Added multicast autodiscovery

[elliptics.git] / include / elliptics / interface.h

/*
 * 2008+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#ifndef __DNET_INTERFACE_H
#define __DNET_INTERFACE_H

#include <elliptics/core.h>

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>

#include <eblob/blob.h>
#include <elliptics/packet.h>
#include <elliptics/srw.h>

#ifdef __cplusplus
extern "C" {
#endif

#ifndef O_CLOEXEC
#define O_CLOEXEC       02000000
#endif

#ifndef FD_CLOEXEC
#define FD_CLOEXEC      1
#endif

struct dnet_net_state;
struct dnet_node;

int dnet_need_exit(struct dnet_node *n);
void dnet_set_need_exit(struct dnet_node *n);

/*
 * Callback data structures.
 *
 * [dnet_cmd]
 * [attributes]
 *
 * [dnet_cmd] header when present shows number of attached bytes.
 * It should be equal to the al_attr structure at least in the
 * correct message, otherwise it should be discarded.
 * One can also check cmd->flags if it has DNET_FLAGS_MORE or
 * DNET_FLAGS_DESTROY bit set. The former means that callback
 * will be invoked again in the future and transaction is not
 * yet completed. The latter means that transaction is about
 * to be destroyed.
 */

/*
 * IO helpers.
 *
 * dnet_node is a node pointer returned by calling dnet_node_create()
 * dnet_io_attr contains IO details (size, offset and the checksum)
 * completion callback (if present) will be invoked when IO transaction is finished
 * private data will be stored in the appropriate transaction and can be obtained
 * when transaction completion callback is invoked. It will be automatically
 * freed when transaction is completed.
 */

struct dnet_io_control {
        /* Used as cmd->id/group_id - 'address' of the remote node */
        struct dnet_id                  id;

        /*
         * IO control structure - it is copied into resulted transaction as is.
         * During write origin will be replaced with data transformation, and
         * id will be replaced with the object name transformation.
         */
        struct dnet_io_attr             io;

        /*
         * If present, will be invoked when transaction is completed.
         * Can be invoked multiple times, the last one will be when
         * cmd->flags does not have DNET_FLAGS_MORE flag.
         *
         * All parameters are releated to the received transaction reply.
         */
        int                             (* complete)(struct dnet_net_state *st,
                                                        struct dnet_cmd *cmd,
                                                        void *priv);

        /*
         * Transaction completion private data. Will be accessible in the
         * above completion callback.
         */
        void                            *priv;

        /*
         * Data to be sent.
         */
        const void                      *data;

        /*
         * File descriptor to read data from (for the write transaction).
         */
        int                             fd;

        /*
         * This offset represent local data shift, when local and remote offsets differ.
         * For example when we want to put local object into transaction but place it
         * after some bytes in the remote object.
         */
        uint64_t                        local_offset;

        /*
         * IO command.
         */
        unsigned int                    cmd;

        /*
         * Command flags (DNET_FLAGS_*)
         */
        uint64_t                        cflags;

        /* Data transaction timestamp */
        struct timespec                 ts;
};

/*
 * Reads an object identified by the provided ID from the appropriate node.
 * In case of error completion callback may be invoked with all parameters
 * set to null, private pointer will be setto what was provided by the user
 * as private data).
 *
 * Returns negative error value in case of error.
 */
int dnet_read_object(struct dnet_node *n, struct dnet_io_control *ctl);

/*
 * Read @io->size bytes (0 means everything) from @io->offset bytes
 * of data associated with key @ID. Use @io->flags and @cflags for control
 * Returns NULL and set @errp when error happens
 */
void *dnet_read_data_wait(struct dnet_node *n, struct dnet_id *id,
                struct dnet_io_attr *io, uint64_t cflags, int *errp);

/* Read latest data according to stored metadata */
int dnet_read_latest(struct dnet_node *n, struct dnet_id *id,
                struct dnet_io_attr *io, uint64_t cflags, void **datap);

struct dnet_read_latest_prepare {
        struct dnet_node                *n;

        struct dnet_id                  id;

        uint64_t                        cflags;

        int                             *group;
        int                             group_num;
};
int dnet_read_latest_prepare(struct dnet_read_latest_prepare *pr);


