cvmfs 0.4.2

//! # Directory Entry Management for CernVM-FS
//!
//! This module provides functionality for handling directory entries in CernVM-FS.
//! Directory entries represent files, directories, symlinks, and other filesystem
//! objects within a CernVM-FS repository. They contain metadata such as size,
//! permissions, and content hashes.
//!
//! ## Directory Entries
//!
//! Directory entries in CernVM-FS contain the following information:
//! - Path information (including MD5 hashes of paths for lookup)
//! - File attributes (size, mode, modification time)
//! - Content addressing (hashes for retrieving file content)
//! - Type flags (file, directory, symlink, etc.)
//! - Chunk information for large files
//!
//! ## Content Addressing
//!
//! CernVM-FS uses content-addressed storage where file contents are referenced by
//! cryptographic hashes. This module supports multiple hash types and provides
//! functionality for working with these content references.
//!
//! ## Path Hashing
//!
//! For efficient lookups, paths in CernVM-FS are hashed using MD5. This module
//! provides structures for working with these path hashes, which are split into
//! two 64-bit components for database indexing.

use std::ops::BitAnd;

use hex::ToHex;
use rusqlite::{Row, Rows};

use crate::common::CvmfsResult;

/// Enumeration of supported content hash types.
///
/// CernVM-FS supports multiple cryptographic hash algorithms for content
/// addressing. This enum defines the supported hash types and their
/// corresponding identifier values used in the catalog database.
///
/// Hash types are used to determine how file content is addressed and verified
/// in the content-addressed storage system.
#[derive(Debug, Copy, Clone)]
pub enum ContentHashTypes {
	/// Represents an unknown or unsupported hash type (value: -1).
	Unknown = -1,
	/// SHA-1 hash algorithm, the default hash type (value: 1).
	Sha1 = 1,
	/// RIPEMD-160 hash algorithm (value: 2).
	Ripemd160 = 2,
	/// SHA-256 hash algorithm (value: 3).
	Sha256 = 3,
	/// SHAKE-128 hash algorithm with 160-bit output (value: 4).
	Shake128 = 4,
}

impl ContentHashTypes {
	/// Returns the hash suffix used in CernVM-FS's content-addressed storage (CAS).
	///
	/// Different hash algorithms require different suffixes in the content-addressed storage
	/// system. This method returns the appropriate suffix for each hash type:
	/// * `Ripemd160` hash type has a "-rmd160" suffix
	/// * All other hash types (including `Sha1`) have an empty suffix
	///
	/// # Arguments
	///
	/// * `obj` - A reference to the ContentHashTypes enum value
	///
	/// # Returns
	///
	/// A String containing the appropriate suffix for the hash type
	pub fn hash_suffix(obj: &Self) -> String {
		match obj {
			ContentHashTypes::Ripemd160 => "-rmd160".into(),
			ContentHashTypes::Sha256 => "-sha256".into(),
			ContentHashTypes::Shake128 => "-shake128".into(),
			_ => "".into(),
		}
	}
}

impl From<u32> for ContentHashTypes {
	fn from(value: u32) -> Self {
		match value {
			1 => ContentHashTypes::Sha1,
			2 => ContentHashTypes::Ripemd160,
			3 => ContentHashTypes::Sha256,
			4 => ContentHashTypes::Shake128,
			_ => ContentHashTypes::Unknown,
		}
	}
}

