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

#include "wt_internal.h"

/*
 * __config_err --
 *     Error message and return for config string parse failures.
 */
static int
__config_err(WT_CONFIG *conf, const char *msg, int err)
{
    WT_RET_MSG(conf->session, err, "Error parsing '%.*s' at offset %" WT_PTRDIFFT_FMT ": %s",
      (int)(conf->end - conf->orig), conf->orig, conf->cur - conf->orig, msg);
}

/*
 * __wt_config_initn --
 *     Initialize a config handle, used to iterate through a config string of specified length.
 */
void
__wt_config_initn(WT_SESSION_IMPL *session, WT_CONFIG *conf, const char *str, size_t len)
{
    conf->session = session;
    conf->orig = conf->cur = str;
    if ((conf->end = str) != NULL)
        conf->end += len;
    conf->depth = 0;
    conf->top = -1;
    conf->go = NULL;
}

/*
 * __wt_config_init --
 *     Initialize a config handle, used to iterate through a NUL-terminated config string.
 */
void
__wt_config_init(WT_SESSION_IMPL *session, WT_CONFIG *conf, const char *str)
{
    size_t len;

    len = (str == NULL) ? 0 : strlen(str);

    __wt_config_initn(session, conf, str, len);
}

/*
 * __wt_config_subinit --
 *     Initialize a config handle, used to iterate through a config string extracted from another
 *     config string (used for parsing nested structures).
 */
void
__wt_config_subinit(WT_SESSION_IMPL *session, WT_CONFIG *conf, WT_CONFIG_ITEM *item)
{
    __wt_config_initn(session, conf, item->str, item->len);
}

#define PUSH(i, t)                                                                           \
    do {                                                                                     \
        if (conf->top == -1)                                                                 \
            conf->top = conf->depth;                                                         \
        if (conf->depth == conf->top) {                                                      \
            if (out->len > 0)                                                                \
                return (__config_err(conf, "New value starts without a separator", EINVAL)); \
            out->type = (t);                                                                 \
            out->str = (conf->cur + (i));                                                    \
        }                                                                                    \
    } while (0)

#define CAP(i)                                                     \
    do {                                                           \
        if (conf->depth == conf->top)                              \
            out->len = (size_t)((conf->cur + (i) + 1) - out->str); \
    } while (0)

typedef enum {
    A_LOOP,
    A_BAD,
    A_DOWN,
    A_UP,
    A_VALUE,
    A_NEXT,
    A_QDOWN,
    A_QUP,
    A_ESC,
    A_UNESC,
    A_BARE,
    A_NUMBARE,
    A_UNBARE,
    A_UTF8_2,
    A_UTF8_3,
    A_UTF8_4,
    A_UTF_CONTINUE
} CONFIG_ACTION;

/*
 * Some inspiration taken from https://github.com/quartzjer/js0n (public domain). These
 * comments map from constructs in js0n to the equivalent in WiredTiger.
 *
 * static void *gostruct[] = {
 *		[0 ... 255] = &&l_bad,
 *		['\t'] = &&l_loop, [' '] = &&l_loop,
 *		['\r'] = &&l_loop, ['\n'] = &&l_loop,
 *		['"'] = &&l_qup,
 *		[':'] = &&l_value, ['='] = &&l_value,
 *		[','] = &&l_next,
 *		['('] = &&l_up, [')'] = &&l_down,
 *		['['] = &&l_up, [']'] = &&l_down,
 *		['{'] = &&l_up, ['}'] = &&l_down,
 *		['-'] = &&l_numbare,
 *		['0' ... '9'] = &&l_numbare,
 *		['_'] = &&l_bare,
 *		['A' ... 'Z'] = &&l_bare, ['a' ... 'z'] = &&l_bare,
 *		['/'] = &&l_bare,
 *		['%'] = &&l_bare,
 *	};
 */
static const int8_t gostruct[256] = {A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_LOOP, A_LOOP, A_BAD, A_BAD, A_LOOP, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_LOOP, A_BAD, A_QUP, A_BAD,
  A_BAD, A_BARE, A_BAD, A_BAD, A_UP, A_DOWN, A_BAD, A_BAD, A_NEXT, A_NUMBARE, A_BARE, A_BARE,
  A_NUMBARE, A_NUMBARE, A_NUMBARE, A_NUMBARE, A_NUMBARE, A_NUMBARE, A_NUMBARE, A_NUMBARE, A_NUMBARE,
  A_NUMBARE, A_VALUE, A_BAD, A_BAD, A_VALUE, A_BAD, A_BAD, A_BAD, A_BARE, A_BARE, A_BARE, A_BARE,
  A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE,
  A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_UP, A_BAD,
  A_DOWN, A_BAD, A_BARE, A_BAD, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE,
  A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE,
  A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_BARE, A_UP, A_BAD, A_DOWN, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD};