/*
 * Read data from range of keys [io->id, io->parent)
 * Other parameters are treated the same as in dnet_read_data_wait()
 * On success @errp will point to number of dnet_range_data structures.
 */
struct dnet_range_data {
        uint64_t                        size;
        void                            *data;
};

struct dnet_io_attr *dnet_remove_range(struct dnet_node *n, struct dnet_io_attr *io,
                int group_id, uint64_t cflags, int *rep_num, int *errp);

struct dnet_range_data *dnet_read_range(struct dnet_node *n, struct dnet_io_attr *io,
                int group_id, uint64_t cflags, int *errp);

int __attribute__((weak)) dnet_send_read_data(void *state, struct dnet_cmd *cmd, struct dnet_io_attr *io,
                void *data, int fd, uint64_t offset, int close_on_exit);

/*
 * Reads given file from the storage. If there are multiple transformation functions,
 * they will be tried one after another.
 *
 * If @id is set, it is used as a main object ID, otherwise @file transformation
 * is used as object ID.
 *
 * @type is column type, only meaningful with eblob backend, otherwise it is unused
 *
 * Returns negative error value in case of error.
 *
 * dnet_read_file_direct() works the same way except it sets DNET_FLAGS_DIRECT flag,
 * which means it will ask node for given object, which is the closest in routing
 * table and will not allow to forward this request to other nodes.
 */
int dnet_read_file_id(struct dnet_node *n, const char *file, struct dnet_id *id,
                uint64_t offset, uint64_t size);
int dnet_read_file(struct dnet_node *n, const char *file, const void *remote, int remote_size,
                uint64_t offset, uint64_t size, int type);

/*
 * dnet_write_object() returns number of transactions sent. If it is equal to 0,
 * then no transactions were sent which indicates an error.
 *
 * ->complete() can be called multiple times, depending on how server sends data
 */
int dnet_write_object(struct dnet_node *n, struct dnet_io_control *ctl);

/* Returns size of the reply or negative error value */
int __attribute__((weak)) dnet_write_data_wait(struct dnet_node *n, struct dnet_io_control *ctl, void **result);

/*
 * Sends given file to the remote nodes and waits until all of them ack the write.
 *
 * Returns negative error value in case of error.
 */
int dnet_write_file_id(struct dnet_node *n, const char *file, struct dnet_id *id, uint64_t local_offset,
                uint64_t remote_offset, uint64_t size, uint64_t cflags, unsigned int ioflags);

int dnet_write_file(struct dnet_node *n, const char *file, const void *remote, int remote_len,
                uint64_t local_offset, uint64_t remote_offset, uint64_t size,
                uint64_t cflags, unsigned int ioflags, int type);

enum dnet_log_level {
        DNET_LOG_DATA = 0,
        DNET_LOG_ERROR,
        DNET_LOG_INFO,
        DNET_LOG_NOTICE,
        DNET_LOG_DEBUG,
};

#define DNET_MAX_ADDRLEN                256
#define DNET_MAX_PORTLEN                8

/* cfg->flags */
#define DNET_CFG_JOIN_NETWORK           (1<<0)          /* given node joins network and becomes part of the storage */
#define DNET_CFG_NO_ROUTE_LIST          (1<<1)          /* do not request route table from remote nodes */
#define DNET_CFG_MIX_STATES             (1<<2)          /* mix states according to their weights before reading data */
#define DNET_CFG_NO_CSUM                (1<<3)          /* globally disable checksum verification and update */
#define DNET_CFG_NO_META                (1<<4)          /* do not write metadata */
#define DNET_CFG_RANDOMIZE_STATES       (1<<5)          /* randomize states for read requests */

struct dnet_log {
        /*
         * Logging parameters.
         * Mask specifies set of the events we are interested in to log.
         * Private data is used in the log function to get access to whatever
         * user pointed to.
         */
        int                     log_level;
        void                    *log_private;
        void                    (* log)(void *priv, int level, const char *msg);
};

struct dnet_iterate_ctl {
        void                            *iterate_private;

        unsigned int                    flags;
        int                             blob_start;
        int                             blob_num;

        struct eblob_iterate_callbacks  iterate_cb;
        void                            *callback_private;
};

struct dnet_backend_callbacks {
        /* command handler processes DNET_CMD_* commands */
        int                     (* command_handler)(void *state, void *priv, struct dnet_cmd *cmd, void *data);

