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

Copyright (c) 2017, 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 arch/arch0arch.cc
 Common implementation for redo log and dirty page archiver system

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

#include "arch0arch.h"
#include "os0thread-create.h"

/** Log Archiver system global */
Arch_Log_Sys *arch_log_sys = nullptr;

/** Page Archiver system global */
Arch_Page_Sys *arch_page_sys = nullptr;

/** Event to signal the log archiver thread. */
os_event_t log_archiver_thread_event;

/** Wakes up archiver threads.
@return true iff any thread was still alive */
bool arch_wake_threads() {
  bool found_alive = false;
  if (srv_thread_is_active(srv_threads.m_log_archiver)) {
    os_event_set(log_archiver_thread_event);
    found_alive = true;
  }
  if (srv_thread_is_active(srv_threads.m_page_archiver)) {
    os_event_set(page_archiver_thread_event);
    found_alive = true;
  }
  return (found_alive);
}

void arch_remove_file(const char *file_path, const char *file_name) {
  char path[MAX_ARCH_PAGE_FILE_NAME_LEN];

  ut_ad(MAX_ARCH_LOG_FILE_NAME_LEN <= MAX_ARCH_PAGE_FILE_NAME_LEN);
  ut_ad(strlen(file_path) + 1 + strlen(file_name) <
        MAX_ARCH_PAGE_FILE_NAME_LEN);

  /* Remove only LOG and PAGE archival files. */
  if (0 != strncmp(file_name, ARCH_LOG_FILE, strlen(ARCH_LOG_FILE)) &&
      0 != strncmp(file_name, ARCH_PAGE_FILE, strlen(ARCH_PAGE_FILE)) &&
      0 != strncmp(file_name, ARCH_PAGE_GROUP_DURABLE_FILE_NAME,
                   strlen(ARCH_PAGE_GROUP_DURABLE_FILE_NAME))) {
    return;
  }

  snprintf(path, sizeof(path), "%s%c%s", file_path, OS_PATH_SEPARATOR,
           file_name);

#ifdef UNIV_DEBUG
  os_file_type_t type;
  bool exists = false;

  os_file_status(path, &exists, &type);
  ut_a(exists);
  ut_a(type == OS_FILE_TYPE_FILE);
#endif /* UNIV_DEBUG */

  os_file_delete(innodb_arch_file_key, path);
}

void arch_remove_dir(const char *dir_path, const char *dir_name) {
  char path[MAX_ARCH_DIR_NAME_LEN];

  ut_ad(sizeof(ARCH_LOG_DIR) <= sizeof(ARCH_PAGE_DIR));
  ut_ad(strlen(dir_path) + 1 + strlen(dir_name) + 1 < sizeof(path));

  /* Remove only LOG and PAGE archival directories. */
  if (0 != strncmp(dir_name, ARCH_LOG_DIR, strlen(ARCH_LOG_DIR)) &&
      0 != strncmp(dir_name, ARCH_PAGE_DIR, strlen(ARCH_PAGE_DIR))) {
    return;
  }

  snprintf(path, sizeof(path), "%s%c%s", dir_path, OS_PATH_SEPARATOR, dir_name);

#ifdef UNIV_DEBUG
  os_file_type_t type;
  bool exists = false;

  os_file_status(path, &exists, &type);
  ut_a(exists);
  ut_a(type == OS_FILE_TYPE_DIR);
#endif /* UNIV_DEBUG */

  os_file_scan_directory(path, arch_remove_file, true);
}

/** Initialize Page and Log archiver system
@return error code */
dberr_t arch_init() {
  if (arch_log_sys == nullptr) {
    arch_log_sys = UT_NEW(Arch_Log_Sys(), mem_key_archive);

    if (arch_log_sys == nullptr) {
      return (DB_OUT_OF_MEMORY);
    }

    log_archiver_thread_event = os_event_create(0);
  }

  if (arch_page_sys == nullptr) {
    arch_page_sys = UT_NEW(Arch_Page_Sys(), mem_key_archive);

    if (arch_page_sys == nullptr) {
      return (DB_OUT_OF_MEMORY);
    }

    page_archiver_thread_event = os_event_create(0);
  }

  arch_page_sys->recover();

