/**********************************************************************//**
Adds a column definition to a table. */
UNIV_INTERN
void
dict_mem_table_add_col(
/*===================*/
dict_table_t* table, /*!< in: table */
mem_heap_t* heap, /*!< in: temporary memory heap, or NULL */
const char* name, /*!< in: column name, or NULL */
ulint mtype, /*!< in: main datatype */
ulint prtype, /*!< in: precise type */
ulint len) /*!< in: precision */
{
dict_col_t* col;
#ifndef UNIV_HOTBACKUP
ulint mbminlen;
ulint mbmaxlen;
#endif /* !UNIV_HOTBACKUP */
ulint i;
ut_ad(table);
ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
ut_ad(!heap == !name);
i = table->n_def++;
if (name) {
if (UNIV_UNLIKELY(table->n_def == table->n_cols)) {
heap = table->heap;
}
if (UNIV_LIKELY(i) && UNIV_UNLIKELY(!table->col_names)) {
/* All preceding column names are empty. */
char* s = mem_heap_zalloc(heap, table->n_def);
table->col_names = s;
}
table->col_names = dict_add_col_name(table->col_names,
i, name, heap);
}
col = dict_table_get_nth_col(table, i);
col->ind = (unsigned int) i;
col->ord_part = 0;
col->mtype = (unsigned int) mtype;
col->prtype = (unsigned int) prtype;
col->len = (unsigned int) len;
#ifndef UNIV_HOTBACKUP
dtype_get_mblen(mtype, prtype, &mbminlen, &mbmaxlen);
col->mbminlen = (unsigned int) mbminlen;
col->mbmaxlen = (unsigned int) mbmaxlen;
#endif /* !UNIV_HOTBACKUP */
}
/**********************************************************************//**
Adds a column definition to a table. */
UNIV_INTERN
void
dict_mem_table_add_col(
/*===================*/
dict_table_t* table, /*!< in: table */
mem_heap_t* heap, /*!< in: temporary memory heap, or NULL */
const char* name, /*!< in: column name, or NULL */
ulint mtype, /*!< in: main datatype */
ulint prtype, /*!< in: precise type */
ulint len) /*!< in: precision */
{
dict_col_t* col;
ulint i;
ut_ad(table);
ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
ut_ad(!heap == !name);
i = table->n_def++;
if (name) {
if (UNIV_UNLIKELY(table->n_def == table->n_cols)) {
heap = table->heap;
}
if (UNIV_LIKELY(i) && UNIV_UNLIKELY(!table->col_names)) {
/* All preceding column names are empty. */
char* s = mem_heap_zalloc(heap, table->n_def);
table->col_names = s;
}
table->col_names = dict_add_col_name(table->col_names,
i, name, heap);
}
col = dict_table_get_nth_col(table, i);
dict_mem_fill_column_struct(col, i, mtype, prtype, len);
}
/********************************************************//**
Parses a log record written by mlog_open_and_write_index.
@return parsed record end, NULL if not a complete record */
UNIV_INTERN
byte*
mlog_parse_index(
/*=============*/
byte* ptr, /*!< in: buffer */
const byte* end_ptr,/*!< in: buffer end */
ibool comp, /*!< in: TRUE=compact record format */
dict_index_t** index) /*!< out, own: dummy index */
{
ulint i, n, n_uniq;
dict_table_t* table;
dict_index_t* ind;
ut_ad(comp == FALSE || comp == TRUE);
if (comp) {
if (end_ptr < ptr + 4) {
return(NULL);
}
n = mach_read_from_2(ptr);
ptr += 2;
n_uniq = mach_read_from_2(ptr);
ptr += 2;
ut_ad(n_uniq <= n);
if (end_ptr < ptr + n * 2) {
return(NULL);
}
} else {
n = n_uniq = 1;
}
table = dict_mem_table_create("LOG_DUMMY", DICT_HDR_SPACE, n,
comp ? DICT_TF_COMPACT : 0);
ind = dict_mem_index_create("LOG_DUMMY", "LOG_DUMMY",
DICT_HDR_SPACE, 0, n);
ind->table = table;
ind->n_uniq = (unsigned int) n_uniq;
if (n_uniq != n) {
