memcached.h File Reference

The main memcached header holding commonly used data structures and function prototypes. More...

#include <pthread.h>
#include <config_static.h>
#include <memcached/protocol_binary.h>
#include <memcached/engine.h>
#include <memcached/extension.h>
#include "cache.h"
#include "topkeys.h"
#include "sasl_defs.h"
#include "stats.h"
#include "trace.h"
#include "hash.h"
#include <memcached/util.h>

Go to the source code of this file.

Classes
struct	slab_stats
	Stats stored per slab (and per thread). More...
struct	thread_stats
	Stats stored per-thread. More...
struct	independent_stats
	The stats structure the engine keeps track of. More...
struct	stats
	Global stats. More...
struct	settings
	Globally accessible settings as derived from the commandline. More...
struct	engine_event_handler
struct	LIBEVENT_THREAD
struct	conn
	The structure representing a connection into memcached. More...

Macros
#define	KEY_MAX_LENGTH   250
	Maximum length of a key. More...
#define	INCR_MAX_STORAGE_LEN   24
	Size of an incr buf. More...
#define	DATA_BUFFER_SIZE   2048
#define	UDP_READ_BUFFER_SIZE   65536
#define	UDP_MAX_PAYLOAD_SIZE   1400
#define	UDP_HEADER_SIZE   8
#define	MAX_SENDBUF_SIZE   (256 * 1024 * 1024)
#define	SUFFIX_SIZE   24
#define	ITEM_LIST_INITIAL   200
	Initial size of list of items being returned by "get". More...
#define	SUFFIX_LIST_INITIAL   20
	Initial size of list of CAS suffixes appended to "gets" lines. More...
#define	IOV_LIST_INITIAL   400
	Initial size of the sendmsg() scatter/gather array. More...
#define	MSG_LIST_INITIAL   10
	Initial number of sendmsg() argument structures to allocate. More...
#define	READ_BUFFER_HIGHWAT   8192
	High water marks for buffer shrinking. More...
#define	ITEM_LIST_HIGHWAT   400
#define	IOV_LIST_HIGHWAT   600
#define	MSG_LIST_HIGHWAT   100
#define	MIN_BIN_PKT_LENGTH   16
#define	BIN_PKT_HDR_WORDS   (MIN_BIN_PKT_LENGTH/sizeof(uint32_t))
#define	POWER_SMALLEST   1
#define	POWER_LARGEST   200
#define	CHUNK_ALIGN_BYTES   8
#define	DONT_PREALLOC_SLABS
#define	MAX_NUMBER_OF_SLAB_CLASSES   (POWER_LARGEST + 1)
#define	STAT_KEY_LEN   128
#define	STAT_VAL_LEN   128
#define	DEFAULT_REQS_PER_EVENT   20
#define	DEFAULT_REQS_PER_TAP_EVENT   50
#define	APPEND_STAT(name, fmt, val)   append_stat(name, add_stats, c, fmt, val);
	Append a simple stat with a stat name, value format and value. More...
#define	APPEND_NUM_FMT_STAT(name_fmt, num, name, fmt, val)
	Append an indexed stat with a stat name (with format), value format and value. More...
#define	APPEND_NUM_STAT(num, name, fmt, val)   APPEND_NUM_FMT_STAT("%d:%s", num, name, fmt, val)
	Common APPEND_NUM_FMT_STAT format. More...
#define	IS_UDP(x)   (x == udp_transport)
#define	MAX_VERBOSITY_LEVEL   2
#define	LOCK_THREAD(t)
#define	UNLOCK_THREAD(t)
#define	LIST_STATE_PROCESSING   1
#define	LIST_STATE_REQ_PENDING_IO   2
#define	LIST_STATE_REQ_PENDING_CLOSE   4
#define	drop_privileges()
#define	__builtin_expect(x, expected_value)   (x)
#define	likely(x)   __builtin_expect((x),1)
#define	unlikely(x)   __builtin_expect((x),0)

Typedefs
typedef struct conn	conn
typedef bool(*	STATE_FUNC) (conn *)

Enumerations
enum	bin_substates {   bin_no_state, bin_reading_set_header, bin_reading_cas_header, bin_read_set_value,   bin_reading_get_key, bin_reading_stat, bin_reading_del_header, bin_reading_incr_header,   bin_read_flush_exptime, bin_reading_sasl_auth, bin_reading_sasl_auth_data, bin_reading_packet }
enum	protocol { ascii_prot = 3, binary_prot, negotiating_prot }
enum	network_transport { local_transport, tcp_transport, udp_transport }
enum	thread_type { GENERAL = 11, TAP = 13, DISPATCHER = 15 }

