Return OK on QUIT

[redis.git] / src / redis.h

#ifndef __REDIS_H
#define __REDIS_H

#include "fmacros.h"
#include "config.h"

#if defined(__sun)
#include "solarisfixes.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <limits.h>
#include <unistd.h>
#include <errno.h>
#include <inttypes.h>
#include <pthread.h>

#include "ae.h"     /* Event driven programming library */
#include "sds.h"    /* Dynamic safe strings */
#include "dict.h"   /* Hash tables */
#include "adlist.h" /* Linked lists */
#include "zmalloc.h" /* total memory usage aware version of malloc/free */
#include "anet.h"   /* Networking the easy way */
#include "zipmap.h" /* Compact string -> string data structure */
#include "ziplist.h" /* Compact list data structure */
#include "intset.h" /* Compact integer set structure */
#include "version.h"

/* Error codes */
#define REDIS_OK                0
#define REDIS_ERR               -1

/* Static server configuration */
#define REDIS_SERVERPORT        6379    /* TCP port */
#define REDIS_MAXIDLETIME       (60*5)  /* default client timeout */
#define REDIS_IOBUF_LEN         1024
#define REDIS_LOADBUF_LEN       1024
#define REDIS_STATIC_ARGS       8
#define REDIS_DEFAULT_DBNUM     16
#define REDIS_CONFIGLINE_MAX    1024
#define REDIS_OBJFREELIST_MAX   1000000 /* Max number of objects to cache */
#define REDIS_MAX_SYNC_TIME     60      /* Slave can't take more to sync */
#define REDIS_EXPIRELOOKUPS_PER_CRON    10 /* lookup 10 expires per loop */
#define REDIS_MAX_WRITE_PER_EVENT (1024*64)
#define REDIS_REQUEST_MAX_SIZE (1024*1024*256) /* max bytes in inline command */
#define REDIS_SHARED_INTEGERS 10000
#define REDIS_REPLY_CHUNK_BYTES (5*1500) /* 5 TCP packets with default MTU */

/* If more then REDIS_WRITEV_THRESHOLD write packets are pending use writev */
#define REDIS_WRITEV_THRESHOLD      3
/* Max number of iovecs used for each writev call */
#define REDIS_WRITEV_IOVEC_COUNT    256

/* Hash table parameters */
#define REDIS_HT_MINFILL        10      /* Minimal hash table fill 10% */

/* Command flags */
#define REDIS_CMD_BULK          1       /* Bulk write command */
#define REDIS_CMD_INLINE        2       /* Inline command */
/* REDIS_CMD_DENYOOM reserves a longer comment: all the commands marked with
   this flags will return an error when the 'maxmemory' option is set in the
   config file and the server is using more than maxmemory bytes of memory.
   In short this commands are denied on low memory conditions. */
#define REDIS_CMD_DENYOOM       4
#define REDIS_CMD_FORCE_REPLICATION 8 /* Force replication even if dirty is 0 */

/* Object types */
#define REDIS_STRING 0
#define REDIS_LIST 1
#define REDIS_SET 2
#define REDIS_ZSET 3
#define REDIS_HASH 4
#define REDIS_VMPOINTER 8

/* Objects encoding. Some kind of objects like Strings and Hashes can be
 * internally represented in multiple ways. The 'encoding' field of the object
 * is set to one of this fields for this object. */
#define REDIS_ENCODING_RAW 0     /* Raw representation */
#define REDIS_ENCODING_INT 1     /* Encoded as integer */
#define REDIS_ENCODING_HT 2      /* Encoded as hash table */
#define REDIS_ENCODING_ZIPMAP 3  /* Encoded as zipmap */
#define REDIS_ENCODING_LINKEDLIST 4 /* Encoded as regular linked list */
#define REDIS_ENCODING_ZIPLIST 5 /* Encoded as ziplist */
#define REDIS_ENCODING_INTSET 6  /* Encoded as intset */

/* Object types only used for dumping to disk */
#define REDIS_EXPIRETIME 253
#define REDIS_SELECTDB 254
#define REDIS_EOF 255

/* Defines related to the dump file format. To store 32 bits lengths for short
 * keys requires a lot of space, so we check the most significant 2 bits of
 * the first byte to interpreter the length:
 *
 * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
 * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
 * 10|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
 * 11|000000 this means: specially encoded object will follow. The six bits
 *           number specify the kind of object that follows.
 *           See the REDIS_RDB_ENC_* defines.
 *
 * Lenghts up to 63 are stored using a single byte, most DB keys, and may
 * values, will fit inside. */
#define REDIS_RDB_6BITLEN 0
#define REDIS_RDB_14BITLEN 1
#define REDIS_RDB_32BITLEN 2
#define REDIS_RDB_ENCVAL 3
#define REDIS_RDB_LENERR UINT_MAX

/* When a length of a string object stored on disk has the first two bits
 * set, the remaining two bits specify a special encoding for the object
 * accordingly to the following defines: */
#define REDIS_RDB_ENC_INT8 0        /* 8 bit signed integer */
#define REDIS_RDB_ENC_INT16 1       /* 16 bit signed integer */
#define REDIS_RDB_ENC_INT32 2       /* 32 bit signed integer */
#define REDIS_RDB_ENC_LZF 3         /* string compressed with FASTLZ */