/// Flags representing the type and properties of directory entries.
///
/// This enum defines bit flags that indicate what type of filesystem object
/// a directory entry represents (file, directory, symlink, etc.) and its special
/// properties (nested catalog points, chunked files, etc.).
///
/// These flags are stored in the catalog database and used to determine how
/// the entry should be handled by the filesystem operations.
#[derive(Debug, Copy, Clone)]
pub enum Flags {
	/// Entry is a directory (value: 1).
	Directory = 1,
	/// Entry is a mountpoint for a nested catalog (value: 2).
	NestedCatalogMountpoint = 2,
	/// Entry is a regular file (value: 4).
	File = 4,
	/// Entry is a symbolic link (value: 8).
	Link = 8,
	/// Entry has file statistics (value: 16).
	FileStat = 16,
	/// Entry is the root of a nested catalog (value: 32).
	NestedCatalogRoot = 32,
	/// Entry represents a chunk of a large file (value: 64).
	FileChunk = 64,
	/// Entry content is stored externally, outside the CAS (value: 2048).
	ExternalFile = 2048,
	/// Bitmask for content hash type (values: 256 + 512 + 1024).
	ContentHashTypes = 256 + 512 + 1024,
}

/// Implementation of bitwise AND operation between two Flags enum values.
///
/// This allows using the & operator to check if a particular flag is set
/// by comparing the numeric values of the flags.
impl BitAnd<Flags> for Flags {
	type Output = u32;

	fn bitand(self, rhs: Flags) -> Self::Output {
		self as u32 & rhs
	}
}

impl BitAnd<u32> for Flags {
	type Output = u32;

	fn bitand(self, rhs: u32) -> Self::Output {
		self as u32 & rhs
	}
}

impl BitAnd<Flags> for u32 {
	type Output = u32;

	fn bitand(self, rhs: Flags) -> Self::Output {
		self & rhs as u32
	}
}

/// Represents a chunk of a large file in CernVM-FS.
///
/// In CernVM-FS, large files are split into multiple chunks for efficient storage
/// and transfer. Each chunk has its own content hash and can be retrieved independently.
/// This struct contains the metadata for a single chunk, including its position within
/// the file (offset), size, and content addressing information.
///
/// File chunks allow for random access to parts of large files without downloading
/// the entire file, and enable more efficient delta updates when only parts of a file
/// change.
#[derive(Debug, Clone)]
pub struct Chunk {
	pub offset: i64,
	pub size: i64,
	pub content_hash: String,
	pub content_hash_type: ContentHashTypes,
}

impl Chunk {
	/// Returns the complete content hash string for this chunk.
	///
	/// This method combines the raw content hash with the appropriate hash suffix
	/// based on the hash type. The resulting string is used to locate the chunk
	/// in the content-addressed storage system.
	///
	/// # Returns
	///
	/// A String containing the complete content hash identifier, including any
	/// necessary hash type suffix.
	pub fn content_hash_string(&self) -> String {
		format!("{}{}", &self.content_hash, ContentHashTypes::hash_suffix(&self.content_hash_type))
	}
}

/// Represents a split MD5 path hash used for efficient catalog lookups.
///
/// In CernVM-FS, paths are hashed using MD5 and the resulting 128-bit hash is
/// split into two 64-bit components (hash1 and hash2) for efficient database indexing
/// and lookup operations.
///
/// This split representation is used throughout the catalog database for path-based
/// operations like finding directory entries and listing directory contents.
#[derive(Debug)]
pub struct PathHash {
	pub hash1: i64,
	pub hash2: i64,
}

/// Wraps a DirectoryEntry with its full path string.
///
/// This struct combines a DirectoryEntry with its string path representation,
/// making it easier to work with directory entries in contexts where both the
/// entry metadata and the full path are needed together.
#[derive(Debug)]
pub struct DirectoryEntryWrapper {
	pub directory_entry: DirectoryEntry,
	pub path: String,
}