ut_a(n_uniq + DATA_ROLL_PTR <= n);
ind->type = DICT_CLUSTERED;
}
if (comp) {
for (i = 0; i < n; i++) {
ulint len = mach_read_from_2(ptr);
ptr += 2;
/* The high-order bit of len is the NOT NULL flag;
the rest is 0 or 0x7fff for variable-length fields,
and 1..0x7ffe for fixed-length fields. */
dict_mem_table_add_col(
table, NULL, NULL,
((len + 1) & 0x7fff) <= 1
? DATA_BINARY : DATA_FIXBINARY,
len & 0x8000 ? DATA_NOT_NULL : 0,
len & 0x7fff);
dict_index_add_col(ind, table,
dict_table_get_nth_col(table, i),
0);
}
dict_table_add_system_columns(table, table->heap);
if (n_uniq != n) {
/* Identify DB_TRX_ID and DB_ROLL_PTR in the index. */
ut_a(DATA_TRX_ID_LEN
== dict_index_get_nth_col(ind, DATA_TRX_ID - 1
+ n_uniq)->len);
ut_a(DATA_ROLL_PTR_LEN
== dict_index_get_nth_col(ind, DATA_ROLL_PTR - 1
+ n_uniq)->len);
ind->fields[DATA_TRX_ID - 1 + n_uniq].col
= &table->cols[n + DATA_TRX_ID];
ind->fields[DATA_ROLL_PTR - 1 + n_uniq].col
= &table->cols[n + DATA_ROLL_PTR];
}
}
/* avoid ut_ad(index->cached) in dict_index_get_n_unique_in_tree */
ind->cached = TRUE;
*index = ind;
return(ptr);
}
/*********************************************************************
Based on a table object, this function builds the entry to be inserted
in the SYS_COLUMNS system table. */
static
dtuple_t*
dict_create_sys_columns_tuple(
/*==========================*/
/* out: the tuple which should be inserted */
dict_table_t* table, /* in: table */
ulint i, /* in: column number */
mem_heap_t* heap) /* in: memory heap from which the memory for
the built tuple is allocated */
{
dict_table_t* sys_columns;
dtuple_t* entry;
const dict_col_t* column;
dfield_t* dfield;
byte* ptr;
const char* col_name;
ut_ad(table && heap);
column = dict_table_get_nth_col(table, i);
sys_columns = dict_sys->sys_columns;
entry = dtuple_create(heap, 7 + DATA_N_SYS_COLS);
/* 0: TABLE_ID -----------------------*/
dfield = dtuple_get_nth_field(entry, 0);
ptr = mem_heap_alloc(heap, 8);
mach_write_to_8(ptr, table->id);
dfield_set_data(dfield, ptr, 8);
/* 1: POS ----------------------------*/
dfield = dtuple_get_nth_field(entry, 1);
ptr = mem_heap_alloc(heap, 4);
mach_write_to_4(ptr, i);
dfield_set_data(dfield, ptr, 4);
/* 4: NAME ---------------------------*/
dfield = dtuple_get_nth_field(entry, 2);
col_name = dict_table_get_col_name(table, i);
dfield_set_data(dfield, col_name, ut_strlen(col_name));
/* 5: MTYPE --------------------------*/
dfield = dtuple_get_nth_field(entry, 3);
ptr = mem_heap_alloc(heap, 4);
mach_write_to_4(ptr, column->mtype);
dfield_set_data(dfield, ptr, 4);
/* 6: PRTYPE -------------------------*/
dfield = dtuple_get_nth_field(entry, 4);
ptr = mem_heap_alloc(heap, 4);
mach_write_to_4(ptr, column->prtype);
dfield_set_data(dfield, ptr, 4);
/* 7: LEN ----------------------------*/
dfield = dtuple_get_nth_field(entry, 5);
ptr = mem_heap_alloc(heap, 4);
mach_write_to_4(ptr, column->len);
dfield_set_data(dfield, ptr, 4);
/* 8: PREC ---------------------------*/
dfield = dtuple_get_nth_field(entry, 6);
ptr = mem_heap_alloc(heap, 4);
mach_write_to_4(ptr, 0/* unused */);
dfield_set_data(dfield, ptr, 4);
/*---------------------------------*/
dict_table_copy_types(entry, sys_columns);
return(entry);
}
/**********************************************************************//**
Reports in the undo log of an update or delete marking of a clustered index
record.
