#include <evo/async/memcached_client.h>

Inheritance diagram for MemcachedClient:

[legend]

Detailed Description

Implements Memcached protocol for an async client.

See Asynchronous I/O for general overview

Usage:

Implement handlers for desired response events:
- This can be a general handler implementing async::MemcachedClient::OnEvent
- or can be separate handlers for each request type: OnConnect, OnStore, OnIncrement, OnRemove, OnGet
- Implement an OnError handler if desired
Instantiate a MemcachedClient
- Call setup methods as needed: set_timeout(), set_on_connect(), set_on_error(), set_logger()
- For non-blocking client: Not yet implemented
Call a connect method like connect_ip() to start a connection
- Note that this doesn't block and requests are queued while connecting
Use requests methods to make requests, create and pass event handlers as needed – not that some methods have alternate variants:
For blocking client: call runlocal() to process all pending requests

Example

#include <evo/async/memcached_client.h>
#include <evo/io.h>
using namespace evo;
struct OnEvent : async::MemcachedClient::OnEvent {
    void on_connect() {
        con().out << "on_connect()" << NL;
    }
    void on_store(const SubString& key, Memcached::StoreResult result) {
        con().out << "on_store() " << key << ' ' << Memcached::StoreResultEnum::get_string(result) << NL;
    }
    void on_get(const SubString& key, const SubString& value, uint32 flags) {
        con().out << "on_get() " << key << " '" << value << "' " << flags << NL;
    }
};
int main() {
    Socket::sysinit();
    const ushort MEMC_PORT = 11211;
    OnEvent on_event;
    async::MemcachedClient memc;
    memc.set_on_connect(&on_event);
    memc.connect_ip("127.0.0.1", MEMC_PORT);
    memc.set("key1", "value1", on_event);
    memc.set("key2", "value2", on_event);
    memc.runlocal();
    memc.get("key1", on_event);
    memc.get("key2", on_event);
    memc.runlocal();
    return 0;
}

Classes
struct	OnEvent
	Base interface used as a shortcut that inherits all the non-error event interfaces: OnConnect, OnStore, OnIncrement, OnTouch, OnRemove, OnGet. More...

struct	OnGet
	Base interface for on_get() and on_get_end() events. More...

struct	OnIncrement
	Base interface for on_increment() event. More...

struct	OnRemove
	Base interface for on_remove() event. More...

struct	OnStore
	Base interface for on_store() event. More...

struct	OnTouch
	Base interface for on_touch() event. More...

Public Types
typedef AsyncClient< MemcachedClient, impl_memc::ClientQueueItem >	Base

typedef MemcachedClient	ProtocolHandler
	Derived protocol hander type (must inherit from AsyncClient) More...

enum	State
	Client state. More...

typedef AsyncClient< MemcachedClient, impl_memc::ClientQueueItem >	This
	This type More...

Public Member Functions
	MemcachedClient (SizeT max_queue_size=DEFAULT_QUEUE_SIZE, SizeT max_read_size=DEFAULT_MAX_READ)
	Constructor to initialize client. More...

This &	attach_to (AsyncBase &parent)
	Attach to a parent AsyncClient or AsyncServer and use the same event-loop as the parent. More...

void	close ()
	Close connection. More...

bool	connect_ip (const char *host, ushort port, int family=AF_INET)
	Start IP connection. More...

bool	decr (const SubString &key, uint64 count=1, OnIncrement on_increment=NULL, OnError on_error=NULL)
	Send a request to decrement value for given key. More...

bool	get (const SubString &key, OnGet &on_get, OnError on_error=NULL, bool track_notfound=false, int64 expire=NULL)
	Send a request to get value for one or more keys. More...

bool	get_cas (const SubString &key, OnGet &on_get, OnError on_error=NULL, bool track_notfound=false, int64 expire=NULL)
	Send a request to get value for one or more keys for Compare-And-Swap. More...

ulong	get_id () const
	Get current client ID. More...