        /* this must be provided as @priv argument to all above and below callbacks*/
        void                    *command_private;

        /* sends object with given ID to specified @state */
        int                     (* send)(void *state, void *priv, struct dnet_id *id);

        /* fills storage statistics */
        int                     (* storage_stat)(void *priv, struct dnet_stat *st);

        /* cleanups backend at exit */
        void                    (* backend_cleanup)(void *command_private);

        /* metadata read/write/remove commands */
        ssize_t                 (* meta_read)(void *priv, struct dnet_raw_id *id, void **datap);
        int                     (* meta_write)(void *priv, struct dnet_raw_id *id, void *data, size_t size);
        int                     (* meta_remove)(void *priv, struct dnet_raw_id *id, int real_remove);

        /*
         * parallel metadata iterator
         * given callback will be executed for every not deleted record found,
         * if it returns negative error value, iteration stops
         * @callback_private will be accessible in @callback as argument @p
         */
        int                     (* meta_iterate)(struct dnet_iterate_ctl *ctl);

        /* returns number of metadata elements */
        long long               (* meta_total_elements)(void *priv);
};

/*
 * Node configuration interface.
 */
struct dnet_config
{
        /*
         * Socket type (SOCK_STREAM, SOCK_DGRAM and so on),
         * a protocol (IPPROTO_TCP for example) and
         * a family (AF_INET, AF_INET6 and so on)
         * of the appropriate socket. These parameters are
         * sent in the lookup replies so that remote nodes
         * could know how to connect to this one.
         */
        int                     sock_type, proto, family;

        /*
         * Socket address/port suitable for the getaddrinfo().
         */
        char                    addr[DNET_MAX_ADDRLEN];
        char                    port[DNET_MAX_PORTLEN];

        /*
         * Wait timeout in seconds used for example to wait
         * for remote content sync.
         */
        unsigned int            wait_timeout;

        /*
         * Specifies wether given node will join the network,
         * or it is a client node and its ID should not be checked
         * against collision with others.
         *
         * Also has a bit to forbid route list download.
         */
        int                     flags;

        /*
         * If node joins network this will be used to find a group to join.
         */
        int                     group_id;

        /* Private logger */
        struct dnet_log         *log;

        /*
         * Network command handler.
         * Returns negative error value or zero in case of success.
         *
         * Private data is accessible from the handler as parameter.
         */
        struct dnet_backend_callbacks   *cb;

        /*
         * Free and total space on given storage.
         */
        unsigned long long      storage_free;
        unsigned long long      storage_size;

        /* Notify hash table size */
        unsigned int            hash_size;

        /*
         * Wait until transaction acknowledge is received.
         */
        long                    check_timeout;

        /*
         * Destroy state if stall_count transactions stalled.
         */
        long                    stall_count;

        /*
         * Number of IO threads in processing pool
         */
        int                     io_thread_num;

        /*
         * Number of IO threads in processing pool dedicated to non-blocking operations
         * Those operations are started from recursive commands like from DNET_CMD_EXEC handler
         */
        int                     nonblocking_io_thread_num;

        /*
         * Number of threads in network processing pool
         */
        int                     net_thread_num;

        /* Temporary metadata for CHECK process directory path */
        char                    temp_meta_env[1024];

        /*
         * This dir hosts:
         *  - 'ids' file automatically generated for ID ranges
         *  - python.init script used to initialize external python workers
         *  - all scripts are hosted here and are chrooted here
         */
        char                    history_env[1024];

        /* Namespace */
        char                    *ns;
        int                     nsize;

        /* IO nice parameters for background operations */
        int                     bg_ionice_class;
        int                     bg_ionice_prio;
        int                     removal_delay;

        char                    cookie[DNET_AUTH_COOKIE_SIZE];

