/*-
 * Copyright (c) 2014-2020 MongoDB, Inc.
 * Copyright (c) 2008-2014 WiredTiger, Inc.
 *	All rights reserved.
 *
 * See the file LICENSE for redistribution information.
 */

#include "wt_internal.h"

#ifdef HAVE_DIAGNOSTIC
/*
 * We pass around a session handle and output information, group it together.
 */
typedef struct __wt_dbg WT_DBG;
struct __wt_dbg {
    WT_SESSION_IMPL *session; /* Enclosing session */

    /*
     * When using the standard event handlers, the debugging output has to do its own message
     * handling because its output isn't line-oriented.
     */
    FILE *fp;     /* Optional file handle */
    WT_ITEM *msg; /* Buffered message */

    int (*f)(WT_DBG *, const char *, ...) /* Function to write */
      WT_GCC_FUNC_DECL_ATTRIBUTE((format(printf, 2, 3)));

    const char *key_format;
    const char *value_format;

    WT_ITEM *t1, *t2; /* Temporary space */
};

static const /* Output separator */
  char *const sep = "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n";

static int __debug_cell(WT_DBG *, const WT_PAGE_HEADER *, WT_CELL_UNPACK *);
static int __debug_cell_data(WT_DBG *, WT_PAGE *, int, const char *, WT_CELL_UNPACK *);
static int __debug_col_skip(WT_DBG *, WT_INSERT_HEAD *, const char *, bool);
static int __debug_config(WT_SESSION_IMPL *, WT_DBG *, const char *);
static int __debug_dsk_cell(WT_DBG *, const WT_PAGE_HEADER *);
static int __debug_dsk_col_fix(WT_DBG *, const WT_PAGE_HEADER *);
static int __debug_page(WT_DBG *, WT_REF *, uint32_t);
static int __debug_page_col_fix(WT_DBG *, WT_REF *);
static int __debug_page_col_int(WT_DBG *, WT_PAGE *, uint32_t);
static int __debug_page_col_var(WT_DBG *, WT_REF *);
static int __debug_page_metadata(WT_DBG *, WT_REF *);
static int __debug_page_row_int(WT_DBG *, WT_PAGE *, uint32_t);
static int __debug_page_row_leaf(WT_DBG *, WT_PAGE *);
static int __debug_ref(WT_DBG *, WT_REF *);
static int __debug_row_skip(WT_DBG *, WT_INSERT_HEAD *);
static int __debug_tree(WT_SESSION_IMPL *, WT_REF *, const char *, uint32_t);
static int __debug_update(WT_DBG *, WT_UPDATE *, bool);
static int __debug_wrapup(WT_DBG *);

/*
 * __wt_debug_set_verbose --
 *     Set verbose flags from the debugger.
 */
int
__wt_debug_set_verbose(WT_SESSION_IMPL *session, const char *v)
{
    char buf[256];
    const char *cfg[2] = {NULL, NULL};

    WT_RET(__wt_snprintf(buf, sizeof(buf), "verbose=[%s]", v));
    cfg[0] = buf;
    return (__wt_verbose_config(session, cfg));
}

/*
 * __debug_hex_byte --
 *     Output a single byte in hex.
 */
static inline int
__debug_hex_byte(WT_DBG *ds, uint8_t v)
{
    return (ds->f(ds, "#%c%c", __wt_hex((v & 0xf0) >> 4), __wt_hex(v & 0x0f)));
}

/*
 * __debug_bytes --
 *     Dump a single set of bytes.
 */
static int
__debug_bytes(WT_DBG *ds, const void *data_arg, size_t size)
{
    size_t i;
    const uint8_t *data;
    u_char ch;

    for (data = data_arg, i = 0; i < size; ++i, ++data) {
        ch = data[0];
        if (__wt_isprint(ch))
            WT_RET(ds->f(ds, "%c", (int)ch));
        else
            WT_RET(__debug_hex_byte(ds, data[0]));
    }
    return (0);
}

/*
 * __debug_item --
 *     Dump a single data/size item, with an optional tag.
 */
static int
__debug_item(WT_DBG *ds, const char *tag, const void *data_arg, size_t size)
{
    WT_RET(ds->f(ds, "\t%s%s{", tag == NULL ? "" : tag, tag == NULL ? "" : " "));
    WT_RET(__debug_bytes(ds, data_arg, size));
    WT_RET(ds->f(ds, "}\n"));
    return (0);
}

/*
 * __debug_item_key --
 *     Dump a single data/size key item, with an optional tag.
 */
static int
__debug_item_key(WT_DBG *ds, const char *tag, const void *data_arg, size_t size)
{
    WT_SESSION_IMPL *session;

    session = ds->session;

    /*
     * If the format is 'S', it's a string and our version of it may not yet be nul-terminated.
     */
    if (WT_STREQ(ds->key_format, "S") && ((char *)data_arg)[size - 1] != '\0') {
        WT_RET(__wt_buf_fmt(session, ds->t2, "%.*s", (int)size, (char *)data_arg));
        data_arg = ds->t2->data;
        size = ds->t2->size + 1;
    }
    return (ds->f(ds, "\t%s%s{%s}\n", tag == NULL ? "" : tag, tag == NULL ? "" : " ",
      __wt_buf_set_printable_format(session, data_arg, size, ds->key_format, ds->t1)));
}

/*
 * __debug_item_value --
 *     Dump a single data/size value item, with an optional tag.
 */
static int
__debug_item_value(WT_DBG *ds, const char *tag, const void *data_arg, size_t size)
{
    WT_SESSION_IMPL *session;

    session = ds->session;

    if (size == 0)
        return (ds->f(ds, "\t%s%s{}\n", tag == NULL ? "" : tag, tag == NULL ? "" : " "));

    /*
     * If the format is 'S', it's a string and our version of it may not yet be nul-terminated.
     */
    if (WT_STREQ(ds->value_format, "S") && ((char *)data_arg)[size - 1] != '\0') {
        WT_RET(__wt_buf_fmt(session, ds->t2, "%.*s", (int)size, (char *)data_arg));
        data_arg = ds->t2->data;
        size = ds->t2->size + 1;
    }
    return (ds->f(ds, "\t%s%s{%s}\n", tag == NULL ? "" : tag, tag == NULL ? "" : " ",
      __wt_buf_set_printable_format(session, data_arg, size, ds->value_format, ds->t1)));
}

