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[IRC.git] / Robust / Transactions / tuplesoupdstm2version / src / com / solidosystems / tuplesoup / filter / RowBuffer.java

diff --git a/Robust/Transactions/tuplesoupdstm2version/src/com/solidosystems/tuplesoup/filter/RowBuffer.java b/Robust/Transactions/tuplesoupdstm2version/src/com/solidosystems/tuplesoup/filter/RowBuffer.java
new file mode 100644 (file)
index 0000000..3635c2b
--- /dev/null
+++ b/Robust/Transactions/tuplesoupdstm2version/src/com/solidosystems/tuplesoup/filter/RowBuffer.java
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2007, Solido Systems
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of Solido Systems nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+ 
+package com.solidosystems.tuplesoup.filter;
+
+import java.util.*;
+import java.io.*;
+import com.solidosystems.tuplesoup.core.*;
+
+public class RowBuffer extends TupleStream{
+    private int CACHESIZE=32768;
+    private int cacheusage=0;
+    
+    private int mempointer=0;
+    private boolean diskused=false;
+    
+    private List<Row> membuffer;
+    private String diskbuffer;
+    private DataOutputStream out;
+    private DataInputStream in;
+    
+    private Row next=null;
+    
+    public RowBuffer(String filename){
+        membuffer=new ArrayList<Row>();
+        diskbuffer=filename;
+        out=null;
+        in=null;
+    }
+    
+    public void setCacheSize(int size){
+        CACHESIZE=size;
+    }
+    public int getCacheSize(){
+        return CACHESIZE;
+    }
+    
+    public void addRow(Row row) throws IOException{
+        if(cacheusage+row.getSize()<=CACHESIZE){
+            membuffer.add(row);
+            cacheusage+=row.getSize();
+        }else{
+            cacheusage=CACHESIZE;
+            if(out==null)out=new DataOutputStream(new BufferedOutputStream(new FileOutputStream(diskbuffer),2048));
+            row.writeToStream(out);
+            diskused=true;
+        }
+    }
+    
+    public void prepare() throws IOException{
+        if(out!=null){
+            out.flush();
+            out.close();
+        }
+        mempointer=0;
+        if(diskused)in=new DataInputStream(new BufferedInputStream(new FileInputStream(diskbuffer),2048));
+        readNext();
+    }
+    
+    public void close(){
+        try{
+            File ftest=new File(diskbuffer);
+            if(ftest.exists()){
+                if(out!=null)out.close();
+                if(in!=null)in.close();
+                ftest.delete();
+            }
+        }catch(Exception e){
+            
+        }
+    }
+    
+    private void readNext() throws IOException{
+        if(mempointer<membuffer.size()){
+            next=membuffer.get(mempointer++);
+        }else{
+            if(diskused){
+                try{
+                    next=Row.readFromStream(in);
+                }catch(EOFException e){
+                    next=null;
+                }
+            }else next=null;
+        }
+    }
+    
+    public boolean hasNext() throws IOException{
+        if(next!=null)return true;
+        return false;
+    }
+    
+    public Row next() throws IOException{
+        try{
+            if(next!=null){
+                Row tmp=next;
+                readNext();
+                return tmp;
+            }
+        }catch(Exception e){
+            e.printStackTrace();
+        }
+        return null;
+    }
+}
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