/*****************************************************************************

Copyright (c) 1995, 2011, Oracle and/or its affiliates. All Rights Reserved.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, version 2.0,
as published by the Free Software Foundation.

This program is also distributed with certain software (including
but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation.  The authors of MySQL hereby grant you an additional
permission to link the program and your derivative works with the
separately licensed software that they have included with MySQL.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License, version 2.0, for more details.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA

*****************************************************************************/

/**************************************************//**
@file mtr/mtr0log.cc
Mini-transaction log routines

Created 12/7/1995 Heikki Tuuri
*******************************************************/

#include "mtr0log.h"

#ifdef UNIV_NONINL
#include "mtr0log.ic"
#endif

#include "buf0buf.h"
#include "dict0dict.h"
#include "log0recv.h"
#include "page0page.h"

#ifndef UNIV_HOTBACKUP
# include "dict0boot.h"

/********************************************************//**
Catenates n bytes to the mtr log. */
UNIV_INTERN
void
mlog_catenate_string(
/*=================*/
	mtr_t*		mtr,	/*!< in: mtr */
	const byte*	str,	/*!< in: string to write */
	ulint		len)	/*!< in: string length */
{
	dyn_array_t*	mlog;

	if (mtr_get_log_mode(mtr) == MTR_LOG_NONE) {

		return;
	}

	mlog = &(mtr->log);

	dyn_push_string(mlog, str, len);
}

/********************************************************//**
Writes the initial part of a log record consisting of one-byte item
type and four-byte space and page numbers. Also pushes info
to the mtr memo that a buffer page has been modified. */
UNIV_INTERN
void
mlog_write_initial_log_record(
/*==========================*/
	const byte*	ptr,	/*!< in: pointer to (inside) a buffer
				frame holding the file page where
				modification is made */
	byte		type,	/*!< in: log item type: MLOG_1BYTE, ... */
	mtr_t*		mtr)	/*!< in: mini-transaction handle */
{
	byte*	log_ptr;

	ut_ad(type <= MLOG_BIGGEST_TYPE);
	ut_ad(type > MLOG_8BYTES);

	log_ptr = mlog_open(mtr, 11);

	/* If no logging is requested, we may return now */
	if (log_ptr == NULL) {

		return;
	}

	log_ptr = mlog_write_initial_log_record_fast(ptr, type, log_ptr, mtr);

	mlog_close(mtr, log_ptr);
}
#endif /* !UNIV_HOTBACKUP */

/********************************************************//**
Parses an initial log record written by mlog_write_initial_log_record.
@return	parsed record end, NULL if not a complete record */
UNIV_INTERN
byte*
mlog_parse_initial_log_record(
/*==========================*/
	byte*	ptr,	/*!< in: buffer */
	byte*	end_ptr,/*!< in: buffer end */
	byte*	type,	/*!< out: log record type: MLOG_1BYTE, ... */
	ulint*	space,	/*!< out: space id */
	ulint*	page_no)/*!< out: page number */
{
	if (end_ptr < ptr + 1) {

		return(NULL);
	}

	*type = (byte)((ulint)*ptr & ~MLOG_SINGLE_REC_FLAG);
	ut_ad(*type <= MLOG_BIGGEST_TYPE);

	ptr++;

	if (end_ptr < ptr + 2) {

		return(NULL);
	}

	ptr = mach_parse_compressed(ptr, end_ptr, space);

	if (ptr == NULL) {

		return(NULL);
	}

	ptr = mach_parse_compressed(ptr, end_ptr, page_no);

	return(ptr);
}

/********************************************************//**
Parses a log record written by mlog_write_ulint or mlog_write_ull.
@return	parsed record end, NULL if not a complete record or a corrupt record */
UNIV_INTERN
byte*
mlog_parse_nbytes(
/*==============*/
	ulint	type,	/*!< in: log record type: MLOG_1BYTE, ... */
	byte*	ptr,	/*!< in: buffer */
	byte*	end_ptr,/*!< in: buffer end */
	byte*	page,	/*!< in: page where to apply the log record, or NULL */
	void*	page_zip)/*!< in/out: compressed page, or NULL */
{
	ulint		offset;
	ulint		val;
	ib_uint64_t	dval;