Functions
void	notify_thread (LIBEVENT_THREAD *thread)
void	notify_dispatcher (void)
bool	create_notification_pipe (LIBEVENT_THREAD *me)
conn *	conn_new (const SOCKET sfd, STATE_FUNC init_state, const int event_flags, const int read_buffer_size, enum network_transport transport, struct event_base *base, struct timeval *timeout)
int	daemonize (int nochdir, int noclose)
bool	register_event (conn *c, struct timeval *timeout)
bool	unregister_event (conn *c)
bool	update_event (conn *c, const int new_flags)
void	thread_init (int nthreads, struct event_base *main_base, void(*dispatcher_callback)(int, short, void *))
void	threads_shutdown (void)
int	dispatch_event_add (int thread, conn *c)
void	dispatch_conn_new (SOCKET sfd, STATE_FUNC init_state, int event_flags, int read_buffer_size, enum network_transport transport)
void	accept_new_conns (const bool do_accept)
conn *	conn_from_freelist (void)
bool	conn_add_to_freelist (conn *c)
int	is_listen_thread (void)
void	STATS_LOCK (void)
void	STATS_UNLOCK (void)
void	threadlocal_stats_clear (struct thread_stats *stats)
void	threadlocal_stats_reset (struct thread_stats *thread_stats)
void	threadlocal_stats_aggregate (struct thread_stats *thread_stats, struct thread_stats *stats)
void	slab_stats_aggregate (struct thread_stats *stats, struct slab_stats *out)
void	append_stat (const char *name, ADD_STAT add_stats, conn *c, const char *fmt,...)
void	notify_io_complete (const void *cookie, ENGINE_ERROR_CODE status)
void	conn_set_state (conn *c, STATE_FUNC state)
const char *	state_text (STATE_FUNC state)
	Convert a state name to a human readable form. More...
void	safe_close (SOCKET sfd)
int	number_of_pending (conn *c, conn *pending)
bool	has_cycle (conn *c)
bool	list_contains (conn *h, conn *n)
conn *	list_remove (conn *h, conn *n)
size_t	list_to_array (conn **dest, size_t max_items, conn **l)
void	enlist_conn (conn *c, conn **list)
void	finalize_list (conn **list, size_t items)
bool	set_socket_nonblocking (SOCKET sfd)
void	conn_close (conn *c)
bool	conn_listening (conn *c)
bool	conn_new_cmd (conn *c)
bool	conn_waiting (conn *c)
bool	conn_read (conn *c)
bool	conn_parse_cmd (conn *c)
bool	conn_write (conn *c)
bool	conn_nread (conn *c)
bool	conn_swallow (conn *c)
bool	conn_pending_close (conn *c)
bool	conn_immediate_close (conn *c)
bool	conn_closing (conn *c)
bool	conn_mwrite (conn *c)
bool	conn_ship_log (conn *c)
	Ship tap log to the other end. More...
bool	conn_add_tap_client (conn *c)
bool	conn_setup_tap_stream (conn *c)

Variables
struct stats	stats
	exported globals More...
struct settings	settings
LIBEVENT_THREAD *	tap_thread

Detailed Description

The main memcached header holding commonly used data structures and function prototypes.

Macro Definition Documentation

__builtin_expect

#define __builtin_expect	(		x,
			expected_value
	)		(x)

APPEND_NUM_FMT_STAT

#define APPEND_NUM_FMT_STAT	(		name_fmt,
			num,
			name,
			fmt,
			val
	)

Value:

klen = snprintf(key_str, STAT_KEY_LEN, name_fmt, num, name);    \
    vlen = snprintf(val_str, STAT_VAL_LEN, fmt, val);               \
    add_stats(key_str, klen, val_str, vlen, c);

Append an indexed stat with a stat name (with format), value format and value.

APPEND_NUM_STAT

#define APPEND_NUM_STAT	(		num,
			name,
			fmt,
			val
	)		APPEND_NUM_FMT_STAT("%d:%s", num, name, fmt, val)

Common APPEND_NUM_FMT_STAT format.

APPEND_STAT

#define APPEND_STAT	(		name,
			fmt,
			val
	)		append_stat(name, add_stats, c, fmt, val);

Append a simple stat with a stat name, value format and value.

BIN_PKT_HDR_WORDS

#define BIN_PKT_HDR_WORDS   (MIN_BIN_PKT_LENGTH/sizeof(uint32_t))

CHUNK_ALIGN_BYTES

#define CHUNK_ALIGN_BYTES   8

DATA_BUFFER_SIZE

#define DATA_BUFFER_SIZE   2048

DEFAULT_REQS_PER_EVENT

#define DEFAULT_REQS_PER_EVENT   20

DEFAULT_REQS_PER_TAP_EVENT

#define DEFAULT_REQS_PER_TAP_EVENT   50

DONT_PREALLOC_SLABS

#define DONT_PREALLOC_SLABS

drop_privileges

#define drop_privileges

(

void

)

INCR_MAX_STORAGE_LEN

#define INCR_MAX_STORAGE_LEN   24

Size of an incr buf.

