mariadb/storage/tokudb/hatoku_hton.cc

/* -*- mode: C; c-basic-offset: 4 -*- */
#define MYSQL_SERVER 1
#include "hatoku_defines.h"
#include <db.h>

#include "stdint.h"
#if defined(_WIN32)
#include "misc.h"
#endif
#define __STDC_FORMAT_MACROS
#include <inttypes.h>
#include "toku_os.h"
#include "toku_time.h"
#include "partitioned_counter.h"

/* We define DTRACE after mysql_priv.h in case it disabled dtrace in the main server */
#ifdef HAVE_DTRACE
#define _DTRACE_VERSION 1
#else
#endif

#include <mysql/plugin.h>
#include "hatoku_hton.h"
#include "ha_tokudb.h"

#undef PACKAGE
#undef VERSION
#undef HAVE_DTRACE
#undef _DTRACE_VERSION

#define TOKU_METADB_NAME "tokudb_meta"

typedef struct savepoint_info {
    DB_TXN* txn;
    tokudb_trx_data* trx;
    bool in_sub_stmt;
} *SP_INFO, SP_INFO_T;

static uchar *tokudb_get_key(TOKUDB_SHARE * share, size_t * length, my_bool not_used __attribute__ ((unused))) {
    *length = share->table_name_length;
    return (uchar *) share->table_name;
}

static handler *tokudb_create_handler(handlerton * hton, TABLE_SHARE * table, MEM_ROOT * mem_root);

static MYSQL_THDVAR_BOOL(commit_sync, 
    PLUGIN_VAR_THDLOCAL, 
    "sync on txn commit",
    /* check */ NULL, 
    /* update */ NULL,
    /* default*/ true
);
static MYSQL_THDVAR_UINT(pk_insert_mode,
    0,
    "set the primary key insert mode",
    NULL, 
    NULL, 
    1, // default
    0, // min?
    2, // max
    1 // blocksize
);
static MYSQL_THDVAR_BOOL(load_save_space,
    0,
    "if on, intial loads are slower but take less space",
    NULL, 
    NULL, 
    false
);
static MYSQL_THDVAR_BOOL(disable_slow_alter,
    0,
    "if on, alter tables that require copy are disabled",
    NULL, 
    NULL, 
    false
);
static MYSQL_THDVAR_BOOL(disable_hot_alter,
    0,
    "if on, hot alter table is disabled",
    NULL, 
    NULL, 
    false
);
static MYSQL_THDVAR_BOOL(create_index_online,
    0,
    "if on, create index done online",
    NULL, 
    NULL, 
    true
);
static MYSQL_THDVAR_BOOL(disable_prefetching,
    0,
    "if on, prefetching disabled",
    NULL, 
    NULL, 
   false
);
static MYSQL_THDVAR_BOOL(prelock_empty,
    0,
    "Tokudb Prelock Empty Table",
    NULL, 
    NULL, 
    true
);
static MYSQL_THDVAR_BOOL(log_client_errors,
    0,
    "Tokudb Log Client Errors",
    NULL, 
    NULL, 
    false
);
static MYSQL_THDVAR_UINT(block_size,
    0,
    "fractal tree block size",
    NULL, 
    NULL, 
    4<<20, // default
    4096,  // min
    ~0U,   // max
    1      // blocksize???
);
static MYSQL_THDVAR_UINT(read_block_size,
    0,
    "fractal tree read block size",
    NULL, 
    NULL, 
    128*1024, // default
    4096,  // min
    ~0U,   // max
    1      // blocksize???
);
static MYSQL_THDVAR_UINT(read_buf_size,
    0,
    "fractal tree read block size", //TODO: Is this a typo?
    NULL, 
    NULL, 
    128*1024, // default
    0,  // min
    1*1024*1024,   // max
    1      // blocksize???
);

static void tokudb_checkpoint_lock(THD * thd);
static void tokudb_checkpoint_unlock(THD * thd);

static void
tokudb_checkpoint_lock_update(
    THD* thd,
    struct st_mysql_sys_var* var,
    void* var_ptr,
    const void* save) 
{
    my_bool* val = (my_bool *) var_ptr;
    *val= *(my_bool *) save ? true : false;
    if (*val) {
        tokudb_checkpoint_lock(thd);
    }
    else {
        tokudb_checkpoint_unlock(thd);
    }
}
  
static MYSQL_THDVAR_BOOL(checkpoint_lock,
    0,
    "Tokudb Checkpoint Lock",
    NULL, 
    tokudb_checkpoint_lock_update, 
    false
);

static const char *tokudb_row_format_names[] = {
    "tokudb_uncompressed",
    "tokudb_zlib",
    "tokudb_quicklz",
    "tokudb_lzma",
    "tokudb_fast",
    "tokudb_small",
    "tokudb_default",
    NullS
};

static TYPELIB tokudb_row_format_typelib = {
    array_elements(tokudb_row_format_names) - 1,
    "tokudb_row_format_typelib",
    tokudb_row_format_names,
    NULL
};

static MYSQL_THDVAR_ENUM(row_format, PLUGIN_VAR_OPCMDARG,
                         "Specifies the compression method for a table during this session. "
                         "Possible values are TOKUDB_UNCOMPRESSED, TOKUDB_ZLIB, TOKUDB_QUICKLZ, "
                         "TOKUDB_LZMA, TOKUDB_FAST, TOKUDB_SMALL and TOKUDB_DEFAULT",
                         NULL, NULL, SRV_ROW_FORMAT_DEFAULT, &tokudb_row_format_typelib);

srv_row_format_t get_row_format(THD *thd)
{
    return (srv_row_format_t) THDVAR(thd, row_format);
}

static void tokudb_print_error(const DB_ENV * db_env, const char *db_errpfx, const char *buffer);
static void tokudb_cleanup_log_files(void);
static int tokudb_end(handlerton * hton, ha_panic_function type);
static bool tokudb_flush_logs(handlerton * hton);
static bool tokudb_show_status(handlerton * hton, THD * thd, stat_print_fn * print, enum ha_stat_type);
static int tokudb_close_connection(handlerton * hton, THD * thd);
static int tokudb_commit(handlerton * hton, THD * thd, bool all);
static int tokudb_rollback(handlerton * hton, THD * thd, bool all);
#if TOKU_INCLUDE_XA
static int tokudb_xa_prepare(handlerton* hton, THD* thd, bool all);
static int tokudb_xa_recover(handlerton* hton, XID*  xid_list, uint  len);
static int tokudb_commit_by_xid(handlerton* hton, XID* xid);
static int tokudb_rollback_by_xid(handlerton* hton, XID*  xid);
#endif

#if defined(HA_GENERAL_ONLINE) || defined(HA_INPLACE_ADD_INDEX_NO_READ_WRITE)
static uint tokudb_alter_table_flags(uint flags);
#endif
static int tokudb_rollback_to_savepoint(handlerton * hton, THD * thd, void *savepoint);
static int tokudb_savepoint(handlerton * hton, THD * thd, void *savepoint);
static int tokudb_release_savepoint(handlerton * hton, THD * thd, void *savepoint);
static int tokudb_discover(handlerton *hton, THD* thd, const char *db, const char *name, uchar **frmblob, size_t *frmlen);
static int tokudb_discover2(handlerton *hton, THD* thd, const char *db, const char *name, bool translate_name,uchar **frmblob, size_t *frmlen);
handlerton *tokudb_hton;

const char *ha_tokudb_ext = ".tokudb";
char *tokudb_data_dir;
ulong tokudb_debug;
DB_ENV *db_env;
DB* metadata_db;
HASH tokudb_open_tables;
pthread_mutex_t tokudb_mutex;
pthread_mutex_t tokudb_meta_mutex;

static ulonglong tokudb_lock_timeout;
static ulong tokudb_cleaner_period;
static ulong tokudb_cleaner_iterations;

#define ASSERT_MSGLEN 1024

void toku_hton_assert_fail(const char* expr_as_string, const char * fun, const char * file, int line, int caller_errno) {
    char msg[ASSERT_MSGLEN];
    if (db_env) {
        snprintf(msg, ASSERT_MSGLEN, "Handlerton: %s ", expr_as_string);
        db_env->crash(db_env, msg, fun, file, line,caller_errno);
    }
    else {
        snprintf(msg, ASSERT_MSGLEN, "Handlerton assertion failed, no env, %s, %d, %s, %s (errno=%d)\n", file, line, fun, expr_as_string, caller_errno);
        perror(msg);
        fflush(stderr);
    }
    abort();
}

//my_bool tokudb_shared_data = false;
static uint32_t tokudb_init_flags = 
    DB_CREATE | DB_THREAD | DB_PRIVATE | 
    DB_INIT_LOCK | 
    DB_INIT_MPOOL |
    DB_INIT_TXN | 
    DB_INIT_LOG |
    DB_RECOVER;
static uint32_t tokudb_env_flags = 0;
// static uint32_t tokudb_lock_type = DB_LOCK_DEFAULT;
// static ulong tokudb_log_buffer_size = 0;
// static ulong tokudb_log_file_size = 0;
static ulonglong tokudb_cache_size = 0;
static ulonglong tokudb_max_lock_memory = 0;
static char *tokudb_home;
static char *tokudb_tmp_dir;
static char *tokudb_log_dir;
// static long tokudb_lock_scan_time = 0;
// static ulong tokudb_region_size = 0;
// static ulong tokudb_cache_parts = 1;
const char *tokudb_hton_name = "TokuDB";
static uint32_t tokudb_checkpointing_period;
uint32_t tokudb_write_status_frequency;
uint32_t tokudb_read_status_frequency;
#ifdef TOKUDB_VERSION
char *tokudb_version = (char*) TOKUDB_VERSION;
#else
char *tokudb_version;
#endif
static int tokudb_fs_reserve_percent;  // file system reserve as a percentage of total disk space

