Refactored to use JSONWriter to be more efficient at generating output.

Added created and modified time fields to project metadata.

git-svn-id: http://google-refine.googlecode.com/svn/trunk@18 7d457c2a-affb-35e4-300a-418c747d4874

src/main/java/com/metaweb/gridlock/Jsonizable.java

@@ -0,0 +1,10 @@
+package com.metaweb.gridlock;
+
+import java.util.Properties;
+
+import org.json.JSONException;
+import org.json.JSONWriter;
+
+public interface Jsonizable {
+	public void write(JSONWriter writer, Properties options) throws JSONException;
+}

src/main/java/com/metaweb/gridlock/ProjectMetadata.java

@@ -1,21 +1,31 @@
 package com.metaweb.gridlock;
 
 import java.io.Serializable;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
-public class ProjectMetadata implements Serializable {
+public class ProjectMetadata implements Serializable, Jsonizable {
 	private static final long serialVersionUID = 7959027046468240844L;
 	
-	public String name;
+	public String 	name;
-	public String password;
+	public String 	password;
+	public Date 	created = new Date();
+	public Date 	modified = new Date();
 	
-	public JSONObject getJSON() throws JSONException {
+	@Override
-		JSONObject o = new JSONObject();
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
 		
-		o.put("name", name);
+		SimpleDateFormat sdf = (SimpleDateFormat) SimpleDateFormat.getDateTimeInstance();
 		
-		return o;
+		writer.object();
+		writer.key("name"); writer.value(name);
+		writer.key("created"); writer.value(sdf.format(created));
+		writer.key("modified"); writer.value(sdf.format(modified));
+		writer.endObject();
 	}
 }

src/main/java/com/metaweb/gridlock/browsing/DecoratedValue.java

@@ -3,9 +3,11 @@ package com.metaweb.gridlock.browsing;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
-public class DecoratedValue {
+import com.metaweb.gridlock.Jsonizable;
+
+public class DecoratedValue implements Jsonizable {
 	final public Object value;
 	final public String	label;
 	
@@ -14,12 +16,12 @@ public class DecoratedValue {
 		this.label = label;
 	}
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
+	@Override
-		JSONObject o = new JSONObject();
+	public void write(JSONWriter writer, Properties options)
-		
+			throws JSONException {
-		o.put("v", value);
+		writer.object();
-		o.put("l", label);
+		writer.key("v"); writer.value(value);
-		
+		writer.key("l"); writer.value(label);
-		return o;
+		writer.endObject();
 	}
 }

src/main/java/com/metaweb/gridlock/browsing/Engine.java

@@ -1,6 +1,5 @@
 package com.metaweb.gridlock.browsing;
 
-import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Properties;
@@ -8,13 +7,15 @@ import java.util.Properties;
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
+import org.json.JSONWriter;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.browsing.facets.Facet;
 import com.metaweb.gridlock.browsing.facets.ListFacet;
 import com.metaweb.gridlock.browsing.filters.RowFilter;
 import com.metaweb.gridlock.model.Project;
 
-public class Engine {
+public class Engine implements Jsonizable {
 	protected Project 		_project;
 	protected List<Facet> 	_facets = new LinkedList<Facet>();
 	
@@ -39,18 +40,6 @@ public class Engine {
 		return cfr;
 	}
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
-		JSONObject o = new JSONObject();
-		
-		List<JSONObject> a = new ArrayList<JSONObject>(_facets.size());
-		for (Facet facet : _facets) {
-			a.add(facet.getJSON(options));
-		}
-		o.put("facets", a);
-		
-		return o;
-	}
-
 	public void initializeFromJSON(JSONObject o) throws Exception {
 		JSONArray a = o.getJSONArray("facets");
 		int length = a.length();
@@ -78,4 +67,17 @@ public class Engine {
 			facet.computeChoices(_project, filteredRows);
 		}
 	}
+
+	@Override
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
+		
+		writer.object();
+		writer.key("facets"); writer.array();
+		for (Facet facet : _facets) {
+			facet.write(writer, options);
+		}
+		writer.endArray();
+		writer.endObject();
+	}
 }

src/main/java/com/metaweb/gridlock/browsing/facets/Facet.java

@@ -1,20 +1,16 @@
 package com.metaweb.gridlock.browsing.facets;
 
