diff --git a/sql/field.cc b/sql/field.cc index 7c25e4ad9f7..946351efe36 100644 --- a/sql/field.cc +++ b/sql/field.cc @@ -1515,7 +1515,8 @@ bool Field::optimize_range(uint idx, uint part) } -Field *Field::new_field(MEM_ROOT *root, struct st_table *new_table) +Field *Field::new_field(MEM_ROOT *root, struct st_table *new_table, + bool keep_type __attribute__((unused))) { Field *tmp; if (!(tmp= (Field*) memdup_root(root,(char*) this,size_of()))) @@ -1540,7 +1541,7 @@ Field *Field::new_key_field(MEM_ROOT *root, struct st_table *new_table, uint new_null_bit) { Field *tmp; - if ((tmp= new_field(root, new_table))) + if ((tmp= new_field(root, new_table, table == new_table))) { tmp->ptr= new_ptr; tmp->null_ptr= new_null_ptr; @@ -6227,29 +6228,21 @@ uint Field_string::max_packed_col_length(uint max_length) } -Field *Field_string::new_field(MEM_ROOT *root, struct st_table *new_table) +Field *Field_string::new_field(MEM_ROOT *root, struct st_table *new_table, + bool keep_type) { Field *new_field; - if (type() != MYSQL_TYPE_VAR_STRING || table == new_table) - return Field::new_field(root, new_table); + if (type() != MYSQL_TYPE_VAR_STRING || keep_type) + return Field::new_field(root, new_table, keep_type); /* Old VARCHAR field which should be modified to a VARCHAR on copy This is done to ensure that ALTER TABLE will convert old VARCHAR fields to now VARCHAR fields. */ - if ((new_field= new Field_varstring(field_length, maybe_null(), - field_name, new_table, charset()))) - { - /* - delayed_insert::get_local_table() needs a ptr copied from old table. - This is what other new_field() methods do too. The above method of - Field_varstring sets ptr to NULL. - */ - new_field->ptr= ptr; - } - return new_field; + return new Field_varstring(field_length, maybe_null(), + field_name, new_table, charset()); } /**************************************************************************** @@ -6741,9 +6734,11 @@ int Field_varstring::cmp_binary(const char *a_ptr, const char *b_ptr, } -Field *Field_varstring::new_field(MEM_ROOT *root, struct st_table *new_table) +Field *Field_varstring::new_field(MEM_ROOT *root, struct st_table *new_table, + bool keep_type) { - Field_varstring *res= (Field_varstring*) Field::new_field(root, new_table); + Field_varstring *res= (Field_varstring*) Field::new_field(root, new_table, + keep_type); if (res) res->length_bytes= length_bytes; return res; diff --git a/sql/field.h b/sql/field.h index ed13372df71..3b33d3651e3 100644 --- a/sql/field.h +++ b/sql/field.h @@ -211,7 +211,8 @@ public: */ virtual bool can_be_compared_as_longlong() const { return FALSE; } virtual void free() {} - virtual Field *new_field(MEM_ROOT *root, struct st_table *new_table); + virtual Field *new_field(MEM_ROOT *root, struct st_table *new_table, + bool keep_type); virtual Field *new_key_field(MEM_ROOT *root, struct st_table *new_table, char *new_ptr, uchar *new_null_ptr, uint new_null_bit); @@ -1033,7 +1034,7 @@ public: enum_field_types real_type() const { return FIELD_TYPE_STRING; } bool has_charset(void) const { return charset() == &my_charset_bin ? FALSE : TRUE; } - Field *new_field(MEM_ROOT *root, struct st_table *new_table); + Field *new_field(MEM_ROOT *root, struct st_table *new_table, bool keep_type); }; @@ -1105,7 +1106,7 @@ public: enum_field_types real_type() const { return MYSQL_TYPE_VARCHAR; } bool has_charset(void) const { return charset() == &my_charset_bin ? FALSE : TRUE; } - Field *new_field(MEM_ROOT *root, struct st_table *new_table); + Field *new_field(MEM_ROOT *root, struct st_table *new_table, bool keep_type); Field *new_key_field(MEM_ROOT *root, struct st_table *new_table, char *new_ptr, uchar *new_null_ptr, uint new_null_bit); diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc index ba0d2d00f2c..5db387d557c 100644 --- a/sql/sql_insert.cc +++ b/sql/sql_insert.cc @@ -17,6 +17,44 @@ /* Insert of records */ +/* + INSERT DELAYED + + Insert delayed is distinguished from a normal insert by lock_type == + TL_WRITE_DELAYED instead of TL_WRITE. It first tries to open a + "delayed" table (delayed_get_table()), but falls back to + open_and_lock_tables() on error and proceeds as normal insert then. + + Opening a "delayed" table means to find a delayed insert thread that + has the table open already. If this fails, a new thread is created and + waited for to open and lock the table. + + If accessing the thread succeeded, in + delayed_insert::get_local_table() the table of the thread is copied + for local use. A copy is required because the normal insert logic + works on a target table, but the other threads table object must not + be used. The insert logic uses the record buffer to create a record. + And the delayed insert thread uses the record buffer to pass the + record to the table handler. So there must be different objects. Also + the copied table is not included in the lock, so that the statement + can proceed even if the real table cannot be accessed at this moment. + + Copying a table object is not a trivial operation. Besides the TABLE + object there are the field pointer array, the field objects and the + record buffer. After copying the field objects, their pointers into + the record must be "moved" to point to the new record buffer. + + After