memcached.h File Reference

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <event.h>
#include <netdb.h>
#include <stdbool.h>
#include <stdint.h>
#include <pthread.h>
#include "protocol_binary.h"
#include "cache.h"
#include "stats.h"
#include "slabs.h"
#include "assoc.h"
#include "items.h"
#include "trace.h"
#include "hash.h"
#include "util.h"

Go to the source code of this file.

Classes

struct slab_stats

struct thread_stats

struct stats

struct settings

struct _stritem

struct LIBEVENT_THREAD

struct LIBEVENT_DISPATCHER_THREAD

struct conn

Defines

#define KEY_MAX_LENGTH   250

#define INCR_MAX_STORAGE_LEN   24

#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

#define SUFFIX_LIST_INITIAL   20

#define IOV_LIST_INITIAL   400

#define MSG_LIST_INITIAL   10

#define READ_BUFFER_HIGHWAT   8192

#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 TAIL_REPAIR_TIME   (3 * 3600)

#define ITEM_get_cas(i)

#define ITEM_set_cas(i, v)

#define ITEM_key(item)

#define ITEM_suffix(item)

#define ITEM_data(item)

#define ITEM_ntotal(item)

#define STAT_KEY_LEN   128

#define STAT_VAL_LEN   128

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

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

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

#define IS_UDP(x)   (x == udp_transport)

#define NREAD_ADD   1

#define NREAD_SET   2

#define NREAD_REPLACE   3

#define NREAD_APPEND   4

#define NREAD_PREPEND   5

#define NREAD_CAS   6

#define MAX_VERBOSITY_LEVEL   2

#define ITEM_LINKED   1

#define ITEM_CAS   2

#define ITEM_SLABBED   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 void(* ADD_STAT )(const char *key, const uint16_t klen, const char *val, const uint32_t vlen, const void *cookie)

typedef unsigned int rel_time_t

typedef struct _stritem item

typedef struct conn conn

Enumerations

enum conn_states {
  conn_listening, conn_new_cmd, conn_waiting, conn_read,
  conn_parse_cmd, conn_write, conn_nread, conn_swallow,
  conn_closing, conn_mwrite, conn_max_state
}

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
}

enum protocol { ascii_prot = 3, binary_prot, negotiating_prot }

enum network_transport { local_transport, tcp_transport, udp_transport }

enum store_item_type { NOT_STORED = 0, STORED, EXISTS, NOT_FOUND }

enum delta_result_type { OK, NON_NUMERIC, EOM }

Functions

void do_accept_new_conns (const bool do_accept)

enum delta_result_type do_add_delta (conn *c, item *item, const bool incr, const int64_t delta, char *buf)

enum store_item_type do_store_item (item *item, int comm, conn *c)

conn * conn_new (const int sfd, const enum conn_states init_state, const int event_flags, const int read_buffer_size, enum network_transport transport, struct event_base *base)

int daemonize (int nochdir, int noclose)

void thread_init (int nthreads, struct event_base *main_base)

int dispatch_event_add (int thread, conn *c)

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

enum delta_result_type add_delta (conn *c, item *item, const int incr, const int64_t delta, char *buf)

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)

item * item_alloc (char *key, size_t nkey, int flags, rel_time_t exptime, int nbytes)

char * item_cachedump (const unsigned int slabs_clsid, const unsigned int limit, unsigned int *bytes)

void item_flush_expired (void)

item * item_get (const char *key, const size_t nkey)

int item_link (item *it)

void item_remove (item *it)

int item_replace (item *it, item *new_it)

void item_stats (ADD_STAT add_stats, void *c)

void item_stats_sizes (ADD_STAT add_stats, void *c)

void item_unlink (item *it)

void item_update (item *it)

void STATS_LOCK (void)

void STATS_UNLOCK (void)

void threadlocal_stats_reset (void)

void threadlocal_stats_aggregate (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,...)

enum store_item_type store_item (item *item, int comm, conn *c)

Variables

struct stats stats

time_t process_started

struct settings settings

volatile rel_time_t current_time

Detailed Description

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

Define Documentation

#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

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

Common APPEND_NUM_FMT_STAT format.

#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

#define INCR_MAX_STORAGE_LEN 24

Size of an incr buf.

#define IOV_LIST_INITIAL 400

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

#define ITEM_data ( item )

Value:

((char*) &((item)->end[0]) + (item)->nkey + 1 \
         + (item)->nsuffix \
         + (((item)->it_flags & ITEM_CAS) ? sizeof(uint64_t) : 0))

#define ITEM_get_cas ( i )

Value:

((uint64_t)(((i)->it_flags & ITEM_CAS) ? \
                                    *(uint64_t*)&((i)->end[0]) : 0x0))

#define ITEM_key ( item )

Value:

(((char*)&((item)->end[0])) \
         + (((item)->it_flags & ITEM_CAS) ? sizeof(uint64_t) : 0))

#define ITEM_LIST_INITIAL 200

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

#define ITEM_ntotal ( item )

Value:

(sizeof(struct _stritem) + (item)->nkey + 1 \
         + (item)->nsuffix + (item)->nbytes \
         + (((item)->it_flags & ITEM_CAS) ? sizeof(uint64_t) : 0))

#define ITEM_set_cas	(	i,
		v		)

Value:

{ if ((i)->it_flags & ITEM_CAS) { \
                          *(uint64_t*)&((i)->end[0]) = v; } }

#define ITEM_suffix ( item )

Value:

((char*) &((item)->end[0]) + (item)->nkey + 1 \
         + (((item)->it_flags & ITEM_CAS) ? sizeof(uint64_t) : 0))

#define KEY_MAX_LENGTH 250

Maximum length of a key.

#define MSG_LIST_INITIAL 10

Initial number of sendmsg() argument structures to allocate.