/* Virtual memory object->where field. */
#define REDIS_VM_MEMORY 0       /* The object is on memory */
#define REDIS_VM_SWAPPED 1      /* The object is on disk */
#define REDIS_VM_SWAPPING 2     /* Redis is swapping this object on disk */
#define REDIS_VM_LOADING 3      /* Redis is loading this object from disk */

/* Virtual memory static configuration stuff.
 * Check vmFindContiguousPages() to know more about this magic numbers. */
#define REDIS_VM_MAX_NEAR_PAGES 65536
#define REDIS_VM_MAX_RANDOM_JUMP 4096
#define REDIS_VM_MAX_THREADS 32
#define REDIS_THREAD_STACK_SIZE (1024*1024*4)
/* The following is the *percentage* of completed I/O jobs to process when the
 * handelr is called. While Virtual Memory I/O operations are performed by
 * threads, this operations must be processed by the main thread when completed
 * in order to take effect. */
#define REDIS_MAX_COMPLETED_JOBS_PROCESSED 1

/* Client flags */
#define REDIS_SLAVE 1       /* This client is a slave server */
#define REDIS_MASTER 2      /* This client is a master server */
#define REDIS_MONITOR 4     /* This client is a slave monitor, see MONITOR */
#define REDIS_MULTI 8       /* This client is in a MULTI context */
#define REDIS_BLOCKED 16    /* The client is waiting in a blocking operation */
#define REDIS_IO_WAIT 32    /* The client is waiting for Virtual Memory I/O */
#define REDIS_DIRTY_CAS 64  /* Watched keys modified. EXEC will fail. */
#define REDIS_QUIT 128      /* Client will be disconnected after reply is sent */

/* Slave replication state - slave side */
#define REDIS_REPL_NONE 0   /* No active replication */
#define REDIS_REPL_CONNECT 1    /* Must connect to master */
#define REDIS_REPL_CONNECTED 2  /* Connected to master */

/* Slave replication state - from the point of view of master
 * Note that in SEND_BULK and ONLINE state the slave receives new updates
 * in its output queue. In the WAIT_BGSAVE state instead the server is waiting
 * to start the next background saving in order to send updates to it. */
#define REDIS_REPL_WAIT_BGSAVE_START 3 /* master waits bgsave to start feeding it */
#define REDIS_REPL_WAIT_BGSAVE_END 4 /* master waits bgsave to start bulk DB transmission */
#define REDIS_REPL_SEND_BULK 5 /* master is sending the bulk DB */
#define REDIS_REPL_ONLINE 6 /* bulk DB already transmitted, receive updates */

/* List related stuff */
#define REDIS_HEAD 0
#define REDIS_TAIL 1

/* Sort operations */
#define REDIS_SORT_GET 0
#define REDIS_SORT_ASC 1
#define REDIS_SORT_DESC 2
#define REDIS_SORTKEY_MAX 1024

/* Log levels */
#define REDIS_DEBUG 0
#define REDIS_VERBOSE 1
#define REDIS_NOTICE 2
#define REDIS_WARNING 3

/* Anti-warning macro... */
#define REDIS_NOTUSED(V) ((void) V)

#define ZSKIPLIST_MAXLEVEL 32 /* Should be enough for 2^32 elements */
#define ZSKIPLIST_P 0.25      /* Skiplist P = 1/4 */

/* Append only defines */
#define APPENDFSYNC_NO 0
#define APPENDFSYNC_ALWAYS 1
#define APPENDFSYNC_EVERYSEC 2

/* Zip structure related defaults */
#define REDIS_HASH_MAX_ZIPMAP_ENTRIES 64
#define REDIS_HASH_MAX_ZIPMAP_VALUE 512
#define REDIS_LIST_MAX_ZIPLIST_ENTRIES 1024
#define REDIS_LIST_MAX_ZIPLIST_VALUE 32
#define REDIS_SET_MAX_INTSET_ENTRIES 4096

/* Sets operations codes */
#define REDIS_OP_UNION 0
#define REDIS_OP_DIFF 1
#define REDIS_OP_INTER 2

/* We can print the stacktrace, so our assert is defined this way: */
#define redisAssert(_e) ((_e)?(void)0 : (_redisAssert(#_e,__FILE__,__LINE__),_exit(1)))
#define redisPanic(_e) _redisPanic(#_e,__FILE__,__LINE__),_exit(1)
void _redisAssert(char *estr, char *file, int line);
void _redisPanic(char *msg, char *file, int line);

/*-----------------------------------------------------------------------------
 * Data types
 *----------------------------------------------------------------------------*/