/*
 * __dmsg_event --
 *     Send a debug message to the event handler.
 */
static int
__dmsg_event(WT_DBG *ds, const char *fmt, ...)
{
    WT_DECL_RET;
    WT_ITEM *msg;
    WT_SESSION_IMPL *session;
    size_t len, space;
    char *p;
    va_list ap;

    session = ds->session;

    /*
     * Debug output chunks are not necessarily terminated with a newline character. It's easy if
     * we're dumping to a stream, but if we're dumping to an event handler, which is line-oriented,
     * we must buffer the output chunk, and pass it to the event handler once we see a terminating
     * newline.
     */
    msg = ds->msg;
    for (;;) {
        p = (char *)msg->mem + msg->size;
        space = msg->memsize - msg->size;
        va_start(ap, fmt);
        ret = __wt_vsnprintf_len_set(p, space, &len, fmt, ap);
        va_end(ap);
        WT_RET(ret);

        /* Check if there was enough space. */
        if (len < space) {
            msg->size += len;
            break;
        }

        /*
         * There's not much to do on error without checking for an error return on every single
         * printf. Anyway, it's pretty unlikely and this is debugging output, I'm not going to worry
         * about it.
         */
        WT_RET(__wt_buf_grow(session, msg, msg->memsize + len + 128));
    }
    if (((uint8_t *)msg->mem)[msg->size - 1] == '\n') {
        ((uint8_t *)msg->mem)[msg->size - 1] = '\0';
        WT_RET(__wt_msg(session, "%s", (char *)msg->mem));
        msg->size = 0;
    }

    return (0);
}

/*
 * __dmsg_file --
 *     Send a debug message to a file.
 */
static int
__dmsg_file(WT_DBG *ds, const char *fmt, ...)
{
    WT_DECL_RET;
    va_list ap;

    va_start(ap, fmt);
    ret = vfprintf(ds->fp, fmt, ap) < 0 ? EIO : 0;
    va_end(ap);

    return (ret);
}

/*
 * __debug_config --
 *     Configure debugging output.
 */
static int
__debug_config(WT_SESSION_IMPL *session, WT_DBG *ds, const char *ofile)
{
    WT_BTREE *btree;
    WT_DECL_RET;

    memset(ds, 0, sizeof(WT_DBG));

    ds->session = session;

    WT_ERR(__wt_scr_alloc(session, 512, &ds->t1));
    WT_ERR(__wt_scr_alloc(session, 512, &ds->t2));

    /*
     * If we weren't given a file, we use the default event handler, and we'll have to buffer
     * messages.
     */
    if (ofile == NULL) {
        WT_ERR(__wt_scr_alloc(session, 512, &ds->msg));
        ds->f = __dmsg_event;
    } else {
        if ((ds->fp = fopen(ofile, "w")) == NULL)
            WT_ERR(__wt_set_return(session, EIO));
        __wt_stream_set_line_buffer(ds->fp);
        ds->f = __dmsg_file;
    }

    btree = S2BT(session);
    ds->key_format = btree->key_format;
    ds->value_format = btree->value_format;
    return (0);

err:
    WT_TRET(__debug_wrapup(ds));
    return (ret);
}

/*
 * __debug_wrapup --
 *     Flush any remaining output, release resources.
 */
static int
__debug_wrapup(WT_DBG *ds)
{
    WT_DECL_RET;
    WT_ITEM *msg;
    WT_SESSION_IMPL *session;

    session = ds->session;
    msg = ds->msg;

    __wt_scr_free(session, &ds->t1);
    __wt_scr_free(session, &ds->t2);

    /*
     * Discard the buffer -- it shouldn't have anything in it, but might as well be cautious.
     */
    if (msg != NULL) {
        if (msg->size != 0)
            ret = __wt_msg(session, "%s", (char *)msg->mem);
        __wt_scr_free(session, &ds->msg);
    }

    /* Close any file we opened. */
    if (ds->fp != NULL)
        (void)fclose(ds->fp);

    return (ret);
}

/*
 * __wt_debug_addr_print --
 *     Print out an address.
 */
int
__wt_debug_addr_print(WT_SESSION_IMPL *session, const uint8_t *addr, size_t addr_size)
{
    WT_DECL_ITEM(buf);
    WT_DECL_RET;

    WT_RET(__wt_scr_alloc(session, 128, &buf));
    ret = __wt_fprintf(
      session, WT_STDERR(session), "%s\n", __wt_addr_string(session, addr, addr_size, buf));
    __wt_scr_free(session, &buf);

    return (ret);
}

/*
 * __wt_debug_addr --
 *     Read and dump a disk page in debugging mode, using an addr/size pair.
 */
int
__wt_debug_addr(WT_SESSION_IMPL *session, const uint8_t *addr, size_t addr_size, const char *ofile)
{
    WT_BM *bm;
    WT_DECL_ITEM(buf);
    WT_DECL_RET;

    WT_ASSERT(session, S2BT_SAFE(session) != NULL);

    bm = S2BT(session)->bm;

    WT_RET(__wt_scr_alloc(session, 1024, &buf));
    WT_ERR(bm->read(bm, session, buf, addr, addr_size));
    ret = __wt_debug_disk(session, buf->mem, ofile);

err:
    __wt_scr_free(session, &buf);
    return (ret);
}

/*
 * __wt_debug_offset_blind --
 *     Read and dump a disk page in debugging mode, using a file offset.
 */
int
__wt_debug_offset_blind(WT_SESSION_IMPL *session, wt_off_t offset, const char *ofile)
{
    uint32_t checksum, size;

    WT_ASSERT(session, S2BT_SAFE(session) != NULL);

    /*
     * This routine depends on the default block manager's view of files, where an address consists
     * of a file offset, length, and checksum. This is for debugging only.
     */
    WT_RET(__wt_block_read_off_blind(session, S2BT(session)->bm->block, offset, &size, &checksum));
    return (__wt_debug_offset(session, offset, size, checksum, ofile));
}