#if defined(_WIN32)
extern "C" {
#include "ydb.h"
}
#endif

// A flag set if the handlerton is in an initialized, usable state,
// plus a reader-write lock to protect it without serializing reads.
// Since we don't have static initializers for the opaque rwlock type,
// use constructor and destructor functions to create and destroy
// the lock before and after main(), respectively.
static int tokudb_hton_initialized;
static rw_lock_t tokudb_hton_initialized_lock;

static void create_tokudb_hton_intialized_lock(void)  __attribute__((constructor));
static void destroy_tokudb_hton_initialized_lock(void) __attribute__((destructor));

static void create_tokudb_hton_intialized_lock(void)
{
    my_rwlock_init(&tokudb_hton_initialized_lock, 0);
}

static void destroy_tokudb_hton_initialized_lock(void)
{
    rwlock_destroy(&tokudb_hton_initialized_lock);
}

static int tokudb_init_func(void *p) {
    TOKUDB_DBUG_ENTER("tokudb_init_func");
    int r;
#if defined(_WIN64)
        r = toku_ydb_init();
        if (r) {
            printf("got error %d\n", r);
            goto error;
        }
#endif

    // 3938: lock the handlerton's initialized status flag for writing
    r = rw_wrlock(&tokudb_hton_initialized_lock);
    assert(r == 0);

    db_env = NULL;
    metadata_db = NULL;

    tokudb_hton = (handlerton *) p;

    pthread_mutex_init(&tokudb_mutex, MY_MUTEX_INIT_FAST);
    pthread_mutex_init(&tokudb_meta_mutex, MY_MUTEX_INIT_FAST);
    (void) my_hash_init(&tokudb_open_tables, table_alias_charset, 32, 0, 0, (my_hash_get_key) tokudb_get_key, 0, 0);

    tokudb_hton->state = SHOW_OPTION_YES;
    // tokudb_hton->flags= HTON_CAN_RECREATE;  // QQQ this came from skeleton
    tokudb_hton->flags = HTON_CLOSE_CURSORS_AT_COMMIT;
#ifdef DB_TYPE_TOKUDB
    tokudb_hton->db_type = DB_TYPE_TOKUDB;
#else
    tokudb_hton->db_type = DB_TYPE_UNKNOWN;
#endif

    tokudb_hton->create = tokudb_create_handler;
    tokudb_hton->close_connection = tokudb_close_connection;

    tokudb_hton->savepoint_offset = sizeof(SP_INFO_T);
    tokudb_hton->savepoint_set = tokudb_savepoint;
    tokudb_hton->savepoint_rollback = tokudb_rollback_to_savepoint;
    tokudb_hton->savepoint_release = tokudb_release_savepoint;

    tokudb_hton->discover = tokudb_discover;
#if defined(MYSQL_HANDLERTON_INCLUDE_DISCOVER2)
    tokudb_hton->discover2 = tokudb_discover2;
#endif
    tokudb_hton->commit = tokudb_commit;
    tokudb_hton->rollback = tokudb_rollback;
#if TOKU_INCLUDE_XA
    tokudb_hton->prepare=tokudb_xa_prepare;
    tokudb_hton->recover=tokudb_xa_recover;
    tokudb_hton->commit_by_xid=tokudb_commit_by_xid;
    tokudb_hton->rollback_by_xid=tokudb_rollback_by_xid;
#endif

    tokudb_hton->panic = tokudb_end;
    tokudb_hton->flush_logs = tokudb_flush_logs;
    tokudb_hton->show_status = tokudb_show_status;
#if defined(HA_GENERAL_ONLINE) || defined(HA_INPLACE_ADD_INDEX_NO_READ_WRITE)
    tokudb_hton->alter_table_flags = tokudb_alter_table_flags;
#endif
    if (!tokudb_home)
        tokudb_home = mysql_real_data_home;
    DBUG_PRINT("info", ("tokudb_home: %s", tokudb_home));
#if 0
    if (!tokudb_log_buffer_size) { // QQQ
        tokudb_log_buffer_size = max(table_cache_size * 512, 32 * 1024);
        DBUG_PRINT("info", ("computing tokudb_log_buffer_size %ld\n", tokudb_log_buffer_size));
    }
    tokudb_log_file_size = tokudb_log_buffer_size * 4;
    tokudb_log_file_size = MY_ALIGN(tokudb_log_file_size, 1024 * 1024L);
    tokudb_log_file_size = max(tokudb_log_file_size, 10 * 1024 * 1024L);
    DBUG_PRINT("info", ("computing tokudb_log_file_size: %ld\n", tokudb_log_file_size));
#endif
    if ((r = db_env_create(&db_env, 0))) {
        DBUG_PRINT("info", ("db_env_create %d\n", r));
        goto error;
    }

    DBUG_PRINT("info", ("tokudb_env_flags: 0x%x\n", tokudb_env_flags));
    r = db_env->set_flags(db_env, tokudb_env_flags, 1);
    if (r) { // QQQ
        if (tokudb_debug & TOKUDB_DEBUG_INIT) 
            TOKUDB_TRACE("%s:WARNING: flags=%x r=%d\n", __FUNCTION__, tokudb_env_flags, r); 
        // goto error;
    }

    // config error handling
    db_env->set_errcall(db_env, tokudb_print_error);
    db_env->set_errpfx(db_env, "TokuDB");

    //
    // set default comparison functions
    //
    r = db_env->set_default_bt_compare(db_env, tokudb_cmp_dbt_key);
    if (r) {
        DBUG_PRINT("info", ("set_default_bt_compare%d\n", r));
        goto error; 
    }

    {
    char *tmp_dir = tokudb_tmp_dir;
    char *data_dir = tokudb_data_dir;
    if (data_dir == 0) {
        data_dir = mysql_data_home;
    }
    if (tmp_dir == 0) {
        tmp_dir = data_dir;
    }
    DBUG_PRINT("info", ("tokudb_data_dir: %s\n", data_dir));
    db_env->set_data_dir(db_env, data_dir);

    DBUG_PRINT("info", ("tokudb_tmp_dir: %s\n", tmp_dir));
    db_env->set_tmp_dir(db_env, tmp_dir);
    }

    if (tokudb_log_dir) {
        DBUG_PRINT("info", ("tokudb_log_dir: %s\n", tokudb_log_dir));
        db_env->set_lg_dir(db_env, tokudb_log_dir);
    }

    // config the cache table size to min(1/2 of physical memory, 1/8 of the process address space)
    if (tokudb_cache_size == 0) {
        uint64_t physmem, maxdata;
        physmem = toku_os_get_phys_memory_size();
        tokudb_cache_size = physmem / 2;
        r = toku_os_get_max_process_data_size(&maxdata);
        if (r == 0) {
            if (tokudb_cache_size > maxdata / 8)
                tokudb_cache_size = maxdata / 8;
        }
    }
    if (tokudb_cache_size) {
        DBUG_PRINT("info", ("tokudb_cache_size: %lld\n", tokudb_cache_size));
        r = db_env->set_cachesize(db_env, (uint32_t)(tokudb_cache_size >> 30), (uint32_t)(tokudb_cache_size % (1024L * 1024L * 1024L)), 1);
        if (r) {
            DBUG_PRINT("info", ("set_cachesize %d\n", r));
            goto error; 
        }
    }
    if (tokudb_max_lock_memory == 0) {
        tokudb_max_lock_memory = tokudb_cache_size/8;
    }
    if (tokudb_max_lock_memory) {
        DBUG_PRINT("info", ("tokudb_max_lock_memory: %lld\n", tokudb_max_lock_memory));
        r = db_env->set_lk_max_memory(db_env, tokudb_max_lock_memory);
        if (r) {
            DBUG_PRINT("info", ("set_lk_max_memory %d\n", r));
            goto error; 
        }
    }
    
    uint32_t gbytes, bytes; int parts;
    r = db_env->get_cachesize(db_env, &gbytes, &bytes, &parts);
    if (r == 0) 
        if (tokudb_debug & TOKUDB_DEBUG_INIT) 
            TOKUDB_TRACE("%s:tokudb_cache_size=%lld\n", __FUNCTION__, ((unsigned long long) gbytes << 30) + bytes);

