polardbxengine/storage/innobase/include/clone0desc.h

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/** @file include/clone0desc.h
 Innodb clone descriptors

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

#ifndef CLONE_DESC_INCLUDE
#define CLONE_DESC_INCLUDE

#include "mem0mem.h"
#include "os0file.h"
#include "univ.i"

/** Invalid locator ID. */
const ib_uint64_t CLONE_LOC_INVALID_ID = 0;

/** Maximum base length for any serialized descriptor. This is only used for
optimal allocation and has no impact on version compatibility. */
const uint32_t CLONE_DESC_MAX_BASE_LEN = 64;

/** Align by 4K for O_DIRECT */
const uint32_t CLONE_ALIGN_DIRECT_IO = 4 * 1024;

/** Maximum number of concurrent tasks for each clone */
const int CLONE_MAX_TASKS = 128;

/** Snapshot state transfer during clone.

Clone Type: HA_CLONE_BLOCKING
@startuml
  state CLONE_SNAPSHOT_INIT
  state CLONE_SNAPSHOT_FILE_COPY
  state CLONE_SNAPSHOT_DONE

  [*] -down-> CLONE_SNAPSHOT_INIT : Build snapshot
  CLONE_SNAPSHOT_INIT -right-> CLONE_SNAPSHOT_FILE_COPY
  CLONE_SNAPSHOT_FILE_COPY -right-> CLONE_SNAPSHOT_DONE
  CLONE_SNAPSHOT_DONE -down-> [*] : Destroy snapshot
@enduml

Clone Type: HA_CLONE_REDO
@startuml
  state CLONE_SNAPSHOT_REDO_COPY

  [*] -down-> CLONE_SNAPSHOT_INIT : Build snapshot
  CLONE_SNAPSHOT_INIT -right-> CLONE_SNAPSHOT_FILE_COPY : Start redo archiving
  CLONE_SNAPSHOT_FILE_COPY -right-> CLONE_SNAPSHOT_REDO_COPY
  CLONE_SNAPSHOT_REDO_COPY -right-> CLONE_SNAPSHOT_DONE
  CLONE_SNAPSHOT_DONE -down-> [*] : Destroy snapshot
@enduml

Clone Type: HA_CLONE_HYBRID
@startuml
  state CLONE_SNAPSHOT_PAGE_COPY

  [*] -down-> CLONE_SNAPSHOT_INIT : Build snapshot
  CLONE_SNAPSHOT_INIT -right-> CLONE_SNAPSHOT_FILE_COPY : Start page tracking
  CLONE_SNAPSHOT_FILE_COPY -right-> CLONE_SNAPSHOT_PAGE_COPY : Start redo \
  archiving
  CLONE_SNAPSHOT_PAGE_COPY -right-> CLONE_SNAPSHOT_REDO_COPY
  CLONE_SNAPSHOT_REDO_COPY -right> CLONE_SNAPSHOT_DONE
  CLONE_SNAPSHOT_DONE -down-> [*] : Destroy snapshot
@enduml

Clone Type: HA_CLONE_PAGE: Not implemented
*/
enum Snapshot_State {
  /** Invalid state */
  CLONE_SNAPSHOT_NONE = 0,

  /** Initialize state when snapshot object is created */
  CLONE_SNAPSHOT_INIT,

  /** Snapshot state while transferring files. */
  CLONE_SNAPSHOT_FILE_COPY,

  /** Snapshot state while transferring pages. */
  CLONE_SNAPSHOT_PAGE_COPY,

  /** Snapshot state while transferring redo. */
  CLONE_SNAPSHOT_REDO_COPY,

  /** Snapshot state at end after finishing transfer. */
  CLONE_SNAPSHOT_DONE
};

/** Choose lowest descriptor version between reference locator
and currently supported version.
@param[in]	ref_loc	reference locator
@return chosen version */
uint choose_desc_version(const byte *ref_loc);

/** Check if clone locator is valid
@param[in]	desc_loc	serialized descriptor
@param[in]	desc_len	descriptor length
@return true, if valid locator */
bool clone_validate_locator(const byte *desc_loc, uint desc_len);

/** Clone descriptors contain meta information needed for applying cloned data.
These are PODs with interface to serialize and deserialize them. */
enum Clone_Desc_Type {
  /** Logical pointer to identify a clone operation */
  CLONE_DESC_LOCATOR = 1,

  /** Metadata for a Task/Thread for clone operation */
  CLONE_DESC_TASK_METADATA,