	ut_a(type <= MLOG_8BYTES);
	ut_a(!page || !page_zip || fil_page_get_type(page) != FIL_PAGE_INDEX);

	if (end_ptr < ptr + 2) {

		return(NULL);
	}

	offset = mach_read_from_2(ptr);
	ptr += 2;

	if (offset >= UNIV_PAGE_SIZE) {
		recv_sys->found_corrupt_log = TRUE;

		return(NULL);
	}

	if (type == MLOG_8BYTES) {
		ptr = mach_ull_parse_compressed(ptr, end_ptr, &dval);

		if (ptr == NULL) {

			return(NULL);
		}

		if (page) {
			if (page_zip) {
				mach_write_to_8
					(((page_zip_des_t*) page_zip)->data
					 + offset, dval);
			}
			mach_write_to_8(page + offset, dval);
		}

		return(ptr);
	}

	ptr = mach_parse_compressed(ptr, end_ptr, &val);

	if (ptr == NULL) {

		return(NULL);
	}

	switch (type) {
	case MLOG_1BYTE:
		if (UNIV_UNLIKELY(val > 0xFFUL)) {
			goto corrupt;
		}
		if (page) {
			if (page_zip) {
				mach_write_to_1
					(((page_zip_des_t*) page_zip)->data
					 + offset, val);
			}
			mach_write_to_1(page + offset, val);
		}
		break;
	case MLOG_2BYTES:
		if (UNIV_UNLIKELY(val > 0xFFFFUL)) {
			goto corrupt;
		}
		if (page) {
			if (page_zip) {
				mach_write_to_2
					(((page_zip_des_t*) page_zip)->data
					 + offset, val);
			}
			mach_write_to_2(page + offset, val);
		}
		break;
	case MLOG_4BYTES:
		if (page) {
			if (page_zip) {
				mach_write_to_4
					(((page_zip_des_t*) page_zip)->data
					 + offset, val);
			}
			mach_write_to_4(page + offset, val);
		}
		break;
	default:
	corrupt:
		recv_sys->found_corrupt_log = TRUE;
		ptr = NULL;
	}

	return(ptr);
}

/********************************************************//**
Writes 1, 2 or 4 bytes to a file page. Writes the corresponding log
record to the mini-transaction log if mtr is not NULL. */
UNIV_INTERN
void
mlog_write_ulint(
/*=============*/
	byte*	ptr,	/*!< in: pointer where to write */
	ulint	val,	/*!< in: value to write */
	byte	type,	/*!< in: MLOG_1BYTE, MLOG_2BYTES, MLOG_4BYTES */
	mtr_t*	mtr)	/*!< in: mini-transaction handle */
{
	switch (type) {
	case MLOG_1BYTE:
		mach_write_to_1(ptr, val);
		break;
	case MLOG_2BYTES:
		mach_write_to_2(ptr, val);
		break;
	case MLOG_4BYTES:
		mach_write_to_4(ptr, val);
		break;
	default:
		ut_error;
	}

	if (mtr != 0) {
		byte*	log_ptr = mlog_open(mtr, 11 + 2 + 5);

		/* If no logging is requested, we may return now */

		if (log_ptr != 0) {

			log_ptr = mlog_write_initial_log_record_fast(
				ptr, type, log_ptr, mtr);

			mach_write_to_2(log_ptr, page_offset(ptr));
			log_ptr += 2;

			log_ptr += mach_write_compressed(log_ptr, val);

			mlog_close(mtr, log_ptr);
		}
	}
}

/********************************************************//**
Writes 8 bytes to a file page. Writes the corresponding log
record to the mini-transaction log, only if mtr is not NULL */
UNIV_INTERN
void
mlog_write_ull(
/*===========*/
	byte*		ptr,	/*!< in: pointer where to write */
	ib_uint64_t	val,	/*!< in: value to write */
	mtr_t*		mtr)	/*!< in: mini-transaction handle */
{
	mach_write_to_8(ptr, val);

	if (mtr != 0) {
		byte*	log_ptr = mlog_open(mtr, 11 + 2 + 9);