/// Represents a file system object in the CernVM-FS repository.
///
/// A DirectoryEntry contains all metadata for a file, directory, or symbolic link
/// in the repository. This includes basic file attributes (size, permissions, timestamps),
/// content addressing information (hashes for retrieving file content), and type flags.
///
/// For large files that are split into chunks, the DirectoryEntry also maintains a list
/// of chunks that make up the complete file.
///
/// Directory entries are stored in the catalog database and are the primary objects
/// used for filesystem operations like listing directories and looking up files.
#[derive(Debug, Clone)]
pub struct DirectoryEntry {
	/// First 64 bits of the MD5 hash of the entry's path.
	pub md5_path_1: i64,
	/// Second 64 bits of the MD5 hash of the entry's path.
	pub md5_path_2: i64,
	/// First 64 bits of the MD5 hash of the parent directory's path.
	pub parent_1: i64,
	/// Second 64 bits of the MD5 hash of the parent directory's path.
	pub parent_2: i64,
	/// Content hash for retrieving the file's content (None for chunked files).
	pub content_hash: Option<String>,
	/// Bit flags indicating the entry type and properties.
	pub flags: u32,
	/// Size of the file in bytes.
	pub size: i64,
	/// Unix file mode/permissions (as a 16-bit value).
	pub mode: u16,
	/// Modification time (Unix timestamp).
	pub mtime: i64,
	/// Base name of the file or directory (without path components).
	pub name: String,
	/// Target path for symbolic links (None for non-symlinks).
	pub symlink: Option<String>,
	/// User ID of the file owner.
	pub uid: u32,
	/// Group ID of the file owner.
	pub gid: u32,
	/// Hardlink group ID (upper 32 bits) and link count (lower 32 bits).
	pub hardlinks: i64,
	/// Extended attributes stored as a serialized blob (None if absent).
	pub xattr: Option<Vec<u8>>,
	/// Type of hash used for content addressing.
	pub content_hash_type: ContentHashTypes,
	/// List of chunks for large files that are split into multiple pieces.
	pub chunks: Vec<Chunk>,
}

impl DirectoryEntry {
	/// Creates a new DirectoryEntry from a database row.
	///
	/// This method constructs a DirectoryEntry by extracting values from a database row
	/// retrieved from the catalog. It parses various fields including path hashes,
	/// content hash, flags, size, permissions, and other metadata.
	///
	/// Note that this method doesn't populate the chunks field - for chunked files,
	/// the `add_chunks` method should be called separately to populate chunk information.
	///
	/// # Arguments
	///
	/// * `row` - A reference to a SQLite row containing directory entry data.
	///
	/// # Returns
	///
	/// Returns a `CvmfsResult<Self>` containing the constructed DirectoryEntry,
	/// or an error if any required field is missing or has an invalid format.
	pub fn new(row: &Row) -> CvmfsResult<Self> {
		let content_hash: Option<Vec<u8>> = row.get(4)?;
		let flags = row.get(5)?;
		Ok(Self {
			md5_path_1: row.get(0)?,
			md5_path_2: row.get(1)?,
			parent_1: row.get(2)?,
			parent_2: row.get(3)?,
			content_hash: content_hash.map(|value| value.encode_hex()),
			flags,
			size: row.get(6)?,
			mode: row.get(7)?,
			mtime: row.get(8)?,
			name: row.get(9)?,
			symlink: row.get(10)?,
			uid: row.get(11)?,
			gid: row.get(12)?,
			hardlinks: row.get(13)?,
			xattr: row.get(14)?,
			content_hash_type: Self::read_content_hash_type(flags),
			chunks: vec![],
		})
	}

	/// Adds chunk information to a directory entry for chunked files.
	///
	/// This method populates the chunks vector from database query results. For large files
	/// that are split into multiple chunks, this method processes each chunk row and
	/// adds the chunk metadata to the directory entry.
	///
	/// # Arguments
	///
	/// * `rows` - An iterator over database rows containing chunk information.
	///
	/// # Returns
	///
	/// Returns `Ok(())` if chunks were successfully added, or an error if the database
	/// query failed or returned malformed data.
	pub fn add_chunks(&mut self, mut rows: Rows) -> CvmfsResult<()> {
		self.chunks.clear();
		loop {
			match rows.next() {
				Ok(row) => {
					if let Some(row) = row {
						let content_hash: Vec<u8> = row.get(4)?;
						self.chunks.push(Chunk {
							offset: row.get(2)?,
							size: row.get(3)?,
							content_hash: content_hash.encode_hex(),
							content_hash_type: self.content_hash_type,
						})
					} else {
						break;
					}
				}
				Err(e) => return Err(e.into()),
			}
		}
		Ok(())
	}