-import java.util.Properties;
-
-import org.json.JSONException;
 import org.json.JSONObject;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.browsing.FilteredRows;
 import com.metaweb.gridlock.browsing.filters.RowFilter;
 import com.metaweb.gridlock.model.Project;
 
-public interface Facet {
+public interface Facet extends Jsonizable {
 	public RowFilter getRowFilter();
 	
 	public void computeChoices(Project project, FilteredRows filteredRows);
 	
-	public JSONObject getJSON(Properties options) throws JSONException;
-
 	public void initializeFromJSON(JSONObject o) throws Exception;
 }

src/main/java/com/metaweb/gridlock/browsing/facets/ListFacet.java

@@ -1,6 +1,5 @@
 package com.metaweb.gridlock.browsing.facets;
 
-import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Properties;
@@ -8,6 +7,7 @@ import java.util.Properties;
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
+import org.json.JSONWriter;
 
 import com.metaweb.gridlock.browsing.DecoratedValue;
 import com.metaweb.gridlock.browsing.FilteredRows;
@@ -30,20 +30,20 @@ public class ListFacet implements Facet {
 	}
 
 	@Override
-	public JSONObject getJSON(Properties options) throws JSONException {
+	public void write(JSONWriter writer, Properties options)
-		JSONObject o = new JSONObject();
+			throws JSONException {
 		
-		o.put("name", _name);
+		writer.object();
-		o.put("expression", _expression);
+		writer.key("name"); writer.value(_name);
-		o.put("cellIndex", _cellIndex);
+		writer.key("expression"); writer.value(_expression);
+		writer.key("cellIndex"); writer.value(_cellIndex);
 		
-		List<JSONObject> a = new ArrayList<JSONObject>(_choices.size());
+		writer.key("choices"); writer.array();
 		for (NominalFacetChoice choice : _choices) {
-			a.add(choice.getJSON(options));
+			choice.write(writer, options);
 		}
-		o.put("choices", a);
+		writer.endArray();
-		
+		writer.endObject();
-		return o;
 	}
 
 	@Override

src/main/java/com/metaweb/gridlock/browsing/facets/NominalFacetChoice.java

@@ -3,11 +3,12 @@ package com.metaweb.gridlock.browsing.facets;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.browsing.DecoratedValue;
 
-public class NominalFacetChoice {
+public class NominalFacetChoice implements Jsonizable {
 	final public DecoratedValue	decoratedValue;
 	public int					count;
 	public boolean				selected;
@@ -16,13 +17,13 @@ public class NominalFacetChoice {
 		this.decoratedValue = decoratedValue;
 	}
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
+	@Override
-		JSONObject o = new JSONObject();
+	public void write(JSONWriter writer, Properties options)
-		
+			throws JSONException {
-		o.put("v", decoratedValue.getJSON(options));
+		writer.object();
-		o.put("c", count);
+		writer.key("v"); decoratedValue.write(writer, options);
-		o.put("s", selected);
+		writer.key("c"); writer.value(count);
-		
+		writer.key("s"); writer.value(selected);
-		return o;
+		writer.endObject();
 	}
 }

src/main/java/com/metaweb/gridlock/commands/Command.java

@@ -18,7 +18,9 @@ import org.apache.commons.lang.NotImplementedException;
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.json.JSONTokener;
+import org.json.JSONWriter;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.ProjectManager;
 import com.metaweb.gridlock.browsing.Engine;
 import com.metaweb.gridlock.model.Project;
@@ -70,9 +72,16 @@ public abstract class Command {
     	}
     }
     