@return byte offset of the inserted undo log entry on the page if
succeed, 0 if fail */
static
ulint
trx_undo_page_report_modify(
/*========================*/
page_t* undo_page, /*!< in: undo log page */
trx_t* trx, /*!< in: transaction */
dict_index_t* index, /*!< in: clustered index where update or
delete marking is done */
const rec_t* rec, /*!< in: clustered index record which
has NOT yet been modified */
const ulint* offsets, /*!< in: rec_get_offsets(rec, index) */
const upd_t* update, /*!< in: update vector which tells the
columns to be updated; in the case of
a delete, this should be set to NULL */
ulint cmpl_info, /*!< in: compiler info on secondary
index updates */
mtr_t* mtr) /*!< in: mtr */
{
dict_table_t* table;
ulint first_free;
byte* ptr;
const byte* field;
ulint flen;
ulint col_no;
ulint type_cmpl;
byte* type_cmpl_ptr;
ulint i;
trx_id_t trx_id;
ibool ignore_prefix = FALSE;
byte ext_buf[REC_MAX_INDEX_COL_LEN
+ BTR_EXTERN_FIELD_REF_SIZE];
ut_a(dict_index_is_clust(index));
ut_ad(rec_offs_validate(rec, index, offsets));
ut_ad(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_TYPE) == TRX_UNDO_UPDATE);
table = index->table;
first_free = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_FREE);
ptr = undo_page + first_free;
ut_ad(first_free <= UNIV_PAGE_SIZE);
if (trx_undo_left(undo_page, ptr) < 50) {
/* NOTE: the value 50 must be big enough so that the general
fields written below fit on the undo log page */
return(0);
}
/* Reserve 2 bytes for the pointer to the next undo log record */
ptr += 2;
/* Store first some general parameters to the undo log */
if (!update) {
type_cmpl = TRX_UNDO_DEL_MARK_REC;
} else if (rec_get_deleted_flag(rec, dict_table_is_comp(table))) {
type_cmpl = TRX_UNDO_UPD_DEL_REC;
/* We are about to update a delete marked record.
We don't typically need the prefix in this case unless
the delete marking is done by the same transaction
(which we check below). */
ignore_prefix = TRUE;
} else {
type_cmpl = TRX_UNDO_UPD_EXIST_REC;
}
type_cmpl |= cmpl_info * TRX_UNDO_CMPL_INFO_MULT;
type_cmpl_ptr = ptr;
*ptr++ = (byte) type_cmpl;
ptr += mach_dulint_write_much_compressed(ptr, trx->undo_no);
ptr += mach_dulint_write_much_compressed(ptr, table->id);
/*----------------------------------------*/
/* Store the state of the info bits */
*ptr++ = (byte) rec_get_info_bits(rec, dict_table_is_comp(table));
/* Store the values of the system columns */
field = rec_get_nth_field(rec, offsets,
dict_index_get_sys_col_pos(
index, DATA_TRX_ID), &flen);
ut_ad(flen == DATA_TRX_ID_LEN);
trx_id = trx_read_trx_id(field);
/* If it is an update of a delete marked record, then we are
allowed to ignore blob prefixes if the delete marking was done
by some other trx as it must have committed by now for us to
allow an over-write. */
if (ignore_prefix) {
ignore_prefix = ut_dulint_cmp(trx_id, trx->id) != 0;
}
ptr += mach_dulint_write_compressed(ptr, trx_id);
field = rec_get_nth_field(rec, offsets,
dict_index_get_sys_col_pos(
index, DATA_ROLL_PTR), &flen);
ut_ad(flen == DATA_ROLL_PTR_LEN);
ptr += mach_dulint_write_compressed(ptr, trx_read_roll_ptr(field));
/*----------------------------------------*/
/* Store then the fields required to uniquely determine the
record which will be modified in the clustered index */
for (i = 0; i < dict_index_get_n_unique(index); i++) {
field = rec_get_nth_field(rec, offsets, i, &flen);
/* The ordering columns must not be stored externally. */
ut_ad(!rec_offs_nth_extern(offsets, i));
ut_ad(dict_index_get_nth_col(index, i)->ord_part);
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
ptr += mach_write_compressed(ptr, flen);
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr) < flen) {
return(0);
}
ut_memcpy(ptr, field, flen);
ptr += flen;
}
}
/*----------------------------------------*/