IOV_LIST_HIGHWAT

#define IOV_LIST_HIGHWAT   600

IOV_LIST_INITIAL

#define IOV_LIST_INITIAL   400

Initial size of the sendmsg() scatter/gather array.

IS_UDP

#define IS_UDP

(

x

)

(x == udp_transport)

ITEM_LIST_HIGHWAT

#define ITEM_LIST_HIGHWAT   400

ITEM_LIST_INITIAL

#define ITEM_LIST_INITIAL   200

Initial size of list of items being returned by "get".

KEY_MAX_LENGTH

#define KEY_MAX_LENGTH   250

Maximum length of a key.

likely

#define likely

(

x

)

__builtin_expect((x),1)

LIST_STATE_PROCESSING

#define LIST_STATE_PROCESSING   1

LIST_STATE_REQ_PENDING_CLOSE

#define LIST_STATE_REQ_PENDING_CLOSE   4

LIST_STATE_REQ_PENDING_IO

#define LIST_STATE_REQ_PENDING_IO   2

LOCK_THREAD

#define LOCK_THREAD

(

t

)

Value:

if (pthread_mutex_lock(&t->mutex) != 0) {   \
        abort();                                \
    }                                           \
    assert(t->is_locked == false);              \
    t->is_locked = true;

MAX_NUMBER_OF_SLAB_CLASSES

#define MAX_NUMBER_OF_SLAB_CLASSES   (POWER_LARGEST + 1)

MAX_SENDBUF_SIZE

#define MAX_SENDBUF_SIZE   (256 * 1024 * 1024)

MAX_VERBOSITY_LEVEL

#define MAX_VERBOSITY_LEVEL   2

MIN_BIN_PKT_LENGTH

#define MIN_BIN_PKT_LENGTH   16

MSG_LIST_HIGHWAT

#define MSG_LIST_HIGHWAT   100

MSG_LIST_INITIAL

#define MSG_LIST_INITIAL   10

Initial number of sendmsg() argument structures to allocate.

POWER_LARGEST

#define POWER_LARGEST   200

POWER_SMALLEST

#define POWER_SMALLEST   1

READ_BUFFER_HIGHWAT

#define READ_BUFFER_HIGHWAT   8192

High water marks for buffer shrinking.

STAT_KEY_LEN

#define STAT_KEY_LEN   128

STAT_VAL_LEN

#define STAT_VAL_LEN   128

SUFFIX_LIST_INITIAL

#define SUFFIX_LIST_INITIAL   20

Initial size of list of CAS suffixes appended to "gets" lines.

SUFFIX_SIZE

#define SUFFIX_SIZE   24

UDP_HEADER_SIZE

#define UDP_HEADER_SIZE   8

UDP_MAX_PAYLOAD_SIZE

#define UDP_MAX_PAYLOAD_SIZE   1400

UDP_READ_BUFFER_SIZE

#define UDP_READ_BUFFER_SIZE   65536

unlikely

#define unlikely

(

x

)

__builtin_expect((x),0)

UNLOCK_THREAD

#define UNLOCK_THREAD

(

t

)

Value:

assert(t->is_locked == true);                \
    t->is_locked = false;                        \
    if (pthread_mutex_unlock(&t->mutex) != 0) {  \
        abort();                                 \
    }

Typedef Documentation

conn

typedef struct conn conn

STATE_FUNC

typedef bool(* STATE_FUNC) (conn *)

Enumeration Type Documentation

bin_substates

enum bin_substates

Enumerator
bin_no_state
bin_reading_set_header
bin_reading_cas_header
bin_read_set_value
bin_reading_get_key
bin_reading_stat
bin_reading_del_header
bin_reading_incr_header
bin_read_flush_exptime
bin_reading_sasl_auth
bin_reading_sasl_auth_data
bin_reading_packet

network_transport

enum network_transport

Enumerator
local_transport
tcp_transport
udp_transport

protocol

enum protocol

Enumerator
ascii_prot
binary_prot
negotiating_prot

thread_type

enum thread_type

Enumerator
GENERAL
TAP
DISPATCHER

Function Documentation

accept_new_conns()

void accept_new_conns

(

const bool

do_accept

)

append_stat()

void append_stat	(	const char *	name,
		ADD_STAT	add_stats,
		conn *	c,
		const char *	fmt,
			...
	)

conn_add_tap_client()

bool conn_add_tap_client

(

conn *

c

)

conn_add_to_freelist()

bool conn_add_to_freelist

(

conn *

c

)

conn_close()

void conn_close

(

conn *

c

)

conn_closing()