	/// Checks if this entry is a directory.
	///
	/// This method tests whether the Directory flag is set in the entry's flags.
	///
	/// # Returns
	///
	/// Returns `true` if this entry is a directory, `false` otherwise.
	pub fn is_directory(&self) -> bool {
		self.flags & Flags::Directory > 0
	}

	/// Checks if this entry is a mountpoint for a nested catalog.
	///
	/// Nested catalog mountpoints are special directory entries that indicate the
	/// presence of a nested catalog at that path. When traversing the filesystem
	/// hierarchy, these mountpoints signal that a different catalog database needs
	/// to be loaded to access entries beneath this point.
	///
	/// # Returns
	///
	/// Returns `true` if this entry is a nested catalog mountpoint, `false` otherwise.
	pub fn is_nested_catalog_mountpoint(&self) -> bool {
		self.flags & Flags::NestedCatalogMountpoint > 0
	}

	/// Checks if this entry is the root of a nested catalog.
	///
	/// Nested catalog roots are the top-level directory entries in a nested catalog.
	/// They represent the same filesystem object as a nested catalog mountpoint,
	/// but from within the nested catalog itself rather than from the parent catalog.
	///
	/// # Returns
	///
	/// Returns `true` if this entry is a nested catalog root, `false` otherwise.
	pub fn is_nested_catalog_root(&self) -> bool {
		self.flags & Flags::NestedCatalogRoot > 0
	}

	/// Checks if this entry is a regular file.
	///
	/// This method tests whether the File flag is set in the entry's flags.
	///
	/// # Returns
	///
	/// Returns `true` if this entry is a regular file, `false` otherwise.
	pub fn is_file(&self) -> bool {
		self.flags & Flags::File > 0
	}

	/// Checks if this entry is a symbolic link.
	///
	/// This method tests whether the Link flag is set in the entry's flags.
	/// Symbolic links in CernVM-FS point to other paths in the repository.
	///
	/// # Returns
	///
	/// Returns `true` if this entry is a symbolic link, `false` otherwise.
	pub fn is_symlink(&self) -> bool {
		self.flags & Flags::Link > 0
	}

	pub fn is_external_file(&self) -> bool {
		self.flags & Flags::ExternalFile > 0
	}

	/// Returns a PathHash struct containing this entry's path hash components.
	///
	/// This method constructs a PathHash struct from the entry's MD5 path hash
	/// components (md5_path_1 and md5_path_2).
	///
	/// # Returns
	///
	/// A PathHash struct containing the two 64-bit components of the path hash.
	pub fn path_hash(&self) -> PathHash {
		PathHash { hash1: self.md5_path_1, hash2: self.md5_path_2 }
	}

	/// Returns a PathHash struct containing this entry's parent directory path hash.
	///
	/// This method constructs a PathHash struct from the entry's parent directory
	/// MD5 path hash components (parent_1 and parent_2).
	///
	/// # Returns
	///
	/// A PathHash struct containing the two 64-bit components of the parent path hash.
	pub fn parent_hash(&self) -> PathHash {
		PathHash { hash1: self.parent_1, hash2: self.parent_2 }
	}

	/// Checks if this entry represents a chunked file.
	///
	/// Large files in CernVM-FS are split into chunks, and their content_hash field
	/// is None to indicate this. This method checks that condition.
	///
	/// # Returns
	///
	/// Returns true if the file is chunked (content_hash is None), false otherwise.
	/// Returns the number of hard links to this entry.
	pub fn nlink(&self) -> u32 {
		(self.hardlinks & 0xFFFF_FFFF) as u32
	}