/* Save to the undo log the old values of the columns to be updated. */
if (update) {
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
ptr += mach_write_compressed(ptr, upd_get_n_fields(update));
for (i = 0; i < upd_get_n_fields(update); i++) {
ulint pos = upd_get_nth_field(update, i)->field_no;
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
ptr += mach_write_compressed(ptr, pos);
/* Save the old value of field */
field = rec_get_nth_field(rec, offsets, pos, &flen);
if (trx_undo_left(undo_page, ptr) < 15) {
return(0);
}
if (rec_offs_nth_extern(offsets, pos)) {
ptr = trx_undo_page_report_modify_ext(
ptr,
dict_index_get_nth_col(index, pos)
->ord_part
&& !ignore_prefix
&& flen < REC_MAX_INDEX_COL_LEN
? ext_buf : NULL,
dict_table_zip_size(table),
&field, &flen);
/* Notify purge that it eventually has to
free the old externally stored field */
trx->update_undo->del_marks = TRUE;
*type_cmpl_ptr |= TRX_UNDO_UPD_EXTERN;
} else {
ptr += mach_write_compressed(ptr, flen);
}
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr) < flen) {
return(0);
}
ut_memcpy(ptr, field, flen);
ptr += flen;
}
}
}
/*----------------------------------------*/
/* In the case of a delete marking, and also in the case of an update
where any ordering field of any index changes, store the values of all
columns which occur as ordering fields in any index. This info is used
in the purge of old versions where we use it to build and search the
delete marked index records, to look if we can remove them from the
index tree. Note that starting from 4.0.14 also externally stored
fields can be ordering in some index. Starting from 5.2, we no longer
store REC_MAX_INDEX_COL_LEN first bytes to the undo log record,
but we can construct the column prefix fields in the index by
fetching the first page of the BLOB that is pointed to by the
clustered index. This works also in crash recovery, because all pages
(including BLOBs) are recovered before anything is rolled back. */
if (!update || !(cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
byte* old_ptr = ptr;
trx->update_undo->del_marks = TRUE;
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
/* Reserve 2 bytes to write the number of bytes the stored
fields take in this undo record */
ptr += 2;
for (col_no = 0; col_no < dict_table_get_n_cols(table);
col_no++) {
const dict_col_t* col
= dict_table_get_nth_col(table, col_no);
if (col->ord_part) {
ulint pos;
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5 + 15) {
return(0);
}
pos = dict_index_get_nth_col_pos(index,
col_no);
ptr += mach_write_compressed(ptr, pos);
/* Save the old value of field */
field = rec_get_nth_field(rec, offsets, pos,
&flen);
if (rec_offs_nth_extern(offsets, pos)) {
ptr = trx_undo_page_report_modify_ext(
ptr,
flen < REC_MAX_INDEX_COL_LEN
&& !ignore_prefix
? ext_buf : NULL,
dict_table_zip_size(table),
&field, &flen);
} else {
ptr += mach_write_compressed(
ptr, flen);
}
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr)
< flen) {
return(0);
}
ut_memcpy(ptr, field, flen);
ptr += flen;
}
}
}
mach_write_to_2(old_ptr, ptr - old_ptr);
}
/*----------------------------------------*/
/* Write pointers to the previous and the next undo log records */
if (trx_undo_left(undo_page, ptr) < 2) {
return(0);
}
mach_write_to_2(ptr, first_free);
ptr += 2;
mach_write_to_2(undo_page + first_free, ptr - undo_page);
mach_write_to_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE,
ptr - undo_page);
/* Write to the REDO log about this change in the UNDO log */
trx_undof_page_add_undo_rec_log(undo_page, first_free,
ptr - undo_page, mtr);
return(first_free);
}
/*******************************************************************//**
An inverse function to row_build_index_entry. Builds a row from a
record in a clustered index.
