed by the caller. memcached_fetch() will
+be DEPRECATED in the near future, memcached_fetch_result() should be used
+instead.
+
+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.
+
+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 (we 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 supported when the C<MEMCACHED_BEHAVIOR_USE_UDP>
+has been set. Executing any of these functions with this behavior on will result in
+C<MEMCACHED_NOT_SUPPORTED> being returned or, for those functions which do not return
+a C<memcached_return_t>, the error function parameter will be set to
+C<MEMCACHED_NOT_SUPPORTED>.
=head1 RETURN
All objects returned must be freed by the calling application.
memcached_get() and memcached_fetch() will return NULL on error. You must
-look at the value of error() to determine what the actual error was.
+look at the value of error to determine what the actual error was.
+
+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.
=head1 HOME
-To find out more information please check: http://tangent.org/552/libmemcached.html
+To find out more information please check:
+L<https://launchpad.net/libmemcached>
=head1 AUTHOR
-Brian Aker, brian@tangent.org
+Brian Aker, E<lt>brian@tangent.orgE<gt>
=head1 SEE ALSO
projects / awesomized / libmemcached / blobdiff