org.apache.hadoop.fs.s3a.s3guard

Class DirListingMetadata

java.lang.Object

org.apache.hadoop.fs.s3a.s3guard.ExpirableMetadata

org.apache.hadoop.fs.s3a.s3guard.DirListingMetadata

@InterfaceAudience.Private
 @InterfaceStability.Evolving
public class DirListingMetadata
extends ExpirableMetadata

DirListingMetadata models a directory listing stored in a MetadataStore. Instances of this class are mutable and thread-safe.

Field Summary

Fields

Modifier and Type	Field and Description
static Collection<PathMetadata>	EMPTY_DIR Convenience parameter for passing into constructor.

Constructor Summary

Constructors

Constructor and Description
DirListingMetadata(DirListingMetadata d) Copy constructor.
DirListingMetadata(org.apache.hadoop.fs.Path path, Collection<PathMetadata> listing, boolean isAuthoritative)
DirListingMetadata(org.apache.hadoop.fs.Path path, Collection<PathMetadata> listing, boolean isAuthoritative, long lastUpdated) Create a directory listing metadata container.

Method Summary

Modifier and Type	Method and Description
PathMetadata	get(org.apache.hadoop.fs.Path childPath) Lookup entry within this directory listing.
Collection<PathMetadata>	getListing()
org.apache.hadoop.fs.Path	getPath()
boolean	isAuthoritative()
Tristate	isEmpty() Is the underlying directory known to be empty?
Set<org.apache.hadoop.fs.Path>	listTombstones() List all tombstones.
void	markDeleted(org.apache.hadoop.fs.Path childPath, long lastUpdated) Replace an entry with a tombstone.
int	numEntries()
String	prettyPrint()
void	prettyPrint(StringBuilder sb) Log contents to supplied StringBuilder in a pretty fashion.
boolean	put(PathMetadata childPathMetadata) Add an entry to the directory listing.
void	remove(org.apache.hadoop.fs.Path childPath) Remove entry from this directory.
List<PathMetadata>	removeExpiredEntriesFromListing(long ttl, long now) Remove expired entries from the listing based on TTL.
void	setAuthoritative(boolean authoritative) Marks this directory listing as full and authoritative.
String	toString()
DirListingMetadata	withoutTombstones() Get the directory listing excluding tombstones.

Methods inherited from class org.apache.hadoop.fs.s3a.s3guard.ExpirableMetadata

getLastUpdated, isExpired, setLastUpdated

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

EMPTY_DIR

public static final Collection<PathMetadata> EMPTY_DIR

Convenience parameter for passing into constructor.

Constructor Detail

DirListingMetadata

public DirListingMetadata(org.apache.hadoop.fs.Path path,
                          Collection<PathMetadata> listing,
                          boolean isAuthoritative,
                          long lastUpdated)

Create a directory listing metadata container.

Parameters:

path - Path of the directory. If this path has a host component, then all paths added later via put(PathMetadata) must also have the same host.

listing - Entries in the directory.

isAuthoritative - true iff listing is the full contents of the directory, and the calling client reports that this may be cached as the full and authoritative listing of all files in the directory.

lastUpdated - last updated time on which expiration is based.

DirListingMetadata

public DirListingMetadata(org.apache.hadoop.fs.Path path,
                          Collection<PathMetadata> listing,
                          boolean isAuthoritative)

DirListingMetadata

public DirListingMetadata(DirListingMetadata d)

Copy constructor.

Parameters:

d - the existing DirListingMetadata object.

Method Detail

getPath

public org.apache.hadoop.fs.Path getPath()

Returns:

Path of the directory that contains this listing.

getListing

public Collection<PathMetadata> getListing()

Returns:

entries in the directory

listTombstones

public Set<org.apache.hadoop.fs.Path> listTombstones()

List all tombstones.

Returns:

all tombstones in the listing.

withoutTombstones

public DirListingMetadata withoutTombstones()

Get the directory listing excluding tombstones. Returns a new DirListingMetadata instances, without the tombstones -the lastUpdated field is copied from this instance.

Returns:

a new DirListingMetadata without the tombstones.

numEntries

public int numEntries()

Returns:

number of entries tracked. This is not the same as the number of entries in the actual directory unless isAuthoritative() is true. It will also include any tombstones.

isAuthoritative

public boolean isAuthoritative()

Returns:

true iff this directory listing is full and authoritative within the scope of the MetadataStore that returned it.

isEmpty

public Tristate isEmpty()

Is the underlying directory known to be empty?

Returns:

FALSE if directory is known to have a child entry, TRUE if directory is known to be empty, UNKNOWN otherwise.

setAuthoritative

public void setAuthoritative(boolean authoritative)

Marks this directory listing as full and authoritative.

Parameters:

authoritative - see isAuthoritative().

get

public PathMetadata get(org.apache.hadoop.fs.Path childPath)

Lookup entry within this directory listing. This may return null if the MetadataStore only tracks a partial set of the directory entries. In the case where isAuthoritative() is true, however, this function returns null iff the directory is known not to contain the listing at given path (within the scope of the MetadataStore that returned it).

Parameters:

childPath - path of entry to look for.

Returns:

entry, or null if it is not present or not being tracked.

markDeleted

public void markDeleted(org.apache.hadoop.fs.Path childPath,
                        long lastUpdated)

Replace an entry with a tombstone.

Parameters:

childPath - path of entry to replace.

remove

public void remove(org.apache.hadoop.fs.Path childPath)

Remove entry from this directory.

Parameters:

childPath - path of entry to remove.

put

public boolean put(PathMetadata childPathMetadata)

Add an entry to the directory listing. If this listing already contains a FileStatus with the same path, it will be replaced.

Parameters:

childPathMetadata - entry to add to this directory listing.

Returns:

true if the status was added or replaced with a new value. False if the same FileStatus value was already present.

toString

public String toString()

Overrides:

toString in class Object

removeExpiredEntriesFromListing

public List<PathMetadata> removeExpiredEntriesFromListing(long ttl,
                                                          long now)

Remove expired entries from the listing based on TTL.

Parameters:

ttl - the ttl time

now - the current time

Returns:

the expired values.

prettyPrint

public void prettyPrint(StringBuilder sb)

Log contents to supplied StringBuilder in a pretty fashion.

Parameters:

sb - target StringBuilder

prettyPrint

public String prettyPrint()