        /* man 7 socket for IP_PRIORITY - priorities are set for joined (server) and others (client) connections */
        int                     server_prio;
        int                     client_prio;

        /* table of operation locks */
        int                     oplock_num;

        struct srw_init_ctl     srw;

        uint64_t                cache_size;

        /* so that we do not change major version frequently */
        int                     reserved_for_future_use[12];
};

struct dnet_node *dnet_get_node_from_state(void *state);

int __attribute__((weak)) dnet_node_set_groups(struct dnet_node *n, int *groups, int group_num);

/*
 * Logging helpers.
 */

/*
 * Initialize private logging system.
 */
int dnet_log_init(struct dnet_node *n, struct dnet_log *l);
void __attribute__((weak)) dnet_log_raw(struct dnet_node *n, int level, const char *format, ...) DNET_LOG_CHECK;

#define NIP6(addr) \
        (addr).s6_addr[0], \
        (addr).s6_addr[1], \
        (addr).s6_addr[2], \
        (addr).s6_addr[3], \
        (addr).s6_addr[4], \
        (addr).s6_addr[5], \
        (addr).s6_addr[6], \
        (addr).s6_addr[7], \
        (addr).s6_addr[8], \
        (addr).s6_addr[9], \
        (addr).s6_addr[10], \
        (addr).s6_addr[11], \
        (addr).s6_addr[12], \
        (addr).s6_addr[13], \
        (addr).s6_addr[14], \
        (addr).s6_addr[15]
#define NIP6_FMT "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x"

/*
 * Logging helpers used for the fine-printed address representation.
 */
static inline char *dnet_server_convert_addr_raw(struct sockaddr *sa, unsigned int len, char *inet_addr, int inet_size)
{
        memset(inet_addr, 0, inet_size);
        if (len == sizeof(struct sockaddr_in)) {
                struct sockaddr_in *in = (struct sockaddr_in *)sa;
                snprintf(inet_addr, inet_size, "%s", inet_ntoa(in->sin_addr));
        } else if (len == sizeof(struct sockaddr_in6)) {
                struct sockaddr_in6 *in = (struct sockaddr_in6 *)sa;
                snprintf(inet_addr, inet_size, NIP6_FMT, NIP6(in->sin6_addr));
        }
        return inet_addr;
}

static inline char *dnet_server_convert_addr(struct sockaddr *sa, unsigned int len)
{
        static char __inet_addr[128];
        return dnet_server_convert_addr_raw(sa, len, __inet_addr, sizeof(__inet_addr));
}

static inline int dnet_server_convert_port(struct sockaddr *sa, unsigned int len)
{
        if (len == sizeof(struct sockaddr_in)) {
                struct sockaddr_in *in = (struct sockaddr_in *)sa;
                return ntohs(in->sin_port);
        } else if (len == sizeof(struct sockaddr_in6)) {
                struct sockaddr_in6 *in = (struct sockaddr_in6 *)sa;
                return ntohs(in->sin6_port);
        }
        return 0;
}

static inline char *dnet_server_convert_dnet_addr_raw(struct dnet_addr *sa, char *inet_addr, int inet_size)
{
        memset(inet_addr, 0, inet_size);
        if (sa->addr_len == sizeof(struct sockaddr_in)) {
                struct sockaddr_in *in = (struct sockaddr_in *)sa->addr;
                snprintf(inet_addr, inet_size, "%s:%d", inet_ntoa(in->sin_addr),
                                ntohs(in->sin_port));
        } else if (sa->addr_len == sizeof(struct sockaddr_in6)) {
                struct sockaddr_in6 *in = (struct sockaddr_in6 *)sa->addr;
                snprintf(inet_addr, inet_size, NIP6_FMT":%d", NIP6(in->sin6_addr),
                                ntohs(in->sin6_port));
        }
        return inet_addr;
}

static inline char *dnet_server_convert_dnet_addr(struct dnet_addr *sa)
{
        static char ___inet_addr[128];
        return dnet_server_convert_dnet_addr_raw(sa, ___inet_addr, sizeof(___inet_addr));
}

struct dnet_addr *dnet_state_addr(struct dnet_net_state *st);
static inline char *dnet_state_dump_addr(struct dnet_net_state *st)
{
        return dnet_server_convert_dnet_addr(dnet_state_addr(st));
}

static inline char *dnet_state_dump_addr_only(struct dnet_addr *a)
{
        return dnet_server_convert_addr((struct sockaddr *)a->addr, a->addr_len);
}

