bees.core.resource
Class File

java.lang.Object
  |
  +--bees.core.Capability
        |
        +--bees.core.resource.PathSpec
              |
              +--bees.core.resource.File

All Implemented Interfaces:

CapabilitySpec, edu.utah.janosvm.kit.comm.jsi.JSIHandler

public final class File

extends PathSpec

implements edu.utah.janosvm.kit.comm.jsi.JSIHandler

Capability to govern access to a disk file.

Field Summary

static PermissionSet	DEFAULT_PERMISSIONS The default permissions for a new file capability.
static FilePermission	FILE_APPEND_PERMISSION Permission to append to the file.
static Permission	FILE_DELETE_PERMISSION Permission to delete the file.
static Permission	FILE_LENGTH_PERMISSION Permission to get the file's length.
static Permission	FILE_READ_LAST_MODIFIED_PERMISSION Permission to read the file's last modified time.
static Permission	FILE_READ_PERMISSION Permission to read the file.
static Permission	FILE_WRITE_LAST_MODIFIED_PERMISSION Permission to write the file's last modified time.
static Permission	FILE_WRITE_PERMISSION Permission to write to the file.

Fields inherited from class bees.core.Capability

DELETE_PERMISSION, id, INVALID_ID

Constructor Summary

File()
Construct an empty File capability.

Method Summary

void	delete() Delete the file on disk.
protected void	fromBytes(byte[] flattened, CapabilityEnvelope[] sub) Bind this capability to the given object.
java.io.InputStream	getInputStream()
java.io.OutputStream	getOutputStream()
java.io.OutputStream	getOutputStream(boolean append)
void	getSuites(edu.utah.janosvm.kit.comm.jsi.JSIMessage jm)
void	handleMessage(edu.utah.janosvm.kit.comm.jsi.JSIHandlerContext jhc, edu.utah.janosvm.kit.comm.jsi.JSIMessage jm)
long	lastModified(Clock clock) Get the last modified time of the file.
long	length()
edu.utah.janosvm.kit.comm.jsi.JSIHandler	resolveSpecifier(edu.utah.janosvm.kit.comm.jsi.JSIMessage jm, edu.utah.janosvm.kit.comm.jsi.JSIPair jp)
void	revoke() Revoke access to the capability.
java.lang.String	toString()

Methods inherited from class bees.core.resource.PathSpec

getFactory, specFromBytes, toBytes

Methods inherited from class bees.core.Capability

checkPermission, clear, clonePermission, deleteCapability, equals, fromBytes, revokedPermission, revokePermission, revokePermissions, valid

Methods inherited from class java.lang.Object

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

Field Detail

FILE_READ_PERMISSION

public static final Permission FILE_READ_PERMISSION

Permission to read the file.

FILE_WRITE_PERMISSION

public static final Permission FILE_WRITE_PERMISSION

Permission to write to the file.

FILE_APPEND_PERMISSION

public static final FilePermission FILE_APPEND_PERMISSION

Permission to append to the file.

FILE_LENGTH_PERMISSION

public static final Permission FILE_LENGTH_PERMISSION

Permission to get the file's length.

FILE_READ_LAST_MODIFIED_PERMISSION

public static final Permission FILE_READ_LAST_MODIFIED_PERMISSION

Permission to read the file's last modified time.

FILE_WRITE_LAST_MODIFIED_PERMISSION

public static final Permission FILE_WRITE_LAST_MODIFIED_PERMISSION

Permission to write the file's last modified time.

FILE_DELETE_PERMISSION

public static final Permission FILE_DELETE_PERMISSION

Permission to delete the file.

DEFAULT_PERMISSIONS

public static final PermissionSet DEFAULT_PERMISSIONS

The default permissions for a new file capability.

Constructor Detail

File

public File()

Construct an empty File capability.

Method Detail

fromBytes

protected void fromBytes(byte[] flattened,
                         CapabilityEnvelope[] sub)
                  throws java.lang.Exception

Description copied from class: Capability

Bind this capability to the given object.

Overrides:

fromBytes in class Capability

See Also:

Capability.fromBytes(byte[], CapabilityEnvelope[])

revoke

public void revoke()

Description copied from class: Capability

Revoke access to the capability.

Overrides:

revoke in class PathSpec

See Also:

Capability.revoke()

lastModified

public long lastModified(Clock clock)

Get the last modified time of the file. Since we cannot allow the actual time to leak out, a clock capability must be provided in order to form a stable base time.

Parameters:

clock - A clock from which to base the returned time value on.

Returns:

If the clock is in uptime mode, then it is the clocks base time minus the number of milliseconds since the file was last modified. Otherwise, it is the absolute time it was last modified.

length

public long length()

Returns:

The length of the file in bytes.

getInputStream

public java.io.InputStream getInputStream()
                                   throws java.io.FileNotFoundException,
                                          java.io.IOException

Returns:

An InputStream for reading from the file.

Throws:

java.io.FileNotFoundException - If the file no longer exists in the local file system. XXX This really shouldn't be here.

java.io.IOException - If there is a problem opening the file.

getOutputStream

public java.io.OutputStream getOutputStream(boolean append)
                                     throws java.io.FileNotFoundException

Parameters:

append - True if the stream should start at the end of the file.

Returns:

An OutputStream for writing to the file.

Throws:

java.io.FileNotFoundException - If the file no longer exists in the local file system. XXX This really shouldn't be here.

getOutputStream

public java.io.OutputStream getOutputStream()
                                     throws java.io.FileNotFoundException

Returns:

An OutputStream for writing to the file.

Throws:

java.io.FileNotFoundException - If the file no longer exists in the local file system. XXX This really shouldn't be here.

delete

public void delete()

Delete the file on disk.

resolveSpecifier

public edu.utah.janosvm.kit.comm.jsi.JSIHandler resolveSpecifier(edu.utah.janosvm.kit.comm.jsi.JSIMessage jm,
                                                                 edu.utah.janosvm.kit.comm.jsi.JSIPair jp)

Specified by:

resolveSpecifier in interface edu.utah.janosvm.kit.comm.jsi.JSIHandler

See Also:

JSIHandler.resolveSpecifier(JSIMessage, JSIPair)

handleMessage

public void handleMessage(edu.utah.janosvm.kit.comm.jsi.JSIHandlerContext jhc,
                          edu.utah.janosvm.kit.comm.jsi.JSIMessage jm)

Specified by:

handleMessage in interface edu.utah.janosvm.kit.comm.jsi.JSIHandler

See Also:

JSIHandler.handleMessage(JSIHandlerContext, JSIMessage)

getSuites

public void getSuites(edu.utah.janosvm.kit.comm.jsi.JSIMessage jm)

Specified by:

getSuites in interface edu.utah.janosvm.kit.comm.jsi.JSIHandler

See Also:

JSIHandler.getSuites(JSIMessage)

toString

public java.lang.String toString()

Overrides:

toString in class PathSpec

See Also:

Object.toString()