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

Copyright (c) 1995, 2019, 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 St, Fifth Floor, Boston, MA 02110-1301  USA

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

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

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

#include "mtr0log.h"

#ifndef UNIV_HOTBACKUP
#include "buf0buf.h"
#include "buf0dblwr.h"
#include "dict0dict.h"
#include "log0recv.h"
#endif /* !UNIV_HOTBACKUP */
#include "page0page.h"

#ifndef UNIV_HOTBACKUP
#include "dict0boot.h"
#endif /* !UNIV_HOTBACKUP */

/** Catenates n bytes to the mtr log. */
void mlog_catenate_string(mtr_t *mtr,      /*!< in: mtr */
                          const byte *str, /*!< in: string to write */
                          ulint len)       /*!< in: string length */
{
  if (mtr_get_log_mode(mtr) == MTR_LOG_NONE) {
    return;
  }

  mtr->get_log()->push(str, ib_uint32_t(len));
}

#ifndef UNIV_HOTBACKUP
/** 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. */
void mlog_write_initial_log_record(
    const byte *ptr, /*!< in: pointer to (inside) a buffer
                     frame holding the file page where
                     modification is made */
    mlog_id_t 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 */

/** Parse an initial log record written by mlog_write_initial_dict_log_record.
@param[in]	ptr		buffer
@param[in]	end_ptr		buffer end
@param[out]	type		log record type, should be
                                MLOG_TABLE_DYNAMIC_META
@param[out]	id		table id
@param[out]	version		table dynamic metadata version
@return parsed record end, NULL if not a complete record */
byte *mlog_parse_initial_dict_log_record(const byte *ptr, const byte *end_ptr,
                                         mlog_id_t *type, table_id_t *id,
                                         uint64 *version) {
  if (end_ptr < ptr + 1) {
    return (nullptr);
  }

  *type = (mlog_id_t)((ulint)*ptr & ~MLOG_SINGLE_REC_FLAG);
  ut_ad(*type == MLOG_TABLE_DYNAMIC_META);

  ptr++;

  if (end_ptr < ptr + 1) {
    return (nullptr);
  }

  *id = mach_parse_u64_much_compressed(&ptr, end_ptr);

  if (ptr == nullptr || end_ptr < ptr + 1) {
    return (nullptr);
  }

  *version = mach_parse_u64_much_compressed(&ptr, end_ptr);

  return (const_cast<byte *>(ptr));
}

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

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

  ptr++;

  if (end_ptr < ptr + 2) {
    return (NULL);
  }

  *space = mach_parse_compressed(&ptr, end_ptr);

  if (ptr != NULL) {
    *page_no = mach_parse_compressed(&ptr, end_ptr);
  }

  return (const_cast<byte *>(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 */
byte *mlog_parse_nbytes(
    mlog_id_t type,      /*!< in: log record type: MLOG_1BYTE, ... */
    const byte *ptr,     /*!< in: buffer */
    const 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_index_page_check(page));

  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) {
    dval = mach_u64_parse_compressed(&ptr, end_ptr);

    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 (const_cast<byte *>(ptr));
  }

  val = mach_parse_compressed(&ptr, end_ptr);

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

  switch (type) {
    case MLOG_1BYTE:
      if (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 (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 (const_cast<byte *>(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. */
void mlog_write_ulint(
    byte *ptr,      /*!< in: pointer where to write */
    ulint val,      /*!< in: value to write */
    mlog_id_t 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 */
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_u64_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. */
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. */
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 */
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 &&
        fil_page_get_type(page) != FIL_PAGE_RTREE));

  if (end_ptr < ptr + 4) {
    return (NULL);
  }

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

  if (offset >= UNIV_PAGE_SIZE || 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);
}

/** 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 */
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 */
    mlog_id_t type,            /*!< in: log item type */
    ulint size)                /*!< in: requested buffer size in bytes
                               (if 0, calls mlog_close() and
                               returns NULL) */
{
#ifndef UNIV_HOTBACKUP
  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 {
    bool instant = index->has_instant_cols();
    ulint i;
    ulint n = dict_index_get_n_fields(index);
    ulint total = 11 + (instant ? 2 : 0) + size + (n + 2) * 2;
    ulint alloc = total;

    if (alloc > mtr_buf_t::MAX_DATA_SIZE) {
      alloc = mtr_buf_t::MAX_DATA_SIZE;
    }

