1.0 preparations

brouter-expressions/src/main/java/btools/expressions/BExpressionMetaData.java

@@ -0,0 +1,91 @@
+// context for simple expression
+// context means:
+// - the local variables
+// - the local variable names
+// - the lookup-input variables
+
+package btools.expressions;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.StringTokenizer;
+import java.util.TreeMap;
+
+import btools.util.BitCoderContext;
+import btools.util.Crc32;
+
+
+public final class BExpressionMetaData
+{
+  private  static final String CONTEXT_TAG = "---context:";
+  private static final String VERSION_TAG = "---lookupversion:";
+  private static final String MINOR_VERSION_TAG = "---minorversion:";
+  private static final String VARLENGTH_TAG = "---readvarlength";
+
+  public short lookupVersion = -1;
+  public short lookupMinorVersion = -1;
+  public boolean readVarLength = false;
+
+  private HashMap<String,BExpressionContext> listeners = new HashMap<String,BExpressionContext>();
+  
+  public void registerListener( String context, BExpressionContext ctx )
+  {
+    listeners.put( context,  ctx );
+  }
+  
+  public void readMetaData( File lookupsFile )
+  {
+   try
+   {
+    BufferedReader br = new BufferedReader( new FileReader( lookupsFile ) );
+    
+    BExpressionContext ctx = null;
+    
+    for(;;)
+    {
+      String line = br.readLine();
+      if ( line == null ) break;
+      line = line.trim();
+      if ( line.length() == 0 || line.startsWith( "#" ) ) continue;
+      if ( line.startsWith( CONTEXT_TAG ) )
+      {
+    	ctx = listeners.get( line.substring( CONTEXT_TAG.length() ) );
+        continue;
+      }
+      if ( line.startsWith( VERSION_TAG ) )
+      {
+        lookupVersion = Short.parseShort( line.substring( VERSION_TAG.length() ) );
+        continue;
+      }
+      if ( line.startsWith( MINOR_VERSION_TAG ) )
+      {
+        lookupMinorVersion = Short.parseShort( line.substring( MINOR_VERSION_TAG.length() ) );
+        continue;
+      }
+      if ( line.startsWith( VARLENGTH_TAG ) )
+      {
+    	readVarLength = true;
+        continue;
+      }
+      if ( ctx != null ) ctx.parseMetaLine( line );
+    }
+    br.close();
+    
+    for( BExpressionContext c : listeners.values() )
+    {
+    	c.finishMetaParsing();
+    }
+    
+   }
+   catch( Exception e )
+   {
+       throw new RuntimeException( e );
+   }
+  }
+}