lob0ins.h

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#ifndef lob0ins_h
#define lob0ins_h
 
#include "lob0lob.h"
 
namespace lob {
 
/** This struct can hold BLOB routines/functions, and state variables,
that are common for compressed and uncompressed BLOB. */
struct BaseInserter {
  /** Constructor.
  @param[in]    ctx     blob operation context. */
  BaseInserter(InsertContext *ctx)
      : m_ctx(ctx),
        m_err(DB_SUCCESS),
        m_prev_page_no(ctx->get_page_no()),
        m_cur_blob_block(nullptr),
        m_cur_blob_page_no(FIL_NULL) {}
 
  /** Start the BLOB mtr.
  @return pointer to the BLOB mtr. */
  mtr_t *start_blob_mtr() {
    mtr_start(&m_blob_mtr);
    m_blob_mtr.set_log_mode(m_ctx->get_log_mode());
    m_blob_mtr.set_flush_observer(m_ctx->get_flush_observer());
    return (&m_blob_mtr);
  }
 
  /** Allocate one BLOB page.
  @return the allocated block of the BLOB page. */
  buf_block_t *alloc_blob_page();
 
  /** Get the previous BLOB page frame.  This will return a BLOB page.
  It should not be called for the first BLOB page, because it will not
  have a previous BLOB page.
  @return       the previous BLOB page frame. */
  page_t *get_previous_blob_page();
 
  /** Get the previous BLOB page block.  This will return a BLOB block.
  It should not be called for the first BLOB page, because it will not
  have a previous BLOB page.
  @return       the previous BLOB block. */
  buf_block_t *get_previous_blob_block();
 
  /** Check if the index is SDI index
  @return true if index is SDI index else false */
  bool is_index_sdi() { return (dict_index_is_sdi(m_ctx->index())); }
 
  /** Get the current BLOB page frame.
  @return the current BLOB page frame. */
  page_t *cur_page() const { return (buf_block_get_frame(m_cur_blob_block)); }
 
 protected:
  /** The BLOB operation context */
  InsertContext *m_ctx;
 
  /** Success or failure status of the operation so far. */
  dberr_t m_err;
 
  /** The mini trx used to write into blob pages */
  mtr_t m_blob_mtr;
 
  /** The previous BLOB page number.  This is needed to maintain
  the linked list of BLOB pages. */
  page_no_t m_prev_page_no;
 
  /** The current BLOB buf_block_t object. */
  buf_block_t *m_cur_blob_block;
 
  /** The current BLOB page number. */
  page_no_t m_cur_blob_page_no;
};
 
/** Insert or write an uncompressed BLOB */
class Inserter : private BaseInserter {
 public:
  /** Constructor.
  @param[in]    ctx     blob operation context. */
  Inserter(InsertContext *ctx) : BaseInserter(ctx) {}
 
  /** Destructor. */
  ~Inserter() = default;
 
  /** Write all the BLOBs of the clustered index record.
  @return DB_SUCCESS on success, error code on failure. */
  dberr_t write();
 
  /** Write one blob field data.
  @param[in]    blob_j  the blob field number
  @return DB_SUCCESS on success, error code on failure. */
  dberr_t write_one_blob(size_t blob_j);
 
  /** Write one blob field data.
  @param[in]    blob_j  the blob field number
  @return DB_SUCCESS on success, error code on failure. */
  dberr_t write_one_small_blob(size_t blob_j);
 
  /** Write one blob page.  This function will be repeatedly called
  with an increasing nth_blob_page to completely write a BLOB.
  @param[in]    field           the big record field.
  @param[in]    nth_blob_page   count of the BLOB page (starting from 1).
  @return DB_SUCCESS or DB_FAIL. */
  dberr_t write_single_blob_page(big_rec_field_t &field, ulint nth_blob_page);
 
  /** Check if the BLOB operation has reported any errors.
  @return       true if BLOB operation is successful, false otherwise. */
  bool is_ok() const { return (m_err == DB_SUCCESS); }
 
  /** Make the current page as next page of previous page.  In other
  words, make the page m_cur_blob_page_no as the next page of page
  m_prev_page_no. */
  void set_page_next();
 
  /** Write the page type of the current BLOB page and also generate the
  redo log record. */
  void log_page_type() {
    page_type_t page_type;
    page_t *blob_page = cur_page();
 
    if (is_index_sdi()) {
      page_type = FIL_PAGE_SDI_BLOB;
    } else {
      page_type = FIL_PAGE_TYPE_BLOB;
    }
 
    mlog_write_ulint(blob_page + FIL_PAGE_TYPE, page_type, MLOG_2BYTES,
                     &m_blob_mtr);
  }
 
  /** Calculate the payload size of the BLOB page.
  @return       payload size in bytes. */
  ulint payload() const {
    const page_size_t page_size = m_ctx->page_size();
    const ulint payload_size =
        page_size.physical() - FIL_PAGE_DATA - LOB_HDR_SIZE - FIL_PAGE_DATA_END;
    return (payload_size);
  }
 
  /** Write contents into a single BLOB page.
  @param[in]    field           the big record field. */
  void write_into_single_page(big_rec_field_t &field);
 
  /** Write first blob page.
  @param[in]    field   the big record field.
  @return DB_SUCCESS on success. */
  dberr_t write_first_page(big_rec_field_t &field);
 
 private:
  /** The BLOB directory information. */
  blob_dir_t m_dir;
 
  /** Data remaining to be written. */
  ulint m_remaining;
};
 
}  // namespace lob
 
#endif /* lob0ins_h */