Method fastClear

fdbserver/KeyValueStoreSQLite.actor.cpp:916–953

		}
	}
	void fastClear(KeyRangeRef keys, bool& freeTableEmpty) {
		std::vector<int> clearBuffer(SERVER_KNOBS->CLEAR_BUFFER_SIZE);
		clearBuffer[0] = 0;

		while (true) {
			if (moveTo(keys.begin) < 0)
				moveNext();
			RawCursor endCursor(db, db.table, false);
			if (endCursor.moveTo(keys.end) >= 0)
				endCursor.movePrevious();

			if (!valid || !endCursor ||
			    (db.fragment_values ? (decodeKVFragment(getEncodedRow()).get().key >=
			                           decodeKVFragment(endCursor.getEncodedRow()).get().key)
			                        : (decodeKV(getEncodedRow()).key > decodeKV(endCursor.getEncodedRow()).key)))
				break; // If empty stop!

			int rc = sqlite3BtreeDeleteRange(
			    cursor, endCursor.cursor, &clearBuffer[0], &clearBuffer[0] + clearBuffer.size());
			if (rc == 201)
				continue;
			if (!rc)
				break;
			db.checkError("BtreeDeleteRange", rc);
		}

		if (clearBuffer[0]) {
			// printf("fastClear(%s,%s): %d pages freed\n", printable(keys.begin).c_str(), printable(keys.end).c_str(),
			// clearBuffer[0]);
			IntKeyCursor fc(db, db.freetable, true);
			int pagesDeleted = 0;
			db.checkError("BtreeLazyDelete",
			              sqlite3BtreeLazyDelete(
			                  fc.cursor, &clearBuffer[0], &clearBuffer[0] + clearBuffer.size(), 0, &pagesDeleted));
			ASSERT(pagesDeleted == 0);
			freeTableEmpty = false;
		}
	}
	int lazyDelete(int desiredPages) {
		std::vector<int> clearBuffer(SERVER_KNOBS->CLEAR_BUFFER_SIZE);
		clearBuffer[0] = 0;