bool conn_closing

(

conn *

c

)

conn_from_freelist()

conn* conn_from_freelist

(

void

)

conn_immediate_close()

bool conn_immediate_close

(

conn *

c

)

conn_listening()

bool conn_listening

(

conn *

c

)

conn_mwrite()

bool conn_mwrite

(

conn *

c

)

conn_new()

conn* conn_new	(	const SOCKET	sfd,
		STATE_FUNC	init_state,
		const int	event_flags,
		const int	read_buffer_size,
		enum network_transport	transport,
		struct event_base *	base,
		struct timeval *	timeout
	)

conn_new_cmd()

bool conn_new_cmd

(

conn *

c

)

conn_nread()

bool conn_nread

(

conn *

c

)

conn_parse_cmd()

bool conn_parse_cmd

(

conn *

c

)

conn_pending_close()

bool conn_pending_close

(

conn *

c

)

conn_read()

bool conn_read

(

conn *

c

)

conn_set_state()

void conn_set_state	(	conn *	c,
		STATE_FUNC	state
	)

conn_setup_tap_stream()

bool conn_setup_tap_stream

(

conn *

c

)

conn_ship_log()

bool conn_ship_log

(

conn *

c

)

Ship tap log to the other end.

This state differs with all other states in the way that it support full duplex dialog. We're listening to both read and write events from libevent most of the time. If a read event occurs we switch to the conn_read state to read and execute the input message (that would be an ack message from the other side). If a write event occurs we continue to send tap log to the other end.

Parameters

c	the tap connection to drive

Returns

true if we should continue to process work for this connection, false if we should start processing events for other connections.

conn_swallow()

bool conn_swallow

(

conn *

c

)

conn_waiting()

bool conn_waiting

(

conn *

c

)

conn_write()

bool conn_write

(

conn *

c

)

create_notification_pipe()

bool create_notification_pipe

(

LIBEVENT_THREAD *

me

)

daemonize()

int daemonize	(	int	nochdir,
		int	noclose
	)

dispatch_conn_new()

void dispatch_conn_new	(	SOCKET	sfd,
		STATE_FUNC	init_state,
		int	event_flags,
		int	read_buffer_size,
		enum network_transport	transport
	)

dispatch_event_add()

int dispatch_event_add	(	int	thread,
		conn *	c
	)

enlist_conn()

void enlist_conn	(	conn *	c,
		conn **	list
	)

finalize_list()

void finalize_list	(	conn **	list,
		size_t	items
	)

has_cycle()

bool has_cycle

(

conn *

c

)

is_listen_thread()

int is_listen_thread

(

void

)

list_contains()

bool list_contains	(	conn *	h,
		conn *	n
	)

list_remove()

conn* list_remove	(	conn *	h,
		conn *	n
	)

list_to_array()

size_t list_to_array	(	conn **	dest,
		size_t	max_items,
		conn **	l
	)

notify_dispatcher()

void notify_dispatcher

(

void

)

notify_io_complete()

void notify_io_complete	(	const void *	cookie,
		ENGINE_ERROR_CODE	status
	)

notify_thread()

void notify_thread

(

LIBEVENT_THREAD *

thread

)

number_of_pending()

int number_of_pending	(	conn *	c,
		conn *	pending
	)

register_event()

bool register_event	(	conn *	c,
		struct timeval *	timeout
	)

safe_close()

void safe_close

(

SOCKET

sfd

)

set_socket_nonblocking()

bool set_socket_nonblocking

(

SOCKET

sfd

)

slab_stats_aggregate()

void slab_stats_aggregate	(	struct thread_stats *	stats,
		struct slab_stats *	out
	)

state_text()

const char* state_text

(

STATE_FUNC

state

)

Convert a state name to a human readable form.

STATS_LOCK()

void STATS_LOCK

(

void

)

STATS_UNLOCK()

void STATS_UNLOCK

(

void

)

thread_init()

void thread_init	(	int	nthreads,
		struct event_base *	main_base,
		void(*)(int, short, void *)	dispatcher_callback
	)

threadlocal_stats_aggregate()

void threadlocal_stats_aggregate	(	struct thread_stats *	thread_stats,
		struct thread_stats *	stats
	)

threadlocal_stats_clear()

void threadlocal_stats_clear

(

struct thread_stats *

stats

)

threadlocal_stats_reset()

void threadlocal_stats_reset

(

struct thread_stats *

thread_stats

)

threads_shutdown()

void threads_shutdown

(

void

)

unregister_event()

bool unregister_event

(

conn *

c

)

update_event()

bool update_event	(	conn *	c,
		const int	new_flags
	)

Variable Documentation

settings

struct settings settings

stats

struct stats stats

exported globals

tap_thread

LIBEVENT_THREAD* tap_thread