	/// Returns the hardlink group ID, or 0 if not part of a group.
	pub fn hardlink_group(&self) -> u32 {
		((self.hardlinks >> 32) & 0xFFFF_FFFF) as u32
	}

	pub fn has_chunks(&self) -> bool {
		self.content_hash.is_none()
	}

	/// Returns the complete content hash string for this entry.
	///
	/// This method combines the raw content hash with the appropriate hash type suffix
	/// to form the complete identifier used in content-addressed storage.
	///
	/// # Returns
	///
	/// Returns None if this is a chunked file, otherwise returns Some containing
	/// the complete hash string with appropriate suffix.
	pub fn content_hash_string(&self) -> Option<String> {
		self.content_hash.clone().map(|value| {
			format!("{}{}", &value, ContentHashTypes::hash_suffix(&self.content_hash_type))
		})
	}

	/// Extracts the content hash type from the entry flags.
	///
	/// This method manipulates the flags bitfield to extract and decode the
	/// content hash type bits. It shifts the ContentHashTypes bits right until
	/// aligned and converts the value to a ContentHashTypes enum.
	///
	/// # Arguments
	///
	/// * `flags` - The entry flags containing the hash type bits.
	///
	/// # Returns
	///
	/// The ContentHashTypes value encoded in the flags.
	pub(crate) fn read_content_hash_type(flags: u32) -> ContentHashTypes {
		let mut bit_mask = Flags::ContentHashTypes as u32;
		let mut right_shifts = 0;
		while (bit_mask & 1) == 0 {
			bit_mask >>= 1;
			right_shifts += 1;
		}
		(((flags & Flags::ContentHashTypes) >> right_shifts) + 1).into()
	}
}

#[cfg(test)]
mod tests {
	use super::*;

	fn make_entry(flags: u32, content_hash: Option<String>) -> DirectoryEntry {
		DirectoryEntry {
			md5_path_1: 1,
			md5_path_2: 2,
			parent_1: 3,
			parent_2: 4,
			content_hash,
			flags,
			size: 100,
			mode: 0o644,
			mtime: 1000,
			name: "test".into(),
			symlink: None,
			uid: 1000,
			gid: 1000,
			hardlinks: 1,
			xattr: None,
			content_hash_type: DirectoryEntry::read_content_hash_type(flags),
			chunks: vec![],
		}
	}

	// --- ContentHashTypes ---

	#[test]
	fn hash_suffix_sha1_is_empty() {
		assert_eq!(ContentHashTypes::hash_suffix(&ContentHashTypes::Sha1), "");
	}

	#[test]
	fn hash_suffix_ripemd160() {
		assert_eq!(ContentHashTypes::hash_suffix(&ContentHashTypes::Ripemd160), "-rmd160");
	}

	#[test]
	fn hash_suffix_unknown_is_empty() {
		assert_eq!(ContentHashTypes::hash_suffix(&ContentHashTypes::Unknown), "");
	}

	#[test]
	fn hash_suffix_sha256() {
		assert_eq!(ContentHashTypes::hash_suffix(&ContentHashTypes::Sha256), "-sha256");
	}

	#[test]
	fn hash_suffix_shake128() {
		assert_eq!(ContentHashTypes::hash_suffix(&ContentHashTypes::Shake128), "-shake128");
	}

	#[test]
	fn content_hash_types_from_1_is_sha1() {
		let t: ContentHashTypes = 1u32.into();
		assert!(matches!(t, ContentHashTypes::Sha1));
	}

	#[test]
	fn content_hash_types_from_2_is_ripemd160() {
		let t: ContentHashTypes = 2u32.into();
		assert!(matches!(t, ContentHashTypes::Ripemd160));
	}

	#[test]
	fn content_hash_types_from_3_is_sha256() {
		let t: ContentHashTypes = 3u32.into();
		assert!(matches!(t, ContentHashTypes::Sha256));
	}

	#[test]
	fn content_hash_types_from_4_is_shake128() {
		let t: ContentHashTypes = 4u32.into();
		assert!(matches!(t, ContentHashTypes::Shake128));
	}

	#[test]
	fn content_hash_types_from_0_is_unknown() {
		let t: ContentHashTypes = 0u32.into();
		assert!(matches!(t, ContentHashTypes::Unknown));
	}

