/*
 * HCLINK.H
 *
 * $DragonFly: src/bin/cpdup/hclink.h,v 1.7 2008/05/24 17:21:36 dillon Exp $
 */

#ifndef _HCLINK_H_
#define _HCLINK_H_

/* Changing the buffer size breaks protocol compatibility! */
#define HC_BUFSIZE      65536

struct HCHostDesc {
    struct HCHostDesc *next;
    intptr_t desc;
    int type;
    void *data;
};

struct HostConf;

typedef struct HCTransaction {
    char        rbuf[HC_BUFSIZE];       /* input buffer */
    char        wbuf[HC_BUFSIZE];       /* output buffer */
    struct HostConf *hc;
    uint16_t    id;             /* assigned transaction id */
    int         swap;           /* have to swap byte order */
    int         windex;         /* output buffer index */
    enum { HCT_IDLE, HCT_SENT, HCT_REPLIED, HCT_DONE, HCT_FAIL } state;
} *hctransaction_t;

struct HostConf {
    char        *host;          /* [user@]host */
    int         fdin;           /* pipe */
    int         fdout;          /* pipe */
    int         error;          /* permanent failure code */
    pid_t       pid;
    int         version;        /* cpdup protocol version */
    struct HCHostDesc *hostdescs;
    struct HCTransaction trans;
};

struct HCHead {
    int32_t magic;              /* magic number / byte ordering */
    int32_t bytes;              /* size of packet */
    int16_t cmd;                /* command code */
    uint16_t id;                /* transaction id */
    int32_t error;              /* error code (response) */
} __aligned(8); /* fix clang warning, not required for correct operation */

#define HCMAGIC         0x48435052      /* compatible byte ordering */
#define HCC_ALIGN(bytes)        (((bytes) + 7) & ~7)

struct HCLeaf {
    int16_t leafid;
    int16_t reserved;           /* reserved must be 0 */
    int32_t bytes;
} __aligned(8); /* fix clang warning, not required for correct operation */

#define HCF_CONTINUE    0x4000          /* expect another reply */
#define HCF_REPLY       0x8000          /* reply */

#define LCF_TYPEMASK    0x0F00
#define LCF_INT32       0x0100          /* 4 byte integer */
#define LCF_INT64       0x0200          /* 8 byte integer */
#define LCF_STRING      0x0300          /* string, must be 0-terminated */
#define LCF_BINARY      0x0F00          /* binary data */

struct HCDesc {
    int16_t cmd;
    int (*func)(hctransaction_t, struct HCHead *);
};

/*
 * Item extraction macros
 */
#define HCC_STRING(item)        ((const char *)((item) + 1))
#define HCC_INT32(item)         (*(int32_t *)((item) + 1))
#define HCC_INT64(item)         (*(int64_t *)((item) + 1))
#define HCC_BINARYDATA(item)    ((void *)((item) + 1))

#define FOR_EACH_ITEM(item, trans, head)        \
                for (item = hcc_firstitem(trans, head); item; \
                     item = hcc_nextitem(trans, head, item))

/*
 * Prototypes
 */
int hcc_connect(struct HostConf *hc, int readonly);
int hcc_slave(int fdin, int fdout, struct HCDesc *descs, int count);

struct HCHead *hcc_read_command(struct HostConf *hc, hctransaction_t trans);
hctransaction_t hcc_start_command(struct HostConf *hc, int16_t cmd);
struct HCHead *hcc_finish_command(hctransaction_t trans);
void hcc_leaf_string(hctransaction_t trans, int16_t leafid, const char *str);
void hcc_leaf_data(hctransaction_t trans, int16_t leafid, const void *ptr, int bytes);
void hcc_leaf_int32(hctransaction_t trans, int16_t leafid, int32_t value);
void hcc_leaf_int64(hctransaction_t trans, int16_t leafid, int64_t value);
int hcc_check_space(hctransaction_t trans, struct HCHead *head, int n, int size);

intptr_t hcc_alloc_descriptor(struct HostConf *hc, void *ptr, int type);
void *hcc_get_descriptor(struct HostConf *hc, intptr_t desc, int type);
void hcc_set_descriptor(struct HostConf *hc, intptr_t desc, void *ptr, int type);

struct HCLeaf *hcc_nextitem(hctransaction_t trans, struct HCHead *head, struct HCLeaf *item);
#define hcc_firstitem(trans, head)      hcc_nextitem(trans, head, NULL)
struct HCLeaf *hcc_nextchaineditem(struct HostConf *hc, struct HCHead *head);
struct HCLeaf *hcc_currentchaineditem(struct HostConf *hc, struct HCHead *head);

void hcc_debug_dump(struct HCHead *head);

#endif