/*
 * __wt_debug_offset --
 *     Read and dump a disk page in debugging mode, using a file offset/size/checksum triplet.
 */
int
__wt_debug_offset(
  WT_SESSION_IMPL *session, wt_off_t offset, uint32_t size, uint32_t checksum, const char *ofile)
{
    WT_DECL_ITEM(buf);
    WT_DECL_RET;
    uint8_t addr[WT_BTREE_MAX_ADDR_COOKIE], *endp;

    WT_ASSERT(session, S2BT_SAFE(session) != NULL);

    /*
     * This routine depends on the default block manager's view of files, where an address consists
     * of a file offset, length, and checksum. This is for debugging only: other block managers
     * might not see a file or address the same way, that's why there's no block manager method.
     *
     * Convert the triplet into an address structure.
     */
    endp = addr;
    WT_RET(__wt_block_addr_to_buffer(S2BT(session)->bm->block, &endp, offset, size, checksum));

    /*
     * Read the address through the btree I/O functions (so the block is decompressed as necessary).
     */
    WT_RET(__wt_scr_alloc(session, 0, &buf));
    WT_ERR(__wt_bt_read(session, buf, addr, WT_PTRDIFF(endp, addr)));
    ret = __wt_debug_disk(session, buf->mem, ofile);

err:
    __wt_scr_free(session, &buf);
    return (ret);
}

/*
 * __wt_debug_disk --
 *     Dump a disk page in debugging mode.
 */
int
__wt_debug_disk(WT_SESSION_IMPL *session, const WT_PAGE_HEADER *dsk, const char *ofile)
{
    WT_DBG *ds, _ds;
    WT_DECL_RET;

    ds = &_ds;
    WT_RET(__debug_config(session, ds, ofile));

    WT_ERR(ds->f(ds, "%s page", __wt_page_type_string(dsk->type)));
    switch (dsk->type) {
    case WT_PAGE_BLOCK_MANAGER:
        break;
    case WT_PAGE_COL_FIX:
    case WT_PAGE_COL_INT:
    case WT_PAGE_COL_VAR:
        WT_ERR(ds->f(ds, ", recno %" PRIu64, dsk->recno));
    /* FALLTHROUGH */
    case WT_PAGE_ROW_INT:
    case WT_PAGE_ROW_LEAF:
        WT_ERR(ds->f(ds, ", entries %" PRIu32, dsk->u.entries));
        break;
    case WT_PAGE_OVFL:
        WT_ERR(ds->f(ds, ", datalen %" PRIu32, dsk->u.datalen));
        break;
    default:
        WT_ERR(__wt_illegal_value(session, dsk->type));
    }

    if (F_ISSET(dsk, WT_PAGE_COMPRESSED))
        WT_ERR(ds->f(ds, ", compressed"));
    if (F_ISSET(dsk, WT_PAGE_ENCRYPTED))
        WT_ERR(ds->f(ds, ", encrypted"));
    if (F_ISSET(dsk, WT_PAGE_EMPTY_V_ALL))
        WT_ERR(ds->f(ds, ", empty-all"));
    if (F_ISSET(dsk, WT_PAGE_EMPTY_V_NONE))
        WT_ERR(ds->f(ds, ", empty-none"));
    if (F_ISSET(dsk, WT_PAGE_LAS_UPDATE))
        WT_ERR(ds->f(ds, ", LAS-update"));

    WT_ERR(ds->f(ds, ", generation %" PRIu64 "\n", dsk->write_gen));

    switch (dsk->type) {
    case WT_PAGE_BLOCK_MANAGER:
        break;
    case WT_PAGE_COL_FIX:
        WT_ERR(__debug_dsk_col_fix(ds, dsk));
        break;
    case WT_PAGE_COL_INT:
    case WT_PAGE_COL_VAR:
    case WT_PAGE_ROW_INT:
    case WT_PAGE_ROW_LEAF:
        WT_ERR(__debug_dsk_cell(ds, dsk));
        break;
    default:
        break;
    }

err:
    WT_TRET(__debug_wrapup(ds));
    return (ret);
}

/*
 * __debug_dsk_col_fix --
 *     Dump a WT_PAGE_COL_FIX page.
 */
static int
__debug_dsk_col_fix(WT_DBG *ds, const WT_PAGE_HEADER *dsk)
{
    WT_BTREE *btree;
    uint32_t i;
    uint8_t v;

    WT_ASSERT(ds->session, S2BT_SAFE(ds->session) != NULL);

    btree = S2BT(ds->session);

    WT_FIX_FOREACH (btree, dsk, v, i) {
        WT_RET(ds->f(ds, "\t{"));
        WT_RET(__debug_hex_byte(ds, v));
        WT_RET(ds->f(ds, "}\n"));
    }
    return (0);
}

/*
 * __debug_dsk_cell --
 *     Dump a page of WT_CELL's.
 */
static int
__debug_dsk_cell(WT_DBG *ds, const WT_PAGE_HEADER *dsk)
{
    WT_BTREE *btree;
    WT_CELL_UNPACK unpack;

    WT_ASSERT(ds->session, S2BT_SAFE(ds->session) != NULL);

    btree = S2BT(ds->session);

    WT_CELL_FOREACH_BEGIN (ds->session, btree, dsk, unpack) {
        WT_RET(__debug_cell(ds, dsk, &unpack));
    }
    WT_CELL_FOREACH_END;
    return (0);
}

/*
 * __debug_tree_shape_info --
 *     Pretty-print information about a page.
 */
static char *
__debug_tree_shape_info(WT_REF *ref, char *buf, size_t len)
{
    WT_PAGE *page;
    uint64_t v;
    const char *unit;

    page = ref->page;
    v = page->memory_footprint;

    if (v > WT_GIGABYTE) {
        v /= WT_GIGABYTE;
        unit = "G";
    } else if (v > WT_MEGABYTE) {
        v /= WT_MEGABYTE;
        unit = "M";
    } else if (v > WT_KILOBYTE) {
        v /= WT_KILOBYTE;
        unit = "K";
    } else {
        unit = "B";
    }

    WT_IGNORE_RET(
      __wt_snprintf(buf, len, "(%p, %" PRIu64 "%s, evict gen %" PRIu64 ", create gen %" PRIu64 ")",
        (void *)ref, v, unit, page->evict_pass_gen, page->cache_create_gen));
    return (buf);
}