@return own: row built; see the NOTE below! */
UNIV_INTERN
dtuple_t*
row_build(
/*======*/
ulint type, /*!< in: ROW_COPY_POINTERS or
ROW_COPY_DATA; the latter
copies also the data fields to
heap while the first only
places pointers to data fields
on the index page, and thus is
more efficient */
const dict_index_t* index, /*!< in: clustered index */
const rec_t* rec, /*!< in: record in the clustered
index; NOTE: in the case
ROW_COPY_POINTERS the data
fields in the row will point
directly into this record,
therefore, the buffer page of
this record must be at least
s-latched and the latch held
as long as the row dtuple is used! */
const ulint* offsets,/*!< in: rec_get_offsets(rec,index)
or NULL, in which case this function
will invoke rec_get_offsets() */
const dict_table_t* col_table,
/*!< in: table, to check which
externally stored columns
occur in the ordering columns
of an index, or NULL if
index->table should be
consulted instead */
row_ext_t** ext, /*!< out, own: cache of
externally stored column
prefixes, or NULL */
mem_heap_t* heap) /*!< in: memory heap from which
the memory needed is allocated */
{
dtuple_t* row;
const dict_table_t* table;
ulint n_fields;
ulint n_ext_cols;
ulint* ext_cols = NULL; /* remove warning */
ulint len;
ulint row_len;
byte* buf;
ulint i;
ulint j;
mem_heap_t* tmp_heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
rec_offs_init(offsets_);
ut_ad(index && rec && heap);
ut_ad(dict_index_is_clust(index));
ut_ad(!mutex_own(&kernel_mutex));
if (!offsets) {
offsets = rec_get_offsets(rec, index, offsets_,
ULINT_UNDEFINED, &tmp_heap);
} else {
ut_ad(rec_offs_validate(rec, index, offsets));
}
#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
if (rec_offs_any_null_extern(rec, offsets)) {
/* This condition can occur during crash recovery
before trx_rollback_active() has completed execution,
or when a concurrently executing
row_ins_index_entry_low() has committed the B-tree
mini-transaction but has not yet managed to restore
the cursor position for writing the big_rec. */
ut_a(trx_undo_roll_ptr_is_insert(
row_get_rec_roll_ptr(rec, index, offsets)));
}
#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
if (type != ROW_COPY_POINTERS) {
/* Take a copy of rec to heap */
buf = mem_heap_alloc(heap, rec_offs_size(offsets));
rec = rec_copy(buf, rec, offsets);
/* Avoid a debug assertion in rec_offs_validate(). */
rec_offs_make_valid(rec, index, (ulint*) offsets);
}
table = index->table;
row_len = dict_table_get_n_cols(table);
row = dtuple_create(heap, row_len);
dict_table_copy_types(row, table);
dtuple_set_info_bits(row, rec_get_info_bits(
rec, dict_table_is_comp(table)));
n_fields = rec_offs_n_fields(offsets);
n_ext_cols = rec_offs_n_extern(offsets);
if (n_ext_cols) {
ext_cols = mem_heap_alloc(heap, n_ext_cols * sizeof *ext_cols);
}
for (i = j = 0; i < n_fields; i++) {
dict_field_t* ind_field
= dict_index_get_nth_field(index, i);
const dict_col_t* col
= dict_field_get_col(ind_field);
ulint col_no
= dict_col_get_no(col);
dfield_t* dfield
= dtuple_get_nth_field(row, col_no);
if (ind_field->prefix_len == 0) {
const byte* field = rec_get_nth_field(
rec, offsets, i, &len);
dfield_set_data(dfield, field, len);
}
if (rec_offs_nth_extern(offsets, i)) {
dfield_set_ext(dfield);
if (UNIV_LIKELY_NULL(col_table)) {
ut_a(col_no
< dict_table_get_n_cols(col_table));
col = dict_table_get_nth_col(
col_table, col_no);
}
if (col->ord_part) {
/* We will have to fetch prefixes of
externally stored columns that are
referenced by column prefixes. */
ext_cols[j++] = col_no;
}
}
}
ut_ad(dtuple_check_typed(row));
if (!ext) {
/* REDUNDANT and COMPACT formats store a local
768-byte prefix of each externally stored
column. No cache is needed. */
ut_ad(dict_table_get_format(index->table)
< DICT_TF_FORMAT_ZIP);
} else if (j) {
*ext = row_ext_create(j, ext_cols, row,
dict_table_zip_size(index->table),
heap);
} else {
*ext = NULL;
}
if (tmp_heap) {
mem_heap_free(tmp_heap);
}
return(row);
}
byte*
mlog_parse_index(
/*=============*/
/* out: parsed record end,
NULL if not a complete record */