/*
 *	static void *gobare[] =
 *	{
 *		[0 ... 31] = &&l_bad,
 *		[32 ... 126] = &&l_loop,
 *		['\t'] = &&l_unbare, [' '] = &&l_unbare,
 *		['\r'] = &&l_unbare, ['\n'] = &&l_unbare,
 *		[':'] = &&l_unbare, ['='] = &&l_unbare,
 *		[','] = &&l_unbare,
 *		[')'] = &&l_unbare, [']'] = &&l_unbare, ['}'] = &&l_unbare,
 *		[127 ... 255] = &&l_bad
 *	};
 */
static const int8_t gobare[256] = {A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_UNBARE, A_UNBARE, A_BAD, A_BAD, A_UNBARE, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_UNBARE, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_UNBARE, A_LOOP, A_LOOP, A_UNBARE,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_UNBARE, A_LOOP, A_LOOP, A_UNBARE, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_UNBARE, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_UNBARE, A_LOOP, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD};

/*
 *	static void *gostring[] =
 *	{
 *		[0 ... 31] = &&l_bad, [127] = &&l_bad,
 *		[32 ... 126] = &&l_loop,
 *		['\\'] = &&l_esc, ['"'] = &&l_qdown,
 *		[128 ... 191] = &&l_bad,
 *		[192 ... 223] = &&l_utf8_2,
 *		[224 ... 239] = &&l_utf8_3,
 *		[240 ... 247] = &&l_utf8_4,
 *		[248 ... 255] = &&l_bad
 *	};
 */
static const int8_t gostring[256] = {A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_LOOP, A_LOOP, A_QDOWN, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_ESC, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP,
  A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_LOOP, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2,
  A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2,
  A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2,
  A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_2, A_UTF8_3, A_UTF8_3,
  A_UTF8_3, A_UTF8_3, A_UTF8_3, A_UTF8_3, A_UTF8_3, A_UTF8_3, A_UTF8_3, A_UTF8_3, A_UTF8_3,
  A_UTF8_3, A_UTF8_3, A_UTF8_3, A_UTF8_3, A_UTF8_3, A_UTF8_4, A_UTF8_4, A_UTF8_4, A_UTF8_4,
  A_UTF8_4, A_UTF8_4, A_UTF8_4, A_UTF8_4, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD};

/*
 *	static void *goutf8_continue[] =
 *	{
 *		[0 ... 127] = &&l_bad,
 *		[128 ... 191] = &&l_utf_continue,
 *		[192 ... 255] = &&l_bad
 *	};
 */
static const int8_t goutf8_continue[256] = {A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE, A_UTF_CONTINUE,
  A_UTF_CONTINUE, A_UTF_CONTINUE, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD};

/*
 *	static void *goesc[] =
 *	{
 *		[0 ... 255] = &&l_bad,
 *		['"'] = &&l_unesc, ['\\'] = &&l_unesc,
 *		['/'] = &&l_unesc, ['b'] = &&l_unesc,
 *		['f'] = &&l_unesc, ['n'] = &&l_unesc,
 *		['r'] = &&l_unesc, ['t'] = &&l_unesc, ['u'] = &&l_unesc
 *	};
 */
static const int8_t goesc[256] = {A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_UNESC, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_UNESC, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_UNESC, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_UNESC, A_BAD, A_BAD, A_BAD, A_UNESC, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_UNESC, A_BAD, A_BAD, A_BAD, A_UNESC, A_BAD, A_UNESC,
  A_UNESC, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD,
  A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD, A_BAD};

/*
 * __config_next --
 *     Get the next config item in the string without processing the value.
 */
static int
__config_next(WT_CONFIG *conf, WT_CONFIG_ITEM *key, WT_CONFIG_ITEM *value)
{
    WT_CONFIG_ITEM *out;
    int utf8_remain;
    static const WT_CONFIG_ITEM true_value = {"", 0, 1, WT_CONFIG_ITEM_BOOL};