/*
 * __debug_tree_shape_worker --
 *     Dump information about the current page and descend.
 */
static int
__debug_tree_shape_worker(WT_DBG *ds, WT_REF *ref, int level)
{
    WT_REF *walk;
    WT_SESSION_IMPL *session;
    char buf[128];

    session = ds->session;

    if (WT_PAGE_IS_INTERNAL(ref->page)) {
        WT_RET(ds->f(ds,
          "%*s"
          "I"
          "%d %s\n",
          level * 3, " ", level, __debug_tree_shape_info(ref, buf, sizeof(buf))));
        WT_INTL_FOREACH_BEGIN (session, ref->page, walk) {
            if (walk->state == WT_REF_MEM)
                WT_RET(__debug_tree_shape_worker(ds, walk, level + 1));
        }
        WT_INTL_FOREACH_END;
    } else
        WT_RET(ds->f(ds,
          "%*s"
          "L"
          " %s\n",
          level * 3, " ", __debug_tree_shape_info(ref, buf, sizeof(buf))));
    return (0);
}

/*
 * __wt_debug_tree_shape --
 *     Dump the shape of the in-memory tree.
 */
int
__wt_debug_tree_shape(WT_SESSION_IMPL *session, WT_REF *ref, const char *ofile)
{
    WT_DBG *ds, _ds;
    WT_DECL_RET;

    WT_ASSERT(session, S2BT_SAFE(session) != NULL);

    ds = &_ds;
    WT_RET(__debug_config(session, ds, ofile));

    /* A NULL WT_REF starts at the top of the tree -- it's a convenience. */
    if (ref == NULL)
        ref = &S2BT(session)->root;

    WT_WITH_PAGE_INDEX(session, ret = __debug_tree_shape_worker(ds, ref, 1));

    WT_TRET(__debug_wrapup(ds));
    return (ret);
}

/* AUTOMATIC FLAG VALUE GENERATION START */
#define WT_DEBUG_TREE_LEAF 0x1u /* Debug leaf pages */
#define WT_DEBUG_TREE_WALK 0x2u /* Descend the tree */
                                /* AUTOMATIC FLAG VALUE GENERATION STOP */

/*
 * __wt_debug_tree_all --
 *     Dump the in-memory information for a tree, including leaf pages.
 */
int
__wt_debug_tree_all(void *session_arg, WT_BTREE *btree, WT_REF *ref, const char *ofile)
{
    WT_DECL_RET;
    WT_SESSION_IMPL *session;

    /*
     * Allow an explicit btree as an argument, as one may not yet be set on the session.
     */
    session = (WT_SESSION_IMPL *)session_arg;
    if (btree == NULL)
        btree = S2BT(session);

    WT_WITH_BTREE(session, btree,
      ret = __debug_tree(session, ref, ofile, WT_DEBUG_TREE_LEAF | WT_DEBUG_TREE_WALK));
    return (ret);
}

/*
 * __wt_debug_tree --
 *     Dump the in-memory information for a tree, not including leaf pages.
 */
int
__wt_debug_tree(void *session_arg, WT_BTREE *btree, WT_REF *ref, const char *ofile)
{
    WT_DECL_RET;
    WT_SESSION_IMPL *session;

    /*
     * Allow an explicit btree as an argument, as one may not yet be set on the session.
     */
    session = (WT_SESSION_IMPL *)session_arg;
    if (btree == NULL)
        btree = S2BT(session);

    WT_WITH_BTREE(session, btree, ret = __debug_tree(session, ref, ofile, WT_DEBUG_TREE_WALK));
    return (ret);
}

/*
 * __wt_debug_page --
 *     Dump the in-memory information for a page.
 */
int
__wt_debug_page(void *session_arg, WT_BTREE *btree, WT_REF *ref, const char *ofile)
{
    WT_DBG *ds, _ds;
    WT_DECL_RET;
    WT_SESSION_IMPL *session;

    /*
     * Allow an explicit btree as an argument, as one may not yet be set on the session.
     */
    session = (WT_SESSION_IMPL *)session_arg;
    if (btree == NULL)
        btree = S2BT(session);

    ds = &_ds;
    WT_WITH_BTREE(session, btree, ret = __debug_config(session, ds, ofile));
    WT_RET(ret);

    WT_WITH_BTREE(session, btree, ret = __debug_page(ds, ref, WT_DEBUG_TREE_LEAF));

    WT_TRET(__debug_wrapup(ds));
    return (ret);
}

/*
 * __wt_debug_cursor_page --
 *     Dump the in-memory information for a cursor-referenced page.
 */
int
__wt_debug_cursor_page(void *cursor_arg, const char *ofile)
  WT_GCC_FUNC_ATTRIBUTE((visibility("default")))
{
    WT_CURSOR *cursor;
    WT_CURSOR_BTREE *cbt;

    cursor = cursor_arg;
    cbt = cursor_arg;
    return (__wt_debug_page(cursor->session, cbt->btree, cbt->ref, ofile));
}

/*
 * __wt_debug_cursor_las --
 *     Dump the LAS tree given a user cursor.
 */
int
__wt_debug_cursor_las(void *cursor_arg, const char *ofile)
  WT_GCC_FUNC_ATTRIBUTE((visibility("default")))
{
    WT_CONNECTION_IMPL *conn;
    WT_CURSOR *cursor;
    WT_CURSOR_BTREE *cbt;
    WT_SESSION_IMPL *las_session;

    cursor = cursor_arg;
    conn = S2C((WT_SESSION_IMPL *)cursor->session);
    las_session = conn->cache->las_session[0];
    if (las_session == NULL)
        return (0);
    cbt = (WT_CURSOR_BTREE *)las_session->las_cursor;
    return (__wt_debug_tree_all(las_session, cbt->btree, NULL, ofile));
}

/*
 * __debug_tree --
 *     Dump the in-memory information for a tree.
 */
static int
__debug_tree(WT_SESSION_IMPL *session, WT_REF *ref, const char *ofile, uint32_t flags)
{
    WT_DBG *ds, _ds;
    WT_DECL_RET;

    ds = &_ds;
    WT_RET(__debug_config(session, ds, ofile));

    /* A NULL page starts at the top of the tree -- it's a convenience. */
    if (ref == NULL)
        ref = &S2BT(session)->root;

    ret = __debug_page(ds, ref, flags);

