~drizzle-trunk/drizzle/development

/* Copyright (C) 2000-2003 MySQL AB

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program; if not, write to the Free Software

   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include <drizzled/server_includes.h>

#include "rpl_filter.h"

#define TABLE_RULE_HASH_SIZE   16

#define TABLE_RULE_ARR_SIZE   16

Rpl_filter::Rpl_filter() : 

  table_rules_on(0), do_table_inited(0), ignore_table_inited(0),

  wild_do_table_inited(0), wild_ignore_table_inited(0)

{

  do_db.empty();

  ignore_db.empty();

  rewrite_db.empty();

}

Rpl_filter::~Rpl_filter() 

{

  if (do_table_inited) 

    hash_free(&do_table);

  if (ignore_table_inited)

    hash_free(&ignore_table);

  if (wild_do_table_inited)

    free_string_array(&wild_do_table);

  if (wild_ignore_table_inited)

    free_string_array(&wild_ignore_table);

  free_list(&do_db);

  free_list(&ignore_db);

  free_list(&rewrite_db);

}

/*

  Returns true if table should be logged/replicated 

  SYNOPSIS

    tables_ok()

    db              db to use if db in TABLE_LIST is undefined for a table

    tables          list of tables to check

  NOTES

    Changing table order in the list can lead to different results. 

    Note also order of precedence of do/ignore rules (see code).  For

    that reason, users should not set conflicting rules because they

    may get unpredicted results (precedence order is explained in the

    manual).

    If no table in the list is marked "updating", then we always

    return 0, because there is no reason to execute this statement on

    slave if it updates nothing.  (Currently, this can only happen if

    statement is a multi-delete (SQLCOM_DELETE_MULTI) and "tables" are

    the tables in the FROM):

    In the case of SQLCOM_DELETE_MULTI, there will be a second call to

    tables_ok(), with tables having "updating==TRUE" (those after the

    DELETE), so this second call will make the decision (because

    all_tables_not_ok() = !tables_ok(1st_list) &&

    !tables_ok(2nd_list)).

  TODO

    "Include all tables like "abc.%" except "%.EFG"". (Can't be done now.)

    If we supported Perl regexps, we could do it with pattern: /^abc\.(?!EFG)/

    (I could not find an equivalent in the regex library MySQL uses).

  RETURN VALUES

    0           should not be logged/replicated

    1           should be logged/replicated                  

*/

bool 

Rpl_filter::tables_ok(const char* db, TABLE_LIST* tables)

{

  bool some_tables_updating= 0;

  for (; tables; tables= tables->next_global)

  {

    char hash_key[2*NAME_LEN+2];

    char *end;

    uint len;

    if (!tables->updating) 

      continue;

    some_tables_updating= 1;

    end= stpcpy(hash_key, tables->db ? tables->db : db);

    *end++= '.';

    len= (uint) (stpcpy(end, tables->table_name) - hash_key);

    if (do_table_inited) // if there are any do's

    {

      if (hash_search(&do_table, (uchar*) hash_key, len))

	return(1);

    }

    if (ignore_table_inited) // if there are any ignores

    {

      if (hash_search(&ignore_table, (uchar*) hash_key, len))

	return(0); 

    }

    if (wild_do_table_inited && 

	find_wild(&wild_do_table, hash_key, len))

      return(1);

    if (wild_ignore_table_inited && 

	find_wild(&wild_ignore_table, hash_key, len))

      return(0);

  }

  /*

    If no table was to be updated, ignore statement (no reason we play it on

    slave, slave is supposed to replicate _changes_ only).

    If no explicit rule found and there was a do list, do not replicate.

    If there was no do list, go ahead

  */

  return(some_tables_updating &&

              !do_table_inited && !wild_do_table_inited);

}

/*

  Checks whether a db matches some do_db and ignore_db rules

  SYNOPSIS

    db_ok()

    db              name of the db to check

  RETURN VALUES

    0           should not be logged/replicated

    1           should be logged/replicated                  

*/

bool

Rpl_filter::db_ok(const char* db)

{

  if (do_db.is_empty() && ignore_db.is_empty())

    return(1); // Ok to replicate if the user puts no constraints

  /*

    If the user has specified restrictions on which databases to replicate

    and db was not selected, do not replicate.

  */

  if (!db)

    return(0);

  if (!do_db.is_empty()) // if the do's are not empty

  {

    I_List_iterator<i_string> it(do_db);

    i_string* tmp;

    while ((tmp=it++))

    {

      if (!strcmp(tmp->ptr, db))

	return(1); // match

    }

    return(0);

  }

  else // there are some elements in the don't, otherwise we cannot get here

  {

    I_List_iterator<i_string> it(ignore_db);

    i_string* tmp;

    while ((tmp=it++))

    {

      if (!strcmp(tmp->ptr, db))

	return(0); // match

    }

    return(1);

  }

}

/*

  Checks whether a db matches wild_do_table and wild_ignore_table

  rules (for replication)

  SYNOPSIS

    db_ok_with_wild_table()

    db		name of the db to check.

