/*-
 * Copyright (c) 2014-2019 MongoDB, Inc.
 * Copyright (c) 2008-2014 WiredTiger, Inc.
 *	All rights reserved.
 *
 * See the file LICENSE for redistribution information.
 */

#include "wt_internal.h"

/*
 * Streaming interface to packing.
 *
 * This allows applications to pack or unpack records one field at a time.
 */
struct __wt_pack_stream {
    WT_PACK pack;
    uint8_t *end, *p, *start;
};

/*
 * wiredtiger_pack_start --
 *     Open a stream for packing.
 */
int
wiredtiger_pack_start(
  WT_SESSION *wt_session, const char *format, void *buffer, size_t size, WT_PACK_STREAM **psp)
{
    WT_DECL_RET;
    WT_PACK_STREAM *ps;
    WT_SESSION_IMPL *session;

    session = (WT_SESSION_IMPL *)wt_session;
    WT_RET(__wt_calloc_one(session, &ps));
    WT_ERR(__pack_init(session, &ps->pack, format));
    ps->p = ps->start = buffer;
    ps->end = ps->p + size;
    *psp = ps;

    if (0) {
err:
        (void)wiredtiger_pack_close(ps, NULL);
    }
    return (ret);
}

/*
 * wiredtiger_unpack_start --
 *     Open a stream for unpacking.
 */
int
wiredtiger_unpack_start(
  WT_SESSION *wt_session, const char *format, const void *buffer, size_t size, WT_PACK_STREAM **psp)
{
    return (wiredtiger_pack_start(wt_session, format, (void *)buffer, size, psp));
}

/*
 * wiredtiger_pack_close --
 *     Close a packing stream.
 */
int
wiredtiger_pack_close(WT_PACK_STREAM *ps, size_t *usedp)
{
    if (usedp != NULL)
        *usedp = WT_PTRDIFF(ps->p, ps->start);

    __wt_free(ps->pack.session, ps);

    return (0);
}

/*
 * wiredtiger_pack_item --
 *     Pack an item.
 */
int
wiredtiger_pack_item(WT_PACK_STREAM *ps, WT_ITEM *item)
{
    WT_DECL_PACK_VALUE(pv);
    WT_SESSION_IMPL *session;

    session = ps->pack.session;

    /* Lower-level packing routines treat a length of zero as unchecked. */
    if (ps->p >= ps->end)
        return (ENOMEM);

    WT_RET(__pack_next(&ps->pack, &pv));
    switch (pv.type) {
    case 'U':
    case 'u':
        pv.u.item.data = item->data;
        pv.u.item.size = item->size;
        WT_RET(__pack_write(session, &pv, &ps->p, (size_t)(ps->end - ps->p)));
        break;
    default:
        return (__wt_illegal_value(session, pv.type));
    }

    return (0);
}

/*
 * wiredtiger_pack_int --
 *     Pack a signed integer.
 */
int
wiredtiger_pack_int(WT_PACK_STREAM *ps, int64_t i)
{
    WT_DECL_PACK_VALUE(pv);
    WT_SESSION_IMPL *session;

    session = ps->pack.session;

    /* Lower-level packing routines treat a length of zero as unchecked. */
    if (ps->p >= ps->end)
        return (ENOMEM);

    WT_RET(__pack_next(&ps->pack, &pv));
    switch (pv.type) {
    case 'b':
    case 'h':
    case 'i':
    case 'l':
    case 'q':
        pv.u.i = i;
        WT_RET(__pack_write(session, &pv, &ps->p, (size_t)(ps->end - ps->p)));
        break;
    default:
        return (__wt_illegal_value(session, pv.type));
    }

    return (0);
}

/*
 * wiredtiger_pack_str --
 *     Pack a string.
 */
int
wiredtiger_pack_str(WT_PACK_STREAM *ps, const char *s)
{
    WT_DECL_PACK_VALUE(pv);
    WT_SESSION_IMPL *session;

    session = ps->pack.session;

    /* Lower-level packing routines treat a length of zero as unchecked. */
    if (ps->p >= ps->end)
        return (ENOMEM);

    WT_RET(__pack_next(&ps->pack, &pv));
    switch (pv.type) {
    case 'S':
    case 's':
        pv.u.s = s;
        WT_RET(__pack_write(session, &pv, &ps->p, (size_t)(ps->end - ps->p)));
        break;
    default:
        return (__wt_illegal_value(session, pv.type));
    }

    return (0);
}

/*
 * wiredtiger_pack_uint --
 *     Pack an unsigned int.
 */
int
wiredtiger_pack_uint(WT_PACK_STREAM *ps, uint64_t u)
{
    WT_DECL_PACK_VALUE(pv);
    WT_SESSION_IMPL *session;

    session = ps->pack.session;