  return (DB_SUCCESS);
}

/** Free Page and Log archiver system */
void arch_free() {
  if (arch_log_sys != nullptr) {
    UT_DELETE(arch_log_sys);
    arch_log_sys = nullptr;

    os_event_destroy(log_archiver_thread_event);
  }

  if (arch_page_sys != nullptr) {
    UT_DELETE(arch_page_sys);
    arch_page_sys = nullptr;

    os_event_destroy(page_archiver_thread_event);
  }
}

dberr_t Arch_Group::write_to_file(Arch_File_Ctx *from_file, byte *from_buffer,
                                  uint length, bool partial_write,
                                  bool do_persist) {
  dberr_t err = DB_SUCCESS;
  uint write_size;

  if (m_file_ctx.is_closed()) {
    /* First file in the archive group. */
    ut_ad(m_file_ctx.get_count() == 0);

    DBUG_EXECUTE_IF("crash_before_archive_file_creation", DBUG_SUICIDE(););
    err = m_file_ctx.open_new(m_begin_lsn, m_header_len);

    if (err != DB_SUCCESS) {
      return (err);
    }
  }

  auto len_left = m_file_ctx.bytes_left();

  /* New file is immediately opened when current file is over. */
  ut_ad(len_left != 0);

  while (length > 0) {
    auto len_copy = static_cast<uint64_t>(length);

    /* Write as much as possible in current file. */
    if (len_left < len_copy) {
      write_size = static_cast<uint>(len_left);
    } else {
      write_size = length;
    }

    if (do_persist) {
      Arch_Page_Dblwr_Offset dblwr_offset =
          (partial_write ? ARCH_PAGE_DBLWR_PARTIAL_FLUSH_PAGE
                         : ARCH_PAGE_DBLWR_FULL_FLUSH_PAGE);

      Arch_Group::write_to_doublewrite_file(from_file, from_buffer, write_size,
                                            dblwr_offset);
    }

    if (partial_write) {
      DBUG_EXECUTE_IF("crash_after_partial_block_dblwr_flush", DBUG_SUICIDE(););
      err = m_file_ctx.write(from_file, from_buffer, m_file_ctx.get_offset(),
                             write_size);
    } else {
      DBUG_EXECUTE_IF("crash_after_full_block_dblwr_flush", DBUG_SUICIDE(););
      err = m_file_ctx.write(from_file, from_buffer, write_size);
    }

    if (err != DB_SUCCESS) {
      return (err);
    }

    if (do_persist) {
      /* Flush the file to make sure the changes are made persistent as there
      would be no way to recover the data otherwise in case of a crash. */
      m_file_ctx.flush();
    }

    ut_ad(length >= write_size);
    length -= write_size;

    len_left = m_file_ctx.bytes_left();

    /* Current file is over, switch to next file. */
    if (len_left == 0) {
      m_file_ctx.close();

      err = m_file_ctx.open_new(m_begin_lsn, m_header_len);
      DBUG_EXECUTE_IF("crash_after_archive_file_creation", DBUG_SUICIDE(););

      if (err != DB_SUCCESS) {
        return (err);
      }

      len_left = m_file_ctx.bytes_left();
    }
  }

  return (DB_SUCCESS);
}

bool Arch_File_Ctx::delete_file(uint file_index, lsn_t begin_lsn) {
  bool success;
  char file_name[MAX_ARCH_PAGE_FILE_NAME_LEN];

  build_name(file_index, begin_lsn, file_name, MAX_ARCH_PAGE_FILE_NAME_LEN);

  os_file_type_t type;
  bool exists = false;

  success = os_file_status(file_name, &exists, &type);

  if (!success || !exists) {
    return (false);
  }

  ut_ad(type == OS_FILE_TYPE_FILE);

  success = os_file_delete(innodb_arch_file_key, file_name);

  return (success);
}

void Arch_File_Ctx::delete_files(lsn_t begin_lsn) {
  bool exists = false;
  char dir_name[MAX_ARCH_DIR_NAME_LEN];

  os_file_type_t type;

  build_dir_name(begin_lsn, dir_name, MAX_ARCH_DIR_NAME_LEN);
  os_file_status(dir_name, &exists, &type);

  if (exists) {
    ut_ad(type == OS_FILE_TYPE_DIR);
    os_file_scan_directory(dir_name, arch_remove_file, true);
  }
}

dberr_t Arch_File_Ctx::init(const char *path, const char *base_dir,
                            const char *base_file, uint num_files,
                            uint64_t file_size) {
  m_base_len = static_cast<uint>(strlen(path));

  m_name_len =
      m_base_len + static_cast<uint>(strlen(base_file)) + MAX_LSN_DECIMAL_DIGIT;

  if (base_dir != nullptr) {
    m_name_len += static_cast<uint>(strlen(base_dir));
    m_name_len += MAX_LSN_DECIMAL_DIGIT;
  }