    WT_TRET(__debug_wrapup(ds));
    return (ret);
}

/*
 * __debug_page --
 *     Dump the in-memory information for an in-memory page.
 */
static int
__debug_page(WT_DBG *ds, WT_REF *ref, uint32_t flags)
{
    WT_DECL_RET;
    WT_SESSION_IMPL *session;

    session = ds->session;

    /* Dump the page metadata. */
    WT_WITH_PAGE_INDEX(session, ret = __debug_page_metadata(ds, ref));
    WT_RET(ret);

    /* Dump the page. */
    switch (ref->page->type) {
    case WT_PAGE_COL_FIX:
        if (LF_ISSET(WT_DEBUG_TREE_LEAF))
            WT_RET(__debug_page_col_fix(ds, ref));
        break;
    case WT_PAGE_COL_INT:
        WT_WITH_PAGE_INDEX(session, ret = __debug_page_col_int(ds, ref->page, flags));
        WT_RET(ret);
        break;
    case WT_PAGE_COL_VAR:
        if (LF_ISSET(WT_DEBUG_TREE_LEAF))
            WT_RET(__debug_page_col_var(ds, ref));
        break;
    case WT_PAGE_ROW_INT:
        WT_WITH_PAGE_INDEX(session, ret = __debug_page_row_int(ds, ref->page, flags));
        WT_RET(ret);
        break;
    case WT_PAGE_ROW_LEAF:
        if (LF_ISSET(WT_DEBUG_TREE_LEAF))
            WT_RET(__debug_page_row_leaf(ds, ref->page));
        break;
    default:
        return (__wt_illegal_value(session, ref->page->type));
    }

    return (0);
}

/*
 * __debug_page_metadata --
 *     Dump an in-memory page's metadata.
 */
static int
__debug_page_metadata(WT_DBG *ds, WT_REF *ref)
{
    WT_PAGE *page;
    WT_PAGE_INDEX *pindex;
    WT_PAGE_MODIFY *mod;
    WT_SESSION_IMPL *session;
    uint64_t split_gen;
    uint32_t entries;

    session = ds->session;
    page = ref->page;
    mod = page->modify;
    split_gen = 0;

    WT_RET(ds->f(ds, "%p", (void *)ref));

    switch (page->type) {
    case WT_PAGE_COL_INT:
        WT_RET(ds->f(ds, " recno %" PRIu64, ref->ref_recno));
        WT_INTL_INDEX_GET(session, page, pindex);
        entries = pindex->entries;
        split_gen = page->pg_intl_split_gen;
        break;
    case WT_PAGE_COL_FIX:
        WT_RET(ds->f(ds, " recno %" PRIu64, ref->ref_recno));
        entries = page->entries;
        break;
    case WT_PAGE_COL_VAR:
        WT_RET(ds->f(ds, " recno %" PRIu64, ref->ref_recno));
        entries = page->entries;
        break;
    case WT_PAGE_ROW_INT:
        WT_INTL_INDEX_GET(session, page, pindex);
        entries = pindex->entries;
        split_gen = page->pg_intl_split_gen;
        break;
    case WT_PAGE_ROW_LEAF:
        entries = page->entries;
        break;
    default:
        return (__wt_illegal_value(session, page->type));
    }

    WT_RET(ds->f(ds, ": %s\n", __wt_page_type_string(page->type)));
    WT_RET(ds->f(ds,
      "\t"
      "disk %p",
      (void *)page->dsk));
    if (page->dsk != NULL)
        WT_RET(ds->f(ds, ", dsk_mem_size %" PRIu32, page->dsk->mem_size));
    WT_RET(ds->f(ds, ", entries %" PRIu32, entries));
    WT_RET(ds->f(ds, ", %s", __wt_page_is_modified(page) ? "dirty" : "clean"));

    if (F_ISSET_ATOMIC(page, WT_PAGE_BUILD_KEYS))
        WT_RET(ds->f(ds, ", keys-built"));
    if (F_ISSET_ATOMIC(page, WT_PAGE_DISK_ALLOC))
        WT_RET(ds->f(ds, ", disk-alloc"));
    if (F_ISSET_ATOMIC(page, WT_PAGE_DISK_MAPPED))
        WT_RET(ds->f(ds, ", disk-mapped"));
    if (F_ISSET_ATOMIC(page, WT_PAGE_EVICT_LRU))
        WT_RET(ds->f(ds, ", evict-lru"));
    if (F_ISSET_ATOMIC(page, WT_PAGE_OVERFLOW_KEYS))
        WT_RET(ds->f(ds, ", overflow-keys"));
    if (F_ISSET_ATOMIC(page, WT_PAGE_SPLIT_INSERT))
        WT_RET(ds->f(ds, ", split-insert"));
    if (F_ISSET_ATOMIC(page, WT_PAGE_UPDATE_IGNORE))
        WT_RET(ds->f(ds, ", update-ignore"));

    if (mod != NULL)
        switch (mod->rec_result) {
        case WT_PM_REC_EMPTY:
            WT_RET(ds->f(ds, ", empty"));
            break;
        case WT_PM_REC_MULTIBLOCK:
            WT_RET(ds->f(ds, ", multiblock"));
            break;
        case WT_PM_REC_REPLACE:
            WT_RET(ds->f(ds, ", replaced"));
            break;
        case 0:
            break;
        default:
            return (__wt_illegal_value(session, mod->rec_result));
        }
    if (split_gen != 0)
        WT_RET(ds->f(ds, ", split-gen=%" PRIu64, split_gen));
    if (mod != NULL)
        WT_RET(ds->f(ds, ", page-state=%" PRIu32, mod->page_state));
    WT_RET(ds->f(ds, ", memory-size %" WT_SIZET_FMT, page->memory_footprint));
    WT_RET(ds->f(ds, "\n"));

    return (0);
}

/*
 * __debug_page_col_fix --
 *     Dump an in-memory WT_PAGE_COL_FIX page.
 */
static int
__debug_page_col_fix(WT_DBG *ds, WT_REF *ref)
{
    WT_BTREE *btree;
    WT_INSERT *ins;
    WT_PAGE *page;
    const WT_PAGE_HEADER *dsk;
    WT_SESSION_IMPL *session;
    uint64_t recno;
    uint32_t i;
    uint8_t v;

