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/* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
#ifndef MEMCACHED_H
#define MEMCACHED_H
/** \file
* The main memcached header holding commonly used data
* structures and function prototypes.
*/
#include <event.h>
#include <pthread.h>
#include <memcached/protocol_binary.h>
#include <memcached/engine.h>
#include <memcached/extension.h>
#include "cache.h"
#include "topkeys.h"
#include "sasl_defs.h"
/** Maximum length of a key. */
#define KEY_MAX_LENGTH 250
/** Size of an incr buf. */
#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)
/* I'm told the max length of a 64-bit num converted to string is 20 bytes.
* Plus a few for spaces, \r\n, \0 */
#define SUFFIX_SIZE 24
/** Initial size of list of items being returned by "get". */
#define ITEM_LIST_INITIAL 200
/** Initial size of list of CAS suffixes appended to "gets" lines. */
#define SUFFIX_LIST_INITIAL 20
/** Initial size of the sendmsg() scatter/gather array. */
#define IOV_LIST_INITIAL 400
/** Initial number of sendmsg() argument structures to allocate. */
#define MSG_LIST_INITIAL 10
/** High water marks for buffer shrinking */
#define READ_BUFFER_HIGHWAT 8192
#define ITEM_LIST_HIGHWAT 400
#define IOV_LIST_HIGHWAT 600
#define MSG_LIST_HIGHWAT 100
/* Binary protocol stuff */
#define MIN_BIN_PKT_LENGTH 16
#define BIN_PKT_HDR_WORDS (MIN_BIN_PKT_LENGTH/sizeof(uint32_t))
/* Slab sizing definitions. */
#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
/** Append a simple stat with a stat name, value format and value */
#define APPEND_STAT(name, fmt, val) \
append_stat(name, add_stats, c, fmt, val);
/** Append an indexed stat with a stat name (with format), value format
and value */
#define APPEND_NUM_FMT_STAT(name_fmt, num, name, fmt, val) \
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);
/** Common APPEND_NUM_FMT_STAT format. */
#define APPEND_NUM_STAT(num, name, fmt, val) \
APPEND_NUM_FMT_STAT("%d:%s", num, name, fmt, val)
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, /* arbitrary value. */
binary_prot,
negotiating_prot /* Discovering the protocol */
};
enum network_transport {
local_transport, /* Unix sockets*/
tcp_transport,
udp_transport
};
#define IS_UDP(x) (x == udp_transport)
/** Stats stored per slab (and per thread). */
struct slab_stats {
uint64_t cmd_set;
uint64_t get_hits;
uint64_t delete_hits;
uint64_t cas_hits;
uint64_t cas_badval;
};
/**
* Stats stored per-thread.
*/
struct thread_stats {
pthread_mutex_t mutex;
uint64_t cmd_get;
uint64_t get_misses;
uint64_t delete_misses;
uint64_t incr_misses;
uint64_t decr_misses;
uint64_t incr_hits;
uint64_t decr_hits;
uint64_t cas_misses;
uint64_t bytes_read;
uint64_t bytes_written;
uint64_t cmd_flush;
uint64_t conn_yields; /* # of yields for connections (-R option)*/
uint64_t auth_cmds;
uint64_t auth_errors;
struct slab_stats slab_stats[MAX_NUMBER_OF_SLAB_CLASSES];
};
/**
* The stats structure the engine keeps track of
*/
struct independent_stats {
topkeys_t *topkeys;
struct thread_stats thread_stats[];
};
/**
* Global stats.
*/
struct stats {
pthread_mutex_t mutex;
unsigned int daemon_conns; /* conns used by the server */
unsigned int curr_conns;
unsigned int total_conns;
unsigned int conn_structs;
time_t started; /* when the process was started */
uint64_t rejected_conns; /* number of times I reject a client */
};
#define MAX_VERBOSITY_LEVEL 2
/* When adding a setting, be sure to update process_stat_settings */
/**
* Globally accessible settings as derived from the commandline.