  /* Add some extra buffer. */
  m_name_len += MAX_LSN_DECIMAL_DIGIT;

  /* In case of reinitialise. */
  if (m_name_buf != nullptr) {
    ut_free(m_name_buf);
    m_name_buf = nullptr;
  }

  m_name_buf = static_cast<char *>(ut_malloc(m_name_len, mem_key_archive));

  if (m_name_buf == nullptr) {
    return (DB_OUT_OF_MEMORY);
  }

  m_path_name = path;
  m_dir_name = base_dir;
  m_file_name = base_file;

  strcpy(m_name_buf, path);

  if (m_name_buf[m_base_len - 1] != OS_PATH_SEPARATOR) {
    m_name_buf[m_base_len] = OS_PATH_SEPARATOR;
    ++m_base_len;
    m_name_buf[m_base_len] = '\0';
  }

  m_file.m_file = OS_FILE_CLOSED;

  m_index = 0;
  m_count = num_files;

  m_offset = 0;
  m_size = file_size;

  m_reset.clear();
  m_stop_points.clear();

  return (DB_SUCCESS);
}

dberr_t Arch_File_Ctx::open(bool read_only, lsn_t start_lsn, uint file_index,
                            uint64_t file_offset) {
  os_file_create_t option;
  os_file_type_t type;

  bool success;
  bool exists;

  /* Close current file, if open. */
  close();

  m_index = file_index;
  m_offset = file_offset;

  ut_ad(m_offset <= m_size);

  build_name(m_index, start_lsn, nullptr, 0);

  success = os_file_status(m_name_buf, &exists, &type);

  if (!success) {
    return (DB_CANNOT_OPEN_FILE);
  }

  if (read_only) {
    if (!exists) {
      return (DB_CANNOT_OPEN_FILE);
    }

    option = OS_FILE_OPEN;
  } else {
    option = exists ? OS_FILE_OPEN : OS_FILE_CREATE_PATH;
  }

  m_file =
      os_file_create(innodb_arch_file_key, m_name_buf, option, OS_FILE_NORMAL,
                     OS_CLONE_LOG_FILE, read_only, &success);

  if (!success) {
    return (DB_CANNOT_OPEN_FILE);
  }

  success = os_file_seek(m_name_buf, m_file.m_file, file_offset);

  return (success ? DB_SUCCESS : DB_IO_ERROR);
}

dberr_t Arch_File_Ctx::open_new(lsn_t start_lsn, uint64_t file_offset) {
  dberr_t error;

  /* Create and open next file. */
  error = open(false, start_lsn, m_count, file_offset);

  if (error != DB_SUCCESS) {
    return (error);
  }

  /* Increase file count. */
  ++m_count;
  return (DB_SUCCESS);
}

dberr_t Arch_File_Ctx::open_next(lsn_t start_lsn, uint64_t file_offset) {
  dberr_t error;

  /* Get next file index. */
  ++m_index;
  if (m_index == m_count) {
    m_index = 0;
  }

  /* Open next file. */
  error = open(true, start_lsn, m_index, file_offset);

  return (error);
}

dberr_t Arch_File_Ctx::read(byte *to_buffer, uint offset, uint size) {
  ut_ad(offset + size <= m_size);
  ut_ad(!is_closed());

  IORequest request(IORequest::READ);
  request.disable_compression();
  request.clear_encrypted();

  auto err =
      os_file_read(request, m_path_name, m_file, to_buffer, offset, size);

  return (err);
}

dberr_t Arch_File_Ctx::write(Arch_File_Ctx *from_file, byte *from_buffer,
                             uint size) {
  dberr_t err;

  if (from_buffer == nullptr) {
    /* write from File */
    err = os_file_copy(from_file->m_file, from_file->m_offset, m_file, m_offset,
                       size);

    if (err == DB_SUCCESS) {
      from_file->m_offset += size;
      ut_ad(from_file->m_offset <= from_file->m_size);
    }