    /* Keys with no value default to true. */
    *value = true_value;

    out = key;
    utf8_remain = 0;
    key->len = 0;

    if (conf->go == NULL)
        conf->go = gostruct;

    while (conf->cur < conf->end) {
        switch (conf->go[*(const uint8_t *)conf->cur]) {
        case A_LOOP:
            break;

        case A_BAD:
            return (__config_err(conf, "Unexpected character", EINVAL));

        case A_DOWN:
            if (conf->top == -1)
                return (__config_err(conf, "Unbalanced brackets", EINVAL));
            --conf->depth;
            CAP(0);
            break;

        case A_UP:
            if (conf->top == -1)
                conf->top = 1;
            PUSH(0, WT_CONFIG_ITEM_STRUCT);
            ++conf->depth;
            break;

        case A_VALUE:
            if (conf->depth == conf->top) {
                /*
                 * Special case: ':' is permitted in unquoted values.
                 */
                if (out == value && *conf->cur != ':')
                    return (__config_err(conf, "Value already complete", EINVAL));
                out = value;
            }
            break;

        case A_NEXT:
            /*
             * If we're at the top level and we have a complete key (and optional value), we're
             * done.
             */
            if (conf->depth == conf->top && key->len > 0) {
                ++conf->cur;
                return (0);
            } else
                break;

        case A_QDOWN:
            CAP(-1);
            conf->go = gostruct;
            break;

        case A_QUP:
            PUSH(1, WT_CONFIG_ITEM_STRING);
            conf->go = gostring;
            break;

        case A_ESC:
            conf->go = goesc;
            break;

        case A_UNESC:
            conf->go = gostring;
            break;

        case A_BARE:
            PUSH(0, WT_CONFIG_ITEM_ID);
            conf->go = gobare;
            break;

        case A_NUMBARE:
            PUSH(0, WT_CONFIG_ITEM_NUM);
            conf->go = gobare;
            break;

        case A_UNBARE:
            CAP(-1);
            conf->go = gostruct;
            continue;

        case A_UTF8_2:
            conf->go = goutf8_continue;
            utf8_remain = 1;
            break;

        case A_UTF8_3:
            conf->go = goutf8_continue;
            utf8_remain = 2;
            break;

        case A_UTF8_4:
            conf->go = goutf8_continue;
            utf8_remain = 3;
            break;

        case A_UTF_CONTINUE:
            if (!--utf8_remain)
                conf->go = gostring;
            break;
        }

        conf->cur++;
    }

    /* Might have a trailing key/value without a closing brace */
    if (conf->go == gobare) {
        CAP(-1);
        conf->go = gostruct;
    }

    /* Did we find something? */
    if (conf->depth <= conf->top && key->len > 0)
        return (0);

    /* We're either at the end of the string or we failed to parse. */
    if (conf->depth == 0)
        return (WT_NOTFOUND);

    return (__config_err(conf, "Unbalanced brackets", EINVAL));
}

/*
 * Arithmetic shift of a negative number is undefined by ISO/IEC 9899, and the WiredTiger API
 * supports negative numbers. Check it's not a negative number, and then cast the shift out of
 * paranoia.
 */
#define WT_SHIFT_INT64(v, s)                     \
    do {                                         \
        if ((v) < 0)                             \
            goto nonum;                          \
        (v) = (int64_t)(((uint64_t)(v)) << (s)); \
        if ((v) < 0)                             \
            goto nonum;                          \
    } while (0)

/*
 * __config_process_value --
 *     Deal with special config values like true / false.
 */
static void
__config_process_value(WT_CONFIG_ITEM *value)
{
    char *endptr;

    /* Empty values are okay: we can't do anything interesting with them. */
    if (value->len == 0)
        return;

    if (value->type == WT_CONFIG_ITEM_ID) {
        if (WT_CONFIG_LIT_MATCH("false", *value)) {
            value->type = WT_CONFIG_ITEM_BOOL;
            value->val = 0;
        } else if (WT_CONFIG_LIT_MATCH("true", *value)) {
            value->type = WT_CONFIG_ITEM_BOOL;
            value->val = 1;
        }
    } else if (value->type == WT_CONFIG_ITEM_NUM) {
        errno = 0;
        value->val = strtoll(value->str, &endptr, 10);

        /*
         * If we parsed the string but the number is out of range, treat the value as an identifier.
         * If an integer is expected, that will be caught by __wt_config_check.
         */
        if (value->type == WT_CONFIG_ITEM_NUM && errno == ERANGE)
            goto nonum;