#if 0
    // QQQ config the logs
    DBUG_PRINT("info", ("tokudb_log_file_size: %ld\n", tokudb_log_file_size));
    db_env->set_lg_max(db_env, tokudb_log_file_size);
    DBUG_PRINT("info", ("tokudb_log_buffer_size: %ld\n", tokudb_log_buffer_size));
    db_env->set_lg_bsize(db_env, tokudb_log_buffer_size);
    // DBUG_PRINT("info",("tokudb_region_size: %ld\n", tokudb_region_size));
    // db_env->set_lg_regionmax(db_env, tokudb_region_size);
#endif

    if (db_env->set_redzone) {
        r = db_env->set_redzone(db_env, tokudb_fs_reserve_percent);
        if (r && (tokudb_debug & TOKUDB_DEBUG_INIT))
            TOKUDB_TRACE("%s:%d r=%d\n", __FUNCTION__, __LINE__, r);
    }

    if (tokudb_debug & TOKUDB_DEBUG_INIT) TOKUDB_TRACE("%s:env open:flags=%x\n", __FUNCTION__, tokudb_init_flags);

    r = db_env->set_generate_row_callback_for_put(db_env,generate_row_for_put);
    assert(!r);
    r = db_env->set_generate_row_callback_for_del(db_env,generate_row_for_del);
    assert(!r);
    db_env->set_update(db_env, tokudb_update_fun);
    r = db_env->open(db_env, tokudb_home, tokudb_init_flags, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);

    if (tokudb_debug & TOKUDB_DEBUG_INIT) TOKUDB_TRACE("%s:env opened:return=%d\n", __FUNCTION__, r);

    if (r) {
        DBUG_PRINT("info", ("env->open %d\n", r));
        goto error;
    }

    r = db_env->checkpointing_set_period(db_env, tokudb_checkpointing_period);
    assert(!r);
    r = db_env->cleaner_set_period(db_env, tokudb_cleaner_period);
    assert(r == 0);
    r = db_env->cleaner_set_iterations(db_env, tokudb_cleaner_iterations);
    assert(r == 0);

    r = db_env->set_lock_timeout(db_env, tokudb_lock_timeout);
    assert(r == 0);

    r = db_create(&metadata_db, db_env, 0);
    if (r) {
        DBUG_PRINT("info", ("failed to create metadata db %d\n", r));
        goto error;
    }
    

    r= metadata_db->open(metadata_db, NULL, TOKU_METADB_NAME, NULL, DB_BTREE, DB_THREAD, 0);
    if (r) {
        if (r != ENOENT) {
            sql_print_error("Got error %d when trying to open metadata_db", r);
            goto error;
        }
        r = metadata_db->close(metadata_db,0);
        assert(r == 0);
        r = db_create(&metadata_db, db_env, 0);
        if (r) {
            DBUG_PRINT("info", ("failed to create metadata db %d\n", r));
            goto error;
        }

        r= metadata_db->open(metadata_db, NULL, TOKU_METADB_NAME, NULL, DB_BTREE, DB_THREAD | DB_CREATE | DB_EXCL, my_umask);
        if (r) {
            goto error;
        }
    }

    //3938: succeeded, set the init status flag and unlock
    tokudb_hton_initialized = 1;
    rw_unlock(&tokudb_hton_initialized_lock);
    DBUG_RETURN(false);

error:
    if (metadata_db) {
        int rr = metadata_db->close(metadata_db, 0);
        assert(rr==0);
    }
    if (db_env) {
        int rr= db_env->close(db_env, 0);
        assert(rr==0);
        db_env = 0;
    }

    // 3938: failed to initialized, drop the flag and lock
    tokudb_hton_initialized = 0;
    rw_unlock(&tokudb_hton_initialized_lock);
    DBUG_RETURN(true);
}

static int tokudb_done_func(void *p) {
    TOKUDB_DBUG_ENTER("tokudb_done_func");
    my_hash_free(&tokudb_open_tables);
    pthread_mutex_destroy(&tokudb_mutex);
    pthread_mutex_destroy(&tokudb_meta_mutex);
#if defined(_WIN64)
    toku_ydb_destroy();
#endif
    TOKUDB_DBUG_RETURN(0);
}

static handler *tokudb_create_handler(handlerton * hton, TABLE_SHARE * table, MEM_ROOT * mem_root) {
    return new(mem_root) ha_tokudb(hton, table);
}

int tokudb_end(handlerton * hton, ha_panic_function type) {
    TOKUDB_DBUG_ENTER("tokudb_end");
    int error = 0;
    
    // 3938: if we finalize the storage engine plugin, it is no longer
    // initialized. grab a writer lock for the duration of the
    // call, so we can drop the flag and destroy the mutexes
    // in isolation.
    rw_wrlock(&tokudb_hton_initialized_lock);
    assert(tokudb_hton_initialized);

    if (metadata_db) {
        int r = metadata_db->close(metadata_db, 0);
        assert(r==0);
    }
    if (db_env) {
        if (tokudb_init_flags & DB_INIT_LOG)
            tokudb_cleanup_log_files();
        error = db_env->close(db_env, 0);       // Error is logged
        assert(error==0);
        db_env = NULL;
    }

    // 3938: drop the initialized flag and unlock
    tokudb_hton_initialized = 0;
    rw_unlock(&tokudb_hton_initialized_lock);

    TOKUDB_DBUG_RETURN(error);
}

static int tokudb_close_connection(handlerton * hton, THD * thd) {
    int error = 0;
    tokudb_trx_data* trx = NULL;
    trx = (tokudb_trx_data *) thd_data_get(thd, tokudb_hton->slot);
    if (trx && trx->checkpoint_lock_taken) {
        error = db_env->checkpointing_resume(db_env);
    }
    my_free(trx, MYF(0));
    return error;
}

bool tokudb_flush_logs(handlerton * hton) {
    TOKUDB_DBUG_ENTER("tokudb_flush_logs");
    int error;
    bool result = 0;
    uint32_t curr_tokudb_checkpointing_period = 0;

    //
    // get the current checkpointing period
    //
    error = db_env->checkpointing_get_period(
        db_env, 
        &curr_tokudb_checkpointing_period
        );
    if (error) {
        my_error(ER_ERROR_DURING_CHECKPOINT, MYF(0), error);
        result = 1;
        goto exit;
    }

    //
    // if the current period is not the same as the variable, that means
    // the user has changed the period and now we need to update it
    //
    if (tokudb_checkpointing_period != curr_tokudb_checkpointing_period) {
        error = db_env->checkpointing_set_period(
            db_env, 
            tokudb_checkpointing_period
            );
        if (error) {
            my_error(ER_ERROR_DURING_CHECKPOINT, MYF(0), error);
            result = 1;
            goto exit;
        }
    }
    
    //
    // take the checkpoint
    //
    error = db_env->txn_checkpoint(db_env, 0, 0, 0);
    if (error) {
        my_error(ER_ERROR_DURING_CHECKPOINT, MYF(0), error);
        result = 1;
        goto exit;
    }

    result = 0;
exit:
    TOKUDB_DBUG_RETURN(result);
}

uint get_pk_insert_mode(THD* thd) {
    return THDVAR(thd, pk_insert_mode);
}

bool get_load_save_space(THD* thd) {
    return (THDVAR(thd, load_save_space) != 0);
}

bool get_disable_slow_alter(THD* thd) {
    return (THDVAR(thd, disable_slow_alter) != 0);
}

bool get_disable_hot_alter(THD* thd) {
    return THDVAR(thd, disable_hot_alter) != 0;
}

bool get_create_index_online(THD* thd) {
    return (THDVAR(thd, create_index_online) != 0);
}

bool get_disable_prefetching(THD* thd) {
    return (THDVAR(thd, disable_prefetching) != 0);
}

bool get_prelock_empty(THD* thd) {
    return (THDVAR(thd, prelock_empty) != 0);
}

bool get_log_client_errors(THD* thd) {
    return (THDVAR(thd, log_client_errors) != 0);
}

uint get_tokudb_block_size(THD* thd) {
    return THDVAR(thd, block_size);
}

uint get_tokudb_read_block_size(THD* thd) {
    return THDVAR(thd, read_block_size);
}

uint get_tokudb_read_buf_size(THD* thd) {
    return THDVAR(thd, read_buf_size);
}

typedef struct txn_progress_info {
    char status[200];
    THD* thd;
} *TXN_PROGRESS_INFO;


void txn_progress_func(TOKU_TXN_PROGRESS progress, void* extra) {
    TXN_PROGRESS_INFO progress_info = (TXN_PROGRESS_INFO)extra;
    int r;
    if (progress->stalled_on_checkpoint) {
        if (progress->is_commit) {
            r = sprintf(
                progress_info->status, 
                "Writing committed changes to disk, processing commit of transaction, %"PRId64" out of %"PRId64, 
                progress->entries_processed, 
                progress->entries_total
                ); 
            assert(r >= 0);
        }
        else {
            r = sprintf(
                progress_info->status, 
                "Writing committed changes to disk, processing abort of transaction, %"PRId64" out of %"PRId64, 
                progress->entries_processed, 
                progress->entries_total
                ); 
            assert(r >= 0);
        }
    }
    else {
        if (progress->is_commit) {
            r = sprintf(
                progress_info->status, 
                "processing commit of transaction, %"PRId64" out of %"PRId64, 
                progress->entries_processed, 
                progress->entries_total
                ); 
            assert(r >= 0);
        }
        else {
            r = sprintf(
                progress_info->status, 
                "processing abort of transaction, %"PRId64" out of %"PRId64, 
                progress->entries_processed, 
                progress->entries_total
                ); 
            assert(r >= 0);
        }
    }
    thd_proc_info(progress_info->thd, progress_info->status);
}