State	get_state () const
	Get current state. More...

bool	get_touch (const SubString &key, int64 expire, OnGet &on_get, OnError *on_error=NULL, bool track_notfound=false)
	Send a request to get value for one or more keys and touch (update) the stored expiration time. More...

bool	get_touch_cas (const SubString &key, int64 expire, OnGet &on_get, OnError *on_error=NULL, bool track_notfound=false)
	Send a request to get value for one or more keys for Compare-And-Swap and touch (update) the stored expiration time. More...

bool	incr (const SubString &key, uint64 count=1, OnIncrement on_increment=NULL, OnError on_error=NULL)
	Send a request to increment value for given key. More...

bool	increment (const SubString &key, uint64 count=1, bool decrement=false, OnIncrement on_increment=NULL, OnError on_error=NULL)
	Send a request to increment or decrement value for given key. More...

bool	remove (const SubString &key, OnRemove on_remove=NULL, OnError on_error=NULL)
	Send a request to delete key and value. More...

bool	runlocal ()
	Run the event-loop locally in current thread until all pending requests are handled (client only). More...

bool	set (const SubString &key, const SubString &value, uint32 flags=0, int64 expire=0, uint64 cas_id=NULL, OnStore on_store=NULL, OnError *on_error=NULL)
	Send a request to set a key and value. More...

bool	set (const SubString &key, const SubString &value, OnStore &on_store, OnError on_error=NULL, uint32 flags=0, int64 expire=0, uint64 cas_id=NULL)
	Send a request to set a key and value. More...

bool	set_add (const SubString &key, const SubString &value, uint32 flags=0, int64 expire=0, OnStore on_store=NULL, OnError on_error=NULL)
	Send a request to add a new key and value and fail if key already exists. More...

bool	set_append (const SubString &key, const SubString &value, OnStore on_store=NULL, OnError on_error=NULL)
	Send a request to append to existing value for key. More...

bool	set_cas (const SubString &key, const SubString &value, uint64 cas_id, OnStore &on_store, OnError *on_error=NULL, uint32 flags=0, int64 expire=0)
	Send a request to set a key and value using Compare-And-Swap. More...

virtual void	set_logger (LoggerBase *newlogger)
	Set logger to use. More...

This &	set_on_connect (OnConnect *cb)
	Set general handler to call when a connection is established. More...

This &	set_on_error (OnError *cb)
	Set general handler to call when an unexpected error occurs. More...

bool	set_prepend (const SubString &key, const SubString &value, OnStore on_store=NULL, OnError on_error=NULL)
	Send a request to prepend to existing value for key. More...

bool	set_replace (const SubString &key, const SubString &value, uint32 flags=0, int64 expire=0, OnStore on_store=NULL, OnError on_error=NULL)
	Send a request to replace an existing value under key and fail if key doesn't exist. More...

void	set_timeout (ulong read_timeout_ms=0, ulong write_timeout_ms=0)
	Set read/write timeouts to use. More...

bool	set_timer (OnTimer &on_timer, ulong msec)
	Activate timer so it expires after given time elapses. More...

bool	touch (const SubString &key, int64 expire, OnTouch on_touch, OnError on_error=NULL)
	Send a request to touch (update) the expiration time for given key. More...

Static Public Member Functions
static int64	calc_expire_time (int64 seconds, int64 base=0)
	Calculate memcached expiration time for given number of seconds from now. More...

Public Attributes
LoggerPtr	logger
	Logger for protocol and debug messages, set to enable logging – see set_logger() More...

Static Public Attributes
static const size_t	DEFAULT_MAX_READ = 524288

static const SizeT	DEFAULT_QUEUE_SIZE = 256

static const size_t	MIN_INITIAL_READ = 0

Protected Member Functions
void	init ()
	Initialize event-loop. More...

void	init_attach (AsyncBase &parent)
	Initialize and attach to a parent event-loop. More...

bool	run_eventloop ()
	Run event loop and process all events and repeat until shutdown. More...

bool	run_eventloop_once ()
	Run event loop with one pass and process all events. More...

Static Protected Member Functions
static struct timeval *	get_timeout_ptr (struct timeval &out, ulong ms)
	Get timeval struct pointer from timeout in milliseconds. More...

Protected Attributes
AsyncBase *	child_base_
	Pointer to child in AsyncBase chain (always an AsyncClient), NULL for none. More...

AsyncEventLoop *	evloop_
	Event loop pointer, either owned by this or a parent. More...

bool	local_
	Whether event-loop is local (same thread), false if separate thread. More...