/* A redis object, that is a type able to hold a string / list / set */

/* The actual Redis Object */
typedef struct redisObject {
    unsigned type:4;
    unsigned storage:2;     /* REDIS_VM_MEMORY or REDIS_VM_SWAPPING */
    unsigned encoding:4;
    unsigned lru:22;        /* lru time (relative to server.lruclock) */
    int refcount;
    void *ptr;
    /* VM fields are only allocated if VM is active, otherwise the
     * object allocation function will just allocate
     * sizeof(redisObjct) minus sizeof(redisObjectVM), so using
     * Redis without VM active will not have any overhead. */
} robj;

/* The VM pointer structure - identifies an object in the swap file.
 *
 * This object is stored in place of the value
 * object in the main key->value hash table representing a database.
 * Note that the first fields (type, storage) are the same as the redisObject
 * structure so that vmPointer strucuters can be accessed even when casted
 * as redisObject structures.
 *
 * This is useful as we don't know if a value object is or not on disk, but we
 * are always able to read obj->storage to check this. For vmPointer
 * structures "type" is set to REDIS_VMPOINTER (even if without this field
 * is still possible to check the kind of object from the value of 'storage').*/
typedef struct vmPointer {
    unsigned type:4;
    unsigned storage:2; /* REDIS_VM_SWAPPED or REDIS_VM_LOADING */
    unsigned notused:26;
    unsigned int vtype; /* type of the object stored in the swap file */
    off_t page;         /* the page at witch the object is stored on disk */
    off_t usedpages;    /* number of pages used on disk */
} vmpointer;

/* Macro used to initalize a Redis object allocated on the stack.
 * Note that this macro is taken near the structure definition to make sure
 * we'll update it when the structure is changed, to avoid bugs like
 * bug #85 introduced exactly in this way. */
#define initStaticStringObject(_var,_ptr) do { \
    _var.refcount = 1; \
    _var.type = REDIS_STRING; \
    _var.encoding = REDIS_ENCODING_RAW; \
    _var.ptr = _ptr; \
    _var.storage = REDIS_VM_MEMORY; \
} while(0);

typedef struct redisDb {
    dict *dict;                 /* The keyspace for this DB */
    dict *expires;              /* Timeout of keys with a timeout set */
    dict *blocking_keys;        /* Keys with clients waiting for data (BLPOP) */
    dict *io_keys;              /* Keys with clients waiting for VM I/O */
    dict *watched_keys;         /* WATCHED keys for MULTI/EXEC CAS */
    int id;
} redisDb;

/* Client MULTI/EXEC state */
typedef struct multiCmd {
    robj **argv;
    int argc;
    struct redisCommand *cmd;
} multiCmd;

typedef struct multiState {
    multiCmd *commands;     /* Array of MULTI commands */
    int count;              /* Total number of MULTI commands */
} multiState;

/* With multiplexing we need to take per-clinet state.
 * Clients are taken in a liked list. */
typedef struct redisClient {
    int fd;
    redisDb *db;
    int dictid;
    sds querybuf;
    robj **argv, **mbargv;
    char *newline;          /* pointing to the detected newline in querybuf */
    int argc, mbargc;
    long bulklen;            /* bulk read len. -1 if not in bulk read mode */
    int multibulk;          /* multi bulk command format active */
    list *reply;
    int sentlen;
    time_t lastinteraction; /* time of the last interaction, used for timeout */
    int flags;              /* REDIS_SLAVE | REDIS_MONITOR | REDIS_MULTI ... */
    int slaveseldb;         /* slave selected db, if this client is a slave */
    int authenticated;      /* when requirepass is non-NULL */
    int replstate;          /* replication state if this is a slave */
    int repldbfd;           /* replication DB file descriptor */
    long repldboff;         /* replication DB file offset */
    off_t repldbsize;       /* replication DB file size */
    multiState mstate;      /* MULTI/EXEC state */
    robj **blocking_keys;   /* The key we are waiting to terminate a blocking
                             * operation such as BLPOP. Otherwise NULL. */
    int blocking_keys_num;  /* Number of blocking keys */
    time_t blockingto;      /* Blocking operation timeout. If UNIX current time
                             * is >= blockingto then the operation timed out. */
    list *io_keys;          /* Keys this client is waiting to be loaded from the
                             * swap file in order to continue. */
    list *watched_keys;     /* Keys WATCHED for MULTI/EXEC CAS */
    dict *pubsub_channels;  /* channels a client is interested in (SUBSCRIBE) */
    list *pubsub_patterns;  /* patterns a client is interested in (SUBSCRIBE) */

    /* Response buffer */
    int bufpos;
    char buf[REDIS_REPLY_CHUNK_BYTES];
} redisClient;

struct saveparam {
    time_t seconds;
    int changes;
};

struct sharedObjectsStruct {
    robj *crlf, *ok, *err, *emptybulk, *czero, *cone, *cnegone, *pong, *space,
    *colon, *nullbulk, *nullmultibulk, *queued,
    *emptymultibulk, *wrongtypeerr, *nokeyerr, *syntaxerr, *sameobjecterr,
    *outofrangeerr, *plus,
    *select0, *select1, *select2, *select3, *select4,
    *select5, *select6, *select7, *select8, *select9,
    *messagebulk, *pmessagebulk, *subscribebulk, *unsubscribebulk, *mbulk3,
    *mbulk4, *psubscribebulk, *punsubscribebulk,
    *integers[REDIS_SHARED_INTEGERS];
};