		Is tested with check_db_name() before calling this function.

  NOTES

    Here is the reason for this function.

    We advise users who want to exclude a database 'db1' safely to do it

    with replicate_wild_ignore_table='db1.%' instead of binlog_ignore_db or

    replicate_ignore_db because the two lasts only check for the selected db,

    which won't work in that case:

    USE db2;

    UPDATE db1.t SET ... #this will be replicated and should not

    whereas replicate_wild_ignore_table will work in all cases.

    With replicate_wild_ignore_table, we only check tables. When

    one does 'DROP DATABASE db1', tables are not involved and the

    statement will be replicated, while users could expect it would not (as it

    rougly means 'DROP db1.first_table, DROP db1.second_table...').

    In other words, we want to interpret 'db1.%' as "everything touching db1".

    That is why we want to match 'db1' against 'db1.%' wild table rules.

  RETURN VALUES

    0           should not be logged/replicated

    1           should be logged/replicated

*/

bool

Rpl_filter::db_ok_with_wild_table(const char *db)

{

  char hash_key[NAME_LEN+2];

  char *end;

  int len;

  end= stpcpy(hash_key, db);

  *end++= '.';

  len= end - hash_key ;

  if (wild_do_table_inited && find_wild(&wild_do_table, hash_key, len))

  {

    return(1);

  }

  if (wild_ignore_table_inited && find_wild(&wild_ignore_table, hash_key, len))

  {

    return(0);

  }  

  /*

    If no explicit rule found and there was a do list, do not replicate.

    If there was no do list, go ahead

  */

  return(!wild_do_table_inited);

}

bool

Rpl_filter::is_on()

{

  return table_rules_on;

}

int 

Rpl_filter::add_do_table(const char* table_spec) 

{

  if (!do_table_inited)

    init_table_rule_hash(&do_table, &do_table_inited);

  table_rules_on= 1;

  return(add_table_rule(&do_table, table_spec));

}

int 

Rpl_filter::add_ignore_table(const char* table_spec) 

{

  if (!ignore_table_inited)

    init_table_rule_hash(&ignore_table, &ignore_table_inited);

  table_rules_on= 1;

  return(add_table_rule(&ignore_table, table_spec));

}

int 

Rpl_filter::add_wild_do_table(const char* table_spec)

{

  if (!wild_do_table_inited)

    init_table_rule_array(&wild_do_table, &wild_do_table_inited);

  table_rules_on= 1;

  return(add_wild_table_rule(&wild_do_table, table_spec));

}

int 

Rpl_filter::add_wild_ignore_table(const char* table_spec) 

{

  if (!wild_ignore_table_inited)

    init_table_rule_array(&wild_ignore_table, &wild_ignore_table_inited);

  table_rules_on= 1;

  return(add_wild_table_rule(&wild_ignore_table, table_spec));

}

void

Rpl_filter::add_db_rewrite(const char* from_db, const char* to_db)

{

  i_string_pair *db_pair = new i_string_pair(from_db, to_db);

  rewrite_db.push_back(db_pair);

}

int 

Rpl_filter::add_table_rule(HASH* h, const char* table_spec)

{

  const char* dot = strchr(table_spec, '.');

  if (!dot) return 1;

  // len is always > 0 because we know the there exists a '.'

  uint len = (uint)strlen(table_spec);

  TABLE_RULE_ENT* e = (TABLE_RULE_ENT*)my_malloc(sizeof(TABLE_RULE_ENT)

						 + len, MYF(MY_WME));

  if (!e) return 1;

  e->db= (char*)e + sizeof(TABLE_RULE_ENT);

  e->tbl_name= e->db + (dot - table_spec) + 1;

  e->key_len= len;

  memcpy(e->db, table_spec, len);

  return my_hash_insert(h, (uchar*)e);

}

/*

  Add table expression with wildcards to dynamic array

*/

int 

Rpl_filter::add_wild_table_rule(DYNAMIC_ARRAY* a, const char* table_spec)

{

  const char* dot = strchr(table_spec, '.');

  if (!dot) return 1;

  uint len = (uint)strlen(table_spec);

  TABLE_RULE_ENT* e = (TABLE_RULE_ENT*)my_malloc(sizeof(TABLE_RULE_ENT)

						 + len, MYF(MY_WME));

  if (!e) return 1;

  e->db= (char*)e + sizeof(TABLE_RULE_ENT);

  e->tbl_name= e->db + (dot - table_spec) + 1;

  e->key_len= len;

  memcpy(e->db, table_spec, len);

  insert_dynamic(a, (uchar*)&e);

  return 0;

}

void

Rpl_filter::add_do_db(const char* table_spec)