    /* Lower-level packing routines treat a length of zero as unchecked. */
    if (ps->p >= ps->end)
        return (ENOMEM);

    WT_RET(__pack_next(&ps->pack, &pv));
    switch (pv.type) {
    case 'B':
    case 'H':
    case 'I':
    case 'L':
    case 'Q':
    case 'R':
    case 'r':
    case 't':
        pv.u.u = u;
        WT_RET(__pack_write(session, &pv, &ps->p, (size_t)(ps->end - ps->p)));
        break;
    default:
        return (__wt_illegal_value(session, pv.type));
    }

    return (0);
}

/*
 * wiredtiger_unpack_item --
 *     Unpack an item.
 */
int
wiredtiger_unpack_item(WT_PACK_STREAM *ps, WT_ITEM *item)
{
    WT_DECL_PACK_VALUE(pv);
    WT_SESSION_IMPL *session;

    session = ps->pack.session;

    /* Lower-level packing routines treat a length of zero as unchecked. */
    if (ps->p >= ps->end)
        return (ENOMEM);

    WT_RET(__pack_next(&ps->pack, &pv));
    switch (pv.type) {
    case 'U':
    case 'u':
        WT_RET(__unpack_read(session, &pv, (const uint8_t **)&ps->p, (size_t)(ps->end - ps->p)));
        item->data = pv.u.item.data;
        item->size = pv.u.item.size;
        break;
    default:
        return (__wt_illegal_value(session, pv.type));
    }

    return (0);
}

/*
 * wiredtiger_unpack_int --
 *     Unpack a signed integer.
 */
int
wiredtiger_unpack_int(WT_PACK_STREAM *ps, int64_t *ip)
{
    WT_DECL_PACK_VALUE(pv);
    WT_SESSION_IMPL *session;

    session = ps->pack.session;

    /* Lower-level packing routines treat a length of zero as unchecked. */
    if (ps->p >= ps->end)
        return (ENOMEM);

    WT_RET(__pack_next(&ps->pack, &pv));
    switch (pv.type) {
    case 'b':
    case 'h':
    case 'i':
    case 'l':
    case 'q':
        WT_RET(__unpack_read(session, &pv, (const uint8_t **)&ps->p, (size_t)(ps->end - ps->p)));
        *ip = pv.u.i;
        break;
    default:
        return (__wt_illegal_value(session, pv.type));
    }
    return (0);
}

/*
 * wiredtiger_unpack_str --
 *     Unpack a string.
 */
int
wiredtiger_unpack_str(WT_PACK_STREAM *ps, const char **sp)
{
    WT_DECL_PACK_VALUE(pv);
    WT_SESSION_IMPL *session;

    session = ps->pack.session;

    /* Lower-level packing routines treat a length of zero as unchecked. */
    if (ps->p >= ps->end)
        return (ENOMEM);

    WT_RET(__pack_next(&ps->pack, &pv));
    switch (pv.type) {
    case 'S':
    case 's':
        WT_RET(__unpack_read(session, &pv, (const uint8_t **)&ps->p, (size_t)(ps->end - ps->p)));
        *sp = pv.u.s;
        break;
    default:
        return (__wt_illegal_value(session, pv.type));
    }
    return (0);
}

/*
 * wiredtiger_unpack_uint --
 *     Unpack an unsigned integer.
 */
int
wiredtiger_unpack_uint(WT_PACK_STREAM *ps, uint64_t *up)
{
    WT_DECL_PACK_VALUE(pv);
    WT_SESSION_IMPL *session;

    session = ps->pack.session;

    /* Lower-level packing routines treat a length of zero as unchecked. */
    if (ps->p >= ps->end)
        return (ENOMEM);

    WT_RET(__pack_next(&ps->pack, &pv));
    switch (pv.type) {
    case 'B':
    case 'H':
    case 'I':
    case 'L':
    case 'Q':
    case 'R':
    case 'r':
    case 't':
        WT_RET(__unpack_read(session, &pv, (const uint8_t **)&ps->p, (size_t)(ps->end - ps->p)));
        *up = pv.u.u;
        break;
    default:
        return (__wt_illegal_value(session, pv.type));
    }
    return (0);
}