/* Global server state structure */
struct redisServer {
    pthread_t mainthread;
    int port;
    int fd;
    redisDb *db;
    long long dirty;            /* changes to DB from the last save */
    long long dirty_before_bgsave; /* used to restore dirty on failed BGSAVE */
    list *clients;
    list *slaves, *monitors;
    char neterr[ANET_ERR_LEN];
    aeEventLoop *el;
    int cronloops;              /* number of times the cron function run */
    list *objfreelist;          /* A list of freed objects to avoid malloc() */
    time_t lastsave;            /* Unix time of last save succeeede */
    /* Fields used only for stats */
    time_t stat_starttime;         /* server start time */
    long long stat_numcommands;    /* number of processed commands */
    long long stat_numconnections; /* number of connections received */
    long long stat_expiredkeys;   /* number of expired keys */
    /* Configuration */
    int verbosity;
    int glueoutputbuf;
    int maxidletime;
    int dbnum;
    int daemonize;
    int appendonly;
    int appendfsync;
    int no_appendfsync_on_rewrite;
    int shutdown_asap;
    time_t lastfsync;
    int appendfd;
    int appendseldb;
    char *pidfile;
    pid_t bgsavechildpid;
    pid_t bgrewritechildpid;
    sds bgrewritebuf; /* buffer taken by parent during oppend only rewrite */
    sds aofbuf;       /* AOF buffer, written before entering the event loop */
    struct saveparam *saveparams;
    int saveparamslen;
    char *logfile;
    char *bindaddr;
    char *dbfilename;
    char *appendfilename;
    char *requirepass;
    int rdbcompression;
    int activerehashing;
    /* Replication related */
    int isslave;
    char *masterauth;
    char *masterhost;
    int masterport;
    redisClient *master;    /* client that is master for this slave */
    int replstate;
    unsigned int maxclients;
    unsigned long long maxmemory;
    unsigned int blpop_blocked_clients;
    unsigned int vm_blocked_clients;
    /* Sort parameters - qsort_r() is only available under BSD so we
     * have to take this state global, in order to pass it to sortCompare() */
    int sort_desc;
    int sort_alpha;
    int sort_bypattern;
    /* Virtual memory configuration */
    int vm_enabled;
    char *vm_swap_file;
    off_t vm_page_size;
    off_t vm_pages;
    unsigned long long vm_max_memory;
    /* Zip structure config */
    size_t hash_max_zipmap_entries;
    size_t hash_max_zipmap_value;
    size_t list_max_ziplist_entries;
    size_t list_max_ziplist_value;
    size_t set_max_intset_entries;
    /* Virtual memory state */
    FILE *vm_fp;
    int vm_fd;
    off_t vm_next_page; /* Next probably empty page */
    off_t vm_near_pages; /* Number of pages allocated sequentially */
    unsigned char *vm_bitmap; /* Bitmap of free/used pages */
    time_t unixtime;    /* Unix time sampled every second. */
    /* Virtual memory I/O threads stuff */
    /* An I/O thread process an element taken from the io_jobs queue and
     * put the result of the operation in the io_done list. While the
     * job is being processed, it's put on io_processing queue. */
    list *io_newjobs; /* List of VM I/O jobs yet to be processed */
    list *io_processing; /* List of VM I/O jobs being processed */
    list *io_processed; /* List of VM I/O jobs already processed */
    list *io_ready_clients; /* Clients ready to be unblocked. All keys loaded */
    pthread_mutex_t io_mutex; /* lock to access io_jobs/io_done/io_thread_job */
    pthread_mutex_t obj_freelist_mutex; /* safe redis objects creation/free */
    pthread_mutex_t io_swapfile_mutex; /* So we can lseek + write */
    pthread_attr_t io_threads_attr; /* attributes for threads creation */
    int io_active_threads; /* Number of running I/O threads */
    int vm_max_threads; /* Max number of I/O threads running at the same time */
    /* Our main thread is blocked on the event loop, locking for sockets ready
     * to be read or written, so when a threaded I/O operation is ready to be
     * processed by the main thread, the I/O thread will use a unix pipe to
     * awake the main thread. The followings are the two pipe FDs. */
    int io_ready_pipe_read;
    int io_ready_pipe_write;
    /* Virtual memory stats */
    unsigned long long vm_stats_used_pages;
    unsigned long long vm_stats_swapped_objects;
    unsigned long long vm_stats_swapouts;
    unsigned long long vm_stats_swapins;
    /* Pubsub */
    dict *pubsub_channels; /* Map channels to list of subscribed clients */
    list *pubsub_patterns; /* A list of pubsub_patterns */
    /* Misc */
    FILE *devnull;
    unsigned lruclock:22;        /* clock incrementing every minute, for LRU */
    unsigned lruclock_padding:10;
};

typedef struct pubsubPattern {
    redisClient *client;
    robj *pattern;
} pubsubPattern;