{

  i_string *db = new i_string(table_spec);

  do_db.push_back(db);

}

void

Rpl_filter::add_ignore_db(const char* table_spec)

{

  i_string *db = new i_string(table_spec);

  ignore_db.push_back(db);

}

extern "C" uchar *get_table_key(const uchar *, size_t *, bool);

extern "C" void free_table_ent(void* a);

uchar *get_table_key(const uchar* a, size_t *len,

                     bool __attribute__((unused)))

{

  TABLE_RULE_ENT *e= (TABLE_RULE_ENT *) a;

  *len= e->key_len;

  return (uchar*)e->db;

}

void free_table_ent(void* a)

{

  TABLE_RULE_ENT *e= (TABLE_RULE_ENT *) a;

  my_free((uchar*) e, MYF(0));

}

void 

Rpl_filter::init_table_rule_hash(HASH* h, bool* h_inited)

{

  hash_init(h, system_charset_info,TABLE_RULE_HASH_SIZE,0,0,

	    get_table_key, free_table_ent, 0);

  *h_inited = 1;

}

void 

Rpl_filter::init_table_rule_array(DYNAMIC_ARRAY* a, bool* a_inited)

{

  my_init_dynamic_array(a, sizeof(TABLE_RULE_ENT*), TABLE_RULE_ARR_SIZE,

			TABLE_RULE_ARR_SIZE);

  *a_inited = 1;

}

TABLE_RULE_ENT* 

Rpl_filter::find_wild(DYNAMIC_ARRAY *a, const char* key, int len)

{

  uint i;

  const char* key_end= key + len;

  for (i= 0; i < a->elements; i++)

  {

    TABLE_RULE_ENT* e ;

    get_dynamic(a, (uchar*)&e, i);

    if (!my_wildcmp(system_charset_info, key, key_end, 

		    (const char*)e->db,

		    (const char*)(e->db + e->key_len),

		    '\\',wild_one,wild_many))

      return e;

  }

  return 0;

}

void 

Rpl_filter::free_string_array(DYNAMIC_ARRAY *a)

{

  uint i;

  for (i= 0; i < a->elements; i++)

  {

    char* p;

    get_dynamic(a, (uchar*) &p, i);

    my_free(p, MYF(MY_WME));

  }

  delete_dynamic(a);

}

/*

  Builds a String from a HASH of TABLE_RULE_ENT. Cannot be used for any other 

  hash, as it assumes that the hash entries are TABLE_RULE_ENT.

  SYNOPSIS

    table_rule_ent_hash_to_str()

    s               pointer to the String to fill

    h               pointer to the HASH to read

  RETURN VALUES

    none

*/

void 

Rpl_filter::table_rule_ent_hash_to_str(String* s, HASH* h, bool inited)

{

  s->length(0);

  if (inited)

  {

    for (uint i= 0; i < h->records; i++)

    {

      TABLE_RULE_ENT* e= (TABLE_RULE_ENT*) hash_element(h, i);

      if (s->length())

        s->append(',');

      s->append(e->db,e->key_len);

    }

  }

}

void 

Rpl_filter::table_rule_ent_dynamic_array_to_str(String* s, DYNAMIC_ARRAY* a,

                                                bool inited)

{

  s->length(0);

  if (inited)

  {

    for (uint i= 0; i < a->elements; i++)

    {

      TABLE_RULE_ENT* e;

      get_dynamic(a, (uchar*)&e, i);

      if (s->length())

        s->append(',');

      s->append(e->db,e->key_len);

    }

  }

}

void

Rpl_filter::get_do_table(String* str)

{

  table_rule_ent_hash_to_str(str, &do_table, do_table_inited);

}

void

Rpl_filter::get_ignore_table(String* str)

{

  table_rule_ent_hash_to_str(str, &ignore_table, ignore_table_inited);

}

void

Rpl_filter::get_wild_do_table(String* str)

{

  table_rule_ent_dynamic_array_to_str(str, &wild_do_table, wild_do_table_inited);

}

void

Rpl_filter::get_wild_ignore_table(String* str)

{

  table_rule_ent_dynamic_array_to_str(str, &wild_ignore_table, wild_ignore_table_inited);

}

const char*

Rpl_filter::get_rewrite_db(const char* db, size_t *new_len)

{

  if (rewrite_db.is_empty() || !db)

    return db;

  I_List_iterator<i_string_pair> it(rewrite_db);

  i_string_pair* tmp;

  while ((tmp=it++))

  {

    if (!strcmp(tmp->key, db))

    {

      *new_len= strlen(tmp->val);

      return tmp->val;

    }

  }

  return db;

}

I_List<i_string>*

Rpl_filter::get_do_db()

{

  return &do_db;

}

I_List<i_string>*

Rpl_filter::get_ignore_db()

{

  return &ignore_db;

}