	#[test]
	fn content_hash_types_from_99_is_unknown() {
		let t: ContentHashTypes = 99u32.into();
		assert!(matches!(t, ContentHashTypes::Unknown));
	}

	// --- Flags bitwise AND ---

	#[test]
	fn u32_bitand_flags() {
		let result: u32 = 7u32 & Flags::File;
		assert_eq!(result, 4); // Flags::File = 4, 7 & 4 = 4
	}

	#[test]
	fn flags_bitand_u32() {
		let result: u32 = Flags::File & 7u32;
		assert_eq!(result, 4);
	}

	#[test]
	fn flags_bitand_flags() {
		let result: u32 = Flags::Directory & Flags::Directory;
		assert_eq!(result, 1);
	}

	#[test]
	fn flags_bitand_no_overlap() {
		let result: u32 = Flags::Directory & Flags::File;
		assert_eq!(result, 0);
	}

	// --- Chunk ---

	#[test]
	fn chunk_content_hash_string_sha1() {
		let chunk = Chunk {
			offset: 0,
			size: 100,
			content_hash: "abc123".into(),
			content_hash_type: ContentHashTypes::Sha1,
		};
		assert_eq!(chunk.content_hash_string(), "abc123");
	}

	#[test]
	fn chunk_content_hash_string_ripemd160() {
		let chunk = Chunk {
			offset: 0,
			size: 100,
			content_hash: "deadbeef".into(),
			content_hash_type: ContentHashTypes::Ripemd160,
		};
		assert_eq!(chunk.content_hash_string(), "deadbeef-rmd160");
	}

	// --- DirectoryEntry helper methods ---

	#[test]
	fn entry_is_directory() {
		let entry = make_entry(Flags::Directory as u32, Some("hash".into()));
		assert!(entry.is_directory());
		assert!(!entry.is_file());
		assert!(!entry.is_symlink());
	}

	#[test]
	fn entry_is_file() {
		let entry = make_entry(Flags::File as u32, Some("hash".into()));
		assert!(entry.is_file());
		assert!(!entry.is_directory());
		assert!(!entry.is_symlink());
	}

	#[test]
	fn entry_is_symlink() {
		let entry = make_entry(Flags::Link as u32, Some("hash".into()));
		assert!(entry.is_symlink());
		assert!(!entry.is_file());
		assert!(!entry.is_directory());
	}

	#[test]
	fn entry_is_nested_catalog_mountpoint() {
		let entry = make_entry(Flags::NestedCatalogMountpoint as u32, Some("hash".into()));
		assert!(entry.is_nested_catalog_mountpoint());
	}

	#[test]
	fn entry_is_nested_catalog_root() {
		let entry = make_entry(Flags::NestedCatalogRoot as u32, Some("hash".into()));
		assert!(entry.is_nested_catalog_root());
	}

	#[test]
	fn entry_has_chunks_when_no_content_hash() {
		let entry = make_entry(Flags::File as u32, None);
		assert!(entry.has_chunks());
	}

	#[test]
	fn entry_no_chunks_when_content_hash_present() {
		let entry = make_entry(Flags::File as u32, Some("abc".into()));
		assert!(!entry.has_chunks());
	}

	#[test]
	fn entry_content_hash_string_with_sha1() {
		// flags = Flags::File (4), hash bits = 0 => read_content_hash_type => (0+1) = 1 => Sha1
		let entry = make_entry(Flags::File as u32, Some("abc123".into()));
		assert_eq!(entry.content_hash_string(), Some("abc123".to_string()));
	}

	#[test]
	fn entry_content_hash_string_with_ripemd160() {
		// To get Ripemd160 we need hash bits = 1 (shifted left 8 = 256)
		// read_content_hash_type: (1 + 1) = 2 => Ripemd160
		let flags = Flags::File as u32 | 256;
		let entry = make_entry(flags, Some("abc123".into()));
		assert_eq!(entry.content_hash_string(), Some("abc123-rmd160".to_string()));
	}