*/
struct settings {
size_t maxbytes;
int maxconns;
int port;
int udpport;
char *inter;
int verbose;
rel_time_t oldest_live; /* ignore existing items older than this */
int evict_to_free;
char *socketpath; /* path to unix socket if using local socket */
int access; /* access mask (a la chmod) for unix domain socket */
double factor; /* chunk size growth factor */
int chunk_size;
int num_threads; /* number of worker (without dispatcher) libevent threads to run */
int num_threads_per_udp; /* number of worker threads serving each udp socket */
char prefix_delimiter; /* character that marks a key prefix (for stats) */
int detail_enabled; /* nonzero if we're collecting detailed stats */
bool allow_detailed; /* detailed stats commands are allowed */
int reqs_per_event; /* Maximum number of io to process on each
io-event. */
int reqs_per_tap_event; /* Maximum number of tap io to process on each
io-event. */
bool use_cas;
enum protocol binding_protocol;
int backlog;
size_t item_size_max; /* Maximum item size, and upper end for slabs */
bool sasl; /* SASL on/off */
bool require_sasl; /* require SASL auth */
int topkeys; /* Number of top keys to track */
union {
ENGINE_HANDLE *v0;
ENGINE_HANDLE_V1 *v1;
} engine;
struct {
EXTENSION_DAEMON_DESCRIPTOR *daemons;
EXTENSION_LOGGER_DESCRIPTOR *logger;
EXTENSION_ASCII_PROTOCOL_DESCRIPTOR *ascii;
EXTENSION_BINARY_PROTOCOL_DESCRIPTOR *binary;
} extensions;
};
struct engine_event_handler {
EVENT_CALLBACK cb;
const void *cb_data;
struct engine_event_handler *next;
};
extern struct stats stats;
extern struct settings settings;
enum thread_type {
GENERAL = 11,
TAP = 13,
DISPATCHER = 15
};
typedef struct {
pthread_t thread_id; /* unique ID of this thread */
struct event_base *base; /* libevent handle this thread uses */
struct event notify_event; /* listen event for notify pipe */
SOCKET notify[2]; /* notification pipes */
struct conn_queue *new_conn_queue; /* queue of new connections to handle */
cache_t *suffix_cache; /* suffix cache */
pthread_mutex_t mutex; /* Mutex to lock protect access to the pending_io */
bool is_locked;
struct conn *pending_io; /* List of connection with pending async io ops */
int index; /* index of this thread in the threads array */
enum thread_type type; /* Type of IO this thread processes */
rel_time_t last_checked;
struct conn *pending_close; /* list of connections close at a later time */
} LIBEVENT_THREAD;
#define LOCK_THREAD(t) \
if (pthread_mutex_lock(&t->mutex) != 0) { \
abort(); \
} \
assert(t->is_locked == false); \
t->is_locked = true;
#define UNLOCK_THREAD(t) \
assert(t->is_locked == true); \
t->is_locked = false; \
if (pthread_mutex_unlock(&t->mutex) != 0) { \
abort(); \
}
extern void notify_thread(LIBEVENT_THREAD *thread);
extern void notify_dispatcher(void);
extern bool create_notification_pipe(LIBEVENT_THREAD *me);
extern LIBEVENT_THREAD* tap_thread;
typedef struct conn conn;
typedef bool (*STATE_FUNC)(conn *);
/**
* The structure representing a connection into memcached.
*/
struct conn {
SOCKET sfd;
int nevents;
sasl_conn_t *sasl_conn;
STATE_FUNC state;
enum bin_substates substate;
bool registered_in_libevent;
struct event event;
short ev_flags;
short which; /** which events were just triggered */
char *rbuf; /** buffer to read commands into */
char *rcurr; /** but if we parsed some already, this is where we stopped */
uint32_t rsize; /** total allocated size of rbuf */
uint32_t rbytes; /** how much data, starting from rcur, do we have unparsed */
char *wbuf;
char *wcurr;
uint32_t wsize;
uint32_t wbytes;
/** which state to go into after finishing current write */
STATE_FUNC write_and_go;
void *write_and_free; /** free this memory after finishing writing */
char *ritem; /** when we read in an item's value, it goes here */
uint32_t rlbytes;
/* data for the nread state */
/**
* item is used to hold an item structure created after reading the command
* line of set/add/replace commands, but before we finished reading the actual
* data. The data is read into ITEM_data(item) to avoid extra copying.