    /* For spatial index, on non-leaf page, we just keep
    2 fields, MBR and page no. */
    if (dict_index_is_spatial(index) && !page_is_leaf(page_align(rec))) {
      n = DICT_INDEX_SPATIAL_NODEPTR_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);

    if (instant) {
      /* Since the max columns could only be 1017,
      The leading bit is leveraged to indicate if the
      index is instant one and number of columns when
      first instant ADD COLUMN stored */
      mach_write_to_2(log_ptr, index->get_instant_fields() | 0x8000);
      log_ptr += 2;
    }
    mach_write_to_2(log_ptr, n);
    log_ptr += 2;

    if (page_is_leaf(page_align(rec))) {
      mach_write_to_2(log_ptr, dict_index_get_n_unique_in_tree(index));
    } else {
      mach_write_to_2(log_ptr, dict_index_get_n_unique_in_tree_nonleaf(index));
    }

    log_ptr += 2;

    for (i = 0; i < n; i++) {
      dict_field_t *field;
      const dict_col_t *col;
      ulint len;

      field = index->get_field(i);
      col = field->col;
      len = field->fixed_len;
      ut_ad(len < 0x7fff);
      if (len == 0 && (DATA_BIG_COL(col))) {
        /* 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 > mtr_buf_t::MAX_DATA_SIZE) {
          alloc = mtr_buf_t::MAX_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);
#else  /* !UNIV_HOTBACKUP */
  return (NULL);
#endif /* !UNIV_HOTBACKUP */
}

/** Parses a log record written by mlog_open_and_write_index.
 @return parsed record end, NULL if not a complete record */
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;
  dict_table_t *table;
  dict_index_t *ind;
  bool instant = false;
  uint16_t n, n_uniq;
  uint16_t instant_cols = 0;

  ut_ad(comp == FALSE || comp == TRUE);

  if (comp) {
    if (end_ptr < ptr + 4) {
      return (NULL);
    }
    n = mach_read_from_2(ptr);
    ptr += 2;
    if ((n & 0x8000) != 0) {
      /* This is instant fields,
      see also mlog_open_and_write_index() */
      instant = true;
      instant_cols = n & ~0x8000;
      n = mach_read_from_2(ptr);
      ptr += 2;
      ut_ad((n & 0x8000) == 0);
      ut_ad(instant_cols <= n);

      if (end_ptr < ptr + 2) {
        return (nullptr);
      }
    }
    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, 0, 0,
                                comp ? DICT_TF_COMPACT : 0, 0);
  if (instant) {
    table->set_instant_cols(instant_cols);
  }

  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);

      /* The is_ascending flag does not matter during
      redo log apply, because we do not compare for
      "less than" or "greater than". */
      dict_index_add_col(ind, table, table->get_col(i), 0, true);
    }
    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 == ind->get_col(DATA_TRX_ID - 1 + n_uniq)->len);
      ut_a(DATA_ROLL_PTR_LEN == ind->get_col(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];

      /* Lizard: Identify DATA_SCN_ID and DATA_UNDO_PTR in the index. */
      ut_a(DATA_SCN_ID_LEN == ind->get_col(DATA_SCN_ID - 1 + n_uniq)->len);
      ut_a(DATA_UNDO_PTR_LEN == ind->get_col(DATA_UNDO_PTR - 1 + n_uniq)->len);
      ut_a(DATA_GCN_ID_LEN == ind->get_col(DATA_GCN_ID - 1 + n_uniq)->len);
      ind->fields[DATA_SCN_ID - 1 + n_uniq].col = &table->cols[n + DATA_SCN_ID];
      ind->fields[DATA_UNDO_PTR - 1 + n_uniq].col =
          &table->cols[n + DATA_UNDO_PTR];
      ind->fields[DATA_GCN_ID - 1 + n_uniq].col = &table->cols[n + DATA_GCN_ID];
    }

    if (ind->is_clustered() && ind->table->has_instant_cols()) {
      ind->instant_cols = true;
      ind->n_instant_nullable =
          ind->get_n_nullable_before(ind->get_instant_fields());
    } else {
      ind->instant_cols = false;
      ind->n_instant_nullable = ind->n_nullable;
    }
  }
  /* avoid ut_ad(index->cached) in dict_index_get_n_unique_in_tree */
  ind->cached = TRUE;
  *index = ind;
  return (ptr);
}