/*
 * Node creation/destruction callbacks. Node is a building block of the storage
 * and it is needed for every operation one may want to do with the network.
 */
struct dnet_node *dnet_node_create(struct dnet_config *);
void dnet_node_destroy(struct dnet_node *n);

/* Server node creation/destruction.
 */
struct dnet_node *dnet_server_node_create(struct dnet_config *);
void dnet_server_node_destroy(struct dnet_node *n);

/*
 * dnet_add_state() is used to add a node into the route list, the more
 * routes are added the less network lookups will be performed to send/receive
 * data requests.
 */
int dnet_add_state(struct dnet_node *n, struct dnet_config *cfg);

/*
 * Returns number of states we are connected to.
 * It does not check whether they are alive though.
 */

int dnet_state_num(struct dnet_node *n);

#define DNET_DUMP_NUM   6
/*
 * Logging helper used to print ID (DNET_ID_SIZE bytes) as a hex string.
 */
static inline char *dnet_dump_id_len_raw(const unsigned char *id, unsigned int len, char *dst)
{
        unsigned int i;

        if (len > DNET_ID_SIZE)
                len = DNET_ID_SIZE;

        for (i=0; i<len; ++i)
                sprintf(&dst[2*i], "%02x", id[i]);
        return dst;
}

static inline char *dnet_dump_id_len(const struct dnet_id *id, unsigned int len)
{
        static char __dnet_dump_str[2 * DNET_ID_SIZE + 16 + 3];
        char tmp[2*DNET_ID_SIZE + 1];
        
        snprintf(__dnet_dump_str, sizeof(__dnet_dump_str), "%d:%s", id->group_id,
                        dnet_dump_id_len_raw(id->id, len, tmp));
        return __dnet_dump_str;
}

static inline char *dnet_dump_id(const struct dnet_id *id)
{
        return dnet_dump_id_len(id, DNET_DUMP_NUM);
}

static inline char *dnet_dump_id_str(const unsigned char *id)
{
        static char __dnet_dump_id_str[2 * DNET_ID_SIZE + 1];
        return dnet_dump_id_len_raw(id, DNET_DUMP_NUM, __dnet_dump_id_str);
}

/*
 * Lookup a node which hosts given ID.
 *
 * dnet_lookup_object() will invoke given callback when lookup reply is received.
 * dnet_lookup() will add received address into local route table.
 * dnet_lookup_complete() is a completion function which adds received address
 *      into local route table.
 *
 * Effectively dnet_lookup() is a dnet_lookup_object() with dnet_lookup_complete()
 *      completion function.
 */
int dnet_lookup_object(struct dnet_node *n, struct dnet_id *id, uint64_t cflags,
        int (* complete)(struct dnet_net_state *, struct dnet_cmd *, void *),
        void *priv);
int dnet_lookup(struct dnet_node *n, const char *file);
int dnet_lookup_complete(struct dnet_net_state *st, struct dnet_cmd *cmd, void *priv);
int dnet_stat_local(struct dnet_net_state *st, struct dnet_id *id);

