### Creating the `Settings` only once with `lru_cache` { #creating-the-settings-only-once-with-lru-cache }

Reading a file from disk is normally a costly (slow) operation, so you probably want to do it only once and then reuse the same settings object, instead of reading it for each request.

But every time we do:

 * and field configuration handling during the document transformation process.
 */
public interface FessTransformer {

    /**
     * Synchronized LRU cache for storing parent URL encodings.
     * Maps session+parent URL keys to their corresponding character encodings.
     */
    Map<String, String> parentEncodingMap = Collections.synchronizedMap(new LruHashMap<>(1000));

        }).orElse(StringUtil.EMPTY_STRINGS);
    }

    /**
     * Retrieves or creates the result document IDs cache from the session.
     * The cache is implemented as an LRU map to limit memory usage.
     *
     * @param session the HTTP session
     * @return the result document IDs cache map
     */
    private Map<String, String[]> getResultDocIdsCache(final HttpSession session) {

   *
   *   o CLEAN lines track a cache entry that has been successfully published and may be read. A
   *     publish line is followed by the lengths of each of its values.
   *
   *   o READ lines track accesses for LRU.
   *
   *   o REMOVE lines track entries that have been deleted.
   *
   * The journal file is appended to as cache operations occur. The journal may occasionally be

	github.com/hashicorp/errwrap v1.1.0 // indirect
	github.com/hashicorp/go-multierror v1.1.1 // indirect
	github.com/hashicorp/go-uuid v1.0.3 // indirect
	github.com/hashicorp/golang-lru v1.0.2 // indirect
	github.com/jcmturner/aescts/v2 v2.0.0 // indirect
	github.com/jcmturner/dnsutils/v2 v2.0.0 // indirect
	github.com/jcmturner/gofork v1.7.6 // indirect
	github.com/jcmturner/gokrb5/v8 v8.4.4 // indirect

        // Verify caching behavior
        assertTrue(file.canCacheWrite());
    }
}
```

## 9. Performance Considerations

### 9.1 Memory Management
- Lease entries should be evicted based on LRU when max leases reached
- Implement periodic cleanup of expired leases

### 9.2 Thread Safety
- Use concurrent data structures for lease storage
- Minimize lock contention in hot paths
- Async handling of lease breaks

	NowFunc func() time.Time
	// DryRun generate sql without execute
	DryRun bool
	// PrepareStmt executes the given query in cached statement
	PrepareStmt bool
	// PrepareStmt cache support LRU expired,
	// default maxsize=int64 Max value and ttl=1h
	PrepareStmtMaxSize int
	PrepareStmtTTL     time.Duration

	// DisableAutomaticPing
	DisableAutomaticPing bool
	// DisableForeignKeyConstraintWhenMigrating

    public void registerFileCache(String path, SmbFile file) {
        if (file != null) {
            fileCache.put(path, new WeakReference<>(file));
        }
    }

    /**
     * Evict oldest leases based on LRU
     *
     * @param count number of leases to evict
     */
    private void evictOldestLeases(int count) {
        if (count <= 0 || leases.isEmpty()) {
            return;
        }

  }

  void incrementModCount() {
    metadata += CompactHashing.MODIFICATION_COUNT_INCREMENT;
  }

  /**
   * Mark an access of the specified entry. Used only in {@code CompactLinkedHashMap} for LRU
   * ordering.
   */
  void accessEntry(int index) {
    // no-op by default
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable V put(@ParametricNullness K key, @ParametricNullness V value) {

github.com/hashicorp/go-uuid v1.0.3/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
github.com/hashicorp/golang-lru v1.0.2 h1:dV3g9Z/unq5DpblPpw+Oqcv4dU/1omnb4Ok8iPY6p1c=
github.com/hashicorp/golang-lru v1.0.2/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=