-    protected void respondJSON(HttpServletResponse response, JSONObject o) throws IOException {
+    protected void respondJSON(HttpServletResponse response, Jsonizable o) throws IOException, JSONException {
+    	respondJSON(response, o, new Properties());
+    }
+    
+    protected void respondJSON(HttpServletResponse response, Jsonizable o, Properties options) throws IOException, JSONException {
     	response.setHeader("Content-Type", "application/json");
-    	respond(response, o.toString());
+    	
+		JSONWriter writer = new JSONWriter(response.getWriter());
+		
+		o.write(writer, options);
     }
     
     protected void respondException(HttpServletResponse response, Exception e) throws IOException {
@@ -89,7 +98,8 @@ public abstract class Command {
 			
 			o.put("stack", sw.toString());
 			
-			respondJSON(response, o);
+	    	response.setHeader("Content-Type", "application/json");
+			respond(response, o.toString());
 		} catch (JSONException e1) {
 	   		e.printStackTrace(response.getWriter());
 		}

src/main/java/com/metaweb/gridlock/commands/ComputeFacetsCommand.java

@@ -1,7 +1,6 @@
 package com.metaweb.gridlock.commands;
 
 import java.io.IOException;
-import java.util.Properties;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -21,8 +20,7 @@ public class ComputeFacetsCommand extends Command {
 			
 			engine.computeFacets();
 			
-			Properties options = new Properties();
+			respondJSON(response, engine);
-			respondJSON(response, engine.getJSON(options));
 		} catch (Exception e) {
 			respondException(response, e);
 		}

src/main/java/com/metaweb/gridlock/commands/GetColumnModelCommand.java

@@ -1,7 +1,6 @@
 package com.metaweb.gridlock.commands;
 
 import java.io.IOException;
-import java.util.Properties;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -17,10 +16,9 @@ public class GetColumnModelCommand extends Command {
 			throws ServletException, IOException {
 		
 		Project project = getProject(request);
-		Properties options = new Properties();
 		
 		try {
-			respondJSON(response, project.columnModel.getJSON(options));
+			respondJSON(response, project.columnModel);
 		} catch (JSONException e) {
 			respondException(response, e);
 		}

src/main/java/com/metaweb/gridlock/commands/GetHistoryCommand.java

@@ -1,7 +1,6 @@
 package com.metaweb.gridlock.commands;
 
 import java.io.IOException;
-import java.util.Properties;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -17,10 +16,8 @@ public class GetHistoryCommand extends Command {
 			throws ServletException, IOException {
 		
 		Project project = getProject(request);
-		Properties options = new Properties();
-		
 		try {
-			respondJSON(response, project.history.getJSON(options));
+			respondJSON(response, project.history);
 		} catch (JSONException e) {
 			respondException(response, e);
 		}

src/main/java/com/metaweb/gridlock/commands/GetProcessesCommand.java

@@ -1,7 +1,6 @@
 package com.metaweb.gridlock.commands;
 
 import java.io.IOException;
-import java.util.Properties;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -19,9 +18,7 @@ public class GetProcessesCommand extends Command {
 		Project project = getProject(request);
 		
 		try {
-			Properties options = new Properties();
+			respondJSON(response, project.processManager);
-			
-			respondJSON(response, project.processManager.getJSON(options));
 		} catch (JSONException e) {
 			respondException(response, e);
 		}

src/main/java/com/metaweb/gridlock/commands/GetProjectMetadataCommand.java

@@ -19,7 +19,7 @@ public class GetProjectMetadataCommand extends Command {
 		Project project = getProject(request);
 		
 		try {
-			respondJSON(response, ProjectManager.singleton.getProjectMetadata(project.id).getJSON());
+			respondJSON(response, ProjectManager.singleton.getProjectMetadata(project.id));
 		} catch (JSONException e) {
 			respondException(response, e);
 		}

src/main/java/com/metaweb/gridlock/commands/GetRowsCommand.java

@@ -1,8 +1,6 @@
 package com.metaweb.gridlock.commands;
 
