1

#ifndef MEMCACHE_H

     2

#define MEMCACHE_H

     3

     4

/*

     5

 * A libevent based memcached client that aims for high performance, concurrency and low latency.

     6

 */

     7

     8

#include "config.h"

     9

    10

/*

    11

 * Used to store the global information for a memcache context. A context contains both servers and active connections.

    12

 */

    13

struct memcache;

    14

    15

/*

    16

 * A transaction.

    17

 */

    18

struct memcache_req;

    19

    20

/*

    21

 * Keys used

    22

 */

    23

struct memcache_key {

    24

    char *buf;

    25

    size_t len;

    26

};

    27

    28

/*

    29

 * Object attributes

    30

 */

    31

struct memcache_obj {

    32

    unsigned int flags;

    33

    time_t exptime;

    34

    size_t bytes;

    35

    unsigned long long cas;

    36

};

    37

    38

/*

    39

 * Object data

    40

 */

    41

struct memcache_buf {

    42

    char *data;

    43

    size_t len;

    44

    size_t offset;

    45

};

    46

    47

/*

    48

 * Available commands

    49

 */

    50

enum memcache_command {

    51

    MEMCACHE_CMD_INVALID,

    52

    53

    MEMCACHE_CMD_FETCH_GET,

    54

    MEMCACHE_CMD_STORE_SET,

    55

    MEMCACHE_CMD_STORE_ADD,

    56

    MEMCACHE_CMD_STORE_REPLACE,

    57

    MEMCACHE_CMD_STORE_APPEND,

    58

    MEMCACHE_CMD_STORE_PREPEND,

    59

    MEMCACHE_CMD_STORE_CAS,

    60

    61

    MEMCACHE_CMD_MAX,

    62

};

    63

    64

enum memcache_reply {

    65

    MEMCACHE_RPL_INVALID,

    66

    67

    MEMCACHE_RPL_ERROR,

    68

    MEMCACHE_RPL_CLIENT_ERROR,

    69

    MEMCACHE_RPL_SERVER_ERROR,

    70

    71

    // MEMCACHE_CMD_FETCH_*

    72

    MEMCACHE_RPL_VALUE,

    73

    MEMCACHE_RPL_END,

    74

    75

    // MEMCACHE_CMD_STORE_*

    76

    MEMCACHE_RPL_STORED,

    77

    MEMCACHE_RPL_NOT_STORED,

    78

    MEMCACHE_RPL_EXISTS,

    79

    MEMCACHE_RPL_NOT_FOUND,

    80

    81

    MEMCACHE_RPL_MAX,

    82

};

    83

    84

enum memcache_req_state {

    85

    MEMCACHE_STATE_INVALID,

    86

    87

    MEMCACHE_STATE_QUEUED,

    88

    MEMCACHE_STATE_SEND,

    89

    MEMCACHE_STATE_REPLY,

    94

    95

    MEMCACHE_STATE_ERROR,

    96

};

    97

    98

/*

    99

 * Callback used

   100

 */

   101

typedef int (*memcache_cb) (struct memcache_req *, void*);

   102

   103

/*

   104

 * Allocate a new memcache context for use with other methods.

   105

 */

   106

struct memcache *memcache_alloc (memcache_cb cb_fn);

   107

   108

/*

   109

 * Add a server to the pool of available servers.

   110

 */

   111

int memcache_add_server (struct memcache *mc, struct config_endpoint *endpoint, int max_connections);

   112

   113

/*

   114

 * Attempt to fetch a key from the cache.

   115

 */

   116

struct memcache_req *memcache_fetch (struct memcache *mc, const struct memcache_key *key, void *cb_arg);

   117

   118

/*

   119

 * Attempt to store a key into the cache

   120

 */

   121

struct memcache_req *memcache_store (struct memcache *mc, enum memcache_command cmd, const struct memcache_key *key, const struct memcache_obj *obj, void *cb_arg);

   122

   123

/*

   124

 * Request state

   125

 */ 

   126

enum memcache_req_state memcache_req_state (struct memcache_req *req);

   127

   128

/*

   129

 * Request key

   130

 */

   131

int memcache_req_key (struct memcache_req *req, const struct memcache_key *key);

   132

   133

/*

   134

 * Request data

   135

 */

   136

int memcache_req_obj (struct memcache_req *req, const struct memcache_obj *obj);

   137

   138

#endif /* MEMCACHE_H */