char *get_next_line(const int fd)
{
static char buffer[BUF_SIZE];
int found;
char c;
int ret;
int count;
count = 0;
found = 0;
while (found == 0)
{
ret = read(fd, &c, READ_SIZE);
if (ret == 0)
{
if (my_eof(count, buffer, &found))
return (NULL);
}
else
my_line(c, buffer, &count, &found);
}
return(my_alloc(buffer));
}
bool mysqld_help(THD *thd, const char *mask)
{
Protocol *protocol= thd->protocol;
SQL_SELECT *select;
st_find_field used_fields[array_elements(init_used_fields)];
TABLE_LIST *leaves= 0;
TABLE_LIST tables[4];
List<String> topics_list, categories_list, subcategories_list;
String name, description, example;
int count_topics, count_categories, error;
uint mlen= strlen(mask);
size_t i;
MEM_ROOT *mem_root= thd->mem_root;
DBUG_ENTER("mysqld_help");
bzero((char *)((uchar*)tables),sizeof(tables));
tables[0].alias= tables[0].table_name= (char*) "help_topic";
tables[0].lock_type= TL_READ;
tables[0].next_global= tables[0].next_local=
tables[0].next_name_resolution_table= &tables[1];
tables[1].alias= tables[1].table_name= (char*) "help_category";
tables[1].lock_type= TL_READ;
tables[1].next_global= tables[1].next_local=
tables[1].next_name_resolution_table= &tables[2];
tables[2].alias= tables[2].table_name= (char*) "help_relation";
tables[2].lock_type= TL_READ;
tables[2].next_global= tables[2].next_local=
tables[2].next_name_resolution_table= &tables[3];
tables[3].alias= tables[3].table_name= (char*) "help_keyword";
tables[3].lock_type= TL_READ;
tables[0].db= tables[1].db= tables[2].db= tables[3].db= (char*) "mysql";
Open_tables_state open_tables_state_backup;
if (open_system_tables_for_read(thd, tables, &open_tables_state_backup))
goto error2;
/*
Init tables and fields to be usable from items
tables do not contain VIEWs => we can pass 0 as conds
*/
thd->lex->select_lex.context.table_list=
thd->lex->select_lex.context.first_name_resolution_table= &tables[0];
if (setup_tables(thd, &thd->lex->select_lex.context,
&thd->lex->select_lex.top_join_list,
tables, &leaves, FALSE))
goto error;
memcpy((char*) used_fields, (char*) init_used_fields, sizeof(used_fields));
if (init_fields(thd, tables, used_fields, array_elements(used_fields)))
goto error;
for (i=0; i<sizeof(tables)/sizeof(TABLE_LIST); i++)
tables[i].table->file->init_table_handle_for_HANDLER();
if (!(select=
prepare_select_for_name(thd,mask,mlen,tables,tables[0].table,
used_fields[help_topic_name].field,&error)))
goto error;
count_topics= search_topics(thd,tables[0].table,used_fields,
select,&topics_list,
&name, &description, &example);
delete select;
if (count_topics == 0)
{
int UNINIT_VAR(key_id);
if (!(select=
prepare_select_for_name(thd,mask,mlen,tables,tables[3].table,
used_fields[help_keyword_name].field,
&error)))
goto error;
count_topics= search_keyword(thd,tables[3].table, used_fields, select,
&key_id);
delete select;
count_topics= (count_topics != 1) ? 0 :
get_topics_for_keyword(thd,tables[0].table,tables[2].table,
used_fields,key_id,&topics_list,&name,
&description,&example);
}
if (count_topics == 0)
{
int16 category_id;
Field *cat_cat_id= used_fields[help_category_parent_category_id].field;
if (!(select=
prepare_select_for_name(thd,mask,mlen,tables,tables[1].table,
used_fields[help_category_name].field,
&error)))
goto error;
count_categories= search_categories(thd, tables[1].table, used_fields,
select,
&categories_list,&category_id);
delete select;
if (!count_categories)
{
if (send_header_2(protocol,FALSE))
goto error;
}
else if (count_categories > 1)
{
if (send_header_2(protocol,FALSE) ||
send_variant_2_list(mem_root,protocol,&categories_list,"Y",0))
goto error;
}
else
{
Field *topic_cat_id= used_fields[help_topic_help_category_id].field;
Item *cond_topic_by_cat=
new Item_func_equal(new Item_field(topic_cat_id),
new Item_int((int32)category_id));
Item *cond_cat_by_cat=
new Item_func_equal(new Item_field(cat_cat_id),
new Item_int((int32)category_id));
if (!(select= prepare_simple_select(thd, cond_topic_by_cat,
tables[0].table, &error)))
goto error;
get_all_items_for_category(thd,tables[0].table,
used_fields[help_topic_name].field,
select,&topics_list);
delete select;
if (!(select= prepare_simple_select(thd, cond_cat_by_cat,
tables[1].table, &error)))
goto error;
get_all_items_for_category(thd,tables[1].table,
used_fields[help_category_name].field,
select,&subcategories_list);
delete select;
String *cat= categories_list.head();
if (send_header_2(protocol, TRUE) ||
send_variant_2_list(mem_root,protocol,&topics_list, "N",cat) ||
send_variant_2_list(mem_root,protocol,&subcategories_list,"Y",cat))
goto error;
}
}
else if (count_topics == 1)
{
if (send_answer_1(protocol,&name,&description,&example))
goto error;
}
else
{
/* First send header and functions */
if (send_header_2(protocol, FALSE) ||
send_variant_2_list(mem_root,protocol, &topics_list, "N", 0))
goto error;
if (!(select=
prepare_select_for_name(thd,mask,mlen,tables,tables[1].table,
used_fields[help_category_name].field,&error)))
goto error;
search_categories(thd, tables[1].table, used_fields,
select,&categories_list, 0);
delete select;
/* Then send categories */
if (send_variant_2_list(mem_root,protocol, &categories_list, "Y", 0))
goto error;
}
my_eof(thd);
close_system_tables(thd, &open_tables_state_backup);
DBUG_RETURN(FALSE);
error:
close_system_tables(thd, &open_tables_state_backup);
error2:
DBUG_RETURN(TRUE);
}