	#[test]
	fn entry_content_hash_string_none_for_chunked() {
		let entry = make_entry(Flags::File as u32, None);
		assert_eq!(entry.content_hash_string(), None);
	}

	#[test]
	fn entry_path_hash() {
		let entry = make_entry(Flags::File as u32, Some("h".into()));
		let ph = entry.path_hash();
		assert_eq!(ph.hash1, 1);
		assert_eq!(ph.hash2, 2);
	}

	#[test]
	fn entry_parent_hash() {
		let entry = make_entry(Flags::File as u32, Some("h".into()));
		let ph = entry.parent_hash();
		assert_eq!(ph.hash1, 3);
		assert_eq!(ph.hash2, 4);
	}

	// --- read_content_hash_type ---

	#[test]
	fn read_content_hash_type_sha1_from_zero_hash_bits() {
		// hash bits = 0 in the ContentHashTypes mask => (0 + 1) = 1 => Sha1
		let t = DirectoryEntry::read_content_hash_type(0);
		assert!(matches!(t, ContentHashTypes::Sha1));
	}

	#[test]
	fn read_content_hash_type_ripemd160_from_256() {
		// 256 >> 8 = 1, +1 = 2 => Ripemd160
		let t = DirectoryEntry::read_content_hash_type(256);
		assert!(matches!(t, ContentHashTypes::Ripemd160));
	}

	#[test]
	fn read_content_hash_type_sha256_from_512() {
		// 512 >> 8 = 2, +1 = 3 => Sha256
		let t = DirectoryEntry::read_content_hash_type(512);
		assert!(matches!(t, ContentHashTypes::Sha256));
	}

	#[test]
	fn read_content_hash_type_shake128_from_768() {
		// 768 >> 8 = 3, +1 = 4 => Shake128
		let t = DirectoryEntry::read_content_hash_type(768);
		assert!(matches!(t, ContentHashTypes::Shake128));
	}

	#[test]
	fn read_content_hash_type_ignores_non_hash_flags() {
		// Flags::File (4) has no overlap with ContentHashTypes mask (0x700)
		let t = DirectoryEntry::read_content_hash_type(Flags::File as u32);
		assert!(matches!(t, ContentHashTypes::Sha1));
	}

	#[test]
	fn entry_combined_flags() {
		let flags = Flags::File as u32 | Flags::FileChunk as u32;
		let entry = make_entry(flags, None);
		assert!(entry.is_file());
		assert!(!entry.is_directory());
		assert!(entry.has_chunks());
	}

	#[test]
	fn entry_nlink() {
		let mut entry = make_entry(Flags::File as u32, Some("h".into()));
		entry.hardlinks = 3;
		assert_eq!(entry.nlink(), 3);
	}

	#[test]
	fn entry_hardlink_group() {
		let mut entry = make_entry(Flags::File as u32, Some("h".into()));
		entry.hardlinks = (5_i64 << 32) | 2;
		assert_eq!(entry.nlink(), 2);
		assert_eq!(entry.hardlink_group(), 5);
	}

	#[test]
	fn entry_uid_gid() {
		let entry = make_entry(Flags::File as u32, Some("h".into()));
		assert_eq!(entry.uid, 1000);
		assert_eq!(entry.gid, 1000);
	}

	#[test]
	fn entry_xattr_none() {
		let entry = make_entry(Flags::File as u32, Some("h".into()));
		assert!(entry.xattr.is_none());
	}

	#[test]
	fn entry_is_external_file() {
		let flags = Flags::File as u32 | Flags::ExternalFile as u32;
		let entry = make_entry(flags, Some("h".into()));
		assert!(entry.is_external_file());
		assert!(entry.is_file());
	}

	#[test]
	fn entry_is_not_external_file() {
		let entry = make_entry(Flags::File as u32, Some("h".into()));
		assert!(!entry.is_external_file());
	}
}