		/* If no logging is requested, we may return now */
		if (log_ptr != 0) {

			log_ptr = mlog_write_initial_log_record_fast(
				ptr, MLOG_8BYTES, log_ptr, mtr);

			mach_write_to_2(log_ptr, page_offset(ptr));
			log_ptr += 2;

			log_ptr += mach_ull_write_compressed(log_ptr, val);

			mlog_close(mtr, log_ptr);
		}
	}
}

#ifndef UNIV_HOTBACKUP
/********************************************************//**
Writes a string to a file page buffered in the buffer pool. Writes the
corresponding log record to the mini-transaction log. */
UNIV_INTERN
void
mlog_write_string(
/*==============*/
	byte*		ptr,	/*!< in: pointer where to write */
	const byte*	str,	/*!< in: string to write */
	ulint		len,	/*!< in: string length */
	mtr_t*		mtr)	/*!< in: mini-transaction handle */
{
	ut_ad(ptr && mtr);
	ut_a(len < UNIV_PAGE_SIZE);

	memcpy(ptr, str, len);

	mlog_log_string(ptr, len, mtr);
}

/********************************************************//**
Logs a write of a string to a file page buffered in the buffer pool.
Writes the corresponding log record to the mini-transaction log. */
UNIV_INTERN
void
mlog_log_string(
/*============*/
	byte*	ptr,	/*!< in: pointer written to */
	ulint	len,	/*!< in: string length */
	mtr_t*	mtr)	/*!< in: mini-transaction handle */
{
	byte*	log_ptr;

	ut_ad(ptr && mtr);
	ut_ad(len <= UNIV_PAGE_SIZE);

	log_ptr = mlog_open(mtr, 30);

	/* If no logging is requested, we may return now */
	if (log_ptr == NULL) {

		return;
	}

	log_ptr = mlog_write_initial_log_record_fast(ptr, MLOG_WRITE_STRING,
						     log_ptr, mtr);
	mach_write_to_2(log_ptr, page_offset(ptr));
	log_ptr += 2;

	mach_write_to_2(log_ptr, len);
	log_ptr += 2;

	mlog_close(mtr, log_ptr);

	mlog_catenate_string(mtr, ptr, len);
}
#endif /* !UNIV_HOTBACKUP */

/********************************************************//**
Parses a log record written by mlog_write_string.
@return	parsed record end, NULL if not a complete record */
UNIV_INTERN
byte*
mlog_parse_string(
/*==============*/
	byte*	ptr,	/*!< in: buffer */
	byte*	end_ptr,/*!< in: buffer end */
	byte*	page,	/*!< in: page where to apply the log record, or NULL */
	void*	page_zip)/*!< in/out: compressed page, or NULL */
{
	ulint	offset;
	ulint	len;

	ut_a(!page || !page_zip || fil_page_get_type(page) != FIL_PAGE_INDEX);

	if (end_ptr < ptr + 4) {

		return(NULL);
	}

	offset = mach_read_from_2(ptr);
	ptr += 2;
	len = mach_read_from_2(ptr);
	ptr += 2;

	if (UNIV_UNLIKELY(offset >= UNIV_PAGE_SIZE)
	    || UNIV_UNLIKELY(len + offset > UNIV_PAGE_SIZE)) {
		recv_sys->found_corrupt_log = TRUE;