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
 import java.util.Properties;
 
 import javax.servlet.ServletException;
@@ -10,7 +8,7 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
 import com.metaweb.gridlock.browsing.Engine;
 import com.metaweb.gridlock.browsing.FilteredRows;
@@ -31,17 +29,18 @@ public class GetRowsCommand extends Command {
 			int limit = Math.min(project.rows.size() - start, Math.max(0, getIntegerParameter(request, "limit", 20)));
 			Properties options = new Properties();
 			
-			JSONObject o = new JSONObject();
+	    	response.setHeader("Content-Type", "application/json");
 	    	
-			List<JSONObject> a = new ArrayList<JSONObject>(limit);
+			JSONWriter writer = new JSONWriter(response.getWriter());
-			try {
+			writer.object();
-				FilteredRows filteredRows = engine.getAllFilteredRows();
+			
+			{
 				RowAccumulator acc = new RowAccumulator(start, limit) {
-					List<JSONObject> list;
+					JSONWriter	writer;
-					Properties		 options;
+					Properties	options;
 					
-					public RowAccumulator init(List<JSONObject> list, Properties options) {
+					public RowAccumulator init(JSONWriter writer, Properties options) {
-						this.list = list;
+						this.writer = writer;
 						this.options = options;
 						return this;
 					}
@@ -49,27 +48,28 @@ public class GetRowsCommand extends Command {
 					@Override
 					public boolean internalVisit(int rowIndex, Row row) {
 						try {
-							JSONObject ro = row.getJSON(options);
+							options.put("rowIndex", rowIndex);
-							ro.put("i", rowIndex);
+							row.write(writer, options);
-							list.add(ro);
 						} catch (JSONException e) {
 						}
 						return false;
 					}
-				}.init(a, options);
+				}.init(writer, options);
 				
+				FilteredRows filteredRows = engine.getAllFilteredRows();
+				
+				writer.key("rows"); writer.array();
 				filteredRows.accept(project, acc);
+				writer.endArray();
 				
-				o.put("filtered", acc.total);
+				writer.key("filtered"); writer.value(acc.total);
-			} catch (JSONException e) {
-				respondException(response, e);
 			}
-			o.put("start", start);
-			o.put("limit", limit);
-			o.put("rows", a);
-			o.put("total", project.rows.size());
 			
-			respondJSON(response, o);
+			writer.key("start"); writer.value(start);
+			writer.key("limit"); writer.value(limit);
+			writer.key("total"); writer.value(project.rows.size());
+			
+			writer.endObject();
 		} catch (Exception e) {
 			respondException(response, e);
 		}

src/main/java/com/metaweb/gridlock/expr/VariableExpr.java

@@ -2,8 +2,6 @@ package com.metaweb.gridlock.expr;
 
 import java.util.Properties;
 
-import org.json.JSONObject;
-
 public class VariableExpr implements Evaluable {
 	final protected String _name;
 	

src/main/java/com/metaweb/gridlock/history/History.java

@@ -2,16 +2,18 @@ package com.metaweb.gridlock.history;
 
 import java.io.Serializable;
 import java.util.ArrayList;
+import java.util.Date;
 import java.util.List;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.ProjectManager;
 import com.metaweb.gridlock.model.Project;
 
-public class History implements Serializable {
+public class History implements Serializable, Jsonizable {
 	private static final long serialVersionUID = -1529783362243627391L;
 	
 	protected long				 _projectID;
@@ -31,7 +33,13 @@ public class History implements Serializable {
 		_futureEntries.clear();
 		
 		_pastEntries.add(entry);
+		
 		entry.apply(ProjectManager.singleton.getProject(_projectID));
+		setModified();
+	}
+	
+	protected void setModified() {
+		ProjectManager.singleton.getProjectMetadata(_projectID).modified = new Date();
 	}
 	
 	public List<HistoryEntry> getLastPastEntries(int count) {
@@ -84,6 +92,7 @@ public class History implements Serializable {
 			
 			_futureEntries.add(0, entry);
 		}
+		setModified();
 	}
 	
 	protected void redo(int times) {
@@ -97,23 +106,27 @@ public class History implements Serializable {
 			