static void commit_txn_with_progress(DB_TXN* txn, uint32_t flags, THD* thd) {
    int r;
    struct txn_progress_info info;
    info.thd = thd;
    r = txn->commit_with_progress(txn, flags, txn_progress_func, &info);
    if (r != 0) {
        sql_print_error("tried committing transaction %p and got error code %d", txn, r);
    }
    assert(r == 0);
}

static void abort_txn_with_progress(DB_TXN* txn, THD* thd) {
    int r;
    struct txn_progress_info info;
    info.thd = thd;
    r = txn->abort_with_progress(txn, txn_progress_func, &info);
    if (r != 0) {
        sql_print_error("tried aborting transaction %p and got error code %d", txn, r);
    }
    assert(r == 0);
}

static int tokudb_commit(handlerton * hton, THD * thd, bool all) {
    TOKUDB_DBUG_ENTER("tokudb_commit");
    DBUG_PRINT("trans", ("ending transaction %s", all ? "all" : "stmt"));
    uint32_t syncflag = THDVAR(thd, commit_sync) ? 0 : DB_TXN_NOSYNC;
    tokudb_trx_data *trx = (tokudb_trx_data *) thd_data_get(thd, hton->slot);
    DB_TXN **txn = all ? &trx->all : &trx->stmt;
    if (*txn) {
        if (tokudb_debug & TOKUDB_DEBUG_TXN) {
            TOKUDB_TRACE("doing txn commit:%d:%p\n", all, *txn);
        }
        // test hook to induce a crash on a debug build
        DBUG_EXECUTE_IF("tokudb_crash_commit_before", DBUG_SUICIDE(););
        commit_txn_with_progress(*txn, syncflag, thd);
        // test hook to induce a crash on a debug build
        DBUG_EXECUTE_IF("tokudb_crash_commit_after", DBUG_SUICIDE(););
        if (*txn == trx->sp_level) {
            trx->sp_level = 0;
        }
        *txn = 0;
        trx->sub_sp_level = NULL;
    } 
    else if (tokudb_debug & TOKUDB_DEBUG_TXN) {
        TOKUDB_TRACE("nothing to commit %d\n", all);
    }
    reset_stmt_progress(&trx->stmt_progress);
    TOKUDB_DBUG_RETURN(0);
}

static int tokudb_rollback(handlerton * hton, THD * thd, bool all) {
    TOKUDB_DBUG_ENTER("tokudb_rollback");
    DBUG_PRINT("trans", ("aborting transaction %s", all ? "all" : "stmt"));
    tokudb_trx_data *trx = (tokudb_trx_data *) thd_data_get(thd, hton->slot);
    DB_TXN **txn = all ? &trx->all : &trx->stmt;
    if (*txn) {
        if (tokudb_debug & TOKUDB_DEBUG_TXN) {
            TOKUDB_TRACE("rollback:%p\n", *txn);
        }
        abort_txn_with_progress(*txn, thd);
        if (*txn == trx->sp_level) {
            trx->sp_level = 0;
        }
        *txn = 0;
        trx->sub_sp_level = NULL;
    } 
    else {
        if (tokudb_debug & TOKUDB_DEBUG_TXN) {
            TOKUDB_TRACE("abort0\n");
        }
    }
    reset_stmt_progress(&trx->stmt_progress);
    TOKUDB_DBUG_RETURN(0);
}

#if TOKU_INCLUDE_XA

static int tokudb_xa_prepare(handlerton* hton, THD* thd, bool all) {
    TOKUDB_DBUG_ENTER("tokudb_xa_prepare");
    int r = 0;
    DBUG_PRINT("trans", ("preparing transaction %s", all ? "all" : "stmt"));
    tokudb_trx_data *trx = (tokudb_trx_data *) thd_data_get(thd, hton->slot);
    DB_TXN* txn = all ? trx->all : trx->stmt;
    if (txn) {
        if (tokudb_debug & TOKUDB_DEBUG_TXN) {
            TOKUDB_TRACE("doing txn prepare:%d:%p\n", all, txn);
        }
        // a TOKU_XA_XID is identical to a MYSQL_XID
        TOKU_XA_XID thd_xid;
        thd_get_xid(thd, (MYSQL_XID*) &thd_xid);
        // test hook to induce a crash on a debug build
        DBUG_EXECUTE_IF("tokudb_crash_prepare_before", DBUG_SUICIDE(););
        r = txn->xa_prepare(txn, &thd_xid);
        // test hook to induce a crash on a debug build
        DBUG_EXECUTE_IF("tokudb_crash_prepare_after", DBUG_SUICIDE(););
    } 
    else if (tokudb_debug & TOKUDB_DEBUG_TXN) {
        TOKUDB_TRACE("nothing to prepare %d\n", all);
    }
    TOKUDB_DBUG_RETURN(r);
}

static int tokudb_xa_recover(handlerton* hton, XID*  xid_list, uint  len) {
    TOKUDB_DBUG_ENTER("tokudb_xa_recover");
    int r = 0;
    if (len == 0 || xid_list == NULL) {
        TOKUDB_DBUG_RETURN(0);
    }
    long num_returned = 0;
    r = db_env->txn_xa_recover(
        db_env,
        (TOKU_XA_XID*)xid_list,
        len,
        &num_returned,
        DB_NEXT
        );
    assert(r == 0);
    TOKUDB_DBUG_RETURN((int)num_returned);
}

static int tokudb_commit_by_xid(handlerton* hton, XID* xid) {
    TOKUDB_DBUG_ENTER("tokudb_commit_by_xid");
    int r = 0;
    DB_TXN* txn = NULL;
    TOKU_XA_XID* toku_xid = (TOKU_XA_XID*)xid;

    r = db_env->get_txn_from_xid(db_env, toku_xid, &txn);
    if (r) { goto cleanup; }

    r = txn->commit(txn, 0);
    if (r) { goto cleanup; }

    r = 0;
cleanup:
    TOKUDB_DBUG_RETURN(r);
}

static int tokudb_rollback_by_xid(handlerton* hton, XID*  xid) {
    TOKUDB_DBUG_ENTER("tokudb_rollback_by_xid");
    int r = 0;
    DB_TXN* txn = NULL;
    TOKU_XA_XID* toku_xid = (TOKU_XA_XID*)xid;

    r = db_env->get_txn_from_xid(db_env, toku_xid, &txn);
    if (r) { goto cleanup; }

    r = txn->abort(txn);
    if (r) { goto cleanup; }

    r = 0;
cleanup:
    TOKUDB_DBUG_RETURN(r);
}

#endif

static int tokudb_savepoint(handlerton * hton, THD * thd, void *savepoint) {
    TOKUDB_DBUG_ENTER("tokudb_savepoint");
    int error;
    SP_INFO save_info = (SP_INFO)savepoint;
    tokudb_trx_data *trx = (tokudb_trx_data *) thd_data_get(thd, hton->slot);
    if (thd->in_sub_stmt) {
        assert(trx->stmt);
        error = db_env->txn_begin(db_env, trx->sub_sp_level, &(save_info->txn), DB_INHERIT_ISOLATION);
        if (error) {
            goto cleanup;
        }
        trx->sub_sp_level = save_info->txn;
        save_info->in_sub_stmt = true;
    }
    else {
        error = db_env->txn_begin(db_env, trx->sp_level, &(save_info->txn), DB_INHERIT_ISOLATION);
        if (error) {
            goto cleanup;
        }
        trx->sp_level = save_info->txn;
        save_info->in_sub_stmt = false;
    }
    save_info->trx = trx;
    error = 0;
cleanup:
    TOKUDB_DBUG_RETURN(error);
}

static int tokudb_rollback_to_savepoint(handlerton * hton, THD * thd, void *savepoint) {
    TOKUDB_DBUG_ENTER("tokudb_rollback_to_savepoint");
    int error;
    SP_INFO save_info = (SP_INFO)savepoint;
    DB_TXN* parent = NULL;
    DB_TXN* txn_to_rollback = save_info->txn;

    tokudb_trx_data *trx = (tokudb_trx_data *) thd_data_get(thd, hton->slot);
    parent = txn_to_rollback->parent;
    if (!(error = txn_to_rollback->abort(txn_to_rollback))) {
        if (save_info->in_sub_stmt) {
            trx->sub_sp_level = parent;
        }
        else {
            trx->sp_level = parent;
        }
        error = tokudb_savepoint(hton, thd, savepoint);
    }
    TOKUDB_DBUG_RETURN(error);
}

static int tokudb_release_savepoint(handlerton * hton, THD * thd, void *savepoint) {
    TOKUDB_DBUG_ENTER("tokudb_release_savepoint");
    int error;