/*
 * Compare two IDs.
 * Returns  1 when id1 > id2
 *         -1 when id1 < id2
 *          0 when id1 = id2
 */
static inline int dnet_id_cmp_str(const unsigned char *id1, const unsigned char *id2)
{
        unsigned int i = 0;

        for (i*=sizeof(unsigned long); i<DNET_ID_SIZE; ++i) {
                if (id1[i] < id2[i])
                        return -1;
                if (id1[i] > id2[i])
                        return 1;
        }

        return 0;
}
static inline int dnet_id_cmp(const struct dnet_id *id1, const struct dnet_id *id2)
{
        if (id1->group_id < id2->group_id)
                return -1;
        if (id1->group_id > id2->group_id)
                return 1;

        return dnet_id_cmp_str(id1->id, id2->id);
}

/*
 * Send given number of bytes as reply command.
 * It will fill transaction, command and ID from the original command and copy given data.
 * It will set DNET_FLAGS_MORE if original command requested acknowledge or @more is set.
 *
 * If cmd->cmd is DNET_CMD_SYNC then plain data will be sent back, otherwise transaction
 * reply will be generated. So effectively difference is in DNET_TRANS_REPLY bit presence.
 */
int __attribute__((weak)) dnet_send_reply(void *state, struct dnet_cmd *cmd, void *odata, unsigned int size, int more);

/*
 * Request statistics from the node corresponding to given ID.
 * If @id is NULL statistics will be requested from all connected nodes.
 * @cmd specified stat command to use (DNET_CMD_STAT or DNET_CMD_STAT_COUNT).
 *
 * Function will sleep and print into DNET_LOG_INFO log level short
 * statistics if no @complete function is provided, otherwise it returns
 * after queueing all transactions and appropriate callback will be
 * invoked asynchronously.
 * 
 * Function returns number of nodes statistics request was sent to
 * or negative error code. In case of error callback completion can
 * still be called.
 */
int dnet_request_stat(struct dnet_node *n, struct dnet_id *id,
        unsigned int cmd, uint64_t cflags,
        int (* complete)(struct dnet_net_state *state,
                        struct dnet_cmd *cmd,
                        void *priv),
        void *priv);

/*
 * Request notifications when given ID is modified.
 * Notifications are sent after update was stored in the IO backend.
 * @id and @complete are not allowed to be NULL.
 *
 * @complete will be invoked each time object with given @id is modified.
 */
int dnet_request_notification(struct dnet_node *n, struct dnet_id *id,
        int (* complete)(struct dnet_net_state *state,
                        struct dnet_cmd *cmd,
                        void *priv),
        void *priv);

/*
 * Drop notifications for given ID.
 */
int dnet_drop_notification(struct dnet_node *n, struct dnet_id *id);

/*
 * Low-level transaction allocation and sending function.
 */
struct dnet_trans_control
{
        struct dnet_id          id;

        unsigned int            cmd;
        uint64_t                cflags;

        unsigned int            size;
        void                    *data;

        int                     (* complete)(struct dnet_net_state *state, struct dnet_cmd *cmd, void *priv);
        void                    *priv;
};

/*
 * Allocate and send transaction according to above control structure.
 */
int dnet_trans_alloc_send(struct dnet_node *n, struct dnet_trans_control *ctl);
int dnet_trans_create_send_all(struct dnet_node *n, struct dnet_io_control *ctl);

int dnet_request_cmd(struct dnet_node *n, struct dnet_trans_control *ctl);

int dnet_fill_addr(struct dnet_addr *addr, const char *saddr, const char *port, const int family,
                const int sock_type, const int proto);

/* Change node status on given address or ID */
int dnet_update_status(struct dnet_node *n, struct dnet_addr *addr, struct dnet_id *id, struct dnet_node_status *status);

/*
 * Remove object by @id
 * If callback is provided, it will be invoked on completion, otherwise
 * function will block until server returns an acknowledge.
 */
int dnet_remove_object(struct dnet_node *n, struct dnet_id *id,
        int (* complete)(struct dnet_net_state *state,
                        struct dnet_cmd *cmd,
                        void *priv),
        void *priv,
        uint64_t cflags, uint64_t ioflags);

/* Remove object with @id from the storage immediately */
int dnet_remove_object_now(struct dnet_node *n, struct dnet_id *id, uint64_t cflags, uint64_t ioflags);

/*
 * Remove given file (identified by name or ID) from the storage.
 */
int dnet_remove_file(struct dnet_node *n, char *remote, int remote_len, struct dnet_id *id, uint64_t cflags, uint64_t ioflags);

