lob0del.h

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#ifndef lob0del_h
#define lob0del_h
 
#include "lob0lob.h"
 
namespace lob {
 
/* Delete a LOB */
class Deleter {
 public:
  /** Constructor */
  Deleter(DeleteContext &ctx) : m_ctx(ctx) {
    ut_ad(ctx.index()->is_clustered());
    ut_ad(mtr_memo_contains_flagged(ctx.get_mtr(),
                                    dict_index_get_lock(ctx.index()),
                                    MTR_MEMO_X_LOCK | MTR_MEMO_SX_LOCK) ||
          ctx.table()->is_intrinsic());
    ut_ad(mtr_is_page_fix(ctx.get_mtr(), ctx.m_blobref.page_align(),
                          MTR_MEMO_PAGE_X_FIX, ctx.table()));
    ut_ad(ctx.rec_offs_validate());
    ut_ad(ctx.validate_blobref());
  }
 
  /** Free the LOB object.
  @return DB_SUCCESS on success. */
  dberr_t destroy();
 
  /** Free the first page of the BLOB and update the BLOB reference
  in the clustered index.
  @return DB_SUCCESS on pass, error code on failure. */
  dberr_t free_first_page();
 
 private:
  /** Obtain an x-latch on the clustered index record page.*/
  void x_latch_rec_page();
 
  /** Validate the page type of the given page frame.
  @param[in]    page    the page frame.
  @return true if valid, false otherwise. */
  bool validate_page_type(const page_t *page) const {
    return (m_ctx.is_compressed() ? validate_zblob_page_type(page)
                                  : validate_blob_page_type(page));
  }
 
  /** Check if the page type is set correctly.
  @param[in]    page    the page frame.
  @return true if page type is correct. */
  bool validate_zblob_page_type(const page_t *page) const {
    const page_type_t pt = fil_page_get_type(page);
    switch (pt) {
      case FIL_PAGE_TYPE_ZBLOB:
      case FIL_PAGE_TYPE_ZBLOB2:
      case FIL_PAGE_SDI_ZBLOB:
        break;
      default:
        ut_error;
    }
    return (true);
  }
 
  /** Check if the page type is set correctly.
  @param[in]    page    the page frame.
  @return true if page type is correct. */
  bool validate_blob_page_type(const page_t *page) const {
    const page_type_t type = fil_page_get_type(page);
 
    switch (type) {
      case FIL_PAGE_TYPE_BLOB:
      case FIL_PAGE_SDI_BLOB:
        break;
      default:
#ifndef UNIV_DEBUG /* Improve debug test coverage */
        if (!m_ctx.has_atomic_blobs()) {
          /* Old versions of InnoDB did not initialize
          FIL_PAGE_TYPE on BLOB pages.  Do not print
          anything about the type mismatch when reading
          a BLOB page that may be from old versions. */
          return (true);
        }
#endif /* !UNIV_DEBUG */
        ut_error;
    }
    return (true);
  }
 
  /** Check if the BLOB can be freed.  If the clustered index record
  is not the owner of the LOB, then it cannot be freed.  Also, during
  rollback, if inherited flag is set, then LOB will not be freed.
  @return true if the BLOB can be freed, false otherwise. */
  bool can_free() const;
 
  DeleteContext &m_ctx;
  mtr_t m_mtr;
};
 
}  // namespace lob
 
#endif  // lob0del_h