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/******************************************************
Database log
(c) 1995 Innobase Oy
Created 12/9/1995 Heikki Tuuri
*******************************************************/
#include "os0file.h"
#include "mach0data.h"
#include "mtr0mtr.h"
/**********************************************************
Checks by parsing that the catenated log segment for a single mtr is
consistent. */
ibool
log_check_log_recs(
/*===============*/
byte* buf, /* in: pointer to the start of the log segment
in the log_sys->buf log buffer */
ulint len, /* in: segment length in bytes */
dulint buf_start_lsn); /* in: buffer start lsn */
/****************************************************************
Gets a log block flush bit. */
UNIV_INLINE
ibool
log_block_get_flush_bit(
/*====================*/
/* out: TRUE if this block was the first
to be written in a log flush */
byte* log_block) /* in: log block */
{
if (LOG_BLOCK_FLUSH_BIT_MASK
& mach_read_from_4(log_block + LOG_BLOCK_HDR_NO)) {
return(TRUE);
}
return(FALSE);
}
/****************************************************************
Sets the log block flush bit. */
UNIV_INLINE
void
log_block_set_flush_bit(
/*====================*/
byte* log_block, /* in: log block */
ibool val) /* in: value to set */
{
ulint field;
field = mach_read_from_4(log_block + LOG_BLOCK_HDR_NO);
if (val) {
field = field | LOG_BLOCK_FLUSH_BIT_MASK;
} else {
field = field & ~LOG_BLOCK_FLUSH_BIT_MASK;
}
mach_write_to_4(log_block + LOG_BLOCK_HDR_NO, field);
}
/****************************************************************
Gets a log block number stored in the header. */
UNIV_INLINE
ulint
log_block_get_hdr_no(
/*=================*/
/* out: log block number stored in the block
header */
byte* log_block) /* in: log block */
{
return(~LOG_BLOCK_FLUSH_BIT_MASK
& mach_read_from_4(log_block + LOG_BLOCK_HDR_NO));
}
/****************************************************************
Sets the log block number stored in the header; NOTE that this must be set
before the flush bit! */
UNIV_INLINE
void
log_block_set_hdr_no(
/*=================*/
byte* log_block, /* in: log block */
ulint n) /* in: log block number: must be > 0 and
< LOG_BLOCK_FLUSH_BIT_MASK */
{
ut_ad(n > 0);
ut_ad(n < LOG_BLOCK_FLUSH_BIT_MASK);
mach_write_to_4(log_block + LOG_BLOCK_HDR_NO, n);
}
/****************************************************************
Gets a log block data length. */
UNIV_INLINE
ulint
log_block_get_data_len(
/*===================*/
/* out: log block data length measured as a
byte offset from the block start */
byte* log_block) /* in: log block */
{
return(mach_read_from_2(log_block + LOG_BLOCK_HDR_DATA_LEN));
}
/****************************************************************
Sets the log block data length. */
UNIV_INLINE
void
log_block_set_data_len(
/*===================*/
byte* log_block, /* in: log block */
ulint len) /* in: data length */
{
mach_write_to_2(log_block + LOG_BLOCK_HDR_DATA_LEN, len);
}
/****************************************************************
Gets a log block first mtr log record group offset. */
UNIV_INLINE
ulint
log_block_get_first_rec_group(
/*==========================*/
/* out: first mtr log record group byte offset
from the block start, 0 if none */
byte* log_block) /* in: log block */
{
return(mach_read_from_2(log_block + LOG_BLOCK_FIRST_REC_GROUP));
}
/****************************************************************
Sets the log block first mtr log record group offset. */
UNIV_INLINE
void
log_block_set_first_rec_group(
/*==========================*/
byte* log_block, /* in: log block */
ulint offset) /* in: offset, 0 if none */
{
mach_write_to_2(log_block + LOG_BLOCK_FIRST_REC_GROUP, offset);
}
/****************************************************************
Gets a log block checkpoint number field (4 lowest bytes). */
UNIV_INLINE
ulint
log_block_get_checkpoint_no(
/*========================*/
/* out: checkpoint no (4 lowest bytes) */
byte* log_block) /* in: log block */
{
return(mach_read_from_4(log_block + LOG_BLOCK_CHECKPOINT_NO));
}
/****************************************************************
Sets a log block checkpoint number field (4 lowest bytes). */
UNIV_INLINE
void
log_block_set_checkpoint_no(
/*========================*/
byte* log_block, /* in: log block */
dulint no) /* in: checkpoint no */
{
mach_write_to_4(log_block + LOG_BLOCK_CHECKPOINT_NO,
ut_dulint_get_low(no));
}
/****************************************************************
Converts a lsn to a log block number. */
UNIV_INLINE
ulint
log_block_convert_lsn_to_no(
/*========================*/
/* out: log block number, it is > 0 and <= 1G */
dulint lsn) /* in: lsn of a byte within the block */
{
ulint no;
no = ut_dulint_get_low(lsn) / OS_FILE_LOG_BLOCK_SIZE;
no += (ut_dulint_get_high(lsn) % OS_FILE_LOG_BLOCK_SIZE)
