pkg syscall (freebsd-arm64), func Kqueue() (int, error)
pkg syscall (freebsd-arm64), func Listen(int, int) error
pkg syscall (freebsd-arm64), func Lstat(string, *Stat_t) error
pkg syscall (freebsd-arm64), func Mkfifo(string, uint32) error
pkg syscall (freebsd-arm64), func Mknod(string, uint32, uint64) error
pkg syscall (freebsd-arm64), func Mmap(int, int64, int, int, int) ([]uint8, error)

	}
	if !quotaCfg.IsValid() {
		if quotaCfg.Type == "fifo" {
			internalLogIf(GlobalContext, errors.New("Detected older 'fifo' quota config, 'fifo' feature is removed and not supported anymore. Please clear your quota configs using 'mc quota clear alias/bucket' and use 'mc ilm add' for expiration of objects"), logger.WarningKind)
			return quotaCfg, fmt.Errorf("invalid quota type 'fifo'")
		}

pkg syscall (freebsd-riscv64), func Listen(int, int) error #53466
pkg syscall (freebsd-riscv64), func Lstat(string, *Stat_t) error #53466
pkg syscall (freebsd-riscv64), func Mkfifo(string, uint32) error #53466
pkg syscall (freebsd-riscv64), func Mknod(string, uint32, uint64) error #53466
pkg syscall (freebsd-riscv64), func Mmap(int, int64, int, int, int) ([]uint8, error) #53466

import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * A bounded {@linkplain BlockingQueue blocking queue} backed by an array. This queue orders
 * elements FIFO (first-in-first-out). The head of the queue is that element that has been
 * on the queue the longest time. The tail of the queue is that element that has been on

 * Executor, and sequentially such that no two will ever be running at the same time.
 *
 * <p>Tasks submitted to {@link #execute(Runnable)} are executed in FIFO order.
 *
 * <p>The execution of tasks is done by one thread as long as there are tasks left in the queue.
 * When a task is {@linkplain Thread#interrupt interrupted}, execution of subsequent tasks

 * Executor, and sequentially such that no two will ever be running at the same time.
 *
 * <p>Tasks submitted to {@link #execute(Runnable)} are executed in FIFO order.
 *
 * <p>The execution of tasks is done by one thread as long as there are tasks left in the queue.
 * When a task is {@linkplain Thread#interrupt interrupted}, execution of subsequent tasks

import java.util.Queue;

/**
 * A non-blocking queue which automatically evicts elements from the head of the queue when
 * attempting to add new elements onto the queue and it is full. This queue orders elements FIFO
 * (first-in-first-out). This data structure is logically equivalent to a circular buffer (i.e.,
 * cyclic buffer or ring buffer).
 *

"^file:.*"         → fileSystemClient
"^ftp://.*"        → ftpClient
"^smb://.*"        → smbClient
"^storage://.*"    → storageClient
```

### Services

**UrlQueueService**: URL queue management (FIFO), duplicate detection via `visited()`
**DataService**: Access result persistence, iteration

**Implementations**:
- `UrlQueueServiceImpl`, `DataServiceImpl`: In-memory (default)

	TypeLink    = '1' // Hard link
	TypeSymlink = '2' // Symbolic link
	TypeChar    = '3' // Character device node
	TypeBlock   = '4' // Block device node
	TypeDir     = '5' // Directory
	TypeFifo    = '6' // FIFO node

	// Type '7' is reserved.
	TypeCont = '7'

	// Type 'x' is used by the PAX format to store key-value records that
	// are only relevant to the next file.
	// This package transparently handles these types.

		// directory.
		h: &Header{
			Name:     "dir/",
			Mode:     0755,
			Size:     0,
			ModTime:  time.Unix(1360601116, 0),
			Typeflag: TypeDir,
		},
		fm: 0755 | fs.ModeDir,
	}, {
		// fifo node.
		h: &Header{
			Name:     "dev/initctl",
			Mode:     0600,
			Size:     0,
			ModTime:  time.Unix(1360578949, 0),
			Typeflag: TypeFifo,
		},
		fm: 0600 | fs.ModeNamedPipe,
	}, {