  /** Information for snapshot state */
  CLONE_DESC_STATE,

  /** Metadata for a database file */
  CLONE_DESC_FILE_METADATA,

  /** Information for a data block */
  CLONE_DESC_DATA,

  /** Must be the last member */
  CLONE_DESC_MAX
};

/** Header common to all descriptors. */
struct Clone_Desc_Header {
  /** Descriptor version */
  uint m_version;

  /** Serialized length of descriptor in bytes */
  uint m_length;

  /** Descriptor type */
  Clone_Desc_Type m_type;

  /** Serialize the descriptor header: Caller must allocate
  the serialized buffer.
  @param[out]	desc_hdr	serialized header */
  void serialize(byte *desc_hdr);

  /** Deserialize the descriptor header.
  @param[in]	desc_hdr	serialized header
  @param[in]	desc_len	descriptor length
  @return true, if successful. */
  bool deserialize(const byte *desc_hdr, uint desc_len);
};

/** Task information in clone operation. */
struct Clone_Task_Meta {
  /** Index in task array. */
  uint m_task_index;

  /** Current chunk number reserved by the task. */
  uint m_chunk_num;

  /** Current block number that is already transferred. */
  uint m_block_num;
};

/** Map for current block number for unfinished chunks. Used during
restart from incomplete clone operation. */
using Chunk_Map = std::map<uint32_t, uint32_t>;

/** Bitmap for completed chunks in current state */
class Chnunk_Bitmap {
 public:
  /** Construct bitmap */
  Chnunk_Bitmap() : m_bitmap(), m_size(), m_bits() {}

  /** Bitmap array index operator implementation */
  class Bitmap_Operator_Impl {
   public:
    /** Construct bitmap operator
    @param[in]	bitmap	reference to bitmap buffer
    @param[in]	index	array operation index */
    Bitmap_Operator_Impl(uint32_t *&bitmap, uint32_t index)

        : m_bitmap_ref(bitmap) {
      /* BYTE position */
      auto byte_index = index >> 3;
      ut_ad(byte_index == index / 8);

      /* MAP array position */
      m_map_index = byte_index >> 2;
      ut_ad(m_map_index == byte_index / 4);

      /* BIT position */
      auto bit_pos = index & 31;
      ut_ad(bit_pos == index % 32);

      m_bit_mask = 1 << bit_pos;
    }

    /** Check value at specified index in BITMAP
    @return true if the BIT is set */
    operator bool() const {
      auto &val = m_bitmap_ref[m_map_index];

      if ((val & m_bit_mask) == 0) {
        return (false);
      }

      return (true);
    }

    /** Set BIT at specific index
    @param[in]	bit	bit value to set */
    void operator=(bool bit) {
      auto &val = m_bitmap_ref[m_map_index];

      if (bit) {
        val |= m_bit_mask;
      } else {
        val &= ~m_bit_mask;
      }
    }

   private:
    /** Refernce to BITMAP array */
    uint32_t *&m_bitmap_ref;

    /** Current array position */
    uint32_t m_map_index;

    /** Mask with current BIT set */
    uint32_t m_bit_mask;
  };

  /** Array index operator
  @param[in]	index	bitmap array index
  @return	operator implementation object */
  Bitmap_Operator_Impl operator[](uint32_t index) {
    /* Convert to zero based index */
    --index;

    ut_a(index < m_bits);
    return (Bitmap_Operator_Impl(m_bitmap, index));
  }

  /** Reset bitmap with new size
  @param[in]	max_bits	number of BITs to hold
  @param[in]	heap		heap for allocating memory
  @return	old buffer pointer */
  uint32_t *reset(uint32_t max_bits, mem_heap_t *heap);

  /** Get minimum BIT position that is not set
  @return BIT position */
  uint32_t get_min_unset_bit();

  /** Get maximum BIT position that is not set
  @return BIT position */
  uint32_t get_max_set_bit();

  /** Serialize the descriptor. Caller should pass
  the length if allocated.
  @param[out]	desc_chunk	serialized chunk info
  @param[in,out]	len		length of serialized descriptor */
  void serialize(byte *&desc_chunk, uint &len);

  /** Deserialize the descriptor.
  @param[in]	desc_chunk	serialized chunk info
  @param[in,out]	len_left	length left in bytes */
  void deserialize(const byte *desc_chunk, uint &len_left);

  /** Get the length of serialized data
  @return length serialized chunk info */
  size_t get_serialized_length();

  /** Maximum bit capacity
  @return maximum number of BITs it can hold */
  size_t capacity() const { return (8 * size()); }

  /** Size of bitmap in bytes
  @return BITMAP buffer size */
  size_t size() const { return (m_size * 4); }