byte* ptr, /* in: buffer */
byte* end_ptr,/* in: buffer end */
/* out: new value of log_ptr */
ibool comp, /* in: TRUE=compact record format */
dict_index_t** index) /* out, own: dummy index */
{
ulint i, n, n_uniq;
dict_table_t* table;
dict_index_t* ind;
ut_ad(comp == FALSE || comp == TRUE);
if (comp) {
if (end_ptr < ptr + 4) {
return(NULL);
}
n = mach_read_from_2(ptr);
ptr += 2;
n_uniq = mach_read_from_2(ptr);
ut_ad(n_uniq <= n);
if (end_ptr < ptr + (n + 1) * 2) {
return(NULL);
}
} else {
n = n_uniq = 1;
}
table = dict_mem_table_create("LOG_DUMMY", DICT_HDR_SPACE, n, comp);
ind = dict_mem_index_create("LOG_DUMMY", "LOG_DUMMY",
DICT_HDR_SPACE, 0, n);
ind->table = table;
ind->n_uniq = n_uniq;
if (n_uniq != n) {
ind->type = DICT_CLUSTERED;
}
/* avoid ut_ad(index->cached) in dict_index_get_n_unique_in_tree */
ind->cached = TRUE;
if (comp) {
for (i = 0; i < n; i++) {
ulint len = mach_read_from_2(ptr += 2);
/* The high-order bit of len is the NOT NULL flag;
the rest is 0 or 0x7fff for variable-length fields,
and 1..0x7ffe for fixed-length fields. */
dict_mem_table_add_col(table, "DUMMY",
((len + 1) & 0x7fff) <= 1
? DATA_BINARY
: DATA_FIXBINARY,
len & 0x8000 ? DATA_NOT_NULL : 0,
len & 0x7fff, 0);
dict_index_add_col(ind,
dict_table_get_nth_col(table, i), 0, 0);
}
ptr += 2;
}
*index = ind;
return(ptr);
}
/**************************************************************************
Reports in the undo log of an update or delete marking of a clustered index
record. */
static
ulint
trx_undo_page_report_modify(
/*========================*/
/* out: byte offset of the inserted
undo log entry on the page if succeed,
0 if fail */
page_t* undo_page, /* in: undo log page */
trx_t* trx, /* in: transaction */
dict_index_t* index, /* in: clustered index where update or
delete marking is done */
rec_t* rec, /* in: clustered index record which
has NOT yet been modified */
const ulint* offsets, /* in: rec_get_offsets(rec, index) */
upd_t* update, /* in: update vector which tells the
columns to be updated; in the case of
a delete, this should be set to NULL */
ulint cmpl_info, /* in: compiler info on secondary
index updates */
mtr_t* mtr) /* in: mtr */
{
dict_table_t* table;
upd_field_t* upd_field;
ulint first_free;
byte* ptr;
ulint len;
byte* field;
ulint flen;
ulint pos;
dulint roll_ptr;
dulint trx_id;
ulint bits;
ulint col_no;
byte* old_ptr;
ulint type_cmpl;
byte* type_cmpl_ptr;
ulint i;
ut_a(index->type & DICT_CLUSTERED);
ut_ad(rec_offs_validate(rec, index, offsets));
ut_ad(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_TYPE) == TRX_UNDO_UPDATE);
table = index->table;
first_free = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_FREE);
ptr = undo_page + first_free;
ut_ad(first_free <= UNIV_PAGE_SIZE);
if (trx_undo_left(undo_page, ptr) < 50) {
/* NOTE: the value 50 must be big enough so that the general
fields written below fit on the undo log page */
return(0);
}
/* Reserve 2 bytes for the pointer to the next undo log record */
ptr += 2;
/* Store first some general parameters to the undo log */
if (update) {
if (rec_get_deleted_flag(rec, dict_table_is_comp(table))) {
type_cmpl = TRX_UNDO_UPD_DEL_REC;
} else {
type_cmpl = TRX_UNDO_UPD_EXIST_REC;
}
} else {
type_cmpl = TRX_UNDO_DEL_MARK_REC;
}
type_cmpl = type_cmpl | (cmpl_info * TRX_UNDO_CMPL_INFO_MULT);
mach_write_to_1(ptr, type_cmpl);
type_cmpl_ptr = ptr;
ptr++;
len = mach_dulint_write_much_compressed(ptr, trx->undo_no);
ptr += len;
len = mach_dulint_write_much_compressed(ptr, table->id);
ptr += len;
/*----------------------------------------*/
/* Store the state of the info bits */
bits = rec_get_info_bits(rec, dict_table_is_comp(table));
mach_write_to_1(ptr, bits);
ptr += 1;
/* Store the values of the system columns */
field = rec_get_nth_field(rec, offsets,
dict_index_get_sys_col_pos(
index, DATA_TRX_ID), &len);
ut_ad(len == DATA_TRX_ID_LEN);
trx_id = trx_read_trx_id(field);
field = rec_get_nth_field(rec, offsets,
dict_index_get_sys_col_pos(
index, DATA_ROLL_PTR), &len);
ut_ad(len == DATA_ROLL_PTR_LEN);
roll_ptr = trx_read_roll_ptr(field);