		return(NULL);
	}

	if (end_ptr < ptr + len) {

		return(NULL);
	}

	if (page) {
		if (page_zip) {
			memcpy(((page_zip_des_t*) page_zip)->data
				+ offset, ptr, len);
		}
		memcpy(page + offset, ptr, len);
	}

	return(ptr + len);
}

#ifndef UNIV_HOTBACKUP
/********************************************************//**
Opens a buffer for mlog, writes the initial log record and,
if needed, the field lengths of an index.
@return	buffer, NULL if log mode MTR_LOG_NONE */
UNIV_INTERN
byte*
mlog_open_and_write_index(
/*======================*/
	mtr_t*			mtr,	/*!< in: mtr */
	const byte*		rec,	/*!< in: index record or page */
	const dict_index_t*	index,	/*!< in: record descriptor */
	byte			type,	/*!< in: log item type */
	ulint			size)	/*!< in: requested buffer size in bytes
					(if 0, calls mlog_close() and
					returns NULL) */
{
	byte*		log_ptr;
	const byte*	log_start;
	const byte*	log_end;

	ut_ad(!!page_rec_is_comp(rec) == dict_table_is_comp(index->table));

	if (!page_rec_is_comp(rec)) {
		log_start = log_ptr = mlog_open(mtr, 11 + size);
		if (!log_ptr) {
			return(NULL); /* logging is disabled */
		}
		log_ptr = mlog_write_initial_log_record_fast(rec, type,
							     log_ptr, mtr);
		log_end = log_ptr + 11 + size;
	} else {
		ulint	i;
		ulint	n	= dict_index_get_n_fields(index);
		/* total size needed */
		ulint	total	= 11 + size + (n + 2) * 2;
		ulint	alloc	= total;
		/* allocate at most DYN_ARRAY_DATA_SIZE at a time */
		if (alloc > DYN_ARRAY_DATA_SIZE) {
			alloc = DYN_ARRAY_DATA_SIZE;
		}
		log_start = log_ptr = mlog_open(mtr, alloc);
		if (!log_ptr) {
			return(NULL); /* logging is disabled */
		}
		log_end = log_ptr + alloc;
		log_ptr = mlog_write_initial_log_record_fast(rec, type,
							     log_ptr, mtr);
		mach_write_to_2(log_ptr, n);
		log_ptr += 2;
		mach_write_to_2(log_ptr,
				dict_index_get_n_unique_in_tree(index));
		log_ptr += 2;
		for (i = 0; i < n; i++) {
			dict_field_t*		field;
			const dict_col_t*	col;
			ulint			len;

			field = dict_index_get_nth_field(index, i);
			col = dict_field_get_col(field);
			len = field->fixed_len;
			ut_ad(len < 0x7fff);
			if (len == 0
			    && (col->len > 255 || col->mtype == DATA_BLOB)) {
				/* variable-length field
				with maximum length > 255 */
				len = 0x7fff;
			}
			if (col->prtype & DATA_NOT_NULL) {
				len |= 0x8000;
			}
			if (log_ptr + 2 > log_end) {
				mlog_close(mtr, log_ptr);
				ut_a(total > (ulint) (log_ptr - log_start));
				total -= log_ptr - log_start;
				alloc = total;
				if (alloc > DYN_ARRAY_DATA_SIZE) {
					alloc = DYN_ARRAY_DATA_SIZE;
				}
				log_start = log_ptr = mlog_open(mtr, alloc);
				if (!log_ptr) {
					return(NULL); /* logging is disabled */
				}
				log_end = log_ptr + alloc;
			}
			mach_write_to_2(log_ptr, len);
			log_ptr += 2;
		}
	}
	if (size == 0) {
		mlog_close(mtr, log_ptr);
		log_ptr = NULL;
	} else if (log_ptr + size > log_end) {
		mlog_close(mtr, log_ptr);
		log_ptr = mlog_open(mtr, size);
	}
	return(log_ptr);
}
#endif /* !UNIV_HOTBACKUP */

/********************************************************//**
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 row 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, 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);
}
