BufferManager/destroy.C at main · LeviCameron1/BufferManager · GitHub

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#include "catalog.h"
#include <string>
#include <cstring>

//
// Destroys a relation. It performs the following steps:
//
// 	removes the catalog entry for the relation
// 	destroys the heap file containing the tuples in the relation
//
// Returns:
// 	OK on success
// 	error code otherwise
//

const Status RelCatalog::destroyRel(const string & relation)
{
  Status status;

  if (relation.empty() ||
      relation == string(RELCATNAME) ||
      relation == string(ATTRCATNAME))
    return BADCATPARM;

  // delete attrcat entries

  if ((status = attrCat->dropRelation(relation)) != OK)
    return status;

  // delete entry from relcat

  if ((status = removeInfo(relation)) != OK)
    return status;

  // destroy file
  if ((status = destroyHeapFile(relation)) != OK)
    return status;

  return OK;
}


//
// Drops a relation. It performs the following steps:
//
// 	removes the catalog entries for the relation
//
// Returns:
// 	OK on success
// 	error code otherwise
//

const Status AttrCatalog::dropRelation(const string & relation)
{
  Status status;
  AttrDesc *attrs;
  int attrCnt, i;

  if (relation.empty())
    return BADCATPARM;

  // get attribute information

  if ((status = getRelInfo(relation, attrCnt, attrs)) != OK)
    return status;

  // remove entries from catalog

  for(i = 0; i < attrCnt; i++) {
    if ((status = removeInfo(relation, attrs[i].attrName)) != OK)
      return status;
  }

  free(attrs);

  return OK;
}