    SP_INFO save_info = (SP_INFO)savepoint;
    DB_TXN* parent = NULL;
    DB_TXN* txn_to_commit = save_info->txn;

    tokudb_trx_data *trx = (tokudb_trx_data *) thd_data_get(thd, hton->slot);
    parent = txn_to_commit->parent;
    if (!(error = txn_to_commit->commit(txn_to_commit, 0))) {
        if (save_info->in_sub_stmt) {
            trx->sub_sp_level = parent;
        }
        else {
            trx->sp_level = parent;
        }
        save_info->txn = NULL;
    }
    TOKUDB_DBUG_RETURN(error);
}

static int tokudb_discover(handlerton *hton, THD* thd, const char *db, const char *name, uchar **frmblob, size_t *frmlen) {
    return tokudb_discover2(hton, thd, db, name, true, frmblob, frmlen);
}

static int tokudb_discover2(handlerton *hton, THD* thd, const char *db, const char *name, bool translate_name,
                            uchar **frmblob, size_t *frmlen) {
    TOKUDB_DBUG_ENTER("tokudb_discover");
    int error;
    DB* status_db = NULL;
    DB_TXN* txn = NULL;
    char path[FN_REFLEN + 1];
    HA_METADATA_KEY curr_key = hatoku_frm_data;
    DBT key, value;    
    memset(&key, 0, sizeof(key));
    memset(&value, 0, sizeof(&value));
    
    error = db_env->txn_begin(db_env, 0, &txn, 0);
    if (error) { goto cleanup; }

    build_table_filename(path, sizeof(path) - 1, db, name, "", translate_name ? 0 : FN_IS_TMP);
    error = open_status_dictionary(&status_db, path, txn);
    if (error) { goto cleanup; }

    key.data = &curr_key;
    key.size = sizeof(curr_key);

    error = status_db->getf_set(
        status_db, 
        txn,
        0,
        &key, 
        smart_dbt_callback_verify_frm,
        &value
        );
    if (error) {
        goto cleanup;
    }

    *frmblob = (uchar *)value.data;
    *frmlen = value.size;

    error = 0;
cleanup:
    if (status_db) {
        status_db->close(status_db,0);
    }
    if (txn) {
        commit_txn(txn, 0);
    }
    TOKUDB_DBUG_RETURN(error);    
}

static int store_dbname_tablename_size(TABLE *table, char *name, uint64_t size, THD *thd) {
    char *tp = strrchr(name, '/');
    assert(tp);
    char *tablename = tp + 1;
    size_t tablename_length = strlen(tablename);

    char *dp = strchr(name, '/');
    char *dbname;
    size_t dbname_length;
    if (dp == tp) {
        dbname = name;
        dbname_length = tp - dbname;
    } else {
        dbname = dp + 1;
        dbname_length = tp - dbname;
    }

    table->field[0]->store(dbname, dbname_length, system_charset_info);
    table->field[1]->store(tablename, tablename_length, system_charset_info);
    table->field[2]->store(size, false);
    int error = schema_table_store_record(thd, table);
    return error;
}

static int tokudb_dictionary_info(TABLE *table, THD *thd) {
    int error;
    DB_TXN* txn = NULL;
    DBC* tmp_cursor = NULL;
    DBT curr_key;
    DBT curr_val;
    memset(&curr_key, 0, sizeof curr_key); 
    memset(&curr_val, 0, sizeof curr_val);
    error = db_env->txn_begin(db_env, 0, &txn, DB_READ_UNCOMMITTED);
    if (error) {
        goto cleanup;
    }
    error = db_env->get_cursor_for_directory(db_env, txn, &tmp_cursor);
    if (error) {
        goto cleanup;
    }
    while (error == 0) {
        error = tmp_cursor->c_get(
            tmp_cursor, 
            &curr_key, 
            &curr_val, 
            DB_NEXT
            );
        if (!error) {
            table->field[0]->store(
                (char *)curr_key.data,
                curr_key.size,
                system_charset_info
                );
            table->field[1]->store(
                (char *)curr_val.data,
                curr_val.size,
                system_charset_info
                );
            error = schema_table_store_record(thd, table);
        }
    }
    if (error == DB_NOTFOUND) {
        error = 0;
    }
cleanup:
    if (tmp_cursor) {
        int r = tmp_cursor->c_close(tmp_cursor);
        assert(r==0);
    }
    if (txn) {
        commit_txn(txn, 0);
    }
    return error;
}

static int tokudb_get_user_data_size(TABLE *table, THD *thd, bool exact) {
    int error;
    DB* curr_db = NULL;
    DB_TXN* txn = NULL;
    DBC* tmp_cursor = NULL;
    DBC* tmp_table_cursor = NULL;
    DBT curr_key;
    DBT curr_val;
    DB_TXN* tmp_txn = NULL;
    memset(&curr_key, 0, sizeof curr_key); 
    memset(&curr_val, 0, sizeof curr_val);
    pthread_mutex_lock(&tokudb_meta_mutex);

    error = db_env->txn_begin(db_env, 0, &txn, DB_READ_UNCOMMITTED);
    if (error) {
        goto cleanup;
    }
    error = metadata_db->cursor(metadata_db, txn, &tmp_cursor, 0);
    if (error) {
        goto cleanup;
    }
    while (error == 0) {
        tmp_txn = NULL;
        //
        // here, and in other places, check if process has been killed
        // if so, get out of function so user is not stalled
        //
        if (thd->killed) {
            break;
        }
        error = db_env->txn_begin(db_env, 0, &tmp_txn, DB_READ_UNCOMMITTED);
        if (error) {
            goto cleanup;
        }

        //
        // do not need this to be super fast, so use old simple API
        //
        error = tmp_cursor->c_get(
            tmp_cursor, 
            &curr_key, 
            &curr_val, 
            DB_NEXT
            );
        if (!error) {
            char* name = (char *)curr_key.data;
            char* newname;
            uint64_t curr_num_bytes = 0;
            DB_BTREE_STAT64 dict_stats;

            error = db_create(&curr_db, db_env, 0);
            if (error) { goto cleanup; }

            newname = (char *)my_malloc(
                get_max_dict_name_path_length(name),
                MYF(MY_WME|MY_ZEROFILL|MY_FAE));

            make_name(newname, name, "main");
            
            error = curr_db->open(curr_db, tmp_txn, newname, NULL, DB_BTREE, DB_THREAD, 0);

            my_free(newname, MYF(0));

            if (error == ENOENT) { error = 0; continue; }
            if (error) { goto cleanup; }

            if (exact) {
                //
                // flatten if exact is required
                //
                uint curr_num_items = 0;                
                error = curr_db->cursor(curr_db, tmp_txn, &tmp_table_cursor, 0);
                if (error) {
                    tmp_table_cursor = NULL;
                    goto cleanup;
                }
                while (error != DB_NOTFOUND) {
                    error = tmp_table_cursor->c_getf_next(tmp_table_cursor, 0, smart_dbt_do_nothing, NULL);
                    if (error && error != DB_NOTFOUND) {
                        goto cleanup;
                    }
                    curr_num_items++;
                    //
                    // allow early exit if command has been killed
                    //
                    if ( (curr_num_items % 1000) == 0 && thd->killed) {
                        goto cleanup;
                    }
                }
                error = tmp_table_cursor->c_close(tmp_table_cursor);
                assert(error==0);
                tmp_table_cursor = NULL;
            }

            error = curr_db->stat64(
                curr_db, 
                tmp_txn, 
                &dict_stats
                );
            if (error) { goto cleanup; }

            curr_num_bytes = dict_stats.bt_dsize;
            if (*(uchar *)curr_val.data) {
                //
                // in this case, we have a hidden primary key, do not
                // want to report space taken up by the hidden primary key to the user
                //
                uint64_t hpk_space = TOKUDB_HIDDEN_PRIMARY_KEY_LENGTH*dict_stats.bt_ndata;
                curr_num_bytes = (hpk_space > curr_num_bytes) ? 0 : curr_num_bytes - hpk_space;
            }
            else {
                //
                // one infinity byte per key needs to be subtracted
                //
                uint64_t inf_byte_space = dict_stats.bt_ndata;
                curr_num_bytes = (inf_byte_space > curr_num_bytes) ? 0 : curr_num_bytes - inf_byte_space;
            }

            error = store_dbname_tablename_size(table, name, curr_num_bytes, thd);
            if (error) goto cleanup;

            {
                int r = curr_db->close(curr_db, 0);
                assert(r==0);
                curr_db = NULL;
            }
        }

        if (tmp_txn) {
            commit_txn(tmp_txn, 0);
            tmp_txn = NULL;
        }
    }

    error = 0;

cleanup:
    if (tmp_cursor) {
        int r = tmp_cursor->c_close(tmp_cursor);
        assert(r==0);
    }
    if (tmp_table_cursor) {
        int r = tmp_table_cursor->c_close(tmp_table_cursor);
        assert(r==0);
    }
    if (curr_db) {
        int r = curr_db->close(curr_db, 0);
        assert(r==0);
    }
    if (tmp_txn) {
        commit_txn(tmp_txn, 0);
    }
    if (txn) {
        commit_txn(txn, 0);
    }
    if (error) {
        sql_print_error("got an error %d in show_data_size\n", error);
    }
    pthread_mutex_unlock(&tokudb_meta_mutex);
    return error;
}