        /* Check any leftover characters. */
        while (endptr < value->str + value->len)
            switch (*endptr++) {
            case 'b':
            case 'B':
                /* Byte: no change. */
                break;
            case 'k':
            case 'K':
                WT_SHIFT_INT64(value->val, 10);
                break;
            case 'm':
            case 'M':
                WT_SHIFT_INT64(value->val, 20);
                break;
            case 'g':
            case 'G':
                WT_SHIFT_INT64(value->val, 30);
                break;
            case 't':
            case 'T':
                WT_SHIFT_INT64(value->val, 40);
                break;
            case 'p':
            case 'P':
                WT_SHIFT_INT64(value->val, 50);
                break;
            default:
                goto nonum;
            }
    }

    if (0) {
nonum:
        /*
         * We didn't get a well-formed number. That might be okay, the required type will be checked
         * by __wt_config_check.
         */
        value->type = WT_CONFIG_ITEM_ID;
    }
}

/*
 * __wt_config_next --
 *     Get the next config item in the string and process the value.
 */
int
__wt_config_next(WT_CONFIG *conf, WT_CONFIG_ITEM *key, WT_CONFIG_ITEM *value)
{
    WT_RET(__config_next(conf, key, value));
    __config_process_value(value);
    return (0);
}

/*
 * __config_getraw --
 *     Given a config parser, find the final value for a given key.
 */
static int
__config_getraw(WT_CONFIG *cparser, WT_CONFIG_ITEM *key, WT_CONFIG_ITEM *value, bool top)
{
    WT_CONFIG sparser;
    WT_CONFIG_ITEM k, v, subk;
    WT_DECL_RET;
    bool found;

    found = false;
    while ((ret = __config_next(cparser, &k, &v)) == 0) {
        if (k.type != WT_CONFIG_ITEM_STRING && k.type != WT_CONFIG_ITEM_ID)
            continue;
        if (k.len == key->len && strncmp(key->str, k.str, k.len) == 0) {
            *value = v;
            found = true;
        } else if (k.len < key->len && key->str[k.len] == '.' &&
          strncmp(key->str, k.str, k.len) == 0) {
            subk.str = key->str + k.len + 1;
            subk.len = (key->len - k.len) - 1;
            __wt_config_initn(cparser->session, &sparser, v.str, v.len);
            if ((ret = __config_getraw(&sparser, &subk, value, false)) == 0)
                found = true;
            WT_RET_NOTFOUND_OK(ret);
        }
    }
    WT_RET_NOTFOUND_OK(ret);

    if (!found)
        return (WT_NOTFOUND);
    if (top)
        __config_process_value(value);
    return (0);
}

/*
 * __wti_config_get --
 *     Given a NULL-terminated list of configuration strings, find the final value for a given key.
 */
int
__wti_config_get(
  WT_SESSION_IMPL *session, const char **cfg_arg, WT_CONFIG_ITEM *key, WT_CONFIG_ITEM *value)
{
    WT_CONFIG cparser;
    WT_DECL_RET;
    const char **cfg;

    if (cfg_arg[0] == NULL)
        return (WT_NOTFOUND);

    /*
     * Search the strings in reverse order, that way the first hit wins and we don't search the base
     * set until there's no other choice.
     */
    for (cfg = cfg_arg; *cfg != NULL; ++cfg)
        ;
    do {
        --cfg;

        __wt_config_init(session, &cparser, *cfg);
        if ((ret = __config_getraw(&cparser, key, value, true)) == 0)
            return (0);
        WT_RET_NOTFOUND_OK(ret);
    } while (cfg != cfg_arg);

    return (WT_NOTFOUND);
}

/*
 * __wt_config_gets --
 *     Given a NULL-terminated list of configuration strings, find the final value for a given
 *     string key.
 */
int
__wt_config_gets(WT_SESSION_IMPL *session, const char **cfg, const char *key, WT_CONFIG_ITEM *value)
{
    WT_CONFIG_ITEM key_item = {key, strlen(key), 0, WT_CONFIG_ITEM_STRING};

    return (__wti_config_get(session, cfg, &key_item, value));
}

/*
 * __wt_config_gets_none --
 *     Given a NULL-terminated list of configuration strings, find the final value for a given
 *     string key. Treat "none" as empty.
 */
int
__wt_config_gets_none(
  WT_SESSION_IMPL *session, const char **cfg, const char *key, WT_CONFIG_ITEM *value)
{
    WT_RET(__wt_config_gets(session, cfg, key, value));
    if (WT_CONFIG_LIT_MATCH("none", *value))
        value->len = 0;
    return (0);
}

