diff options
Diffstat (limited to 'libjava/classpath/java/rmi/server/ObjID.java')
| -rw-r--r-- | libjava/classpath/java/rmi/server/ObjID.java | 202 |
1 files changed, 148 insertions, 54 deletions
diff --git a/libjava/classpath/java/rmi/server/ObjID.java b/libjava/classpath/java/rmi/server/ObjID.java index 07cbbde..1aaa223 100644 --- a/libjava/classpath/java/rmi/server/ObjID.java +++ b/libjava/classpath/java/rmi/server/ObjID.java @@ -1,5 +1,6 @@ -/* ObjID.java -- - Copyright (c) 1996, 1997, 1998, 1999, 2004 Free Software Foundation, Inc. +/* ObjID.java -- Unique object id with respect to the given host. + Copyright (c) 1996, 1997, 1998, 1999, 2004, 2006 + Free Software Foundation, Inc. This file is part of GNU Classpath. @@ -45,59 +46,152 @@ import java.io.ObjectInput; import java.io.ObjectOutput; import java.io.Serializable; -public final class ObjID implements Serializable +/** + * Represents the object identifier, unique for the host that generated it. + * The ObjID contains inside the integer object identifier that, if needed, + * may indicated that this is a reference to one of the well known objects + * on that host (registry, activator or dgc) and the {@link UID} that + * ensures uniqueness. + */ +public final class ObjID + implements Serializable { -static final long serialVersionUID = -6386392263968365220L; -private static long next = 0x8000000000000000L; -private static final Object lock = ObjID.class; - -public static final int REGISTRY_ID = 0; -public static final int ACTIVATOR_ID = 1; -public static final int DGC_ID = 2; - -private long objNum; -private UID space; - -public ObjID() { - synchronized (lock) { - objNum = next++; - } - space = new UID(); -} - -public ObjID(int num) { - objNum = (long)num; - space = new UID((short)0); -} - -public void write(ObjectOutput out) throws IOException { - DataOutput dout = (DataOutput)out; - dout.writeLong(objNum); - space.write(dout); -} - -public static ObjID read(ObjectInput in) throws IOException { - DataInput din = (DataInput)in; - ObjID id = new ObjID(); - id.objNum = din.readLong(); - id.space = UID.read(din); - return (id); -} - -public int hashCode() { - return ((int)objNum); -} - -public boolean equals(Object obj) { - if (obj instanceof ObjID && this.objNum == ((ObjID)obj).objNum) { - return (true); - } - return (false); -} - -public String toString() { - return ("[objNum: " + objNum + ", " + space + "]"); -} + /** + * Use serial version uid for interoperability. + */ + static final long serialVersionUID = - 6386392263968365220L; + + /** + * The object counter, which value is assigned when creating the ordinary + * objects without the known object id. The counter is incremented each time + * the new ObjID is constructed. + */ + private static long next = 0x8000000000000000L; + + /** + * The object to put the lock on when incrementing {@link #next} + */ + private static final Object lock = ObjID.class; + + /** + * Defines the ID of the naming service. + */ + public static final int REGISTRY_ID = 0; + + /** + * Defines the ID of the activator. + */ + public static final int ACTIVATOR_ID = 1; + + /** + * Defines the ID of the distributed garbage collector. + */ + public static final int DGC_ID = 2; + + /** + * The object Id (either well-known value or the value of the incrementing + * object counter. + */ + long objNum; + + /** + * The object unique identifier, generated individually for each object. + */ + UID space; + + /** + * Create the new object id, unique for this host. + */ + public ObjID() + { + synchronized (lock) + { + objNum = next++; + } + space = new UID(); + } + + /** + * Create the new object id defining the well known remotely accessible + * object, present in this host. The well - known objects are: + * <ul> + * <li>{@link #REGISTRY_ID} - RMI naming service.</li> + * <li>{@link #ACTIVATOR_ID} - activator</li> + * <li>{@link #DGC_ID} - distributed garbage collector (grants lease + * durations to keep the object before it is garbage collected.</li> + * </ul> + * + * @param id the well known object id, one of the above. + */ + public ObjID(int id) + { + objNum = (long) id; + space = new UID((short) 0); + } + + /** + * Write object id as long, then the object {@link UID}. + */ + public void write(ObjectOutput out) throws IOException + { + DataOutput dout = (DataOutput) out; + dout.writeLong(objNum); + space.write(dout); + } + + /** + * Read object id (as long), then the object {@link UID}. + */ + public static ObjID read(ObjectInput in) throws IOException + { + DataInput din = (DataInput) in; + ObjID id = new ObjID(); + id.objNum = din.readLong(); + id.space = UID.read(din); + return (id); + } + + /** + * Get the hashcode. + */ + public int hashCode() + { + return space == null ? (int) objNum : space.hashCode() ^ (int) objNum; + } + + /** + * Compare for equality. + */ + public boolean equals(Object obj) + { + if (obj instanceof ObjID) + { + ObjID that = (ObjID) obj; + return that.objNum == objNum && eq(that.space, space); + } + else + return false; + } + + /** + * Compare by .equals if both a and b are not null, compare directly if at + * least one of them is null. + */ + static final boolean eq(Object a, Object b) + { + if (a == null || b == null) + return a == b; + else + return a.equals(b); + } + + /** + * Get the string representation. + */ + public String toString() + { + return (objNum + ":" + space); + } } |