  /** Size of bitmap in bits
  @return number of BITs stored */
  uint32_t size_bits() const { return (m_bits); }

 private:
  /** BITMAP buffer */
  uint32_t *m_bitmap;

  /** BITMAP buffer size: Number of 4 byte blocks */
  size_t m_size;

  /** Total number of BITs in the MAP */
  uint32_t m_bits;
};

/** Incomplete Chunk information */
struct Chunk_Info {
  /** Information about chunks completed */
  Chnunk_Bitmap m_reserved_chunks;

  /** Information about unfinished chunks */
  Chunk_Map m_incomplete_chunks;

  /** Chunks for current state */
  uint32_t m_total_chunks;

  /** Minimum chunk number that is not reserved yet */
  uint32_t m_min_unres_chunk;

  /** Maximum chunk number that is already reserved */
  uint32_t m_max_res_chunk;

  /** Initialize Chunk number ranges */
  void init_chunk_nums() {
    m_min_unres_chunk = m_reserved_chunks.get_min_unset_bit();
    ut_ad(m_min_unres_chunk <= m_total_chunks + 1);

    m_max_res_chunk = m_reserved_chunks.get_max_set_bit();
    ut_ad(m_max_res_chunk <= m_total_chunks);
  }

  /** Serialize the descriptor. Caller should pass
  the length if allocated.
  @param[out]	desc_chunk	serialized chunk info
  @param[in,out]	len		length of serialized descriptor */
  void serialize(byte *desc_chunk, uint &len);

  /** Deserialize the descriptor.
  @param[in]	desc_chunk	serialized chunk info
  @param[in,out]	len_left	length left in bytes */
  void deserialize(const byte *desc_chunk, uint &len_left);

  /** Get the length of serialized data
  @param[in]	num_tasks	number of tasks to include
  @return length serialized chunk info */
  size_t get_serialized_length(uint32_t num_tasks);
};

/** CLONE_DESC_LOCATOR: Descriptor for a task for clone operation.
A task is used by exactly one thread */
struct Clone_Desc_Locator {
  /** Descriptor header */
  Clone_Desc_Header m_header;

  /** Unique identifier for a clone operation. */
  uint64_t m_clone_id;

  /** Unique identifier for a clone snapshot. */
  uint64_t m_snapshot_id;

  /** Index in clone array for fast reference. */
  uint32_t m_clone_index;

  /** Current snapshot State */
  Snapshot_State m_state;

  /** Sub-state information: metadata transferred */
  bool m_metadata_transferred;

  /** Initialize clone locator.
  @param[in]	id	Clone identifier
  @param[in]	snap_id	Snapshot identifier
  @param[in]	state	snapshot state
  @param[in]	version	Descriptor version
  @param[in]	index	clone index */
  void init(ib_uint64_t id, ib_uint64_t snap_id, Snapshot_State state,
            uint version, uint index);

  /** Check if the passed locator matches the current one.
  @param[in]	other_desc	input locator descriptor
  @return true if matches */
  bool match(Clone_Desc_Locator *other_desc);

  /** Serialize the descriptor. Caller should pass
  the length if allocated.
  @param[out]	desc_loc	serialized descriptor
  @param[in,out]	len		length of serialized descriptor
  @param[in]	chunk_info	chunk information to serialize
  @param[in]	heap		heap for allocating memory */
  void serialize(byte *&desc_loc, uint &len, Chunk_Info *chunk_info,
                 mem_heap_t *heap);

  /** Deserialize the descriptor.
  @param[in]	desc_loc	serialized locator
  @param[in]	desc_len	locator length
  @param[in,out]	chunk_info	chunk information */
  void deserialize(const byte *desc_loc, uint desc_len, Chunk_Info *chunk_info);
};

/** CLONE_DESC_TASK_METADATA: Descriptor for a task for clone operation.
A task is used by exactly one thread */
struct Clone_Desc_Task_Meta {
  /** Descriptor header */
  Clone_Desc_Header m_header;

  /** Task information */
  Clone_Task_Meta m_task_meta;

  /** Initialize header
  @param[in]	version	descriptor version */
  void init_header(uint version);

  /** Serialize the descriptor. Caller should pass
  the length if allocated.
  @param[out]	desc_task	serialized descriptor
  @param[in,out]	len		length of serialized descriptor
  @param[in]	heap		heap for allocating memory */
  void serialize(byte *&desc_task, uint &len, mem_heap_t *heap);