 			_pastEntries.add(entry);
 		}
+		setModified();
 	}
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
+	@Override
-		JSONObject o = new JSONObject();
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
 		
-		List<JSONObject> a = new ArrayList<JSONObject>(_pastEntries.size());
+		writer.object();
+		
+		writer.key("past"); writer.array();
 		for (HistoryEntry entry : _pastEntries) {
-			a.add(entry.getJSON(options));
+			entry.write(writer, options);
 		}
-		o.put("past", a);
+		writer.endArray();
 		
-		List<JSONObject> b = new ArrayList<JSONObject>(_futureEntries.size());
+		writer.key("future"); writer.array();
 		for (HistoryEntry entry : _futureEntries) {
-			b.add(entry.getJSON(options));
+			entry.write(writer, options);
 		}
-		o.put("future", b);
+		writer.endArray();
 		
-		return o;
+		writer.endObject();
 	}
 }

src/main/java/com/metaweb/gridlock/history/HistoryEntry.java

@@ -12,12 +12,13 @@ import java.util.Date;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.ProjectManager;
 import com.metaweb.gridlock.model.Project;
 
-public class HistoryEntry implements Serializable {
+public class HistoryEntry implements Serializable, Jsonizable {
 	private static final long serialVersionUID = 532766467813930262L;
 	
 	public long 	id;
@@ -38,16 +39,17 @@ public class HistoryEntry implements Serializable {
 		saveChange();
 	}
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
+	@Override
-		JSONObject o = new JSONObject();
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
 		
 		SimpleDateFormat sdf = (SimpleDateFormat) SimpleDateFormat.getDateTimeInstance();
 		
-		o.put("id", id);
+		writer.object();
-		o.put("description", description);
+		writer.key("id"); writer.value(id);
-		o.put("time", sdf.format(time));
+		writer.key("description"); writer.value(description);
-		
+		writer.key("time"); writer.value(sdf.format(time));
-		return o;
+		writer.endObject();
 	}
 	
 	public void apply(Project project) {

src/main/java/com/metaweb/gridlock/history/HistoryProcess.java

@@ -3,7 +3,7 @@ package com.metaweb.gridlock.history;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
 import com.metaweb.gridlock.model.Project;
 import com.metaweb.gridlock.process.Process;
@@ -49,14 +49,14 @@ public class HistoryProcess extends Process {
 	}
 
 	@Override
-	public JSONObject getJSON(Properties options) throws JSONException {
+	public void write(JSONWriter writer, Properties options)
-		JSONObject o = new JSONObject();
+			throws JSONException {
 		
-		o.put("description", _description);
+		writer.object();
-		o.put("immediate", true);
+		writer.key("description"); writer.value(_description);
-		o.put("status", _done ? "done" : "pending");
+		writer.key("immediate"); writer.value(true);
-		
+		writer.key("status"); writer.value(_done ? "done" : "pending");
-		return o;
+		writer.endObject();
 	}
 
 	@Override

src/main/java/com/metaweb/gridlock/history/MassCellChange.java

@@ -1,6 +1,5 @@
 package com.metaweb.gridlock.history;
 
-import java.util.ArrayList;
 import java.util.List;
 
 import com.metaweb.gridlock.model.Project;

src/main/java/com/metaweb/gridlock/model/Cell.java

@@ -4,27 +4,17 @@ import java.io.Serializable;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.expr.HasFields;
 
-public class Cell implements Serializable, HasFields {
+public class Cell implements Serializable, HasFields, Jsonizable {
 	private static final long serialVersionUID = -5891067829205458102L;
 	
 	public Object value;
 	public Recon  recon;
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
-		JSONObject o = new JSONObject();
-		
-		o.put("v", value);
-		if (recon != null && options.containsKey("cell-recon")) {
-			o.put("recon", recon.getJSON(options));
-		}
-		
-		return o;
-	}
-
 	@Override
 	public Object getField(String name, Properties bindings) {
 		if ("value".equals(name)) {
@@ -34,4 +24,17 @@ public class Cell implements Serializable, HasFields {
 		}
 		return null;
 	}
+
+	@Override
+	public void write(JSONWriter writer, Properties options) throws JSONException {
+		writer.object();
+		writer.key("v");
+		writer.value(value);
+		
+		if (recon != null && options.containsKey("cell-recon")) {
+			writer.key("recon");
+			recon.write(writer, options);
+		}
+		writer.endObject();
+	}
 }