  } else {
    /* write from buffer */
    IORequest request(IORequest::WRITE);
    request.disable_compression();
    request.clear_encrypted();

    err = os_file_write(request, "Track file", m_file, from_buffer, m_offset,
                        size);
  }

  if (err != DB_SUCCESS) {
    return (err);
  }

  m_offset += size;
  ut_ad(m_offset <= m_size);

  return (DB_SUCCESS);
}

void Arch_File_Ctx::build_name(uint idx, lsn_t dir_lsn, char *buffer,
                               uint length) {
  char *buf_ptr;
  uint buf_len;

  /* If user has passed NULL, use pre-allocated buffer. */
  if (buffer == nullptr) {
    buf_ptr = m_name_buf;
    buf_len = m_name_len;
  } else {
    buf_ptr = buffer;
    buf_len = length;

    strncpy(buf_ptr, m_name_buf, buf_len);
  }

  buf_ptr += m_base_len;
  buf_len -= m_base_len;

  if (m_dir_name == nullptr) {
    snprintf(buf_ptr, buf_len, "%s%u", m_file_name, idx);

  } else if (dir_lsn == LSN_MAX) {
    snprintf(buf_ptr, buf_len, "%s%c%s%u", m_dir_name, OS_PATH_SEPARATOR,
             m_file_name, idx);

  } else {
    snprintf(buf_ptr, buf_len, "%s" UINT64PF "%c%s%u", m_dir_name, dir_lsn,
             OS_PATH_SEPARATOR, m_file_name, idx);
  }
}

void Arch_File_Ctx::build_dir_name(lsn_t dir_lsn, char *buffer, uint length) {
  ut_ad(buffer != nullptr);

  if (m_dir_name != nullptr) {
    snprintf(buffer, length, "%s%c%s" UINT64PF, m_path_name, OS_PATH_SEPARATOR,
             m_dir_name, dir_lsn);
  } else {
    snprintf(buffer, length, "%s", m_path_name);
  }
}

int start_log_archiver_background() {
  bool ret;
  char errbuf[MYSYS_STRERROR_SIZE];

  ret = os_file_create_directory(ARCH_DIR, false);

  if (ret) {
    srv_threads.m_log_archiver =
        os_thread_create(log_archiver_thread_key, log_archiver_thread);

    srv_threads.m_log_archiver.start();

  } else {
    my_error(ER_CANT_CREATE_FILE, MYF(0), ARCH_DIR, errno,
             my_strerror(errbuf, sizeof(errbuf), errno));

    return (ER_CANT_CREATE_FILE);
  }

  return (0);
}

int start_page_archiver_background() {
  bool ret;
  char errbuf[MYSYS_STRERROR_SIZE];

  ret = os_file_create_directory(ARCH_DIR, false);

  if (ret) {
    srv_threads.m_page_archiver =
        os_thread_create(page_archiver_thread_key, page_archiver_thread);

    srv_threads.m_page_archiver.start();

  } else {
    my_error(ER_CANT_CREATE_FILE, MYF(0), ARCH_DIR, errno,
             my_strerror(errbuf, sizeof(errbuf), errno));

    return (ER_CANT_CREATE_FILE);
  }

  return (0);
}

/** Archiver background thread */
void log_archiver_thread() {
  Arch_File_Ctx log_file_ctx;
  lsn_t log_arch_lsn = LSN_MAX;

  bool log_abort = false;
  bool log_wait = false;
  bool log_init = true;

  while (true) {
    /* Archive available redo log data. */
    log_abort = arch_log_sys->archive(log_init, &log_file_ctx, &log_arch_lsn,
                                      &log_wait);

    if (log_abort) {
      ib::info(ER_IB_MSG_13) << "Exiting Log Archiver";
      break;
    }

    log_init = false;

    if (log_wait) {
      /* Nothing to archive. Wait until next trigger. */
      os_event_wait(log_archiver_thread_event);
      os_event_reset(log_archiver_thread_event);
    }
  }
}