AsyncBase *	parent_base_
	Pointer to parent in AsyncBase chain, NULL if this is the main parent (and owns evloop_ pointer) More...

AtomicBufferQueue< QueueItem >	queue_
	Queue where each item represents an expected response from server. More...

ulong	read_timeout_ms_
	Socket read timeout in milliseconds, 0 for none (never timeout) More...

ulong	write_timeout_ms_
	Socket write timeout in milliseconds, 0 for none (never timeout) More...

Friends
class	AsyncClient< MemcachedClient, QueueItem >

class	evo::AsyncBuffers

Member Typedef Documentation

◆ Base

typedef AsyncClient<MemcachedClient, impl_memc::ClientQueueItem> Base

◆ ProtocolHandler

typedef MemcachedClient ProtocolHandler

inherited

Derived protocol hander type (must inherit from AsyncClient)

◆ This

typedef AsyncClient<MemcachedClient ,impl_memc::ClientQueueItem > This

inherited

This type

Member Enumeration Documentation

◆ State

enum State

inherited

Client state.

Constructor & Destructor Documentation

◆ MemcachedClient()

MemcachedClient	(	SizeT	max_queue_size = `DEFAULT_QUEUE_SIZE`,
		SizeT	max_read_size = `DEFAULT_MAX_READ`
	)

inline

Constructor to initialize client.

Parameters

max_queue_size	Max size for pending response queue
max_read_size	Max read buffer size, 0 for unlimited – this is used to limit the read buffer size

Member Function Documentation

◆ attach_to()

This& attach_to ( AsyncBase & parent )

inlineinherited

Attach to a parent AsyncClient or AsyncServer and use the same event-loop as the parent.

This must be called before any connect*() method, otherwise this is ignored

Parameters

parent Parent to attach to

Returns: This

◆ calc_expire_time()

static int64 calc_expire_time	(	int64	seconds,
		int64	base = `0`
	)

inlinestatic

Calculate memcached expiration time for given number of seconds from now.

This returns an expiration value understood by memcached servers: number of seconds from now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on

Parameters

seconds	Number of seconds now for expiration time
base	Base timestamp to use, 0 for current time – only used if needed

Returns: Expiration time value for memcached

◆ close()

void close ( )

inlineinherited

Close connection.

This must not be called from an event handler

◆ connect_ip()

bool connect_ip	(	const char *	host,
		ushort	port,
		int	family = `AF_INET`
	)

inlineinherited

Start IP connection.

This is non-blocking and returns immediately while connecting

◆ decr()

bool decr	(	const SubString &	key,
		uint64	count = `1`,
		OnIncrement *	on_increment = `NULL`,
		OnError *	on_error = `NULL`
	)

inline

Send a request to decrement value for given key.

If key doesn't exist then the response event count argument will be null
If value for key is not an integer, the server will return a CLIENT_ERROR and on_error will be called (if not NULL)
If on_increment=NULL then this sends a "noreply" request to tell the server not to respond to this command (reducing overhead)

Parameters

key	Key to use – must not have any spaces
count	Count to decrement by
on_increment	OnIncrement handler to receive response event, NULL for none
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none – ignored if `on_increment=NULL`

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ get()

bool get	(	const SubString &	key,
		OnGet &	on_get,
		OnError *	on_error = `NULL`,
		bool	track_notfound = `false`,
		int64 *	expire = `NULL`
	)

inline

Send a request to get value for one or more keys.

The server only sends back responses for keys that were found, so noting which keys weren't found (cache misses) requires some overhead:
- Use track_notfound to have the client build a list of keys not found, which is passed to OnGet::on_get_end()

Parameters

key	Key(s) to get, multiple keys are space-separated
on_get	OnGet handler to receive response events
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none
track_notfound	Whether to track keys not found (i.e. cache misses), true to enable logic that builds a list of keys not found (passed to OnGet::on_get_end()) – this adds some overhead
expire	Pointer to expiration time used to "touch" while getting the value by updating the expiration time, NULL to disable this Expiration time is in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ get_cas()

bool get_cas	(	const SubString &	key,
		OnGet &	on_get,
		OnError *	on_error = `NULL`,
		bool	track_notfound = `false`,
		int64 *	expire = `NULL`
	)

inline

Send a request to get value for one or more keys for Compare-And-Swap.

