page0cur.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

are no user records, sets the cursor on the infimum record. */

void
page_cur_open_on_rnd_user_rec(
/*==========================*/
	page_t*		page,	/* in: page */
	page_cur_t*	cursor)	/* in/out: page cursor */
{
	ulint	rnd;
	rec_t*	rec;

	if (page_get_n_recs(page) == 0) {
		page_cur_position(page_get_infimum_rec(page), cursor);

		return;
	}	

	page_rnd += 87584577;	

	rnd = page_rnd % page_get_n_recs(page);

	rec = page_get_infimum_rec(page);

	rec = page_rec_get_next(rec);

	while (rnd > 0) {
		rec = page_rec_get_next(rec);

		rnd--;
	}

	page_cur_position(rec, cursor);
}	
	
/***************************************************************
Writes the log record of a record insert on a page. */
static
void
page_cur_insert_rec_write_log(
/*==========================*/
	rec_t*		insert_rec,	/* in: inserted physical record */
	ulint		rec_size,	/* in: insert_rec size */
	rec_t*		cursor_rec,	/* in: record the
					cursor is pointing to */
	dict_index_t*	index,		/* in: record descriptor */
	mtr_t*		mtr)		/* in: mini-transaction handle */
{
	ulint	cur_rec_size;
	ulint	extra_size;
	ulint	cur_extra_size;
	ulint	min_rec_size;
	byte*	ins_ptr;
	byte*	cur_ptr;
	ulint	extra_info_yes;
	byte*	log_ptr;
	byte*	log_end;
	ulint	i;
	ulint	comp;

	ut_a(rec_size < UNIV_PAGE_SIZE);
	ut_ad(buf_frame_align(insert_rec) == buf_frame_align(cursor_rec));
	ut_ad(!page_rec_is_comp(insert_rec) == !index->table->comp);
	comp = page_rec_is_comp(insert_rec);

	{
		mem_heap_t*	heap		= NULL;
		ulint		cur_offs_[REC_OFFS_NORMAL_SIZE];
		ulint		ins_offs_[REC_OFFS_NORMAL_SIZE];

		ulint*		cur_offs;
		ulint*		ins_offs;

		*cur_offs_ = (sizeof cur_offs_) / sizeof *cur_offs_;
		*ins_offs_ = (sizeof ins_offs_) / sizeof *ins_offs_;

		cur_offs = rec_get_offsets(cursor_rec, index, cur_offs_,
						ULINT_UNDEFINED, &heap);
		ins_offs = rec_get_offsets(insert_rec, index, ins_offs_,
						ULINT_UNDEFINED, &heap);

		extra_size = rec_offs_extra_size(ins_offs);
		cur_extra_size = rec_offs_extra_size(cur_offs);
		ut_ad(rec_size == rec_offs_size(ins_offs));
		cur_rec_size = rec_offs_size(cur_offs);

		if (UNIV_LIKELY_NULL(heap)) {
			mem_heap_free(heap);
		}
	}

	ins_ptr = insert_rec - extra_size;

	i = 0;

	if (cur_extra_size == extra_size) {
		min_rec_size = ut_min(cur_rec_size, rec_size);

		cur_ptr = cursor_rec - cur_extra_size;

		/* Find out the first byte in insert_rec which differs from
		cursor_rec; skip the bytes in the record info */
		
		for (;;) {
			if (i >= min_rec_size) {

				break;
			} else if (*ins_ptr == *cur_ptr) {
				i++;
				ins_ptr++;
				cur_ptr++;
			} else if ((i < extra_size)
				   && (i >= extra_size - (comp
					? REC_N_NEW_EXTRA_BYTES
					: REC_N_OLD_EXTRA_BYTES))) {
				i = extra_size;
				ins_ptr = insert_rec;
				cur_ptr = cursor_rec;
			} else {
				break;
			}
		}
	}

	if (mtr_get_log_mode(mtr) != MTR_LOG_SHORT_INSERTS) {

		log_ptr = mlog_open_and_write_index(mtr, insert_rec, index,
				comp
				? MLOG_COMP_REC_INSERT : MLOG_REC_INSERT,
				2 + 5 + 1 + 5 + 5 + MLOG_BUF_MARGIN);

		if (!log_ptr) {
			/* Logging in mtr is switched off during crash
			recovery: in that case mlog_open returns NULL */
			return;
		}

		log_end = &log_ptr[2 + 5 + 1 + 5 + 5 + MLOG_BUF_MARGIN];
		/* Write the cursor rec offset as a 2-byte ulint */
		mach_write_to_2(log_ptr, cursor_rec
					- buf_frame_align(cursor_rec));
		log_ptr += 2;
	} else {
		log_ptr = mlog_open(mtr, 5 + 1 + 5 + 5 + MLOG_BUF_MARGIN);
		if (!log_ptr) {
			/* Logging in mtr is switched off during crash
			recovery: in that case mlog_open returns NULL */
			return;
		}
		log_end = &log_ptr[5 + 1 + 5 + 5 + MLOG_BUF_MARGIN];
	}