typedef void redisCommandProc(redisClient *c);
typedef void redisVmPreloadProc(redisClient *c, struct redisCommand *cmd, int argc, robj **argv);
struct redisCommand {
    char *name;
    redisCommandProc *proc;
    int arity;
    int flags;
    /* Use a function to determine which keys need to be loaded
     * in the background prior to executing this command. Takes precedence
     * over vm_firstkey and others, ignored when NULL */
    redisVmPreloadProc *vm_preload_proc;
    /* What keys should be loaded in background when calling this command? */
    int vm_firstkey; /* The first argument that's a key (0 = no keys) */
    int vm_lastkey;  /* THe last argument that's a key */
    int vm_keystep;  /* The step between first and last key */
};

struct redisFunctionSym {
    char *name;
    unsigned long pointer;
};

typedef struct _redisSortObject {
    robj *obj;
    union {
        double score;
        robj *cmpobj;
    } u;
} redisSortObject;

typedef struct _redisSortOperation {
    int type;
    robj *pattern;
} redisSortOperation;

/* ZSETs use a specialized version of Skiplists */
typedef struct zskiplistNode {
    robj *obj;
    double score;
    struct zskiplistNode *backward;
    struct zskiplistLevel {
        struct zskiplistNode *forward;
        unsigned int span;
    } level[];
} zskiplistNode;

typedef struct zskiplist {
    struct zskiplistNode *header, *tail;
    unsigned long length;
    int level;
} zskiplist;

typedef struct zset {
    dict *dict;
    zskiplist *zsl;
} zset;

/* VM threaded I/O request message */
#define REDIS_IOJOB_LOAD 0          /* Load from disk to memory */
#define REDIS_IOJOB_PREPARE_SWAP 1  /* Compute needed pages */
#define REDIS_IOJOB_DO_SWAP 2       /* Swap from memory to disk */
typedef struct iojob {
    int type;   /* Request type, REDIS_IOJOB_* */
    redisDb *db;/* Redis database */
    robj *key;  /* This I/O request is about swapping this key */
    robj *id;   /* Unique identifier of this job:
                   this is the object to swap for REDIS_IOREQ_*_SWAP, or the
                   vmpointer objct for REDIS_IOREQ_LOAD. */
    robj *val;  /* the value to swap for REDIS_IOREQ_*_SWAP, otherwise this
                 * field is populated by the I/O thread for REDIS_IOREQ_LOAD. */
    off_t page; /* Swap page where to read/write the object */
    off_t pages; /* Swap pages needed to save object. PREPARE_SWAP return val */
    int canceled; /* True if this command was canceled by blocking side of VM */
    pthread_t thread; /* ID of the thread processing this entry */
} iojob;

/* Structure to hold list iteration abstraction. */
typedef struct {
    robj *subject;
    unsigned char encoding;
    unsigned char direction; /* Iteration direction */
    unsigned char *zi;
    listNode *ln;
} listTypeIterator;

/* Structure for an entry while iterating over a list. */
typedef struct {
    listTypeIterator *li;
    unsigned char *zi;  /* Entry in ziplist */
    listNode *ln;       /* Entry in linked list */
} listTypeEntry;

/* Structure to hold set iteration abstraction. */
typedef struct {
    robj *subject;
    int encoding;
    int ii; /* intset iterator */
    dictIterator *di;
} setTypeIterator;

/* Structure to hold hash iteration abstration. Note that iteration over
 * hashes involves both fields and values. Because it is possible that
 * not both are required, store pointers in the iterator to avoid
 * unnecessary memory allocation for fields/values. */
typedef struct {
    int encoding;
    unsigned char *zi;
    unsigned char *zk, *zv;
    unsigned int zklen, zvlen;

    dictIterator *di;
    dictEntry *de;
} hashTypeIterator;

#define REDIS_HASH_KEY 1
#define REDIS_HASH_VALUE 2

/*-----------------------------------------------------------------------------
 * Extern declarations
 *----------------------------------------------------------------------------*/

extern struct redisServer server;
extern struct sharedObjectsStruct shared;
extern dictType setDictType;
extern dictType zsetDictType;
extern double R_Zero, R_PosInf, R_NegInf, R_Nan;
dictType hashDictType;

/*-----------------------------------------------------------------------------
 * Functions prototypes
 *----------------------------------------------------------------------------*/

/* networking.c -- Networking and Client related operations */
redisClient *createClient(int fd);
void closeTimedoutClients(void);
void freeClient(redisClient *c);
void resetClient(redisClient *c);
void sendReplyToClient(aeEventLoop *el, int fd, void *privdata, int mask);
void sendReplyToClientWritev(aeEventLoop *el, int fd, void *privdata, int mask);
void addReply(redisClient *c, robj *obj);
void *addDeferredMultiBulkLength(redisClient *c);
void setDeferredMultiBulkLength(redisClient *c, void *node, long length);
void addReplySds(redisClient *c, sds s);
void processInputBuffer(redisClient *c);
void acceptHandler(aeEventLoop *el, int fd, void *privdata, int mask);
void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask);
void addReplyBulk(redisClient *c, robj *obj);
void addReplyBulkCString(redisClient *c, char *s);
void acceptHandler(aeEventLoop *el, int fd, void *privdata, int mask);
void addReply(redisClient *c, robj *obj);
void addReplySds(redisClient *c, sds s);
void addReplyError(redisClient *c, char *err);
void addReplyStatus(redisClient *c, char *status);
void addReplyDouble(redisClient *c, double d);
void addReplyLongLong(redisClient *c, long long ll);
void addReplyMultiBulkLen(redisClient *c, long length);
void *dupClientReplyValue(void *o);

