Multiple reader thread support for db client

[simantics/platform.git] / bundles / org.simantics.db.impl / src / org / simantics / db / impl / query / CacheEntryBase.java

diff --git a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/CacheEntryBase.java b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/CacheEntryBase.java
index 5776857d330ad98374d9b8c07d575ddb0118f7b2..7c87b50e3acfa0e4630f3eb93ba8859c1eb13c90 100644 (file)
--- a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/CacheEntryBase.java
+++ b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/CacheEntryBase.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * Copyright (c) 2007, 2018 Association for Decentralized Information Management
  * in Industry THTH ry.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -21,7 +21,7 @@ import org.simantics.db.impl.procedure.InternalProcedure;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-abstract public class CacheEntryBase extends CacheEntry {
+public abstract class CacheEntryBase<Procedure> extends CacheEntry<Procedure> {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(CacheEntryBase.class);
     
@@ -34,11 +34,11 @@ abstract public class CacheEntryBase extends CacheEntry {
        
     final public static CacheEntryBase[] NONE = new CacheEntryBase[0];
 
-       static private Object NO_RESULT = new Object();
+       static Object NO_RESULT = new Object();
        static protected Object INVALID_RESULT = new Object();
        
-       // Just created
-    static protected Object FRESH = new Object() { public String toString() { return "CREATED"; }};
+//     // Just created
+//    static protected Object FRESH = new Object() { public String toString() { return "CREATED"; }};
     // Result is computed - no exception
     static protected Object READY = new Object() { public String toString() { return "READY"; }};
     // Computation is under way
@@ -46,12 +46,12 @@ abstract public class CacheEntryBase extends CacheEntry {
     // Entry is discarded and is waiting for garbage collect
     static protected Object DISCARDED = new Object() { public String toString() { return "DISCARDED"; }};
     // The result has been invalidated
-    static protected Object REFUTED = new Object() { public String toString() { return "REFUTED"; }};
+    static protected Object REQUIRES_COMPUTATION = new Object() { public String toString() { return "REFUTED"; }};
     // The computation has excepted - the exception is in the result
     static protected Object EXCEPTED = new Object() { public String toString() { return "EXCEPTED"; }};
 
     // This indicates the status of the entry
-    public Object statusOrException = FRESH;
+    public Object statusOrException = REQUIRES_COMPUTATION;
     
     private CacheEntry p1 = null;
     private Object p2OrParents = null;
@@ -67,10 +67,10 @@ abstract public class CacheEntryBase extends CacheEntry {
     abstract int makeHash();
     
     // This can be tested to see if the result is finished
-    private Object result = NO_RESULT;
+    Object result = NO_RESULT;
     
     final public boolean isFresh() {
-       return FRESH == statusOrException;
+       return REQUIRES_COMPUTATION == statusOrException;
     }
 
     public void setReady() {
@@ -96,23 +96,23 @@ abstract public class CacheEntryBase extends CacheEntry {
     @Override
     final public void refute() {
        if(DebugPolicy.QUERY_STATE) System.out.println("[QUERY STATE]: refuted " + this);
-       statusOrException = REFUTED;
+       statusOrException = REQUIRES_COMPUTATION;
     }
     
     @Override
     final public boolean isRefuted() {
-        return REFUTED == statusOrException;
+        return REQUIRES_COMPUTATION == statusOrException;
     }
 
     @Override
-    final public void except(Throwable t) {
+    public void except(Throwable throwable) {
        if(DebugPolicy.QUERY_STATE) System.out.println("[QUERY STATE]: excepted " + this);
        if(statusOrException != DISCARDED) {
                statusOrException = EXCEPTED;
-               result = t;
+               result = throwable;
        } else {
-               LOGGER.warn("Cache entry got excepted status after being discarded: " + getClass().getSimpleName(), t);
-               result = t;
+               LOGGER.warn("Cache entry got excepted status after being discarded: " + getClass().getSimpleName(), throwable);
+               result = throwable;
        }
     }
     
@@ -130,7 +130,7 @@ abstract public class CacheEntryBase extends CacheEntry {
     }
 
     @Override
-    final public void setPending() {
+    public void setPending() {
        statusOrException = PENDING;
     }
     
@@ -139,6 +139,10 @@ abstract public class CacheEntryBase extends CacheEntry {
         return PENDING == statusOrException;
     }
     
+    final public boolean requiresComputation() {
+       return REQUIRES_COMPUTATION == statusOrException;
+    }
+    
     final public boolean assertPending() {
        boolean result = isPending();
        if(!result) {
@@ -168,6 +172,7 @@ abstract public class CacheEntryBase extends CacheEntry {
        this.result = result;
     }
     
+    @SuppressWarnings("unchecked")
     @Override
     final public <T> T getResult() {
         assert(statusOrException != DISCARDED);
@@ -318,9 +323,9 @@ abstract public class CacheEntryBase extends CacheEntry {
     }
     
     @Override
-       final public Iterable<CacheEntry> getParents(QueryProcessor processor) {
+       final public Iterable<CacheEntry<?>> getParents(QueryProcessor processor) {
 
-               ArrayList<CacheEntry> result = new ArrayList<CacheEntry>();
+               ArrayList<CacheEntry<?>> result = new ArrayList<CacheEntry<?>>();
                if(p1 != null) result.add(p1);
                if(p2OrParents != null) {
                if(p2OrParents instanceof QueryIdentityHashSet) {
@@ -360,8 +365,7 @@ abstract public class CacheEntryBase extends CacheEntry {
        
     }
     
-    protected void fillImpliedParents(QueryProcessor processor, ArrayList<CacheEntry> result) {
-       
+    protected void fillImpliedParents(QueryProcessor processor, ArrayList<CacheEntry<?>> result) {
     }
     
     protected String internalError() {
@@ -369,7 +373,7 @@ abstract public class CacheEntryBase extends CacheEntry {
     }
 
     
-    protected boolean handleException(ReadGraphImpl graph, IntProcedure procedure) {
+    protected boolean handleException(ReadGraphImpl graph, IntProcedure procedure) throws DatabaseException {
        if(isExcepted()) {
                procedure.exception(graph, (Throwable)getResult());
                return true;
@@ -378,7 +382,7 @@ abstract public class CacheEntryBase extends CacheEntry {
        }
     }
     
-    protected boolean handleException(ReadGraphImpl graph, TripleIntProcedure procedure) {
+    protected boolean handleException(ReadGraphImpl graph, TripleIntProcedure procedure) throws DatabaseException {
        if(isExcepted()) {
                procedure.exception(graph, (Throwable)getResult());
                return true;
@@ -387,7 +391,7 @@ abstract public class CacheEntryBase extends CacheEntry {
        }
     }
 
-    protected <T> boolean handleException(ReadGraphImpl graph, InternalProcedure<T> procedure) {
+    protected <T> boolean handleException(ReadGraphImpl graph, InternalProcedure<T> procedure) throws DatabaseException {
        if(isExcepted()) {
                procedure.exception(graph, (Throwable)getResult());
                return true;
@@ -424,10 +428,6 @@ abstract public class CacheEntryBase extends CacheEntry {
                clearResult(querySupport);
     }
     
-    /*
-     * 
-     * 
-     */
     @Override
     int getGCStatus() {
        return GCStatus;
@@ -453,5 +453,8 @@ abstract public class CacheEntryBase extends CacheEntry {
        // This is the original request for all built-in queries
        return getQuery();
     }
-    
+
+    public CacheEntryBase() {
+    }
+
 }