Responses here will include a cas_id, which can be passed to set_cas() or set() to complete the Compare-And-Swap
The server only sends back responses for keys that were found, so noting which keys weren't found (cache misses) requires some overhead:
- Use track_notfound to have the client build a list of keys not found, which is passed to OnGet::on_get_end()

Parameters

key	Key(s) to get, multiple keys are space-separated
on_get	OnGet handler to receive response events
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none
track_notfound	Whether to track keys not found (i.e. cache misses), true to enable logic that builds a list of keys not found (passed to OnGet::on_get_end()) – this adds some overhead
expire	Pointer to expiration time used to "touch" while getting the value by updating the expiration time, NULL to disable this Expiration time is in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ get_id()

ulong get_id ( ) const

inlineinherited

Get current client ID.

Returns: Client ID

◆ get_state()

State get_state ( ) const

inlineinherited

Get current state.

Returns: Current state

◆ get_timeout_ptr()

static struct timeval* get_timeout_ptr	(	struct timeval &	out,
		ulong	ms
	)

inlinestaticprotectedinherited

Get timeval struct pointer from timeout in milliseconds.

Parameters

out	Struct to store timeout
ms	Time in milliseconds to use

Returns: Pointer to out, or NULL if ms is 0

◆ get_touch()

bool get_touch	(	const SubString &	key,
		int64	expire,
		OnGet &	on_get,
		OnError *	on_error = `NULL`,
		bool	track_notfound = `false`
	)

inline

Send a request to get value for one or more keys and touch (update) the stored expiration time.

The server only sends back responses for keys that were found, so noting which keys weren't found (cache misses) requires some overhead:
- Use track_notfound to have the client build a list of keys not found, which is passed to OnGet::on_get_end()

Parameters

key	Key(s) to get, multiple keys are space-separated
expire	New expiration time in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper
on_get	OnGet handler to receive response events
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none
track_notfound	Whether to track keys not found (i.e. cache misses), true to enable logic that builds a list of keys not found (passed to OnGet::on_get_end()) – this adds some overhead

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ get_touch_cas()

bool get_touch_cas	(	const SubString &	key,
		int64	expire,
		OnGet &	on_get,
		OnError *	on_error = `NULL`,
		bool	track_notfound = `false`
	)

inline

Send a request to get value for one or more keys for Compare-And-Swap and touch (update) the stored expiration time.

The server only sends back responses for keys that were found, so noting which keys weren't found (cache misses) requires some overhead:
- Use track_notfound to have the client build a list of keys not found, which is passed to OnGet::on_get_end()

Parameters

key	Key(s) to get, multiple keys are space-separated
expire	New expiration time in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper
on_get	OnGet handler to receive response events
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none
track_notfound	Whether to track keys not found (i.e. cache misses), true to enable logic that builds a list of keys not found (passed to OnGet::on_get_end()) – this adds some overhead

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ incr()

bool incr	(	const SubString &	key,
		uint64	count = `1`,
		OnIncrement *	on_increment = `NULL`,
		OnError *	on_error = `NULL`
	)

inline

Send a request to increment value for given key.

If key doesn't exist then the response event count argument will be null
If value for key is not an integer, the server will return a CLIENT_ERROR and on_error will be called (if not NULL)
If on_increment=NULL then this sends a "noreply" request to tell the server not to respond to this command (reducing overhead)

Parameters

key	Key to use – must not have any spaces
count	Count to increment by
on_increment	OnIncrement handler to receive response event, NULL for none
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none – ignored if `on_increment=NULL`

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ increment()

bool increment	(	const SubString &	key,
		uint64	count = `1`,
		bool	decrement = `false`,
		OnIncrement *	on_increment = `NULL`,
		OnError *	on_error = `NULL`
	)

inline

Send a request to increment or decrement value for given key.