#ifdef __GNUC__
void addReplyErrorFormat(redisClient *c, const char *fmt, ...)
    __attribute__((format(printf, 2, 3)));
void addReplyStatusFormat(redisClient *c, const char *fmt, ...)
    __attribute__((format(printf, 2, 3)));
#else
void addReplyErrorFormat(redisClient *c, const char *fmt, ...);
void addReplyStatusFormat(redisClient *c, const char *fmt, ...);
#endif

/* List data type */
void listTypeTryConversion(robj *subject, robj *value);
void listTypePush(robj *subject, robj *value, int where);
robj *listTypePop(robj *subject, int where);
unsigned long listTypeLength(robj *subject);
listTypeIterator *listTypeInitIterator(robj *subject, int index, unsigned char direction);
void listTypeReleaseIterator(listTypeIterator *li);
int listTypeNext(listTypeIterator *li, listTypeEntry *entry);
robj *listTypeGet(listTypeEntry *entry);
void listTypeInsert(listTypeEntry *entry, robj *value, int where);
int listTypeEqual(listTypeEntry *entry, robj *o);
void listTypeDelete(listTypeEntry *entry);
void listTypeConvert(robj *subject, int enc);
void unblockClientWaitingData(redisClient *c);
int handleClientsWaitingListPush(redisClient *c, robj *key, robj *ele);
void popGenericCommand(redisClient *c, int where);

/* MULTI/EXEC/WATCH... */
void unwatchAllKeys(redisClient *c);
void initClientMultiState(redisClient *c);
void freeClientMultiState(redisClient *c);
void queueMultiCommand(redisClient *c, struct redisCommand *cmd);
void touchWatchedKey(redisDb *db, robj *key);
void touchWatchedKeysOnFlush(int dbid);

/* Redis object implementation */
void decrRefCount(void *o);
void incrRefCount(robj *o);
void freeStringObject(robj *o);
void freeListObject(robj *o);
void freeSetObject(robj *o);
void freeZsetObject(robj *o);
void freeHashObject(robj *o);
robj *createObject(int type, void *ptr);
robj *createStringObject(char *ptr, size_t len);
robj *dupStringObject(robj *o);
robj *tryObjectEncoding(robj *o);
robj *getDecodedObject(robj *o);
size_t stringObjectLen(robj *o);
int tryFreeOneObjectFromFreelist(void);
robj *createStringObjectFromLongLong(long long value);
robj *createListObject(void);
robj *createZiplistObject(void);
robj *createSetObject(void);
robj *createIntsetObject(void);
robj *createHashObject(void);
robj *createZsetObject(void);
int getLongFromObjectOrReply(redisClient *c, robj *o, long *target, const char *msg);
int checkType(redisClient *c, robj *o, int type);
int getLongLongFromObjectOrReply(redisClient *c, robj *o, long long *target, const char *msg);
int getDoubleFromObjectOrReply(redisClient *c, robj *o, double *target, const char *msg);
int getLongLongFromObject(robj *o, long long *target);
char *strEncoding(int encoding);
int compareStringObjects(robj *a, robj *b);
int equalStringObjects(robj *a, robj *b);

/* Replication */
void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc);
void replicationFeedMonitors(list *monitors, int dictid, robj **argv, int argc);
int syncWithMaster(void);
void updateSlavesWaitingBgsave(int bgsaveerr);

/* RDB persistence */
int rdbLoad(char *filename);
int rdbSaveBackground(char *filename);
void rdbRemoveTempFile(pid_t childpid);
int rdbSave(char *filename);
int rdbSaveObject(FILE *fp, robj *o);
off_t rdbSavedObjectPages(robj *o, FILE *fp);
off_t rdbSavedObjectLen(robj *o, FILE *fp);
robj *rdbLoadObject(int type, FILE *fp);
void backgroundSaveDoneHandler(int statloc);

/* AOF persistence */
void flushAppendOnlyFile(void);
void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv, int argc);
void aofRemoveTempFile(pid_t childpid);
int rewriteAppendOnlyFileBackground(void);
int loadAppendOnlyFile(char *filename);
void stopAppendOnly(void);
int startAppendOnly(void);
void backgroundRewriteDoneHandler(int statloc);

/* Sorted sets data type */
zskiplist *zslCreate(void);
void zslFree(zskiplist *zsl);
zskiplistNode *zslInsert(zskiplist *zsl, double score, robj *obj);