* 2 * (0x80000000UL / OS_FILE_LOG_BLOCK_SIZE);
no = no & 0x3FFFFFFFUL;
return(no + 1);
}
/****************************************************************
Calculates the checksum for a log block. */
UNIV_INLINE
ulint
log_block_calc_checksum(
/*====================*/
/* out: checksum */
byte* block) /* in: log block */
{
ulint sum;
ulint sh;
ulint i;
sum = 1;
sh = 0;
for (i = 0; i < OS_FILE_LOG_BLOCK_SIZE - LOG_BLOCK_TRL_SIZE; i++) {
sum = sum & 0x7FFFFFFFUL;
sum += (((ulint)(*(block + i))) << sh) + (ulint)(*(block + i));
sh++;
if (sh > 24) {
sh = 0;
}
}
return(sum);
}
/****************************************************************
Gets a log block checksum field value. */
UNIV_INLINE
ulint
log_block_get_checksum(
/*===================*/
/* out: checksum */
byte* log_block) /* in: log block */
{
return(mach_read_from_4(log_block + OS_FILE_LOG_BLOCK_SIZE
- LOG_BLOCK_CHECKSUM));
}
/****************************************************************
Sets a log block checksum field value. */
UNIV_INLINE
void
log_block_set_checksum(
/*===================*/
byte* log_block, /* in: log block */
ulint checksum) /* in: checksum */
{
mach_write_to_4(log_block + OS_FILE_LOG_BLOCK_SIZE
- LOG_BLOCK_CHECKSUM,
checksum);
}
/****************************************************************
Initializes a log block in the log buffer. */
UNIV_INLINE
void
log_block_init(
/*===========*/
byte* log_block, /* in: pointer to the log buffer */
dulint lsn) /* in: lsn within the log block */
{
ulint no;
#ifdef UNIV_SYNC_DEBUG
ut_ad(mutex_own(&(log_sys->mutex)));
#endif /* UNIV_SYNC_DEBUG */
no = log_block_convert_lsn_to_no(lsn);
log_block_set_hdr_no(log_block, no);
log_block_set_data_len(log_block, LOG_BLOCK_HDR_SIZE);
log_block_set_first_rec_group(log_block, 0);
}
/****************************************************************
Initializes a log block in the log buffer in the old format, where there
was no checksum yet. */
UNIV_INLINE
void
log_block_init_in_old_format(
/*=========================*/
byte* log_block, /* in: pointer to the log buffer */
dulint lsn) /* in: lsn within the log block */
{
ulint no;
#ifdef UNIV_SYNC_DEBUG
ut_ad(mutex_own(&(log_sys->mutex)));
#endif /* UNIV_SYNC_DEBUG */
no = log_block_convert_lsn_to_no(lsn);
log_block_set_hdr_no(log_block, no);
mach_write_to_4(log_block + OS_FILE_LOG_BLOCK_SIZE
- LOG_BLOCK_CHECKSUM, no);
log_block_set_data_len(log_block, LOG_BLOCK_HDR_SIZE);
log_block_set_first_rec_group(log_block, 0);
}
/****************************************************************
Writes to the log the string given. The log must be released with
log_release. */
UNIV_INLINE
dulint
log_reserve_and_write_fast(
/*=======================*/
/* out: end lsn of the log record, ut_dulint_zero if
did not succeed */
byte* str, /* in: string */
ulint len, /* in: string length */
dulint* start_lsn,/* out: start lsn of the log record */
ibool* success)/* out: TRUE if success */
{
log_t* log = log_sys;
ulint data_len;
dulint lsn;
*success = TRUE;
mutex_enter(&(log->mutex));
data_len = len + log->buf_free % OS_FILE_LOG_BLOCK_SIZE;
if (data_len >= OS_FILE_LOG_BLOCK_SIZE - LOG_BLOCK_TRL_SIZE) {
/* The string does not fit within the current log block
or the log block would become full */
*success = FALSE;
mutex_exit(&(log->mutex));
return(ut_dulint_zero);
}
*start_lsn = log->lsn;
ut_memcpy(log->buf + log->buf_free, str, len);
log_block_set_data_len(ut_align_down(log->buf + log->buf_free,
OS_FILE_LOG_BLOCK_SIZE),
data_len);
#ifdef UNIV_LOG_DEBUG
log->old_buf_free = log->buf_free;
log->old_lsn = log->lsn;
#endif
log->buf_free += len;
ut_ad(log->buf_free <= log->buf_size);
lsn = ut_dulint_add(log->lsn, len);
log->lsn = lsn;
#ifdef UNIV_LOG_DEBUG
log_check_log_recs(log->buf + log->old_buf_free,
log->buf_free - log->old_buf_free, log->old_lsn);
#endif
return(lsn);
}
/***************************************************************************
Releases the log mutex. */
UNIV_INLINE
void
log_release(void)
/*=============*/
{
mutex_exit(&(log_sys->mutex));
}
/****************************************************************
Gets the current lsn. */
UNIV_INLINE
dulint
log_get_lsn(void)
/*=============*/
/* out: current lsn */
{
dulint lsn;
mutex_enter(&(log_sys->mutex));
lsn = log_sys->lsn;
mutex_exit(&(log_sys->mutex));
return(lsn);
}
/***************************************************************************
Checks if there is need for a log buffer flush or a new checkpoint, and does
this if yes. Any database operation should call this when it has modified
more than about 4 pages. NOTE that this function may only be called when the
OS thread owns no synchronization objects except the dictionary mutex. */
UNIV_INLINE
void
log_free_check(void)
/*================*/
{
/* ut_ad(sync_thread_levels_empty()); */
if (log_sys->check_flush_or_checkpoint) {
log_check_margins();
}
}