    WT_ASSERT(ds->session, S2BT_SAFE(ds->session) != NULL);

    session = ds->session;
    btree = S2BT(session);
    page = ref->page;
    dsk = page->dsk;
    recno = ref->ref_recno;

    if (dsk != NULL) {
        ins = WT_SKIP_FIRST(WT_COL_UPDATE_SINGLE(page));
        WT_FIX_FOREACH (btree, dsk, v, i) {
            WT_RET(ds->f(ds, "\t%" PRIu64 "\t{", recno));
            WT_RET(__debug_hex_byte(ds, v));
            WT_RET(ds->f(ds, "}\n"));

            /* Check for a match on the update list. */
            if (ins != NULL && WT_INSERT_RECNO(ins) == recno) {
                WT_RET(ds->f(ds, "\tupdate %" PRIu64 "\n", WT_INSERT_RECNO(ins)));
                WT_RET(__debug_update(ds, ins->upd, true));
                ins = WT_SKIP_NEXT(ins);
            }
            ++recno;
        }
    }

    if (WT_COL_UPDATE_SINGLE(page) != NULL) {
        WT_RET(ds->f(ds, "%s", sep));
        WT_RET(__debug_col_skip(ds, WT_COL_UPDATE_SINGLE(page), "update", true));
    }
    if (WT_COL_APPEND(page) != NULL) {
        WT_RET(ds->f(ds, "%s", sep));
        WT_RET(__debug_col_skip(ds, WT_COL_APPEND(page), "append", true));
    }
    return (0);
}

/*
 * __debug_page_col_int --
 *     Dump an in-memory WT_PAGE_COL_INT page.
 */
static int
__debug_page_col_int(WT_DBG *ds, WT_PAGE *page, uint32_t flags)
{
    WT_REF *ref;
    WT_SESSION_IMPL *session;

    session = ds->session;

    WT_INTL_FOREACH_BEGIN (session, page, ref) {
        WT_RET(ds->f(ds, "\trecno %" PRIu64 "\n", ref->ref_recno));
        WT_RET(__debug_ref(ds, ref));
    }
    WT_INTL_FOREACH_END;

    if (LF_ISSET(WT_DEBUG_TREE_WALK)) {
        WT_INTL_FOREACH_BEGIN (session, page, ref) {
            if (ref->state == WT_REF_MEM) {
                WT_RET(ds->f(ds, "\n"));
                WT_RET(__debug_page(ds, ref, flags));
            }
        }
        WT_INTL_FOREACH_END;
    }

    return (0);
}

/*
 * __debug_page_col_var --
 *     Dump an in-memory WT_PAGE_COL_VAR page.
 */
static int
__debug_page_col_var(WT_DBG *ds, WT_REF *ref)
{
    WT_CELL *cell;
    WT_CELL_UNPACK *unpack, _unpack;
    WT_COL *cip;
    WT_INSERT_HEAD *update;
    WT_PAGE *page;
    uint64_t recno, rle;
    uint32_t i;
    char tag[64];

    unpack = &_unpack;
    page = ref->page;
    recno = ref->ref_recno;

    WT_COL_FOREACH (page, cip, i) {
        cell = WT_COL_PTR(page, cip);
        __wt_cell_unpack(ds->session, page, cell, unpack);
        rle = __wt_cell_rle(unpack);
        WT_RET(__wt_snprintf(tag, sizeof(tag), "%" PRIu64 " %" PRIu64, recno, rle));
        WT_RET(__debug_cell_data(ds, page, WT_PAGE_COL_VAR, tag, unpack));

        if ((update = WT_COL_UPDATE(page, cip)) != NULL)
            WT_RET(__debug_col_skip(ds, update, "update", false));
        recno += rle;
    }

    if (WT_COL_APPEND(page) != NULL) {
        WT_RET(ds->f(ds, "%s", sep));
        WT_RET(__debug_col_skip(ds, WT_COL_APPEND(page), "append", false));
    }

    return (0);
}

/*
 * __debug_page_row_int --
 *     Dump an in-memory WT_PAGE_ROW_INT page.
 */
static int
__debug_page_row_int(WT_DBG *ds, WT_PAGE *page, uint32_t flags)
{
    WT_REF *ref;
    WT_SESSION_IMPL *session;
    size_t len;
    void *p;

    session = ds->session;

    WT_INTL_FOREACH_BEGIN (session, page, ref) {
        __wt_ref_key(page, ref, &p, &len);
        WT_RET(__debug_item_key(ds, "K", p, len));
        WT_RET(__debug_ref(ds, ref));
    }
    WT_INTL_FOREACH_END;

    if (LF_ISSET(WT_DEBUG_TREE_WALK)) {
        WT_INTL_FOREACH_BEGIN (session, page, ref) {
            if (ref->state == WT_REF_MEM) {
                WT_RET(ds->f(ds, "\n"));
                WT_RET(__debug_page(ds, ref, flags));
            }
        }
        WT_INTL_FOREACH_END;
    }
    return (0);
}

/*
 * __debug_page_row_leaf --
 *     Dump an in-memory WT_PAGE_ROW_LEAF page.
 */
static int
__debug_page_row_leaf(WT_DBG *ds, WT_PAGE *page)
{
    WT_CELL_UNPACK *unpack, _unpack;
    WT_DECL_ITEM(key);
    WT_DECL_RET;
    WT_INSERT_HEAD *insert;
    WT_ROW *rip;
    WT_SESSION_IMPL *session;
    WT_UPDATE *upd;
    uint32_t i;

    session = ds->session;
    unpack = &_unpack;
    WT_RET(__wt_scr_alloc(session, 256, &key));

    /*
     * Dump any K/V pairs inserted into the page before the first from-disk key on the page.
     */
    if ((insert = WT_ROW_INSERT_SMALLEST(page)) != NULL)
        WT_ERR(__debug_row_skip(ds, insert));

    /* Dump the page's K/V pairs. */
    WT_ROW_FOREACH (page, rip, i) {
        WT_ERR(__wt_row_leaf_key(session, page, rip, key, false));
        WT_ERR(__debug_item_key(ds, "K", key->data, key->size));