	if ((rec_get_info_and_status_bits(insert_rec, comp) !=
	     rec_get_info_and_status_bits(cursor_rec, comp))
	    || (extra_size != cur_extra_size)
	    || (rec_size != cur_rec_size)) {

		extra_info_yes = 1;
	} else {
		extra_info_yes = 0;
	}
	
	/* Write the record end segment length and the extra info storage
	flag */
	log_ptr += mach_write_compressed(log_ptr, 2 * (rec_size - i)
							+ extra_info_yes);
	if (extra_info_yes) {
		/* Write the info bits */
		mach_write_to_1(log_ptr,
			rec_get_info_and_status_bits(insert_rec, comp));
		log_ptr++;

		/* Write the record origin offset */
		log_ptr += mach_write_compressed(log_ptr, extra_size);

		/* Write the mismatch index */
		log_ptr += mach_write_compressed(log_ptr, i);

		ut_a(i < UNIV_PAGE_SIZE);
		ut_a(extra_size < UNIV_PAGE_SIZE);
	}
	
	/* Write to the log the inserted index record end segment which
	differs from the cursor record */

	rec_size -= i;

	if (log_ptr + rec_size <= log_end) {
		memcpy(log_ptr, ins_ptr, rec_size);
		mlog_close(mtr, log_ptr + rec_size);
	} else {
		mlog_close(mtr, log_ptr);
		ut_a(rec_size < UNIV_PAGE_SIZE);
		mlog_catenate_string(mtr, ins_ptr, rec_size);
	}
}	

/***************************************************************
Parses a log record of a record insert on a page. */

byte*
page_cur_parse_insert_rec(
/*======================*/
				/* out: end of log record or NULL */
	ibool		is_short,/* in: TRUE if short inserts */
	byte*		ptr,	/* in: buffer */
	byte*		end_ptr,/* in: buffer end */
	dict_index_t*	index,	/* in: record descriptor */
	page_t*		page,	/* in: page or NULL */
	mtr_t*		mtr)	/* in: mtr or NULL */
{
	ulint	extra_info_yes;
	ulint	offset = 0; /* remove warning */
	ulint	origin_offset;
	ulint	end_seg_len;
	ulint	mismatch_index;
	rec_t*	cursor_rec;
	byte	buf1[1024];
	byte*	buf;
	byte*   ptr2 = ptr;
	ulint	info_and_status_bits = 0; /* remove warning */
	page_cur_t cursor;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	if (!is_short) {
		/* Read the cursor rec offset as a 2-byte ulint */

		if (end_ptr < ptr + 2) {

			return(NULL);
		}

		offset = mach_read_from_2(ptr);

		if (offset >= UNIV_PAGE_SIZE) {

			recv_sys->found_corrupt_log = TRUE;

			return(NULL);
		}
		
		ptr += 2;
	}

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

	if (ptr == NULL) {

		return(NULL);
	}

	extra_info_yes = end_seg_len & 0x1UL;
	end_seg_len >>= 1;

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

		return(NULL);
	}
	
	if (extra_info_yes) {
		/* Read the info bits */

		if (end_ptr < ptr + 1) {

			return(NULL);
		}
		
		info_and_status_bits = mach_read_from_1(ptr);
		ptr++;

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

		if (ptr == NULL) {

			return(NULL);
		}

		ut_a(origin_offset < UNIV_PAGE_SIZE);

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

		if (ptr == NULL) {

			return(NULL);
		}

		ut_a(mismatch_index < UNIV_PAGE_SIZE);
	}

	if (end_ptr < ptr + end_seg_len) {

		return(NULL);
	}
	
	if (page == NULL) {

		return(ptr + end_seg_len);
	}

	ut_ad(!!page_is_comp(page) == index->table->comp);

	/* Read from the log the inserted index record end segment which
	differs from the cursor record */

	if (is_short) {
		cursor_rec = page_rec_get_prev(page_get_supremum_rec(page));
	} else {
		cursor_rec = page + offset;
	}

	offsets = rec_get_offsets(cursor_rec, index, offsets,
						ULINT_UNDEFINED, &heap);

	if (extra_info_yes == 0) {
		info_and_status_bits = rec_get_info_and_status_bits(
					cursor_rec, page_is_comp(page));
		origin_offset = rec_offs_extra_size(offsets);
		mismatch_index = rec_offs_size(offsets) - end_seg_len;
	}
	
	if (mismatch_index + end_seg_len < sizeof buf1) {
		buf = buf1;
	} else {
		buf = mem_alloc(mismatch_index + end_seg_len);
	}