len = mach_dulint_write_compressed(ptr, trx_id);
ptr += len;
len = mach_dulint_write_compressed(ptr, roll_ptr);
ptr += len;
/*----------------------------------------*/
/* Store then the fields required to uniquely determine the
record which will be modified in the clustered index */
for (i = 0; i < dict_index_get_n_unique(index); i++) {
field = rec_get_nth_field(rec, offsets, i, &flen);
if (trx_undo_left(undo_page, ptr) < 4) {
return(0);
}
len = mach_write_compressed(ptr, flen);
ptr += len;
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr) < flen) {
return(0);
}
ut_memcpy(ptr, field, flen);
ptr += flen;
}
}
/*----------------------------------------*/
/* Save to the undo log the old values of the columns to be updated. */
if (update) {
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
len = mach_write_compressed(ptr, upd_get_n_fields(update));
ptr += len;
for (i = 0; i < upd_get_n_fields(update); i++) {
upd_field = upd_get_nth_field(update, i);
pos = upd_field->field_no;
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
len = mach_write_compressed(ptr, pos);
ptr += len;
/* Save the old value of field */
field = rec_get_nth_field(rec, offsets, pos, &flen);
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
if (rec_offs_nth_extern(offsets, pos)) {
/* If a field has external storage, we add
to flen the flag */
len = mach_write_compressed(
ptr,
UNIV_EXTERN_STORAGE_FIELD + flen);
/* Notify purge that it eventually has to
free the old externally stored field */
trx->update_undo->del_marks = TRUE;
*type_cmpl_ptr = *type_cmpl_ptr
| TRX_UNDO_UPD_EXTERN;
} else {
len = mach_write_compressed(ptr, flen);
}
ptr += len;
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr) < flen) {
return(0);
}
ut_memcpy(ptr, field, flen);
ptr += flen;
}
}
}
/*----------------------------------------*/
/* In the case of a delete marking, and also in the case of an update
where any ordering field of any index changes, store the values of all
columns which occur as ordering fields in any index. This info is used
in the purge of old versions where we use it to build and search the
delete marked index records, to look if we can remove them from the
index tree. Note that starting from 4.0.14 also externally stored
fields can be ordering in some index. But we always store at least
384 first bytes locally to the clustered index record, which means
we can construct the column prefix fields in the index from the
stored data. */
if (!update || !(cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
trx->update_undo->del_marks = TRUE;
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
old_ptr = ptr;
/* Reserve 2 bytes to write the number of bytes the stored
fields take in this undo record */
ptr += 2;
for (col_no = 0; col_no < dict_table_get_n_cols(table);
col_no++) {
const dict_col_t* col
= dict_table_get_nth_col(table, col_no);
if (col->ord_part > 0) {
pos = dict_index_get_nth_col_pos(index,
col_no);
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
len = mach_write_compressed(ptr, pos);
ptr += len;
/* Save the old value of field */
field = rec_get_nth_field(rec, offsets, pos,
&flen);
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
len = mach_write_compressed(ptr, flen);
ptr += len;
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr)
< flen) {
return(0);
}
ut_memcpy(ptr, field, flen);
ptr += flen;
}
}
}
mach_write_to_2(old_ptr, ptr - old_ptr);
}
/*----------------------------------------*/
/* Write pointers to the previous and the next undo log records */
if (trx_undo_left(undo_page, ptr) < 2) {
return(0);
}
mach_write_to_2(ptr, first_free);
ptr += 2;
mach_write_to_2(undo_page + first_free, ptr - undo_page);
mach_write_to_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE,
ptr - undo_page);
/* Write to the REDO log about this change in the UNDO log */
trx_undof_page_add_undo_rec_log(undo_page, first_free,
ptr - undo_page, mtr);
return(first_free);
}
/********************************************************//**
Parses a log record written by mlog_open_and_write_index.