*/
void *item; /* for commands set/add/replace */
ENGINE_STORE_OPERATION store_op; /* which one is it: set/add/replace */
/* data for the swallow state */
int sbytes; /* how many bytes to swallow */
/* data for the mwrite state */
struct iovec *iov;
int iovsize; /* number of elements allocated in iov[] */
int iovused; /* number of elements used in iov[] */
struct msghdr *msglist;
int msgsize; /* number of elements allocated in msglist[] */
int msgused; /* number of elements used in msglist[] */
int msgcurr; /* element in msglist[] being transmitted now */
int msgbytes; /* number of bytes in current msg */
item **ilist; /* list of items to write out */
int isize;
item **icurr;
int ileft;
char **suffixlist;
int suffixsize;
char **suffixcurr;
int suffixleft;
enum protocol protocol; /* which protocol this connection speaks */
enum network_transport transport; /* what transport is used by this connection */
/* data for UDP clients */
int request_id; /* Incoming UDP request ID, if this is a UDP "connection" */
struct sockaddr_storage request_addr; /* Who sent the most recent request */
socklen_t request_addr_size;
unsigned char *hdrbuf; /* udp packet headers */
int hdrsize; /* number of headers' worth of space is allocated */
bool noreply; /* True if the reply should not be sent. */
/* current stats command */
uint8_t refcount; /* number of references to the object */
struct {
char *buffer;
size_t size;
size_t offset;
} dynamic_buffer;
void *engine_storage;
/** Current ascii protocol */
EXTENSION_ASCII_PROTOCOL_DESCRIPTOR *ascii_cmd;
/* Binary protocol stuff */
/* This is where the binary header goes */
protocol_binary_request_header binary_header;
uint64_t cas; /* the cas to return */
short cmd; /* current command being processed */
int opaque;
int keylen;
int list_state; /* bitmask of list state data for this connection */
conn *next; /* Used for generating a list of conn structures */
LIBEVENT_THREAD *thread; /* Pointer to the thread object serving this connection */
ENGINE_ERROR_CODE aiostat;
bool ewouldblock;
TAP_ITERATOR tap_iterator;
};
/* States for the connection list_state */
#define LIST_STATE_PROCESSING 1
#define LIST_STATE_REQ_PENDING_IO 2
#define LIST_STATE_REQ_PENDING_CLOSE 4
/*
* Functions
*/
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);
#ifndef WIN32
extern int daemonize(int nochdir, int noclose);
#endif
#include "stats.h"
#include "trace.h"
#include "hash.h"
#include <memcached/util.h>
/*
* Functions to add / update the connection to libevent
*/
bool register_event(conn *c, struct timeval *timeout);
bool unregister_event(conn *c);
bool update_event(conn *c, const int new_flags);
/*
* Functions such as the libevent-related calls that need to do cross-thread
* communication in multithreaded mode (rather than actually doing the work
* in the current thread) are called via "dispatch_" frontends, which are
* also #define-d to directly call the underlying code in singlethreaded mode.
*/
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);
/* Lock wrappers for cache functions that are called from main loop. */
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);
/* Stat processing functions */
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);
void safe_close(SOCKET sfd);
// Number of times this connection is in the given pending list
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);
#if HAVE_DROP_PRIVILEGES
extern void drop_privileges(void);
#else
#define drop_privileges()
#endif
/* connection state machine */
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);
bool conn_add_tap_client(conn *c);
bool conn_setup_tap_stream(conn *c);
/* If supported, give compiler hints for branch prediction. */
#if !defined(__builtin_expect) && (!defined(__GNUC__) || (__GNUC__ == 2 && __GNUC_MINOR__ < 96))
#define __builtin_expect(x, expected_value) (x)
#endif
#define likely(x) __builtin_expect((x),1)
#define unlikely(x) __builtin_expect((x),0)
#endif
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