/*
 * __wt_config_getone --
 *     Get the value for a given key from a single config string.
 */
int
__wt_config_getone(
  WT_SESSION_IMPL *session, const char *config, WT_CONFIG_ITEM *key, WT_CONFIG_ITEM *value)
{
    WT_CONFIG cparser;

    __wt_config_init(session, &cparser, config);
    return (__config_getraw(&cparser, key, value, true));
}

/*
 * __wt_config_getones --
 *     Get the value for a given string key from a single config string.
 */
int
__wt_config_getones(
  WT_SESSION_IMPL *session, const char *config, const char *key, WT_CONFIG_ITEM *value)
{
    WT_CONFIG cparser;
    WT_CONFIG_ITEM key_item = {key, strlen(key), 0, WT_CONFIG_ITEM_STRING};

    __wt_config_init(session, &cparser, config);
    return (__config_getraw(&cparser, &key_item, value, true));
}

/*
 * __wt_config_getones_none --
 *     Get the value for a given string key from a single config string. Treat "none" as empty.
 */
int
__wt_config_getones_none(
  WT_SESSION_IMPL *session, const char *config, const char *key, WT_CONFIG_ITEM *value)
{
    WT_RET(__wt_config_getones(session, config, key, value));
    if (WT_CONFIG_LIT_MATCH("none", *value))
        value->len = 0;
    return (0);
}

/*
 * __wt_config_gets_def --
 *     Performance hack: skip parsing config strings by hard-coding defaults. It's expensive to
 *     repeatedly parse configuration strings, so don't do it unless it's necessary in performance
 *     paths like cursor creation. Assume the second configuration string is the application's
 *     configuration string, and if it's not set (which is true most of the time), then use the
 *     supplied default value. This makes it faster to open cursors when checking for obscure open
 *     configuration strings like "next_random".
 */
int
__wt_config_gets_def(
  WT_SESSION_IMPL *session, const char **cfg, const char *key, int def, WT_CONFIG_ITEM *value)
{
    WT_CONFIG_ITEM_STATIC_INIT(false_value);
    const char **end;

    *value = false_value;
    value->val = def;

    if (cfg == NULL)
        return (0);

    /*
     * Checking the "length" of the pointer array is a little odd, but it's deliberate. The reason
     * is because we pass variable length arrays of pointers as the configuration argument, some of
     * which have only one element and the NULL termination. Static analyzers (like Coverity)
     * complain if we read from an offset past the end of the array, even if we check there's no
     * NULL slots before the offset.
     */
    for (end = cfg; *end != NULL; ++end)
        ;
    switch ((int)(end - cfg)) {
    case 0: /* cfg[0] == NULL */
    case 1: /* cfg[1] == NULL */
        return (0);
    case 2: /* cfg[2] == NULL */
        WT_RET_NOTFOUND_OK(__wt_config_getones(session, cfg[1], key, value));
        return (0);
    default:
        return (__wt_config_gets(session, cfg, key, value));
    }
    /* NOTREACHED */
}

/*
 * __wt_config_subgetraw --
 *     Get the value for a given key from a config string in a WT_CONFIG_ITEM. This is useful for
 *     dealing with nested structs in config strings.
 */
int
__wt_config_subgetraw(
  WT_SESSION_IMPL *session, WT_CONFIG_ITEM *cfg, WT_CONFIG_ITEM *key, WT_CONFIG_ITEM *value)
{
    WT_CONFIG cparser;

    __wt_config_initn(session, &cparser, cfg->str, cfg->len);
    return (__config_getraw(&cparser, key, value, true));
}

/*
 * __wt_config_subgets --
 *     Get the value for a given key from a config string in a WT_CONFIG_ITEM. This is useful for
 *     dealing with nested structs in config strings.
 */
int
__wt_config_subgets(
  WT_SESSION_IMPL *session, WT_CONFIG_ITEM *cfg, const char *key, WT_CONFIG_ITEM *value)
{
    WT_CONFIG_ITEM key_item = {key, strlen(key), 0, WT_CONFIG_ITEM_STRING};

    return (__wt_config_subgetraw(session, cfg, &key_item, value));
}

/*
 * __wt_config_subget_next --
 *     Get the value for a given key from a config string and set the processed value in the given
 *     key structure. This is useful for unusual case of dealing with list in config string.
 */
int
__wt_config_subget_next(WT_CONFIG *conf, WT_CONFIG_ITEM *key)
{
    WT_CONFIG_ITEM value;
    WT_RET(__config_next(conf, key, &value));
    __config_process_value(key);
    return (0);
}