/* Core functions */
void freeMemoryIfNeeded(void);
int processCommand(redisClient *c);
void setupSigSegvAction(void);
struct redisCommand *lookupCommand(char *name);
void call(redisClient *c, struct redisCommand *cmd);
int prepareForShutdown();
void redisLog(int level, const char *fmt, ...);
void usage();
void updateDictResizePolicy(void);
int htNeedsResize(dict *dict);
void oom(const char *msg);

/* Virtual Memory */
void vmInit(void);
void vmMarkPagesFree(off_t page, off_t count);
robj *vmLoadObject(robj *o);
robj *vmPreviewObject(robj *o);
int vmSwapOneObjectBlocking(void);
int vmSwapOneObjectThreaded(void);
int vmCanSwapOut(void);
void vmThreadedIOCompletedJob(aeEventLoop *el, int fd, void *privdata, int mask);
void vmCancelThreadedIOJob(robj *o);
void lockThreadedIO(void);
void unlockThreadedIO(void);
int vmSwapObjectThreaded(robj *key, robj *val, redisDb *db);
void freeIOJob(iojob *j);
void queueIOJob(iojob *j);
int vmWriteObjectOnSwap(robj *o, off_t page);
robj *vmReadObjectFromSwap(off_t page, int type);
void waitEmptyIOJobsQueue(void);
void vmReopenSwapFile(void);
int vmFreePage(off_t page);
void zunionInterBlockClientOnSwappedKeys(redisClient *c, struct redisCommand *cmd, int argc, robj **argv);
void execBlockClientOnSwappedKeys(redisClient *c, struct redisCommand *cmd, int argc, robj **argv);
int blockClientOnSwappedKeys(redisClient *c, struct redisCommand *cmd);
int dontWaitForSwappedKey(redisClient *c, robj *key);
void handleClientsBlockedOnSwappedKey(redisDb *db, robj *key);
vmpointer *vmSwapObjectBlocking(robj *val);

/* Set data type */
robj *setTypeCreate(robj *value);
int setTypeAdd(robj *subject, robj *value);
int setTypeRemove(robj *subject, robj *value);
int setTypeIsMember(robj *subject, robj *value);
setTypeIterator *setTypeInitIterator(robj *subject);
void setTypeReleaseIterator(setTypeIterator *si);
robj *setTypeNext(setTypeIterator *si);
robj *setTypeRandomElement(robj *subject);
unsigned long setTypeSize(robj *subject);
void setTypeConvert(robj *subject, int enc);

/* Hash data type */
void convertToRealHash(robj *o);
void hashTypeTryConversion(robj *subject, robj **argv, int start, int end);
void hashTypeTryObjectEncoding(robj *subject, robj **o1, robj **o2);
robj *hashTypeGet(robj *o, robj *key);
int hashTypeExists(robj *o, robj *key);
int hashTypeSet(robj *o, robj *key, robj *value);
int hashTypeDelete(robj *o, robj *key);
unsigned long hashTypeLength(robj *o);
hashTypeIterator *hashTypeInitIterator(robj *subject);
void hashTypeReleaseIterator(hashTypeIterator *hi);
int hashTypeNext(hashTypeIterator *hi);
robj *hashTypeCurrent(hashTypeIterator *hi, int what);
robj *hashTypeLookupWriteOrCreate(redisClient *c, robj *key);

/* Pub / Sub */
int pubsubUnsubscribeAllChannels(redisClient *c, int notify);
int pubsubUnsubscribeAllPatterns(redisClient *c, int notify);
void freePubsubPattern(void *p);
int listMatchPubsubPattern(void *a, void *b);

/* Utility functions */
int stringmatchlen(const char *pattern, int patternLen,
        const char *string, int stringLen, int nocase);
int stringmatch(const char *pattern, const char *string, int nocase);
long long memtoll(const char *p, int *err);
int ll2string(char *s, size_t len, long long value);
int isStringRepresentableAsLong(sds s, long *longval);
int isStringRepresentableAsLongLong(sds s, long long *longval);
int isObjectRepresentableAsLongLong(robj *o, long long *llongval);

/* Configuration */
void loadServerConfig(char *filename);
void appendServerSaveParams(time_t seconds, int changes);
void resetServerSaveParams();

/* db.c -- Keyspace access API */
int removeExpire(redisDb *db, robj *key);
void propagateExpire(redisDb *db, robj *key);
int expireIfNeeded(redisDb *db, robj *key);
time_t getExpire(redisDb *db, robj *key);
void setExpire(redisDb *db, robj *key, time_t when);
robj *lookupKey(redisDb *db, robj *key);
robj *lookupKeyRead(redisDb *db, robj *key);
robj *lookupKeyWrite(redisDb *db, robj *key);
robj *lookupKeyReadOrReply(redisClient *c, robj *key, robj *reply);
robj *lookupKeyWriteOrReply(redisClient *c, robj *key, robj *reply);
int dbAdd(redisDb *db, robj *key, robj *val);
int dbReplace(redisDb *db, robj *key, robj *val);
int dbExists(redisDb *db, robj *key);
robj *dbRandomKey(redisDb *db);
int dbDelete(redisDb *db, robj *key);
long long emptyDb();
int selectDb(redisClient *c, int id);