If key doesn't exist then the response event count argument will be null
If value for key is not an integer, the server will return a CLIENT_ERROR and on_error will be called (if not NULL)
If on_increment=NULL then this sends a "noreply" request to tell the server not to respond to this command (reducing overhead)

Parameters

key	Key to use – must not have any spaces
count	Count to increment or decrement by
decrement	Whether to decrement, false to increment
on_increment	OnIncrement handler to receive response event, NULL for none
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none – ignored if `on_increment=NULL`

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ init()

void init ( )

inlineprotectedinherited

Initialize event-loop.

Ignored if already initialized

◆ init_attach()

void init_attach ( AsyncBase & parent )

inlineprotectedinherited

Initialize and attach to a parent event-loop.

Ignored if already initialized

Parameters

parent Parent AsyncBase to attach to

◆ remove()

bool remove	(	const SubString &	key,
		OnRemove *	on_remove = `NULL`,
		OnError *	on_error = `NULL`
	)

inline

Send a request to delete key and value.

If on_remove=NULL then this sends a "noreply" request to tell the server not to respond to this command (reducing overhead)

Parameters

key	Key to use – must not have any spaces
on_remove	OnRemove handler to receive response event, NULL for none
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none – ignored if `on_remove=NULL`

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ run_eventloop()

bool run_eventloop ( )

inlineprotectedinherited

Run event loop and process all events and repeat until shutdown.

Returns: Whether successful, false on internal error

◆ run_eventloop_once()

bool run_eventloop_once ( )

inlineprotectedinherited

Run event loop with one pass and process all events.

This waits until some events are active then processes all active events and returns

Returns: Whether successful, false on internal error

◆ runlocal()

bool runlocal ( )

inlineinherited

Run the event-loop locally in current thread until all pending requests are handled (client only).

This blocks while client requests are pending
This returns false immediately if this does not own an event-loop (i.e. was attached to a parent) – only the top parent can run an event-loop

Returns: Whether successful, false if attached to another AsyncBase or on internal error

◆ set() [1/2]

bool set	(	const SubString &	key,
		const SubString &	value,
		uint32	flags = `0`,
		int64	expire = `0`,
		uint64 *	cas_id = `NULL`,
		OnStore *	on_store = `NULL`,
		OnError *	on_error = `NULL`
	)

inline

Send a request to set a key and value.

This replaces the previous value for given key, and overwrites flags and expire time for that key
If on_store=NULL then this sends a "noreply" request to tell the server not to respond to this command (reducing overhead)

Parameters

key	Key to store under – must not have any spaces
value	New value to store
flags	User defined flags to store under key, 0 for none
expire	Expiration time in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper
cas_id	Pointer to Compare-And-Swap ID returned from get_cas() request, NULL if not doing Compare-And-Swap, otherwise this new value is stored unless: If the value has been modified since get_cas() returned this `cas_id` then response will be Memcached::srEXISTS If key doesn't exist then response will be Memcached::srNOT_FOUND
on_store	OnStore handler to receive response event, NULL for none
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none – ignored if `on_store=NULL`

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ set() [2/2]

bool set	(	const SubString &	key,
		const SubString &	value,
		OnStore &	on_store,
		OnError *	on_error = `NULL`,
		uint32	flags = `0`,
		int64	expire = `0`,
		uint64 *	cas_id = `NULL`
	)

inline

Send a request to set a key and value.

This replaces the previous value for given key, and overwrites flags and expire time for that key

Parameters

key	Key to store under – must not have any spaces
value	New value to store
on_store	OnStore handler to receive response event
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none
flags	User defined flags to store under key, 0 for none
expire	Expiration time in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper
cas_id	Pointer to Compare-And-Swap ID returned from get_cas() request, NULL if not doing Compare-And-Swap, otherwise this new value is stored unless: If the value has been modified since get_cas() returned this `cas_id` then response will be Memcached::srEXISTS If key doesn't exist then response will be Memcached::srNOT_FOUND

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ set_add()

bool set_add	(	const SubString &	key,
		const SubString &	value,
		uint32	flags = `0`,
		int64	expire = `0`,
		OnStore *	on_store = `NULL`,
		OnError *	on_error = `NULL`
	)

inline

Send a request to add a new key and value and fail if key already exists.