@return parsed record end, NULL if not a complete record */
UNIV_INTERN
byte*
mlog_parse_index(
/*=============*/
byte* ptr, /*!< in: buffer */
const byte* end_ptr,/*!< in: buffer end */
ibool comp, /*!< in: TRUE=compact record format */
dict_index_t** index) /*!< out, own: dummy index */
{
ulint i, n, n_uniq;
dict_table_t* table;
dict_index_t* ind;
ibool is_gcs = FALSE;
ulint n_fields_before_alter = 0; /* 快速alter table前聚集索引的字段数 */
ut_ad(comp == FALSE || comp == TRUE);
if (comp) {
if (end_ptr < ptr + 4) {
return(NULL);
}
n = mach_read_from_2(ptr);
if (n & 0x8000) /* 最高位为1表示GCS表 */
{
is_gcs = TRUE;
n &= 0x7FFF;
}
ptr += 2;
if (is_gcs)
{
n_fields_before_alter = mach_read_from_2(ptr);
ut_ad(n_fields_before_alter < n && n_fields_before_alter > 0);
ptr += 2;
/* 确保地址有效！*/
if (end_ptr < ptr + 2) {
return(NULL);
}
}
n_uniq = mach_read_from_2(ptr);
ptr += 2;
ut_ad(n_uniq <= n);
if (end_ptr < ptr + n * 2) {
return(NULL);
}
} else {
n = n_uniq = 1;
}
table = dict_mem_table_create("LOG_DUMMY", DICT_HDR_SPACE, n,
comp ? DICT_TF_COMPACT : 0, is_gcs, n_fields_before_alter);
ind = dict_mem_index_create("LOG_DUMMY", "LOG_DUMMY",
DICT_HDR_SPACE, 0, n);
ind->table = table;
ind->n_uniq = (unsigned int) n_uniq;
if (n_uniq != n) {
ut_a(n_uniq + DATA_ROLL_PTR <= n);
ind->type = DICT_CLUSTERED;
}
if (comp) {
for (i = 0; i < n; i++) {
ulint len = mach_read_from_2(ptr);
ptr += 2;
/* The high-order bit of len is the NOT NULL flag;
the rest is 0 or 0x7fff for variable-length fields,
and 1..0x7ffe for fixed-length fields. */
/* redo阶段压缩属性不需指定 */
dict_mem_table_add_col(
table, NULL, NULL,
((len + 1) & 0x7fff) <= 1
? DATA_BINARY : DATA_FIXBINARY, /* 若len 为0或0x7fff，可认为是变长字段；否则是定长字段 */
len & 0x8000 ? DATA_NOT_NULL : 0,
len & 0x7fff);
if (is_gcs && n_fields_before_alter > 0 && n_fields_before_alter <= i)
{
dict_col_t* col = NULL;
col = dict_table_get_nth_col(table, i);
/* 添加默认值信息，但只是占位符，并不需真正的默认值信息 */
if (!dict_col_is_nullable(col))
dict_mem_table_set_col_default(table, col, table->heap);
}
dict_index_add_col(ind, table,
dict_table_get_nth_col(table, i),
0);
}
dict_table_add_system_columns(table, table->heap);
if (n_uniq != n) {
/* Identify DB_TRX_ID and DB_ROLL_PTR in the index. */
ut_a(DATA_TRX_ID_LEN
== dict_index_get_nth_col(ind, DATA_TRX_ID - 1
+ n_uniq)->len);
ut_a(DATA_ROLL_PTR_LEN
== dict_index_get_nth_col(ind, DATA_ROLL_PTR - 1
+ n_uniq)->len);
ind->fields[DATA_TRX_ID - 1 + n_uniq].col
= &table->cols[n + DATA_TRX_ID];
ind->fields[DATA_ROLL_PTR - 1 + n_uniq].col
= &table->cols[n + DATA_ROLL_PTR];
/* set the col_ind col->ind */
ind->fields[DATA_TRX_ID - 1 + n_uniq].col_ind
= ind->fields[DATA_TRX_ID - 1 + n_uniq].col->ind;
ind->fields[DATA_ROLL_PTR - 1 + n_uniq].col_ind
= ind->fields[DATA_ROLL_PTR - 1 + n_uniq].col->ind;
}
if (dict_index_is_gcs_clust_after_alter_table(ind))
{
ut_ad(table->n_cols == table->n_def);
ut_a(table->n_cols_before_alter_table > 0 &&
table->n_cols_before_alter_table <= table->n_cols);
ind->n_fields_before_alter = n_fields_before_alter;
ind->n_nullable_before_alter = dict_index_get_first_n_field_n_nullable(ind, ind->n_fields_before_alter);
}
else
{
ind->n_fields_before_alter = 0;
ind->n_nullable_before_alter = 0;
}
}
/* avoid ut_ad(index->cached) in dict_index_get_n_unique_in_tree */
ind->cached = TRUE;
*index = ind;
return(ptr);
}