/*
 * Transformation helper, which uses *ppos as an index for transformation function.
 * @src and @size correspond to to be transformed source data.
 * @dst and @dsize specify destination buffer.
 */
int __attribute__((weak)) dnet_transform(struct dnet_node *n, const void *src, uint64_t size, struct dnet_id *id);

int dnet_request_ids(struct dnet_node *n, struct dnet_id *id, uint64_t cflags,
        int (* complete)(struct dnet_net_state *state,
                        struct dnet_cmd *cmd,
                        void *priv),
        void *priv);

struct dnet_meta_container {
        struct dnet_id                  id;
        unsigned int                    size;
        void                            *data;
} __attribute__ ((packed));

static inline void dnet_convert_meta_container(struct dnet_meta_container *m)
{
        m->size = dnet_bswap32(m->size);
}

struct dnet_metadata_control {
        struct dnet_id                  id;
        const char                      *obj;
        int                             len;

        int                             *groups;
        int                             group_num;

        uint64_t                        update_flags;
        struct timespec                 ts;

        uint64_t                        cflags;
};

/*
 * Reads meta of given file from the storage. If there are multiple transformation functions,
 * they will be tried one after another.
 *
 * If @id is set, it is used as a main object ID, otherwise @remote transformation
 * is used as object ID.
 *
 * Returns negative error value in case of error.
 */
int dnet_read_meta(struct dnet_node *n, struct dnet_meta_container *mc,
                const void *remote, unsigned int remote_len, struct dnet_id *id);

/*
 * Modify or search metadata in meta object. Data must be realloc()able.
 */
struct dnet_meta *dnet_meta_search(struct dnet_node *n, struct dnet_meta_container *mc, uint32_t type);

void dnet_create_meta_update(struct dnet_meta *m, struct timespec *ts, uint64_t flags_set, uint64_t flags_clear);
int dnet_write_metadata(struct dnet_node *n, struct dnet_meta_container *mc, int convert, uint64_t cflags);
int dnet_create_write_metadata(struct dnet_node *n, struct dnet_metadata_control *ctl);
int dnet_create_write_metadata_strings(struct dnet_node *n, const void *remote, unsigned int remote_len,
                struct dnet_id *id, struct timespec *ts, uint64_t cflags);
int dnet_create_metadata(struct dnet_node *n, struct dnet_metadata_control *ctl, struct dnet_meta_container *mc);
void dnet_meta_print(struct dnet_node *n, struct dnet_meta_container *mc);

int dnet_read_file_info(struct dnet_node *n, struct dnet_id *id, struct dnet_file_info *info);
int dnet_meta_update_check_status_raw(struct dnet_node *n, struct dnet_meta_container *mc);
int dnet_meta_update_check_status(struct dnet_node *n, struct dnet_meta_container *mc);

int dnet_lookup_addr(struct dnet_node *n, const void *remote, int len, struct dnet_id *id, int group_id, char *dst, int dlen);
void dnet_fill_addr_attr(struct dnet_node *n, struct dnet_addr_attr *attr);

struct dnet_id_param {
        unsigned int            group_id;
        uint64_t                param;
        uint64_t                param_reserved;
} __attribute__ ((packed));

enum id_params {
        DNET_ID_PARAM_LA = 1,
        DNET_ID_PARAM_FREE_SPACE,
};

int dnet_generate_ids_by_param(struct dnet_node *n, struct dnet_id *id, enum id_params param, struct dnet_id_param **dst);
int64_t dnet_get_param(struct dnet_node *n, struct dnet_id *id, enum id_params param);

int dnet_read_multiple(struct dnet_node *n, struct dnet_id *id, int num, struct dnet_id_param **dst);

struct dnet_check_reply {
        int                     total;
        int                     completed;
        int                     errors;
        int                     reserved[5];
};

static inline void dnet_convert_check_reply(struct dnet_check_reply *r)
{
        r->total = dnet_bswap32(r->total);
        r->completed = dnet_bswap32(r->completed);
        r->errors = dnet_bswap32(r->errors);
}