#define STATPRINT(legend, val) if (legend != NULL && val != NULL) stat_print(thd,   \
                                          tokudb_hton_name, \
                                          strlen(tokudb_hton_name), \
                                          legend, \
                                          strlen(legend), \
                                          val, \
                                          strlen(val))

extern sys_var *intern_find_sys_var(const char *str, uint length, bool no_error);

static bool tokudb_show_engine_status(THD * thd, stat_print_fn * stat_print) {
    TOKUDB_DBUG_ENTER("tokudb_show_engine_status");
    int error;
    uint64_t panic;
    const int panic_string_len = 1024;
    char panic_string[panic_string_len] = {'\0'};
    uint64_t num_rows;
    fs_redzone_state redzone_state;
    const int bufsiz = 1024;
    char buf[bufsiz];

#if MYSQL_VERSION_ID < 50500
    {
        sys_var * version = intern_find_sys_var("version", 0, false);
        snprintf(buf, bufsiz, "%s", version->value_ptr(thd, (enum_var_type)0, (LEX_STRING*)NULL));
        STATPRINT("Version", buf);
    }
#endif
    error = db_env->get_engine_status_num_rows (db_env, &num_rows);
    TOKU_ENGINE_STATUS_ROW_S mystat[num_rows];
    error = db_env->get_engine_status (db_env, mystat, num_rows, &redzone_state, &panic, panic_string, panic_string_len);

    if (strlen(panic_string)) {
        STATPRINT("Environment panic string", panic_string);
    }
    if (error == 0) {
        if (panic) {
            snprintf(buf, bufsiz, "%" PRIu64, panic);
            STATPRINT("Environment panic", buf);
        }
        
        if(redzone_state == FS_BLOCKED) {
            STATPRINT("*** URGENT WARNING ***", "FILE SYSTEM IS COMPLETELY FULL");
            snprintf(buf, bufsiz, "FILE SYSTEM IS COMPLETELY FULL");
        }
        else if (redzone_state == FS_GREEN) {
            snprintf(buf, bufsiz, "more than %d percent of total file system space", 2*tokudb_fs_reserve_percent);
        }
        else if (redzone_state == FS_YELLOW) {
            snprintf(buf, bufsiz, "*** WARNING *** FILE SYSTEM IS GETTING FULL (less than %d percent free)", 2*tokudb_fs_reserve_percent);
        } 
        else if (redzone_state == FS_RED){
            snprintf(buf, bufsiz, "*** WARNING *** FILE SYSTEM IS GETTING VERY FULL (less than %d percent free): INSERTS ARE PROHIBITED", tokudb_fs_reserve_percent);
        }
        else {
            snprintf(buf, bufsiz, "information unavailable, unknown redzone state %d", redzone_state);
        }
        STATPRINT ("disk free space", buf);

        for (uint64_t row = 0; row < num_rows; row++) {
            switch (mystat[row].type) {
            case FS_STATE:
                snprintf(buf, bufsiz, "%"PRIu64"", mystat[row].value.num);
                break;
            case UINT64:
                snprintf(buf, bufsiz, "%"PRIu64"", mystat[row].value.num);
                break;
            case CHARSTR:
                snprintf(buf, bufsiz, "%s", mystat[row].value.str);
                break;
            case UNIXTIME:
                {
                    time_t t = mystat[row].value.num;
                    char tbuf[26];
                    snprintf(buf, bufsiz, "%.24s", ctime_r(&t, tbuf));
                }
                break;
            case TOKUTIME:
                {
                    double t = tokutime_to_seconds(mystat[row].value.num);
                    snprintf(buf, bufsiz, "%.6f", t);
                }
                break;
            case PARCOUNT:
                {
                    uint64_t v = read_partitioned_counter(mystat[row].value.parcount);
                    snprintf(buf, bufsiz, "%" PRIu64, v);
                }
                break;
#if 0
            case MAXCOUNT:
                {
                    uint64_t v = read_max_partitioned_counter(mystat[row].value.maxcount);
                    snprintf(buf, bufsiz, "%" PRIu64, v);
                }
#endif
            default:
                snprintf(buf, bufsiz, "UNKNOWN STATUS TYPE: %d", mystat[row].type);
                break;                
            }
            STATPRINT(mystat[row].legend, buf);
        }  
    }  
    if (error) { my_errno = error; }
    TOKUDB_DBUG_RETURN(error);
}

static void tokudb_checkpoint_lock(THD * thd) {
    int error;
    tokudb_trx_data* trx = NULL;
    char status_msg[200]; //buffer of 200 should be a good upper bound.
    trx = (tokudb_trx_data *) thd_data_get(thd, tokudb_hton->slot);
    if (!trx) {
        error = create_tokudb_trx_data_instance(&trx);
        //
        // can only fail due to memory allocation, so ok to assert
        //
        assert(!error);
        thd_data_set(thd, tokudb_hton->slot, trx);
    }
    
    if (trx->checkpoint_lock_taken) {
        goto cleanup;
    }
    //
    // This can only fail if environment is not created, which is not possible
    // in handlerton
    //
    sprintf(status_msg, "Trying to grab checkpointing lock.");
    thd_proc_info(thd, status_msg);
    error = db_env->checkpointing_postpone(db_env);
    assert(!error);

    trx->checkpoint_lock_taken = true;
cleanup:
    return;
}

static void tokudb_checkpoint_unlock(THD * thd) {
    int error;
    char status_msg[200]; //buffer of 200 should be a good upper bound.
    tokudb_trx_data* trx = NULL;
    trx = (tokudb_trx_data *) thd_data_get(thd, tokudb_hton->slot);
    if (!trx) {
        error = 0;
        goto  cleanup;
    }
    if (!trx->checkpoint_lock_taken) {
        error = 0;
        goto  cleanup;
    }
    //
    // at this point, we know the checkpoint lock has been taken
    //
    sprintf(status_msg, "Trying to release checkpointing lock.");
    thd_proc_info(thd, status_msg);
    error = db_env->checkpointing_resume(db_env);
    assert(!error);

    trx->checkpoint_lock_taken = false;
    
cleanup:
    return;
}

static bool tokudb_show_status(handlerton * hton, THD * thd, stat_print_fn * stat_print, enum ha_stat_type stat_type) {
    switch (stat_type) {
    case HA_ENGINE_STATUS:
        return tokudb_show_engine_status(thd, stat_print);
        break;
    default:
        break;
    }
    return false;
}

static void tokudb_print_error(const DB_ENV * db_env, const char *db_errpfx, const char *buffer) {
    sql_print_error("%s:  %s", db_errpfx, buffer);
}

static void tokudb_cleanup_log_files(void) {
    TOKUDB_DBUG_ENTER("tokudb_cleanup_log_files");
    char **names;
    int error;

    if ((error = db_env->txn_checkpoint(db_env, 0, 0, 0)))
        my_error(ER_ERROR_DURING_CHECKPOINT, MYF(0), error);

    if ((error = db_env->log_archive(db_env, &names, 0)) != 0) {
        DBUG_PRINT("error", ("log_archive failed (error %d)", error));
        db_env->err(db_env, error, "log_archive");
        DBUG_VOID_RETURN;
    }

    if (names) {
        char **np;
        for (np = names; *np; ++np) {
#if 1
            if (tokudb_debug)
                TOKUDB_TRACE("%s:cleanup:%s\n", __FUNCTION__, *np);
#else
            my_delete(*np, MYF(MY_WME));
#endif
        }

        free(names);
    }

    DBUG_VOID_RETURN;
}

#if defined(HA_GENERAL_ONLINE)
//
// *******NOTE*****
// If the flags HA_ONLINE_DROP_INDEX and HA_ONLINE_DROP_UNIQUE_INDEX
// are ever added, prepare_drop_index and final_drop_index will need to be modified
// so that the actual deletion of DB's is done in final_drop_index and not prepare_drop_index
//
static uint tokudb_alter_table_flags(uint flags)
{
    return (HA_ONLINE_ADD_INDEX_NO_WRITES| HA_ONLINE_DROP_INDEX_NO_WRITES |
            HA_ONLINE_ADD_UNIQUE_INDEX_NO_WRITES| HA_ONLINE_DROP_UNIQUE_INDEX_NO_WRITES|HA_GENERAL_ONLINE);

}
#elif defined(HA_INPLACE_ADD_INDEX_NO_READ_WRITE)
static uint tokudb_alter_table_flags(uint flags) {
    return HA_INPLACE_ADD_INDEX_NO_READ_WRITE
        |  HA_INPLACE_ADD_INDEX_NO_WRITE
        |  HA_INPLACE_DROP_INDEX_NO_READ_WRITE
        |  HA_INPLACE_ADD_UNIQUE_INDEX_NO_READ_WRITE
        |  HA_INPLACE_ADD_UNIQUE_INDEX_NO_WRITE
        |  HA_INPLACE_DROP_UNIQUE_INDEX_NO_READ_WRITE;
}
#endif


// options flags
//   PLUGIN_VAR_THDLOCAL  Variable is per-connection
//   PLUGIN_VAR_READONLY  Server variable is read only
//   PLUGIN_VAR_NOSYSVAR  Not a server variable
//   PLUGIN_VAR_NOCMDOPT  Not a command line option
//   PLUGIN_VAR_NOCMDARG  No argument for cmd line
//   PLUGIN_VAR_RQCMDARG  Argument required for cmd line
//   PLUGIN_VAR_OPCMDARG  Argument optional for cmd line
//   PLUGIN_VAR_MEMALLOC  String needs memory allocated


