/********************************************************//**
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);
}
/********************************************************//**
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);
}
