mariadb/include/row0upd.ic
marko b52a30e09d branches/zip: When storing a longer prefix of an externally stored column
to the undo log, also store the original length of the column, so that the
changes will be correctly undone in transaction rollback or when fetching
previous versions of the row.

innodb-zip.test: New file, for tests of the compression.

upd_field_t: Add orig_len, the original length of new_val.

btr_push_update_extern_fields(): Restore the original prefix of the column.
Add the parameter heap where memory will be allocated if necessary.

trx_undo_rec_get_col_val(): Add the output parameter orig_len.

trx_undo_page_report_modify_ext(): New function: Write an externally
stored column to the undo log.  This is only called from
trx_undo_page_report_modify(), and this is the only caller of
trx_undo_page_fetch_ext().

trx_undo_update_rec_get_update(): Read the original length of the column
prefix to upd_field->orig_len.
2008-01-23 13:46:45 +00:00

142 lines
3.9 KiB
Text

/******************************************************
Update of a row
(c) 1996 Innobase Oy
Created 12/27/1996 Heikki Tuuri
*******************************************************/
#include "mtr0log.h"
#include "trx0trx.h"
#include "trx0undo.h"
#include "row0row.h"
#include "btr0sea.h"
#include "page0zip.h"
/*************************************************************************
Creates an update vector object. */
UNIV_INLINE
upd_t*
upd_create(
/*=======*/
/* out, own: update vector object */
ulint n, /* in: number of fields */
mem_heap_t* heap) /* in: heap from which memory allocated */
{
upd_t* update;
update = (upd_t*) mem_heap_alloc(heap, sizeof(upd_t));
update->info_bits = 0;
update->n_fields = n;
update->fields = (upd_field_t*)
mem_heap_alloc(heap, sizeof(upd_field_t) * n);
return(update);
}
/*************************************************************************
Returns the number of fields in the update vector == number of columns
to be updated by an update vector. */
UNIV_INLINE
ulint
upd_get_n_fields(
/*=============*/
/* out: number of fields */
const upd_t* update) /* in: update vector */
{
ut_ad(update);
return(update->n_fields);
}
#ifdef UNIV_DEBUG
/*************************************************************************
Returns the nth field of an update vector. */
UNIV_INLINE
upd_field_t*
upd_get_nth_field(
/*==============*/
/* out: update vector field */
const upd_t* update, /* in: update vector */
ulint n) /* in: field position in update vector */
{
ut_ad(update);
ut_ad(n < update->n_fields);
return((upd_field_t*) update->fields + n);
}
#endif /* UNIV_DEBUG */
/*************************************************************************
Sets an index field number to be updated by an update vector field. */
UNIV_INLINE
void
upd_field_set_field_no(
/*===================*/
upd_field_t* upd_field, /* in: update vector field */
ulint field_no, /* in: field number in a clustered
index */
dict_index_t* index, /* in: index */
trx_t* trx) /* in: transaction */
{
upd_field->field_no = field_no;
upd_field->orig_len = 0;
if (UNIV_UNLIKELY(field_no >= dict_index_get_n_fields(index))) {
fprintf(stderr,
"InnoDB: Error: trying to access field %lu in ",
(ulong) field_no);
dict_index_name_print(stderr, trx, index);
fprintf(stderr, "\n"
"InnoDB: but index only has %lu fields\n",
(ulong) dict_index_get_n_fields(index));
}
dict_col_copy_type(dict_index_get_nth_col(index, field_no),
dfield_get_type(&upd_field->new_val));
}
/*************************************************************************
Updates the trx id and roll ptr field in a clustered index record when
a row is updated or marked deleted. */
UNIV_INLINE
void
row_upd_rec_sys_fields(
/*===================*/
rec_t* rec, /* in/out: record */
page_zip_des_t* page_zip,/* in/out: compressed page whose
uncompressed part will be updated, or NULL */
dict_index_t* index, /* in: clustered index */
const ulint* offsets,/* in: rec_get_offsets(rec, index) */
trx_t* trx, /* in: transaction */
dulint roll_ptr)/* in: roll ptr of the undo log record */
{
ut_ad(dict_index_is_clust(index));
ut_ad(rec_offs_validate(rec, index, offsets));
#ifdef UNIV_SYNC_DEBUG
if (!rw_lock_own(&btr_search_latch, RW_LOCK_EX)) {
buf_pool_mutex_enter();
ut_ad(!buf_block_align(rec)->is_hashed);
buf_pool_mutex_exit();
}
#endif /* UNIV_SYNC_DEBUG */
if (UNIV_LIKELY_NULL(page_zip)) {
ulint pos = dict_index_get_sys_col_pos(index, DATA_TRX_ID);
page_zip_write_trx_id_and_roll_ptr(page_zip, rec, offsets,
pos, trx->id, roll_ptr);
} else {
ulint offset = index->trx_id_offset;
if (!offset) {
offset = row_get_trx_id_offset(rec, index, offsets);
}
#if DATA_TRX_ID + 1 != DATA_ROLL_PTR
# error "DATA_TRX_ID + 1 != DATA_ROLL_PTR"
#endif
trx_write_trx_id(rec + offset, trx->id);
trx_write_roll_ptr(rec + offset + DATA_TRX_ID_LEN, roll_ptr);
}
}