// system variables

static void tokudb_lock_timeout_update(THD * thd,
        struct st_mysql_sys_var * sys_var, 
        void * var, const void * save)
{
    ulonglong * timeout = (ulonglong *) var;

    *timeout = *(const ulonglong *) save;
    db_env->set_lock_timeout(db_env, *timeout);
}

#define DEFAULT_LOCK_TIMEOUT_MSEC 4000

static MYSQL_SYSVAR_ULONGLONG(lock_timeout, tokudb_lock_timeout,
        0, "TokuDB lock timeout", 
        NULL, tokudb_lock_timeout_update, DEFAULT_LOCK_TIMEOUT_MSEC,
        0, ~0ULL, 0);

static void tokudb_cleaner_period_update(THD * thd,
        struct st_mysql_sys_var * sys_var, 
        void * var, const void * save)
{
    ulong * cleaner_period = (ulong *) var;

    *cleaner_period = *(const ulong *) save;
    int r = db_env->cleaner_set_period(db_env, *cleaner_period);
    assert(r==0);
}

#define DEFAULT_CLEANER_PERIOD 1

static MYSQL_SYSVAR_ULONG(cleaner_period, tokudb_cleaner_period,
        0, "TokuDB cleaner_period", 
        NULL, tokudb_cleaner_period_update, DEFAULT_CLEANER_PERIOD,
        0, ~0UL, 0);

static void tokudb_cleaner_iterations_update(THD * thd,
        struct st_mysql_sys_var * sys_var, 
        void * var, const void * save)
{
    ulong * cleaner_iterations = (ulong *) var;

    *cleaner_iterations = *(const ulong *) save;
    int r = db_env->cleaner_set_iterations(db_env, *cleaner_iterations);
    assert(r==0);
}

#define DEFAULT_CLEANER_ITERATIONS 5

static MYSQL_SYSVAR_ULONG(cleaner_iterations, tokudb_cleaner_iterations,
        0, "TokuDB cleaner_iterations", 
        NULL, tokudb_cleaner_iterations_update, DEFAULT_CLEANER_ITERATIONS,
        0, ~0UL, 0);

static MYSQL_SYSVAR_ULONGLONG(cache_size, tokudb_cache_size,
        PLUGIN_VAR_READONLY, "TokuDB cache table size", NULL, NULL, 0,
        0, ~0ULL, 0);
static MYSQL_SYSVAR_ULONGLONG(max_lock_memory, tokudb_max_lock_memory, PLUGIN_VAR_READONLY, "TokuDB max memory for locks", NULL, NULL, 0, 0, ~0ULL, 0);
static MYSQL_SYSVAR_ULONG(debug, tokudb_debug, 0, "TokuDB Debug", NULL, NULL, 0, 0, ~0UL, 0);

static MYSQL_SYSVAR_STR(log_dir, tokudb_log_dir, PLUGIN_VAR_READONLY, "TokuDB Log Directory", NULL, NULL, NULL);

static MYSQL_SYSVAR_STR(data_dir, tokudb_data_dir, PLUGIN_VAR_READONLY, "TokuDB Data Directory", NULL, NULL, NULL);

static MYSQL_SYSVAR_STR(version, tokudb_version, PLUGIN_VAR_READONLY, "TokuDB Version", NULL, NULL, NULL);

static MYSQL_SYSVAR_UINT(init_flags, tokudb_init_flags, PLUGIN_VAR_READONLY, "Sets TokuDB DB_ENV->open flags", NULL, NULL, tokudb_init_flags, 0, ~0U, 0);

static MYSQL_SYSVAR_UINT(checkpointing_period, tokudb_checkpointing_period, 0, "TokuDB Checkpointing period", NULL, NULL, 60, 0, ~0U, 0);
static MYSQL_SYSVAR_UINT(write_status_frequency, tokudb_write_status_frequency, 0, "TokuDB frequency that show processlist updates status of writes", NULL, NULL, 1000, 0, ~0U, 0);
static MYSQL_SYSVAR_UINT(read_status_frequency, tokudb_read_status_frequency, 0, "TokuDB frequency that show processlist updates status of reads", NULL, NULL, 10000, 0, ~0U, 0);
static MYSQL_SYSVAR_INT(fs_reserve_percent, tokudb_fs_reserve_percent, PLUGIN_VAR_READONLY, "TokuDB file system space reserve (percent free required)", NULL, NULL, 5, 0, 100, 0);
static MYSQL_SYSVAR_STR(tmp_dir, tokudb_tmp_dir, PLUGIN_VAR_READONLY, "Tokudb Tmp Dir", NULL, NULL, NULL);

static struct st_mysql_sys_var *tokudb_system_variables[] = {
    MYSQL_SYSVAR(cache_size),
    MYSQL_SYSVAR(max_lock_memory),
    MYSQL_SYSVAR(data_dir),
    MYSQL_SYSVAR(log_dir),
    MYSQL_SYSVAR(debug),
    MYSQL_SYSVAR(commit_sync),
    MYSQL_SYSVAR(lock_timeout),
    MYSQL_SYSVAR(cleaner_period),
    MYSQL_SYSVAR(cleaner_iterations),
    MYSQL_SYSVAR(pk_insert_mode),
    MYSQL_SYSVAR(load_save_space),
    MYSQL_SYSVAR(disable_slow_alter),
    MYSQL_SYSVAR(disable_hot_alter),
    MYSQL_SYSVAR(create_index_online),
    MYSQL_SYSVAR(disable_prefetching),
    MYSQL_SYSVAR(version),
    MYSQL_SYSVAR(init_flags),
    MYSQL_SYSVAR(checkpointing_period),
    MYSQL_SYSVAR(prelock_empty),
    MYSQL_SYSVAR(log_client_errors),
    MYSQL_SYSVAR(checkpoint_lock),
    MYSQL_SYSVAR(write_status_frequency),
    MYSQL_SYSVAR(read_status_frequency),
    MYSQL_SYSVAR(fs_reserve_percent),
    MYSQL_SYSVAR(tmp_dir),
    MYSQL_SYSVAR(block_size),
    MYSQL_SYSVAR(read_block_size),
    MYSQL_SYSVAR(read_buf_size),
    MYSQL_SYSVAR(row_format),
    NULL
};

struct st_mysql_storage_engine tokudb_storage_engine = { MYSQL_HANDLERTON_INTERFACE_VERSION };

static ST_FIELD_INFO tokudb_user_data_field_info[] = {
    {"database_name", 256, MYSQL_TYPE_STRING, 0, 0, NULL, SKIP_OPEN_TABLE },
    {"table_name", 256, MYSQL_TYPE_STRING, 0, 0, NULL, SKIP_OPEN_TABLE },
    {"data_size", 0, MYSQL_TYPE_LONGLONG, 0, 0, NULL, SKIP_OPEN_TABLE },
    {NULL, 0, MYSQL_TYPE_NULL, 0, 0, NULL, SKIP_OPEN_TABLE}
};

#if MYSQL_VERSION_ID >= 50600
static int tokudb_user_data_fill_table(THD *thd, TABLE_LIST *tables, Item *cond) {
#else
static int tokudb_user_data_fill_table(THD *thd, TABLE_LIST *tables, COND *cond) {
#endif
    int error;
    TABLE *table = tables->table;
    
    // 3938: Get a read lock on the status flag, since we must
    // read it before safely proceeding
    rw_rdlock(&tokudb_hton_initialized_lock);

    if (!tokudb_hton_initialized) {
        my_error(ER_PLUGIN_IS_NOT_LOADED, MYF(0), "TokuDB");
        error = -1;
    } else {
        error = tokudb_get_user_data_size(table, thd, false);
    }

    // 3938: unlock the status flag lock
    rw_unlock(&tokudb_hton_initialized_lock);
    return error;
}

static int tokudb_user_data_init(void *p) {
    ST_SCHEMA_TABLE *schema = (ST_SCHEMA_TABLE *) p;
    schema->fields_info = tokudb_user_data_field_info;
    schema->fill_table = tokudb_user_data_fill_table;
    return 0;
}

static int tokudb_user_data_done(void *p) {
    return 0;
}

static struct st_mysql_information_schema tokudb_user_data_information_schema = { MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION };

static ST_FIELD_INFO tokudb_user_data_exact_field_info[] = {
    {"database_name", 256, MYSQL_TYPE_STRING, 0, 0, NULL, SKIP_OPEN_TABLE },
    {"table_name", 256, MYSQL_TYPE_STRING, 0, 0, NULL, SKIP_OPEN_TABLE },
    {"data_size", 0, MYSQL_TYPE_LONGLONG, 0, 0, NULL, SKIP_OPEN_TABLE },
    {NULL, 0, MYSQL_TYPE_NULL, 0, 0, NULL, SKIP_OPEN_TABLE}
};

static ST_FIELD_INFO tokudb_dictionary_field_info[] = {
    {"dictionary_name", 512, MYSQL_TYPE_BLOB, 0, 0, NULL, SKIP_OPEN_TABLE },
    {"internal_file_name", 512, MYSQL_TYPE_BLOB, 0, 0, NULL, SKIP_OPEN_TABLE },
    {NULL, 0, MYSQL_TYPE_NULL, 0, 0, NULL, SKIP_OPEN_TABLE}
};