#define READ_BUFFER_HIGHWAT 8192

High water marks for buffer shrinking

#define SUFFIX_LIST_INITIAL 20

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

#define TAIL_REPAIR_TIME (3 * 3600)

How long an object can reasonably be assumed to be locked before harvesting it on a low memory condition.

Typedef Documentation

typedef void(* ADD_STAT)(const char *key, const uint16_t klen, const char *val, const uint32_t vlen, const void *cookie)

Callback for any function producing stats.

Parameters:

	key	the stat's key
	klen	length of the key
	val	the stat's value in an ascii form (e.g. text form of a number)
	vlen	length of the value cookie magic callback cookie

typedef struct conn conn

The structure representing a connection into memcached.

typedef struct _stritem item

Structure for storing items within memcached.

typedef unsigned int rel_time_t

Time relative to server start. Smaller than time_t on 64-bit systems.

Enumeration Type Documentation

enum conn_states

Possible states of a connection.

Enumerator:

conn_listening	the socket which listens for connections
conn_new_cmd	Prepare connection for next command
conn_waiting	waiting for a readable socket
conn_read	reading in a command line
conn_parse_cmd	try to parse a command from the input buffer
conn_write	writing out a simple response
conn_nread	reading in a fixed number of bytes
conn_swallow	swallowing unnecessary bytes w/o storing
conn_closing	closing this connection
conn_mwrite	writing out many items sequentially
conn_max_state	Max state value (used for assertion)

Variable Documentation

struct stats stats

exported globals


Classes
struct	slab_stats
struct	thread_stats
struct	stats
struct	settings
struct	_stritem
struct	LIBEVENT_THREAD
struct	LIBEVENT_DISPATCHER_THREAD
struct	conn
Defines
#define	KEY_MAX_LENGTH 250
#define	INCR_MAX_STORAGE_LEN 24
#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
#define	SUFFIX_LIST_INITIAL 20
#define	IOV_LIST_INITIAL 400
#define	MSG_LIST_INITIAL 10
#define	READ_BUFFER_HIGHWAT 8192
#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	TAIL_REPAIR_TIME (3 * 3600)
#define	ITEM_get_cas(i)
#define	ITEM_set_cas(i, v)
#define	ITEM_key(item)
#define	ITEM_suffix(item)
#define	ITEM_data(item)
#define	ITEM_ntotal(item)
#define	STAT_KEY_LEN 128
#define	STAT_VAL_LEN 128
#define	APPEND_STAT(name, fmt, val) append_stat(name, add_stats, c, fmt, val);
#define	APPEND_NUM_FMT_STAT(name_fmt, num, name, fmt, val)
#define	APPEND_NUM_STAT(num, name, fmt, val) APPEND_NUM_FMT_STAT("%d:%s", num, name, fmt, val)
#define	IS_UDP(x) (x == udp_transport)
#define	NREAD_ADD 1
#define	NREAD_SET 2
#define	NREAD_REPLACE 3
#define	NREAD_APPEND 4
#define	NREAD_PREPEND 5
#define	NREAD_CAS 6
#define	MAX_VERBOSITY_LEVEL 2
#define	ITEM_LINKED 1
#define	ITEM_CAS 2
#define	ITEM_SLABBED 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 void(*	ADD_STAT )(const char key, const uint16_t klen, const char val, const uint32_t vlen, const void *cookie)
typedef unsigned int	rel_time_t
typedef struct _stritem	item
typedef struct conn	conn
Enumerations
enum	conn_states { conn_listening, conn_new_cmd, conn_waiting, conn_read, conn_parse_cmd, conn_write, conn_nread, conn_swallow, conn_closing, conn_mwrite, conn_max_state }
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 }
enum	protocol { ascii_prot = 3, binary_prot, negotiating_prot }
enum	network_transport { local_transport, tcp_transport, udp_transport }
enum	store_item_type { NOT_STORED = 0, STORED, EXISTS, NOT_FOUND }
enum	delta_result_type { OK, NON_NUMERIC, EOM }
Functions
void	do_accept_new_conns (const bool do_accept)
enum delta_result_type	do_add_delta (conn c, item item, const bool incr, const int64_t delta, char *buf)
enum store_item_type	do_store_item (item item, int comm, conn c)
conn *	conn_new (const int sfd, const enum conn_states init_state, const int event_flags, const int read_buffer_size, enum network_transport transport, struct event_base *base)
int	daemonize (int nochdir, int noclose)
void	thread_init (int nthreads, struct event_base *main_base)
int	dispatch_event_add (int thread, conn *c)
void	dispatch_conn_new (int sfd, enum conn_states init_state, int event_flags, int read_buffer_size, enum network_transport transport)
enum delta_result_type	add_delta (conn c, item item, const int incr, const int64_t delta, char *buf)
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)
item *	item_alloc (char *key, size_t nkey, int flags, rel_time_t exptime, int nbytes)
char *	item_cachedump (const unsigned int slabs_clsid, const unsigned int limit, unsigned int *bytes)
void	item_flush_expired (void)
item *	item_get (const char *key, const size_t nkey)
int	item_link (item *it)
void	item_remove (item *it)
int	item_replace (item it, item new_it)
void	item_stats (ADD_STAT add_stats, void *c)
void	item_stats_sizes (ADD_STAT add_stats, void *c)
void	item_unlink (item *it)
void	item_update (item *it)
void	STATS_LOCK (void)
void	STATS_UNLOCK (void)
void	threadlocal_stats_reset (void)
void	threadlocal_stats_aggregate (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,...)
enum store_item_type	store_item (item item, int comm, conn c)
Variables
struct stats	stats
time_t	process_started
struct settings	settings
volatile rel_time_t	current_time