If key already exists then nothing is stored and the response will be Memcached::srNOT_STORED
If on_store=NULL then this sends a "noreply" request to tell the server not to respond to this command (reducing overhead)

Parameters

key	Key to store under – must not have any spaces
value	New value to store
flags	User defined flags to store under key, 0 for none
expire	Expiration time in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper
on_store	OnStore handler to receive response event, NULL for none
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none – ignored if `on_store=NULL`

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ set_append()

bool set_append	(	const SubString &	key,
		const SubString &	value,
		OnStore *	on_store = `NULL`,
		OnError *	on_error = `NULL`
	)

inline

Send a request to append to existing value for key.

This appends to the current value for given key
If key doesn't exist then the response will be Memcached::srNOT_STORED

Parameters

key	Key to store under – must not have any spaces
value	New value to append to existing value
on_store	OnStore handler to receive response event
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ set_cas()

bool set_cas	(	const SubString &	key,
		const SubString &	value,
		uint64	cas_id,
		OnStore &	on_store,
		OnError *	on_error = `NULL`,
		uint32	flags = `0`,
		int64	expire = `0`
	)

inline

Send a request to set a key and value using Compare-And-Swap.

This replaces the previous value for given key, and overwrites flags and expire time for that key
get_cas() should be called first to check the current value and cas_id, then if needed this is used to replace that value (if it hasn't changed since)

Parameters

key	Key to store under – must not have any spaces
value	New value to store
cas_id	Compare-And-Swap ID returned from get_cas() request, this new value is stored unless: If the value has been modified since get_cas() returned this `cas_id` then response will be Memcached::srEXISTS If key doesn't exist then response will be Memcached::srNOT_FOUND
on_store	OnStore handler to receive response event
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none
flags	User defined flags to store under key, 0 for none
expire	Expiration time in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ set_logger()

virtual void set_logger ( LoggerBase * newlogger )

inlinevirtualinherited

Set logger to use.

If set, a logger shows low-level details and error information from the framework
The logger pointer must remain valid as long as it's referenced here

Parameters

newlogger Pointer to logger to set, NULL for none (no logging)

◆ set_on_connect()

This& set_on_connect ( OnConnect * cb )

inlineinherited

Set general handler to call when a connection is established.

Parameters

cb	OnConnect event to use, NULL for none

Returns: This

◆ set_on_error()

This& set_on_error ( OnError * cb )

inlineinherited

Set general handler to call when an unexpected error occurs.

Parameters

cb	OnError event to use, NULL for none

Returns: This

◆ set_prepend()

bool set_prepend	(	const SubString &	key,
		const SubString &	value,
		OnStore *	on_store = `NULL`,
		OnError *	on_error = `NULL`
	)

inline

Send a request to prepend to existing value for key.

This prepends to the current value for given key
If key doesn't exist then the response will be Memcached::srNOT_STORED

Parameters

key	Key to store under – must not have any spaces
value	New value to prepend to existing value
on_store	OnStore handler to receive response event
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ set_replace()

bool set_replace	(	const SubString &	key,
		const SubString &	value,
		uint32	flags = `0`,
		int64	expire = `0`,
		OnStore *	on_store = `NULL`,
		OnError *	on_error = `NULL`
	)

inline

Send a request to replace an existing value under key and fail if key doesn't exist.

If key doesn't exist then nothing is stored and the response will be Memcached::srNOT_STORED
If on_store=NULL then this sends a "noreply" request to tell the server not to respond to this command (reducing overhead)

Parameters

key	Key to store under – must not have any spaces
value	New value to store
flags	User defined flags to store under key, 0 for none
expire	Expiration time in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper
on_store	OnStore handler to receive response event, NULL for none
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none – ignored if `on_store=NULL`

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

◆ set_timeout()

void set_timeout	(	ulong	read_timeout_ms = `0`,
		ulong	write_timeout_ms = `0`
	)

inlineinherited

Set read/write timeouts to use.

Parameters

read_timeout_ms	Socket read timeout in milliseconds, 0 for none (never timeout)
write_timeout_ms	Socket write timeout in milliseconds, 0 for none (never timeout)

◆ set_timer()

bool set_timer	(	OnTimer &	on_timer,
		ulong	msec
	)

inlineinherited

Activate timer so it expires after given time elapses.