        __wt_row_leaf_value_cell(session, page, rip, NULL, unpack);
        WT_ERR(__debug_cell_data(ds, page, WT_PAGE_ROW_LEAF, "V", unpack));

        if ((upd = WT_ROW_UPDATE(page, rip)) != NULL)
            WT_ERR(__debug_update(ds, upd, false));

        if ((insert = WT_ROW_INSERT(page, rip)) != NULL)
            WT_ERR(__debug_row_skip(ds, insert));
    }

err:
    __wt_scr_free(session, &key);
    return (ret);
}

/*
 * __debug_col_skip --
 *     Dump a column-store skiplist.
 */
static int
__debug_col_skip(WT_DBG *ds, WT_INSERT_HEAD *head, const char *tag, bool hexbyte)
{
    WT_INSERT *ins;

    WT_SKIP_FOREACH (ins, head) {
        WT_RET(ds->f(ds, "\t%s %" PRIu64 "\n", tag, WT_INSERT_RECNO(ins)));
        WT_RET(__debug_update(ds, ins->upd, hexbyte));
    }
    return (0);
}

/*
 * __debug_row_skip --
 *     Dump an insert list.
 */
static int
__debug_row_skip(WT_DBG *ds, WT_INSERT_HEAD *head)
{
    WT_INSERT *ins;

    WT_SKIP_FOREACH (ins, head) {
        WT_RET(__debug_item_key(ds, "insert", WT_INSERT_KEY(ins), WT_INSERT_KEY_SIZE(ins)));
        WT_RET(__debug_update(ds, ins->upd, false));
    }
    return (0);
}

/*
 * __debug_modify --
 *     Dump a modify update.
 */
static int
__debug_modify(WT_DBG *ds, WT_UPDATE *upd)
{
    size_t nentries, data_size, offset, size;
    const size_t *p;
    const uint8_t *data;

    p = (size_t *)upd->data;
    memcpy(&nentries, p++, sizeof(size_t));
    data = upd->data + sizeof(size_t) + (nentries * 3 * sizeof(size_t));

    WT_RET(ds->f(ds, "%" WT_SIZET_FMT ": ", nentries));
    for (; nentries-- > 0; data += data_size) {
        memcpy(&data_size, p++, sizeof(size_t));
        memcpy(&offset, p++, sizeof(size_t));
        memcpy(&size, p++, sizeof(size_t));
        WT_RET(ds->f(ds, "{%" WT_SIZET_FMT ", %" WT_SIZET_FMT ", %" WT_SIZET_FMT ", ", data_size,
          offset, size));
        WT_RET(__debug_bytes(ds, data, data_size));
        WT_RET(ds->f(ds, "}%s", nentries == 0 ? "" : ", "));
    }

    return (0);
}

/*
 * __debug_update --
 *     Dump an update list.
 */
static int
__debug_update(WT_DBG *ds, WT_UPDATE *upd, bool hexbyte)
{
    char ts_string[WT_TS_INT_STRING_SIZE];
    const char *prepare_state;

    for (; upd != NULL; upd = upd->next) {
        switch (upd->type) {
        case WT_UPDATE_INVALID:
            WT_RET(ds->f(ds, "\tvalue {invalid}\n"));
            break;
        case WT_UPDATE_BIRTHMARK:
            WT_RET(ds->f(ds, "\tvalue {birthmark}\n"));
            break;
        case WT_UPDATE_MODIFY:
            WT_RET(ds->f(ds, "\tvalue {modify: "));
            WT_RET(__debug_modify(ds, upd));
            WT_RET(ds->f(ds, "}\n"));
            break;
        case WT_UPDATE_RESERVE:
            WT_RET(ds->f(ds, "\tvalue {reserve}\n"));
            break;
        case WT_UPDATE_STANDARD:
            if (hexbyte) {
                WT_RET(ds->f(ds, "\t{"));
                WT_RET(__debug_hex_byte(ds, *upd->data));
                WT_RET(ds->f(ds, "}\n"));
            } else
                WT_RET(__debug_item_value(ds, "value", upd->data, upd->size));
            break;
        case WT_UPDATE_TOMBSTONE:
            WT_RET(ds->f(ds, "\tvalue {tombstone}\n"));
            break;
        }

        if (upd->txnid == WT_TXN_ABORTED)
            WT_RET(ds->f(ds,
              "\t"
              "txn id aborted"));
        else
            WT_RET(ds->f(ds,
              "\t"
              "txn id %" PRIu64,
              upd->txnid));

        WT_RET(ds->f(ds, ", start_ts %s", __wt_timestamp_to_string(upd->start_ts, ts_string)));
        if (upd->durable_ts != WT_TS_NONE)
            WT_RET(
              ds->f(ds, ", durable_ts %s", __wt_timestamp_to_string(upd->durable_ts, ts_string)));

        prepare_state = NULL;
        switch (upd->prepare_state) {
        case WT_PREPARE_INIT:
            break;
        case WT_PREPARE_INPROGRESS:
            prepare_state = "in-progress";
            break;
        case WT_PREPARE_LOCKED:
            prepare_state = "locked";
            break;
        case WT_PREPARE_RESOLVED:
            prepare_state = "resolved";
            break;
        }
        if (prepare_state != NULL)
            WT_RET(ds->f(ds, ", prepare %s", prepare_state));

        WT_RET(ds->f(ds, "\n"));
    }
    return (0);
}

/*
 * __debug_ref --
 *     Dump a WT_REF structure.
 */
static int
__debug_ref(WT_DBG *ds, WT_REF *ref)
{
    WT_SESSION_IMPL *session;
    size_t addr_size;
    const uint8_t *addr;
    const char *state;

    session = ds->session;

    switch (ref->state) {
    case WT_REF_DISK:
        state = "disk";
        break;
    case WT_REF_DELETED:
        state = "deleted";
        break;
    case WT_REF_LOCKED:
        state = "locked";
        break;
    case WT_REF_LOOKASIDE:
        state = "lookaside";
        break;
    case WT_REF_MEM:
        state = "memory";
        break;
    case WT_REF_READING:
        state = "reading";
        break;
    case WT_REF_SPLIT:
        state = "split";
        break;
    default:
        state = "INVALID";
        break;
    }

    __wt_ref_info(session, ref, &addr, &addr_size, NULL);
    return (ds->f(ds,
      "\t"
      "%p %s %s\n",
      (void *)ref, state, __wt_addr_string(session, addr, addr_size, ds->t1)));
}