  /** Deserialize the descriptor.
  @param[in]	desc_task	serialized descriptor
  @param[in]	desc_len	descriptor length
  @return true, if successful. */
  bool deserialize(const byte *desc_task, uint desc_len);
};

/** CLONE_DESC_STATE: Descriptor for current snapshot state */
struct Clone_Desc_State {
  /** Descriptor header */
  Clone_Desc_Header m_header;

  /** Current snapshot State */
  Snapshot_State m_state;

  /** Task identifier */
  uint m_task_index;

  /** Number of chunks in current state */
  uint m_num_chunks;

  /** Number of files in current state */
  uint m_num_files;

  /** Number of estimated bytes to transfer */
  uint64_t m_estimate;

  /** Number of estimated bytes on disk */
  uint64_t m_estimate_disk;

  /** If start processing state */
  bool m_is_start;

  /** State transfer Acknowledgement */
  bool m_is_ack;

  /** Initialize header
  @param[in]	version	descriptor version */
  void init_header(uint version);

  /** Serialize the descriptor. Caller should pass
  the length if allocated.
  @param[out]	desc_state	serialized descriptor
  @param[in,out]	len		length of serialized descriptor
  @param[in]	heap		heap for allocating memory */
  void serialize(byte *&desc_state, uint &len, mem_heap_t *heap);

  /** Deserialize the descriptor.
  @param[in]	desc_state	serialized descriptor
  @param[in]	desc_len	descriptor length
  @return true, if successful. */
  bool deserialize(const byte *desc_state, uint desc_len);
};

/** Clone file information */
struct Clone_File_Meta {
  /** File size in bytes */
  uint64_t m_file_size;

  /** File allocation size on disk for sparse files. */
  uint64_t m_alloc_size;

  /** Tablespace FSP flags */
  uint32_t m_fsp_flags;

  /** File compression type */
  Compression::Type m_compress_type;

  /* File encryption type */
  Encryption::Type m_encrypt_type;

  /** If transparent compression is needed. It is derived information
  and is not transferred. */
  bool m_punch_hole;

  /** File system block size. */
  uint32_t m_fsblk_size;

  /** Tablespace ID for the file */
  ulint m_space_id;

  /** File index in clone data file vector */
  uint m_file_index;

  /** Chunk number for the first chunk in file */
  uint m_begin_chunk;

  /** Chunk number for the last chunk in file */
  uint m_end_chunk;

  /** File name length in bytes */
  size_t m_file_name_len;

  /** File name */
  const char *m_file_name;
};

/** CLONE_DESC_FILE_METADATA: Descriptor for file metadata */
struct Clone_Desc_File_MetaData {
  /** Descriptor header */
  Clone_Desc_Header m_header;

  /** Current snapshot State */
  Snapshot_State m_state;

  /** File metadata */
  Clone_File_Meta m_file_meta;

  /** Initialize header
  @param[in]	version	descriptor version */
  void init_header(uint version);

  /** Serialize the descriptor. Caller should pass
  the length if allocated.
  @param[out]	desc_file	serialized descriptor
  @param[in,out]	len		length of serialized descriptor
  @param[in]	heap		heap for allocating memory */
  void serialize(byte *&desc_file, uint &len, mem_heap_t *heap);

  /** Deserialize the descriptor.
  @param[in]	desc_file	serialized descriptor
  @param[in]	desc_len	descriptor length
  @return true, if successful. */
  bool deserialize(const byte *desc_file, uint desc_len);
};

/** CLONE_DESC_DATA: Descriptor for data */
struct Clone_Desc_Data {
  /** Descriptor header */
  Clone_Desc_Header m_header;

  /** Current snapshot State */
  Snapshot_State m_state;

  /** Task information */
  Clone_Task_Meta m_task_meta;

  /** File identifier */
  uint32_t m_file_index;

  /** Data Length */
  uint32_t m_data_len;

  /** File offset for the data */
  uint64_t m_file_offset;

  /** Updated file size */
  uint64_t m_file_size;

  /** Initialize header
  @param[in]	version	descriptor version */
  void init_header(uint version);

  /** Serialize the descriptor. Caller should pass
  the length if allocated.
  @param[out]	desc_data	serialized descriptor
  @param[in,out]	len		length of serialized descriptor
  @param[in]	heap		heap for allocating memory */
  void serialize(byte *&desc_data, uint &len, mem_heap_t *heap);

  /** Deserialize the descriptor.
  @param[in]	desc_data	serialized descriptor
  @param[in]	desc_len	descriptor length
  @return true, if successful. */
  bool deserialize(const byte *desc_data, uint desc_len);
};

#endif /* CLONE_DESC_INCLUDE */