When the timer expires the OnTimer::on_timer() event is called and the timer is deactivated
To reactivate the timer so it expires again the event should call OnTimer::timer_reset()

Parameters

on_timer	Timer to use
msec	Expiration time in milliseconds

Returns: Whether successful, false on internal error

◆ touch()

bool touch	(	const SubString &	key,
		int64	expire,
		OnTouch *	on_touch,
		OnError *	on_error = `NULL`
	)

inline

Send a request to touch (update) the expiration time for given key.

If on_touch=NULL then this sends a "noreply" request to tell the server not to respond to this command (reducing overhead)

Parameters

key	Key to store under – must not have any spaces
expire	New expiration time in seconds from now, 0 for no expiration, negative to expire now, or a value greater than 2592000 (30 days) means a Unix timestamp to expire on See calc_expire_time() helper
on_touch	OnTouch handler to receive response event, NULL for none
on_error	OnError handler to use for unexpected errors (not used for normal fail response), NULL for none – ignored if `on_store=NULL`

Returns: Whether successful, false if unable to send request due to internal error (usually means not connected and no connection in progress)

Friends And Related Function Documentation

◆ AsyncClient< MemcachedClient, QueueItem >

friend class AsyncClient< MemcachedClient, QueueItem >

friend

◆ evo::AsyncBuffers

friend class evo::AsyncBuffers

friend

Member Data Documentation

◆ child_base_

AsyncBase* child_base_

protectedinherited

Pointer to child in AsyncBase chain (always an AsyncClient), NULL for none.

◆ DEFAULT_MAX_READ

const size_t DEFAULT_MAX_READ = 524288

static

◆ DEFAULT_QUEUE_SIZE

const SizeT DEFAULT_QUEUE_SIZE = 256

static

◆ evloop_

AsyncEventLoop* evloop_

protectedinherited

Event loop pointer, either owned by this or a parent.

◆ local_

bool local_

protectedinherited

Whether event-loop is local (same thread), false if separate thread.

◆ logger

LoggerPtr logger

inherited

Logger for protocol and debug messages, set to enable logging – see set_logger()

◆ MIN_INITIAL_READ

const size_t MIN_INITIAL_READ = 0

static

◆ parent_base_

AsyncBase* parent_base_

protectedinherited

Pointer to parent in AsyncBase chain, NULL if this is the main parent (and owns evloop_ pointer)

◆ queue_

AtomicBufferQueue<QueueItem> queue_

protectedinherited

Queue where each item represents an expected response from server.

◆ read_timeout_ms_

ulong read_timeout_ms_

protectedinherited

Socket read timeout in milliseconds, 0 for none (never timeout)

◆ write_timeout_ms_

ulong write_timeout_ms_

protectedinherited

Socket write timeout in milliseconds, 0 for none (never timeout)

The documentation for this class was generated from the following file:

evo/async/memcached_client.h

Detailed Description

Classes

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Friends

Member Typedef Documentation

◆ Base

◆ ProtocolHandler

◆ This

Member Enumeration Documentation

◆ State

Constructor & Destructor Documentation

◆ MemcachedClient()

Member Function Documentation

◆ attach_to()

◆ calc_expire_time()

◆ close()

◆ connect_ip()

◆ decr()

◆ get()

◆ get_cas()

◆ get_id()

◆ get_state()

◆ get_timeout_ptr()

◆ get_touch()

◆ get_touch_cas()

◆ incr()

◆ increment()

◆ init()

◆ init_attach()

◆ remove()

◆ run_eventloop()

◆ run_eventloop_once()

◆ runlocal()

◆ set() [1/2]

◆ set() [2/2]

◆ set_add()

◆ set_append()

◆ set_cas()

◆ set_logger()

◆ set_on_connect()

◆ set_on_error()

◆ set_prepend()

◆ set_replace()

◆ set_timeout()

◆ set_timer()

◆ touch()

Friends And Related Function Documentation

◆ AsyncClient< MemcachedClient, QueueItem >

◆ evo::AsyncBuffers

Member Data Documentation

◆ child_base_

◆ DEFAULT_MAX_READ

◆ DEFAULT_QUEUE_SIZE

◆ evloop_

◆ local_

◆ logger

◆ MIN_INITIAL_READ

◆ parent_base_

◆ queue_

◆ read_timeout_ms_

◆ write_timeout_ms_