/* Set by dnet_check when we only want to merge transaction
 * and do not check copies in other groups
 */
#define DNET_CHECK_MERGE                        (1<<0)
/* Check not only history presence but also try to read part of the data object */
#define DNET_CHECK_FULL                         (1<<1)
/* Do not actually perform any action, just update counters */
#define DNET_CHECK_DRY_RUN                      (1<<2)
/* Physically delete files marked as REMOVED in history */
#define DNET_CHECK_DELETE                       (1<<3)

struct dnet_check_request {
        uint32_t                flags;
        uint32_t                thread_num;
        uint64_t                timestamp;
        uint64_t                updatestamp_start;
        uint64_t                updatestamp_stop;
        uint32_t                obj_num;
        uint32_t                group_num;
        int                     blob_start;
        int                     blob_num;
        uint64_t                reserved;
} __attribute__ ((packed));

static inline void dnet_convert_check_request(struct dnet_check_request *r)
{
        r->flags = dnet_bswap32(r->flags);
        r->thread_num = dnet_bswap32(r->thread_num);
        r->timestamp = dnet_bswap64(r->timestamp);
        r->updatestamp_start = dnet_bswap64(r->updatestamp_start);
        r->updatestamp_stop = dnet_bswap64(r->updatestamp_stop);
        r->obj_num = dnet_bswap32(r->obj_num);
        r->group_num = dnet_bswap32(r->group_num);
        r->blob_start = dnet_bswap32(r->blob_start);
        r->blob_num = dnet_bswap32(r->blob_num);
}

int dnet_request_check(struct dnet_node *n, struct dnet_check_request *r);

void *dnet_node_get_ns(struct dnet_node *n, int *nsize);
void dnet_node_set_ns(struct dnet_node *n, void *ns, int nsize);

long __attribute__((weak)) dnet_get_id(void);

static inline int is_trans_destroyed(struct dnet_net_state *st, struct dnet_cmd *cmd)
{
        int ret = 0;

        if (!st || !cmd || (cmd->flags & DNET_FLAGS_DESTROY)) {
                ret = 1;
                if (cmd && cmd->status)
                        ret = cmd->status;
        }

        return ret;
}

int dnet_mix_states(struct dnet_node *n, struct dnet_id *id, int **groupsp);

char * __attribute__((weak)) dnet_cmd_string(int cmd);
char *dnet_counter_string(int cntr, int cmd_num);

ssize_t dnet_db_read_raw(struct eblob_backend *b, struct dnet_raw_id *id, void **datap);
int dnet_db_write_raw(struct eblob_backend *b, struct dnet_raw_id *id, void *data, unsigned int size);
int dnet_db_remove_raw(struct eblob_backend *b, struct dnet_raw_id *id, int real_del);
int dnet_db_iterate(struct eblob_backend *b, struct dnet_iterate_ctl *ctl);

int dnet_send_file_info(void *state, struct dnet_cmd *cmd, int fd, uint64_t offset, int64_t size);

int dnet_get_routes(struct dnet_node *n, struct dnet_id **ids, struct dnet_addr **addrs);
/*
 * Send a shell/python command to the remote node for execution.
 */
int dnet_send_cmd(struct dnet_node *n, struct dnet_id *id, struct sph *h, void **ret);
int dnet_send_cmd_nolock(struct dnet_node *n, struct dnet_id *id, struct sph *e, void **ret);

struct dnet_range_data *dnet_bulk_read(struct dnet_node *n, struct dnet_io_attr *ios, uint32_t io_num, int group_id, uint64_t cflags, int *errp);
struct dnet_range_data dnet_bulk_write(struct dnet_node *n, struct dnet_io_control *ctl, int ctl_num, int *errp);

int dnet_flags(struct dnet_node *n);
void dnet_set_timeouts(struct dnet_node *n, int wait_timeout, int check_timeout);

#define DNET_CONF_ADDR_DELIM    ':'
int dnet_parse_addr(char *addr, struct dnet_config *cfg);

int dnet_start_defrag(struct dnet_node *n, uint64_t cflags);

int dnet_discovery_add(struct dnet_node *n, struct dnet_config *cfg);

#ifdef __cplusplus
}
#endif

#endif /* __DNET_INTERFACE_H */