	/* Build the inserted record to buf */
	
        if (mismatch_index >= UNIV_PAGE_SIZE) {
		fprintf(stderr,
			"Is short %lu, info_and_status_bits %lu, offset %lu, "
			"o_offset %lu\n"
                    "mismatch index %lu, end_seg_len %lu\n"
                    "parsed len %lu\n",
		    (ulong) is_short, (ulong) info_and_status_bits,
		    (ulong) offset,
		    (ulong) origin_offset,
		    (ulong) mismatch_index, (ulong) end_seg_len,
		    (ulong) (ptr - ptr2));

		fputs("Dump of 300 bytes of log:\n", stderr);
		ut_print_buf(stderr, ptr2, 300);

	       buf_page_print(page);

	       ut_error;
	}

	ut_memcpy(buf, rec_get_start(cursor_rec, offsets), mismatch_index);
	ut_memcpy(buf + mismatch_index, ptr, end_seg_len);

	rec_set_info_and_status_bits(buf + origin_offset, page_is_comp(page),
							info_and_status_bits);

	page_cur_position(cursor_rec, &cursor);

	offsets = rec_get_offsets(buf + origin_offset, index, offsets,
						ULINT_UNDEFINED, &heap);
	page_cur_rec_insert(&cursor, buf + origin_offset, index, offsets, mtr);

	if (buf != buf1) {

		mem_free(buf);
	}

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}

	return(ptr + end_seg_len);
}	

/***************************************************************
Inserts a record next to page cursor. Returns pointer to inserted record if
succeed, i.e., enough space available, NULL otherwise. The record to be
inserted can be in a data tuple or as a physical record. The other parameter
must then be NULL. The cursor stays at the same position. */

rec_t*
page_cur_insert_rec_low(
/*====================*/
				/* out: pointer to record if succeed, NULL
				otherwise */
	page_cur_t*	cursor,	/* in: a page cursor */
	dtuple_t*	tuple,	/* in: pointer to a data tuple or NULL */
	dict_index_t*	index,	/* in: record descriptor */
	rec_t*		rec,	/* in: pointer to a physical record or NULL */
	ulint*		offsets,/* in: rec_get_offsets(rec, index) or NULL */
	mtr_t*		mtr)	/* in: mini-transaction handle */
{
	byte*		insert_buf	= NULL;
	ulint		rec_size;
	byte*		page;		/* the relevant page */
	rec_t*		last_insert;	/* cursor position at previous insert */
	rec_t*		insert_rec;	/* inserted record */
	ulint		heap_no;	/* heap number of the inserted record */
	rec_t*		current_rec;	/* current record after which the
					new record is inserted */
	rec_t*		next_rec;	/* next record after current before
					the insertion */
	ulint		owner_slot;	/* the slot which owns the
					inserted record */
	rec_t*		owner_rec;
	ulint		n_owned;
	mem_heap_t*	heap		= NULL;
	ulint		comp;

	ut_ad(cursor && mtr);
	ut_ad(tuple || rec);
	ut_ad(!(tuple && rec));
	ut_ad(rec || dtuple_check_typed(tuple));

	page = page_cur_get_page(cursor);
	comp = page_is_comp(page);
	ut_ad(index->table->comp == !!comp);

	ut_ad(cursor->rec != page_get_supremum_rec(page));	

	/* 1. Get the size of the physical record in the page */
	if (tuple != NULL) {
		rec_size = rec_get_converted_size(index, tuple);
	} else {
		if (!offsets) {
			offsets = rec_get_offsets(rec, index, offsets,
						ULINT_UNDEFINED, &heap);
		}
		ut_ad(rec_offs_validate(rec, index, offsets));
		rec_size = rec_offs_size(offsets);
	}

	/* 2. Try to find suitable space from page memory management */
	insert_buf = page_mem_alloc(page, rec_size, index, &heap_no);

	if (insert_buf == NULL) {
		if (UNIV_LIKELY_NULL(heap)) {
			mem_heap_free(heap);
		}
		return(NULL);
	}

	/* 3. Create the record */
	if (tuple != NULL) {
		insert_rec = rec_convert_dtuple_to_rec(insert_buf,
							index, tuple);
		offsets = rec_get_offsets(insert_rec, index, offsets,
						ULINT_UNDEFINED, &heap);
	} else {
		insert_rec = rec_copy(insert_buf, rec, offsets);
		ut_ad(rec_offs_validate(rec, index, offsets));
		rec_offs_make_valid(insert_rec, index, offsets);
	}

	ut_ad(insert_rec);
	ut_ad(rec_size == rec_offs_size(offsets));
	
	/* 4. Insert the record in the linked list of records */
	current_rec = cursor->rec;

	ut_ad(!comp || rec_get_status(current_rec) <= REC_STATUS_INFIMUM);
	ut_ad(!comp || rec_get_status(insert_rec) < REC_STATUS_INFIMUM);

	next_rec = page_rec_get_next(current_rec);
	ut_ad(!comp || rec_get_status(next_rec) != REC_STATUS_INFIMUM);
	page_rec_set_next(insert_rec, next_rec);
	page_rec_set_next(current_rec, insert_rec);

	page_header_set_field(page, PAGE_N_RECS, 1 + page_get_n_recs(page));

	/* 5. Set the n_owned field in the inserted record to zero,
	and set the heap_no field */