AccessControlList (Alluxio Parent 2.4.2-SNAPSHOT API)

java.lang.Object
- alluxio.security.authorization.AccessControlList

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

DefaultAccessControlList
```
@NotThreadSafe
public class AccessControlList
extends Object
implements Serializable
```
Access control list for a file or directory. An access control list is conceptually a list of entries, there are different types of entries: 1. owning user entry which specifies permitted actions for the owning user of a file or directory, there is only one owning user entry; 2. named user entry which specifies permitted actions for any user, there is only one named user entry for each user; 3. owning group entry which specifies permitted actions for the owning group of a file or directory, there is only one owning group entry; 4. named group entry which specifies permitted actions for any group, there is only one named group entry for each group; 5. mask entry which specifies the maximum set of permitted actions for users and groups in all the above entries; 6. other entry which specifies permitted actions for users who are neither the owning user nor have a named user entry, and whose belonging groups are neither the owning group nor have a named group entry. Also, the access control list contains owning user and owning group of a file or directory.

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`AccessControlList.AccessControlListDeserializer` This is a custom json deserializer for AccessControlList class.
`static class`	`AccessControlList.AccessControlListSerializer` This is a custom json serializer for AccessControlList class.

Field Summary

Fields
Modifier and Type	Field and Description
`static AccessControlList`	`EMPTY_ACL`
`protected ExtendedACLEntries`	`mExtendedEntries`
`protected short`	`mMode`
`protected String`	`mOwningGroup`
`protected String`	`mOwningUser`
`static String`	`OWNER_FIELD` Keys representing owning user and group for proto ser/de.
`static String`	`OWNING_GROUP_FIELD`
`static String`	`OWNING_GROUP_KEY`
`static String`	`OWNING_USER_KEY`
`static String`	`STRING_ENTRY_FIELD`

Constructor Summary

Constructors
Constructor and Description
`AccessControlList()` Creates a new instance where owning user and owning group are initialized to empty strings, and no action is permitted for any user or group.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`checkPermission(String user, List<String> groups, AclAction action)` Checks whether the user has the permission to perform the action.
`void`	`clearEntries()` Clears out all entries (does not modify the owner name and owning group).
`boolean`	`equals(Object o)`
`static AccessControlList`	`fromStringEntries(String owner, String owningGroup, List<String> stringEntries)` Converts a list of string entries into an AccessControlList or a DefaultAccessControlList.
`List<AclEntry>`	`getEntries()` Returns a list of `AclEntry` which represent this ACL instance.
`ExtendedACLEntries`	`getExtendedEntries()`
`short`	`getMode()`
`AclActions`	`getOtherActions()`
`String`	`getOwningGroup()`
`AclActions`	`getOwningGroupActions()`
`String`	`getOwningUser()`
`AclActions`	`getOwningUserActions()`
`AclActions`	`getPermission(String user, List<String> groups)` Gets the permitted actions for a user.
`boolean`	`hasExtended()`
`int`	`hashCode()`
`void`	`removeEntry(AclEntry entry)` Removes the specified entry.
`void`	`removeExtendedEntries()` Removes all of the exnteded entries.
`void`	`setEntry(AclEntry entry)` Sets an entry into the access control list.
`void`	`setMode(short mode)` Sets permitted actions for owning user, owning group, and other based on the mode.
`void`	`setOwningGroup(String group)` Sets owning group.
`void`	`setOwningUser(String user)` Sets owning user.
`String`	`toString()`
`List<String>`	`toStringEntries()`
`void`	`updateMask()` Update the mask to be the union of owning group entry, named user entry and named group entry.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - EMPTY_ACL
```
public static final AccessControlList EMPTY_ACL
```
  - OWNER_FIELD
```
public static final String OWNER_FIELD
```
    Keys representing owning user and group for proto ser/de.
    
    See Also:
    
    Constant Field Values
  - OWNING_GROUP_FIELD
```
public static final String OWNING_GROUP_FIELD
```
    See Also:
    
    Constant Field Values
  - STRING_ENTRY_FIELD
```
public static final String STRING_ENTRY_FIELD
```
    See Also:
    
    Constant Field Values
  - OWNING_USER_KEY
```
public static final String OWNING_USER_KEY
```
    See Also:
    
    Constant Field Values
  - OWNING_GROUP_KEY
```
public static final String OWNING_GROUP_KEY
```
    See Also:
    
    Constant Field Values
  - mOwningUser
```
protected String mOwningUser
```
  - mOwningGroup
```
protected String mOwningGroup
```
  - mMode
```
protected short mMode
```
  - mExtendedEntries
```
protected ExtendedACLEntries mExtendedEntries
```
- Constructor Detail
  - AccessControlList
```
public AccessControlList()
```
    Creates a new instance where owning user and owning group are initialized to empty strings, and no action is permitted for any user or group.
- Method Detail
  - clearEntries
```
public void clearEntries()
```
    Clears out all entries (does not modify the owner name and owning group).
  - getExtendedEntries
```
public ExtendedACLEntries getExtendedEntries()
```
    Returns:
    
    the extended entries
  - getOwningUser
```
public String getOwningUser()
```
    Returns:
    
    the owning user
  - getOwningGroup
```
public String getOwningGroup()
```
    Returns:
    
    the owning group
  - getOwningUserActions
```
public AclActions getOwningUserActions()
```
    Returns:
    
    the owning user actions
  - getOwningGroupActions
```
public AclActions getOwningGroupActions()
```
    Returns:
    
    the owning group actions
  - getOtherActions
```
public AclActions getOtherActions()
```
    Returns:
    
    other actions
  - getMode
```
public short getMode()
```
    Returns:
    
    the permission mode defined in Mode for owning user, owning group, and other
  - getEntries
```
public List<AclEntry> getEntries()
```
    Returns a list of AclEntry which represent this ACL instance. The mask will only be included if extended ACL entries exist.
    