#if MYSQL_VERSION_ID >= 50600
static int tokudb_dictionary_info_fill_table(THD *thd, TABLE_LIST *tables, Item *cond) {
#else
static int tokudb_dictionary_info_fill_table(THD *thd, TABLE_LIST *tables, COND *cond) {
#endif
    int error;
    TABLE *table = tables->table;

    // 3938: Get a read lock on the status flag, since we must
    // read it before safely proceeding
    rw_rdlock(&tokudb_hton_initialized_lock);

    if (!tokudb_hton_initialized) {
        my_error(ER_PLUGIN_IS_NOT_LOADED, MYF(0), "TokuDB");
        error = -1;
    } else {
        error = tokudb_dictionary_info(table, thd);
    }

    //3938: unlock the status flag lock
    rw_unlock(&tokudb_hton_initialized_lock);
    return error;
}

#if MYSQL_VERSION_ID >= 50600
static int tokudb_user_data_exact_fill_table(THD *thd, TABLE_LIST *tables, Item *cond) {
#else
static int tokudb_user_data_exact_fill_table(THD *thd, TABLE_LIST *tables, COND *cond) {
#endif
    int error;
    TABLE *table = tables->table;

    // 3938: Get a read lock on the status flag, since we must
    // read it before safely proceeding
    rw_rdlock(&tokudb_hton_initialized_lock);

    if (!tokudb_hton_initialized) {
        my_error(ER_PLUGIN_IS_NOT_LOADED, MYF(0), "TokuDB");
        error = -1;
    } else {
        error = tokudb_get_user_data_size(table, thd, true);
    }

    //3938: unlock the status flag lock
    rw_unlock(&tokudb_hton_initialized_lock);
    return error;
}

static int tokudb_user_data_exact_init(void *p) {
    ST_SCHEMA_TABLE *schema = (ST_SCHEMA_TABLE *) p;
    schema->fields_info = tokudb_user_data_exact_field_info;
    schema->fill_table = tokudb_user_data_exact_fill_table;
    return 0;
}

static int tokudb_user_data_exact_done(void *p) {
    return 0;
}

static int tokudb_dictionary_info_init(void *p) {
    ST_SCHEMA_TABLE *schema = (ST_SCHEMA_TABLE *) p;
    schema->fields_info = tokudb_dictionary_field_info;
    schema->fill_table = tokudb_dictionary_info_fill_table;
    return 0;
}

static int tokudb_dictionary_info_done(void *p) {
    return 0;
}

static struct st_mysql_information_schema tokudb_user_data_exact_information_schema = { MYSQL_INFORMATION_SCHEMA_INTERFACE_VERSION };

enum { TOKUDB_PLUGIN_VERSION = 0x0400 };
#define TOKUDB_PLUGIN_VERSION_STR "1024"

mysql_declare_plugin(tokudb) 
{
    MYSQL_STORAGE_ENGINE_PLUGIN, 
    &tokudb_storage_engine, 
    tokudb_hton_name, 
    "Tokutek Inc", 
    "Tokutek TokuDB Storage Engine with Fractal Tree(tm) Technology",
    PLUGIN_LICENSE_PROPRIETARY,
    tokudb_init_func,          /* plugin init */
    tokudb_done_func,          /* plugin deinit */
    TOKUDB_PLUGIN_VERSION,     /* 4.0.0 */
    NULL,                      /* status variables */
    tokudb_system_variables,   /* system variables */
    NULL,                      /* config options */
#if MYSQL_VERSION_ID >= 50521
    0,                         /* flags */
#endif
},
{
    MYSQL_INFORMATION_SCHEMA_PLUGIN, 
    &tokudb_user_data_information_schema, 
    "TokuDB_user_data", 
    "Tokutek Inc", 
    "Tokutek TokuDB Storage Engine with Fractal Tree(tm) Technology",
    PLUGIN_LICENSE_PROPRIETARY,
    tokudb_user_data_init,     /* plugin init */
    tokudb_user_data_done,     /* plugin deinit */
    TOKUDB_PLUGIN_VERSION,     /* 4.0.0 */
    NULL,                      /* status variables */
    NULL,                      /* system variables */
    NULL,                      /* config options */
#if MYSQL_VERSION_ID >= 50521
    0,                         /* flags */
#endif
},
{
    MYSQL_INFORMATION_SCHEMA_PLUGIN, 
    &tokudb_user_data_exact_information_schema, 
    "TokuDB_user_data_exact", 
    "Tokutek Inc", 
    "Tokutek TokuDB Storage Engine with Fractal Tree(tm) Technology",
    PLUGIN_LICENSE_PROPRIETARY,
    tokudb_user_data_exact_init,     /* plugin init */
    tokudb_user_data_exact_done,     /* plugin deinit */
    TOKUDB_PLUGIN_VERSION,     /* 4.0.0 */
    NULL,                      /* status variables */
    NULL,                      /* system variables */
    NULL,                      /* config options */
#if MYSQL_VERSION_ID >= 50521
    0,                         /* flags */
#endif
},
{
    MYSQL_INFORMATION_SCHEMA_PLUGIN, 
    &tokudb_user_data_exact_information_schema, 
    "TokuDB_file_map", 
    "Tokutek Inc", 
    "Tokutek TokuDB Storage Engine with Fractal Tree(tm) Technology",
    PLUGIN_LICENSE_PROPRIETARY,
    tokudb_dictionary_info_init,     /* plugin init */
    tokudb_dictionary_info_done,     /* plugin deinit */
    TOKUDB_PLUGIN_VERSION,     /* 4.0.0 */
    NULL,                      /* status variables */
    NULL,                      /* system variables */
    NULL,                      /* config options */
#if MYSQL_VERSION_ID >= 50521
    0,                         /* flags */
#endif
}
mysql_declare_plugin_end;

#ifdef MARIA_PLUGIN_INTERFACE_VERSION

maria_declare_plugin(tokudb) 
{
    MYSQL_STORAGE_ENGINE_PLUGIN, 
    &tokudb_storage_engine, 
    tokudb_hton_name, 
    "Tokutek Inc", 
    "Tokutek TokuDB Storage Engine with Fractal Tree(tm) Technology",
    PLUGIN_LICENSE_PROPRIETARY,
    tokudb_init_func,          /* plugin init */
    tokudb_done_func,          /* plugin deinit */
    TOKUDB_PLUGIN_VERSION,     /* 4.0.0 */
    NULL,                      /* status variables */
    tokudb_system_variables,   /* system variables */
    TOKUDB_PLUGIN_VERSION_STR, /* string version */
    MariaDB_PLUGIN_MATURITY_STABLE /* maturity */
},
{
    MYSQL_INFORMATION_SCHEMA_PLUGIN, 
    &tokudb_user_data_information_schema, 
    "TokuDB_user_data", 
    "Tokutek Inc", 
    "Tokutek TokuDB Storage Engine with Fractal Tree(tm) Technology",
    PLUGIN_LICENSE_PROPRIETARY,
    tokudb_user_data_init,     /* plugin init */
    tokudb_user_data_done,     /* plugin deinit */
    TOKUDB_PLUGIN_VERSION,     /* 4.0.0 */
    NULL,                      /* status variables */
    NULL,                      /* system variables */
    TOKUDB_PLUGIN_VERSION_STR, /* string version */
    MariaDB_PLUGIN_MATURITY_STABLE /* maturity */
},
{
    MYSQL_INFORMATION_SCHEMA_PLUGIN, 
    &tokudb_user_data_exact_information_schema, 
    "TokuDB_user_data_exact", 
    "Tokutek Inc", 
    "Tokutek TokuDB Storage Engine with Fractal Tree(tm) Technology",
    PLUGIN_LICENSE_PROPRIETARY,
    tokudb_user_data_exact_init,     /* plugin init */
    tokudb_user_data_exact_done,     /* plugin deinit */
    TOKUDB_PLUGIN_VERSION,     /* 4.0.0 */
    NULL,                      /* status variables */
    NULL,                      /* system variables */
    TOKUDB_PLUGIN_VERSION_STR, /* string version */
    MariaDB_PLUGIN_MATURITY_STABLE /* maturity */
},
{
    MYSQL_INFORMATION_SCHEMA_PLUGIN, 
    &tokudb_user_data_exact_information_schema, 
    "TokuDB_file_map", 
    "Tokutek Inc", 
    "Tokutek TokuDB Storage Engine with Fractal Tree(tm) Technology",
    PLUGIN_LICENSE_PROPRIETARY,
    tokudb_dictionary_info_init,     /* plugin init */
    tokudb_dictionary_info_done,     /* plugin deinit */
    TOKUDB_PLUGIN_VERSION,     /* 4.0.0 */
    NULL,                      /* status variables */
    NULL,                      /* system variables */
    TOKUDB_PLUGIN_VERSION_STR, /* string version */
    MariaDB_PLUGIN_MATURITY_STABLE /* maturity */
}
maria_declare_plugin_end;

#endif