/* Git SHA1 */
char *redisGitSHA1(void);
char *redisGitDirty(void);

/* Commands prototypes */
void authCommand(redisClient *c);
void pingCommand(redisClient *c);
void echoCommand(redisClient *c);
void setCommand(redisClient *c);
void setnxCommand(redisClient *c);
void setexCommand(redisClient *c);
void getCommand(redisClient *c);
void delCommand(redisClient *c);
void existsCommand(redisClient *c);
void incrCommand(redisClient *c);
void decrCommand(redisClient *c);
void incrbyCommand(redisClient *c);
void decrbyCommand(redisClient *c);
void selectCommand(redisClient *c);
void randomkeyCommand(redisClient *c);
void keysCommand(redisClient *c);
void dbsizeCommand(redisClient *c);
void lastsaveCommand(redisClient *c);
void saveCommand(redisClient *c);
void bgsaveCommand(redisClient *c);
void bgrewriteaofCommand(redisClient *c);
void shutdownCommand(redisClient *c);
void moveCommand(redisClient *c);
void renameCommand(redisClient *c);
void renamenxCommand(redisClient *c);
void lpushCommand(redisClient *c);
void rpushCommand(redisClient *c);
void lpushxCommand(redisClient *c);
void rpushxCommand(redisClient *c);
void linsertCommand(redisClient *c);
void lpopCommand(redisClient *c);
void rpopCommand(redisClient *c);
void llenCommand(redisClient *c);
void lindexCommand(redisClient *c);
void lrangeCommand(redisClient *c);
void ltrimCommand(redisClient *c);
void typeCommand(redisClient *c);
void lsetCommand(redisClient *c);
void saddCommand(redisClient *c);
void sremCommand(redisClient *c);
void smoveCommand(redisClient *c);
void sismemberCommand(redisClient *c);
void scardCommand(redisClient *c);
void spopCommand(redisClient *c);
void srandmemberCommand(redisClient *c);
void sinterCommand(redisClient *c);
void sinterstoreCommand(redisClient *c);
void sunionCommand(redisClient *c);
void sunionstoreCommand(redisClient *c);
void sdiffCommand(redisClient *c);
void sdiffstoreCommand(redisClient *c);
void syncCommand(redisClient *c);
void flushdbCommand(redisClient *c);
void flushallCommand(redisClient *c);
void sortCommand(redisClient *c);
void lremCommand(redisClient *c);
void rpoplpushcommand(redisClient *c);
void infoCommand(redisClient *c);
void mgetCommand(redisClient *c);
void monitorCommand(redisClient *c);
void expireCommand(redisClient *c);
void expireatCommand(redisClient *c);
void getsetCommand(redisClient *c);
void ttlCommand(redisClient *c);
void persistCommand(redisClient *c);
void slaveofCommand(redisClient *c);
void debugCommand(redisClient *c);
void msetCommand(redisClient *c);
void msetnxCommand(redisClient *c);
void zaddCommand(redisClient *c);
void zincrbyCommand(redisClient *c);
void zrangeCommand(redisClient *c);
void zrangebyscoreCommand(redisClient *c);
void zcountCommand(redisClient *c);
void zrevrangeCommand(redisClient *c);
void zcardCommand(redisClient *c);
void zremCommand(redisClient *c);
void zscoreCommand(redisClient *c);
void zremrangebyscoreCommand(redisClient *c);
void multiCommand(redisClient *c);
void execCommand(redisClient *c);
void discardCommand(redisClient *c);
void blpopCommand(redisClient *c);
void brpopCommand(redisClient *c);
void appendCommand(redisClient *c);
void substrCommand(redisClient *c);
void strlenCommand(redisClient *c);
void zrankCommand(redisClient *c);
void zrevrankCommand(redisClient *c);
void hsetCommand(redisClient *c);
void hsetnxCommand(redisClient *c);
void hgetCommand(redisClient *c);
void hmsetCommand(redisClient *c);
void hmgetCommand(redisClient *c);
void hdelCommand(redisClient *c);
void hlenCommand(redisClient *c);
void zremrangebyrankCommand(redisClient *c);
void zunionstoreCommand(redisClient *c);
void zinterstoreCommand(redisClient *c);
void hkeysCommand(redisClient *c);
void hvalsCommand(redisClient *c);
void hgetallCommand(redisClient *c);
void hexistsCommand(redisClient *c);
void configCommand(redisClient *c);
void hincrbyCommand(redisClient *c);
void subscribeCommand(redisClient *c);
void unsubscribeCommand(redisClient *c);
void psubscribeCommand(redisClient *c);
void punsubscribeCommand(redisClient *c);
void publishCommand(redisClient *c);
void watchCommand(redisClient *c);
void unwatchCommand(redisClient *c);

#if defined(__GNUC__)
void *calloc(size_t count, size_t size) __attribute__ ((deprecated));
void free(void *ptr) __attribute__ ((deprecated));
void *malloc(size_t size) __attribute__ ((deprecated));
void *realloc(void *ptr, size_t size) __attribute__ ((deprecated));
#endif

#endif