/*
 * __debug_cell --
 *     Dump a single unpacked WT_CELL.
 */
static int
__debug_cell(WT_DBG *ds, const WT_PAGE_HEADER *dsk, WT_CELL_UNPACK *unpack)
{
    WT_DECL_ITEM(buf);
    WT_DECL_RET;
    WT_SESSION_IMPL *session;
    char ts_string[3][WT_TS_INT_STRING_SIZE];

    session = ds->session;

    WT_RET(ds->f(ds, "\t%s: len %" PRIu32, __wt_cell_type_string(unpack->raw), unpack->size));

    /* Dump cell's per-disk page type information. */
    switch (dsk->type) {
    case WT_PAGE_COL_INT:
        switch (unpack->type) {
        case WT_CELL_VALUE:
            WT_RET(ds->f(ds, ", recno: %" PRIu64, unpack->v));
            break;
        }
        break;
    case WT_PAGE_COL_VAR:
        switch (unpack->type) {
        case WT_CELL_DEL:
        case WT_CELL_KEY_OVFL_RM:
        case WT_CELL_VALUE:
        case WT_CELL_VALUE_OVFL:
        case WT_CELL_VALUE_OVFL_RM:
            WT_RET(ds->f(ds, ", rle: %" PRIu64, __wt_cell_rle(unpack)));
            break;
        }
        break;
    case WT_PAGE_ROW_INT:
    case WT_PAGE_ROW_LEAF:
        switch (unpack->type) {
        case WT_CELL_KEY:
            WT_RET(ds->f(ds, ", pfx: %" PRIu8, unpack->prefix));
            break;
        }
        break;
    }

    /* Dump timestamps. */
    switch (unpack->raw) {
    case WT_CELL_ADDR_DEL:
    case WT_CELL_ADDR_INT:
    case WT_CELL_ADDR_LEAF:
    case WT_CELL_ADDR_LEAF_NO:
        WT_RET(ds->f(ds, ", ts/txn %s,%s/%" PRIu64 ",%s/%" PRIu64,
          __wt_timestamp_to_string(unpack->newest_durable_ts, ts_string[0]),
          __wt_timestamp_to_string(unpack->oldest_start_ts, ts_string[1]), unpack->oldest_start_txn,
          __wt_timestamp_to_string(unpack->newest_stop_ts, ts_string[2]), unpack->newest_stop_txn));
        break;
    case WT_CELL_DEL:
    case WT_CELL_VALUE:
    case WT_CELL_VALUE_COPY:
    case WT_CELL_VALUE_OVFL:
    case WT_CELL_VALUE_OVFL_RM:
    case WT_CELL_VALUE_SHORT:
        WT_RET(ds->f(ds, ", ts/txn %s/%" PRIu64 ",%s/%" PRIu64,
          __wt_timestamp_to_string(unpack->start_ts, ts_string[0]), unpack->start_txn,
          __wt_timestamp_to_string(unpack->stop_ts, ts_string[1]), unpack->stop_txn));
        break;
    }

    /* Dump addresses. */
    switch (unpack->raw) {
    case WT_CELL_ADDR_DEL:
    case WT_CELL_ADDR_INT:
    case WT_CELL_ADDR_LEAF:
    case WT_CELL_ADDR_LEAF_NO:
    case WT_CELL_KEY_OVFL:
    case WT_CELL_KEY_OVFL_RM:
    case WT_CELL_VALUE_OVFL:
    case WT_CELL_VALUE_OVFL_RM:
        WT_RET(__wt_scr_alloc(session, 128, &buf));
        ret = ds->f(ds, ", %s", __wt_addr_string(session, unpack->data, unpack->size, buf));
        __wt_scr_free(session, &buf);
        WT_RET(ret);
        break;
    }
    WT_RET(ds->f(ds, "\n"));

    return (__debug_cell_data(ds, NULL, dsk->type, NULL, unpack));
}

/*
 * __debug_cell_data --
 *     Dump a single cell's data in debugging mode.
 */
static int
__debug_cell_data(WT_DBG *ds, WT_PAGE *page, int page_type, const char *tag, WT_CELL_UNPACK *unpack)
{
    WT_DECL_ITEM(buf);
    WT_DECL_RET;
    WT_SESSION_IMPL *session;
    const char *p;

    session = ds->session;

    /*
     * Column-store references to deleted cells return a NULL cell reference.
     */
    if (unpack == NULL)
        return (__debug_item(ds, tag, "deleted", strlen("deleted")));

    /*
     * Row-store references to empty cells return a NULL on-page reference.
     */
    if (unpack->cell == NULL)
        return (__debug_item(ds, tag, "", 0));

    switch (unpack->raw) {
    case WT_CELL_ADDR_DEL:
    case WT_CELL_ADDR_INT:
    case WT_CELL_ADDR_LEAF:
    case WT_CELL_ADDR_LEAF_NO:
    case WT_CELL_DEL:
    case WT_CELL_KEY_OVFL_RM:
    case WT_CELL_VALUE_OVFL_RM:
        p = __wt_cell_type_string(unpack->raw);
        return (__debug_item(ds, tag, p, strlen(p)));
    }

    WT_RET(__wt_scr_alloc(session, 256, &buf));
    WT_ERR(page == NULL ? __wt_dsk_cell_data_ref(session, page_type, unpack, buf) :
                          __wt_page_cell_data_ref(session, page, unpack, buf));

    switch (unpack->raw) {
    case WT_CELL_KEY:
    case WT_CELL_KEY_OVFL:
    case WT_CELL_KEY_PFX:
    case WT_CELL_KEY_SHORT:
    case WT_CELL_KEY_SHORT_PFX:
        WT_ERR(__debug_item_key(ds, tag, buf->data, buf->size));
        break;
    case WT_CELL_VALUE:
    case WT_CELL_VALUE_COPY:
    case WT_CELL_VALUE_OVFL:
    case WT_CELL_VALUE_SHORT:
        WT_ERR(__debug_item_value(ds, tag, buf->data, buf->size));
        break;
    default:
        WT_ERR(__wt_illegal_value(session, unpack->raw));
    }

err:
    __wt_scr_free(session, &buf);
    return (ret);
}
#endif