/*
 * __wt_ext_pack_start --
 *     WT_EXTENSION.pack_start method.
 */
int
__wt_ext_pack_start(WT_EXTENSION_API *wt_api, WT_SESSION *wt_session, const char *format,
  void *buffer, size_t size, WT_PACK_STREAM **psp)
{
    WT_CONNECTION_IMPL *conn;

    conn = (WT_CONNECTION_IMPL *)wt_api->conn;
    if (wt_session == NULL)
        wt_session = (WT_SESSION *)conn->default_session;
    return (wiredtiger_pack_start(wt_session, format, buffer, size, psp));
}

/*
 * __wt_ext_unpack_start --
 *     WT_EXTENSION.unpack_start
 */
int
__wt_ext_unpack_start(WT_EXTENSION_API *wt_api, WT_SESSION *wt_session, const char *format,
  const void *buffer, size_t size, WT_PACK_STREAM **psp)
{
    WT_CONNECTION_IMPL *conn;

    conn = (WT_CONNECTION_IMPL *)wt_api->conn;
    if (wt_session == NULL)
        wt_session = (WT_SESSION *)conn->default_session;
    return (wiredtiger_unpack_start(wt_session, format, buffer, size, psp));
}

/*
 * __wt_ext_pack_close --
 *     WT_EXTENSION.pack_close
 */
int
__wt_ext_pack_close(WT_EXTENSION_API *wt_api, WT_PACK_STREAM *ps, size_t *usedp)
{
    WT_UNUSED(wt_api);
    return (wiredtiger_pack_close(ps, usedp));
}

/*
 * __wt_ext_pack_item --
 *     WT_EXTENSION.pack_item
 */
int
__wt_ext_pack_item(WT_EXTENSION_API *wt_api, WT_PACK_STREAM *ps, WT_ITEM *item)
{
    WT_UNUSED(wt_api);
    return (wiredtiger_pack_item(ps, item));
}

/*
 * __wt_ext_pack_int --
 *     WT_EXTENSION.pack_int
 */
int
__wt_ext_pack_int(WT_EXTENSION_API *wt_api, WT_PACK_STREAM *ps, int64_t i)
{
    WT_UNUSED(wt_api);
    return (wiredtiger_pack_int(ps, i));
}

/*
 * __wt_ext_pack_str --
 *     WT_EXTENSION.pack_str
 */
int
__wt_ext_pack_str(WT_EXTENSION_API *wt_api, WT_PACK_STREAM *ps, const char *s)
{
    WT_UNUSED(wt_api);
    return (wiredtiger_pack_str(ps, s));
}

/*
 * __wt_ext_pack_uint --
 *     WT_EXTENSION.pack_uint
 */
int
__wt_ext_pack_uint(WT_EXTENSION_API *wt_api, WT_PACK_STREAM *ps, uint64_t u)
{
    WT_UNUSED(wt_api);
    return (wiredtiger_pack_uint(ps, u));
}

/*
 * __wt_ext_unpack_item --
 *     WT_EXTENSION.unpack_item
 */
int
__wt_ext_unpack_item(WT_EXTENSION_API *wt_api, WT_PACK_STREAM *ps, WT_ITEM *item)
{
    WT_UNUSED(wt_api);
    return (wiredtiger_unpack_item(ps, item));
}

/*
 * __wt_ext_unpack_int --
 *     WT_EXTENSION.unpack_int
 */
int
__wt_ext_unpack_int(WT_EXTENSION_API *wt_api, WT_PACK_STREAM *ps, int64_t *ip)
{
    WT_UNUSED(wt_api);
    return (wiredtiger_unpack_int(ps, ip));
}

/*
 * __wt_ext_unpack_str --
 *     WT_EXTENSION.unpack_str
 */
int
__wt_ext_unpack_str(WT_EXTENSION_API *wt_api, WT_PACK_STREAM *ps, const char **sp)
{
    WT_UNUSED(wt_api);
    return (wiredtiger_unpack_str(ps, sp));
}

/*
 * __wt_ext_unpack_uint --
 *     WT_EXTENSION.unpack_uint
 */
int
__wt_ext_unpack_uint(WT_EXTENSION_API *wt_api, WT_PACK_STREAM *ps, uint64_t *up)
{
    WT_UNUSED(wt_api);
    return (wiredtiger_unpack_uint(ps, up));
}