this setup the normal insert logic is used. Only that for + delayed inserts write_delayed() is called instead of write_record(). + It inserts the rows into a queue and signals the delayed insert thread + instead of writing directly to the table. + + The delayed insert thread awakes from the signal. It locks the table, + inserts the rows from the queue, unlocks the table, and waits for the + next signal. It does normally live until a FLUSH TABLES or SHUTDOWN. + +*/ + #include "mysql_priv.h" #include "sp_head.h" #include "sql_trigger.h" @@ -1441,6 +1479,7 @@ TABLE *delayed_insert::get_local_table(THD* client_thd) my_ptrdiff_t adjust_ptrs; Field **field,**org_field, *found_next_number_field; TABLE *copy; + DBUG_ENTER("delayed_insert::get_local_table"); /* First request insert thread to get a lock */ status=1; @@ -1464,31 +1503,47 @@ TABLE *delayed_insert::get_local_table(THD* client_thd) } } + /* + Allocate memory for the TABLE object, the field pointers array, and + one record buffer of reclength size. Normally a table has three + record buffers of rec_buff_length size, which includes alignment + bytes. Since the table copy is used for creating one record only, + the other record buffers and alignment are unnecessary. + */ client_thd->proc_info="allocating local table"; copy= (TABLE*) client_thd->alloc(sizeof(*copy)+ (table->s->fields+1)*sizeof(Field**)+ table->s->reclength); if (!copy) goto error; + + /* Copy the TABLE object. */ *copy= *table; copy->s= ©->share_not_to_be_used; // No name hashing bzero((char*) ©->s->name_hash,sizeof(copy->s->name_hash)); /* We don't need to change the file handler here */ - field=copy->field=(Field**) (copy+1); - copy->record[0]=(byte*) (field+table->s->fields+1); - memcpy((char*) copy->record[0],(char*) table->record[0],table->s->reclength); + /* Assign the pointers for the field pointers array and the record. */ + field= copy->field= (Field**) (copy + 1); + copy->record[0]= (byte*) (field + table->s->fields + 1); + memcpy((char*) copy->record[0], (char*) table->record[0], + table->s->reclength); - /* Make a copy of all fields */ + /* + Make a copy of all fields. + The copied fields need to point into the copied record. This is done + by copying the field objects with their old pointer values and then + "move" the pointers by the distance between the original and copied + records. That way we preserve the relative positions in the records. + */ + adjust_ptrs= PTR_BYTE_DIFF(copy->record[0], table->record[0]); - adjust_ptrs=PTR_BYTE_DIFF(copy->record[0],table->record[0]); - - found_next_number_field=table->found_next_number_field; - for (org_field=table->field ; *org_field ; org_field++,field++) + found_next_number_field= table->found_next_number_field; + for (org_field= table->field; *org_field; org_field++, field++) { - if (!(*field= (*org_field)->new_field(client_thd->mem_root,copy))) - return 0; + if (!(*field= (*org_field)->new_field(client_thd->mem_root, copy, 1))) + DBUG_RETURN(0); (*field)->orig_table= copy; // Remove connection (*field)->move_field(adjust_ptrs); // Point at copy->record[0] if (*org_field == found_next_number_field) @@ -1515,14 +1570,14 @@ TABLE *delayed_insert::get_local_table(THD* client_thd) /* Adjust lock_count. This table object is not part of a lock. */ copy->lock_count= 0; - return copy; + DBUG_RETURN(copy); /* Got fatal error */ error: tables_in_use--; status=1; pthread_cond_signal(&cond); // Inform thread about abort - return 0; + DBUG_RETURN(0); } diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 41ff9185cfb..400342854a6 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -8017,7 +8017,8 @@ Field* create_tmp_field_from_field(THD *thd, Field* org_field, org_field->field_name, table, org_field->charset()); else - new_field= org_field->new_field(thd->mem_root, table); + new_field= org_field->new_field(thd->mem_root, table, + table == org_field->table); if (new_field) { if (item) @@ -13062,7 +13063,7 @@ setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param, saved value */ Field *field= item->field; - item->result_field=field->new_field(thd->mem_root,field->table); + item->result_field=field->new_field(thd->mem_root,field->table, 1); char *tmp=(char*) sql_alloc(field->pack_length()+1); if (!tmp) goto err; diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc index 28d7dc0bb9d..2773dcb14ff 100644 --- a/sql/sql_trigger.cc +++ b/sql/sql_trigger.cc @@ -747,7 +747,8 @@ bool Table_triggers_list::prepare_record1_accessors(TABLE *table) QQ: it is supposed that it is ok to use this function for field cloning... */ - if (!(*old_fld= (*fld)->new_field(&table->mem_root, table))) + if (!(*old_fld= (*fld)->new_field(&table->mem_root, table, + table == (*fld)->table))) return 1; (*old_fld)->move_field((my_ptrdiff_t)(table->record[1] - table->record[0])); diff --git a/sql/table.cc b/sql/table.cc index 83711577699..728b98b2d35 100644 --- a/sql/table.cc +++ b/sql/table.cc @@ -804,7 +804,8 @@ int openfrm(THD *thd, const char *name, const char *alias, uint db_stat, if (!(field->flags & BLOB_FLAG)) { // Create a new field field=key_part->field=field->new_field(&outparam->mem_root, - outparam); + outparam, + outparam == field->table); field->field_length=key_part->length; } }