    Returns:
    
    an immutable list of ACL entries
  - hasExtended
```
public boolean hasExtended()
```
    Returns:
    
    true if has extended ACL (named users, named groups)
  - removeEntry
```
public void removeEntry(AclEntry entry)
```
    Removes the specified entry. A base entry is not allowed to be removed.
    
    Parameters:
    
    entry - the entry to be removed
  - removeExtendedEntries
```
public void removeExtendedEntries()
```
    Removes all of the exnteded entries. The base entries are retained.
  - setOwningUser
```
public void setOwningUser(String user)
```
    Sets owning user.
    
    Parameters:
    
    user - the owning user
  - setOwningGroup
```
public void setOwningGroup(String group)
```
    Sets owning group.
    
    Parameters:
    
    group - the owning group
  - setMode
```
public void setMode(short mode)
```
    Sets permitted actions for owning user, owning group, and other based on the mode. The format of mode is defined in Mode. The update logic is defined in AclActions.updateByModeBits(Mode.Bits).
    
    Parameters:
    
    mode - the mode
  - updateMask
```
public void updateMask()
```
    Update the mask to be the union of owning group entry, named user entry and named group entry. This method must be called when the aforementioned entries are modified.
  - setEntry
```
public void setEntry(AclEntry entry)
```
    Sets an entry into the access control list. If an entry with the same type and subject already exists, overwrites the existing entry; Otherwise, adds this new entry. After we modify entries for NAMED_GROUP, OWNING_GROUP, NAMED_USER, we need to update the mask.
    
    Parameters:
    
    entry - the entry to be added or updated
  - checkPermission
```
public boolean checkPermission(String user,
                               List<String> groups,
                               AclAction action)
```
    Checks whether the user has the permission to perform the action. 1. If the user is the owner, then the owner entry determines the permission; 2. Else if the user matches the name of one of the named user entries, this entry determines the permission; 3. Else if one of the groups is the owning group and the owning group entry contains the requested permission, the permission is granted; 4. Else if one of the groups matches the name of one of the named group entries and this entry contains the requested permission, the permission is granted; 5. Else if one of the groups is the owning group or matches the name of one of the named group entries, but neither the owning group entry nor any of the matching named group entries contains the requested permission, the permission is denied; 6. Otherwise, the other entry determines the permission.
    
    Parameters:
    
    user - the user
    
    groups - the groups the user belongs to
    
    action - the action
    
    Returns:
    
    whether user has the permission to perform the action
  - getPermission
```
public AclActions getPermission(String user,
                                List<String> groups)
```
    Gets the permitted actions for a user. When AccessControlList is not modified after calling getPermission, for each action returned by this method, checkPermission(user, groups, action) is true, for other actions, checkPermission(user, groups, action) is false. 1. If the user is the owner, then return the permission in the owner entry; 2. Else if the user matches the name of one of the named user entries, then return the AND result of the permission in this entry and the mask ; 3. Else if at least one of the groups is the owning group or matches the name of one of the named group entries, then for the named group entries that match a member of groups, merge the permissions in these entries and return the merged permission ANDed with the mask; 4. Otherwise, return the permission in the other entry.
    
    Parameters:
    
    user - the user
    
    groups - the groups the user belongs to
    
    Returns:
    
    the permitted actions
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - fromStringEntries
```
public static AccessControlList fromStringEntries(String owner,
                                                  String owningGroup,
                                                  List<String> stringEntries)
```
    Converts a list of string entries into an AccessControlList or a DefaultAccessControlList. It assumes the stringEntries contain all default entries or normal entries.
    
    Parameters:
    
    owner - the owner
    
    owningGroup - the owning group
    
    stringEntries - the list of string representations of the entries
    
    Returns:
    
    the AccessControlList instance
  - toStringEntries
```
public List<String> toStringEntries()
```
    Returns:
    
    the list of string entries
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class AccessControlList

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EMPTY_ACL

OWNER_FIELD

OWNING_GROUP_FIELD

STRING_ENTRY_FIELD

OWNING_USER_KEY

OWNING_GROUP_KEY

mOwningUser

mOwningGroup

mMode

mExtendedEntries

Constructor Detail

AccessControlList

Method Detail

clearEntries

getExtendedEntries

getOwningUser

getOwningGroup

getOwningUserActions

getOwningGroupActions

getOtherActions

getMode

getEntries

hasExtended

removeEntry

removeExtendedEntries

setOwningUser

setOwningGroup

setMode

updateMask

setEntry

checkPermission

getPermission

equals

hashCode

fromStringEntries

toStringEntries

toString