src/main/java/com/metaweb/gridlock/model/Column.java

@@ -4,22 +4,25 @@ import java.io.Serializable;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
-public class Column implements Serializable {
+import com.metaweb.gridlock.Jsonizable;
+
+public class Column implements Serializable, Jsonizable {
 	private static final long serialVersionUID = -1063342490951563563L;
 	
 	public int		cellIndex;
 	public String	headerLabel;
 	public Class 	valueType;
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
+	@Override
-		JSONObject o = new JSONObject();
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
 		
-		o.put("cellIndex", cellIndex);
+		writer.object();
-		o.put("headerLabel", headerLabel);
+		writer.key("cellIndex"); writer.value(cellIndex);
-		o.put("valueType", valueType == null ? null : valueType.getSimpleName());
+		writer.key("headerLabel"); writer.value(headerLabel);
-		
+		writer.key("valueType"); writer.value(valueType == null ? null : valueType.getSimpleName());
-		return o;
+		writer.endObject();
 	}
 }

src/main/java/com/metaweb/gridlock/model/ColumnModel.java

@@ -1,34 +1,23 @@
 package com.metaweb.gridlock.model;
 
 import java.io.Serializable;
-import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
-public class ColumnModel implements Serializable {
+import com.metaweb.gridlock.Jsonizable;
+
+public class ColumnModel implements Serializable, Jsonizable {
 	private static final long serialVersionUID = 7679639795211544511L;
 	
 	public List<Column> columns = new LinkedList<Column>();
 	
 	transient protected Map<String, Column> _nameToColumn;
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
-		JSONObject o = new JSONObject();
-		
-		List<JSONObject> a = new ArrayList<JSONObject>(columns.size());
-		for (Column column : columns) {
-			a.add(column.getJSON(options));
-		}
-		o.put("columns", a);
-		
-		return o;
-	}
-	
 	public Column getColumnByName(String name) {
 		if (_nameToColumn == null) {
 			for (Column column : columns) {
@@ -46,4 +35,18 @@ public class ColumnModel implements Serializable {
 		}
 		return null;
 	}
+
+	@Override
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
+		
+		writer.object();
+		writer.key("columns");
+		writer.array();
+		for (Column column : columns) {
+			column.write(writer, options);
+		}
+		writer.endArray();
+		writer.endObject();
+	}
 }

src/main/java/com/metaweb/gridlock/model/Recon.java

@@ -8,11 +8,12 @@ import java.util.Map;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.expr.HasFields;
 
-public class Recon implements Serializable, HasFields {
+public class Recon implements Serializable, HasFields, Jsonizable {
 	private static final long serialVersionUID = 8906257833709315762L;
 	
 	static public enum Judgment {
@@ -26,13 +27,6 @@ public class Recon implements Serializable, HasFields {
 	public Judgment				judgment = Judgment.None;
 	public ReconCandidate		match = null;
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
-		JSONObject o = new JSONObject();
-		o.put("j", judgmentToString());
-		
-		return o;
-	}
-
 	@Override
 	public Object getField(String name, Properties bindings) {
 		if ("best".equals(name)) {
@@ -65,4 +59,14 @@ public class Recon implements Serializable, HasFields {
 			return features.get(name);
 		}
 	}
+
+	@Override
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
+		
+		writer.object();
+		writer.key("j");
+		writer.value(judgmentToString());
+		writer.endObject();
+	}
 }

src/main/java/com/metaweb/gridlock/model/ReconCandidate.java

@@ -4,11 +4,12 @@ import java.io.Serializable;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.expr.HasFields;
 
-public class ReconCandidate implements Serializable, HasFields {
+public class ReconCandidate implements Serializable, HasFields, Jsonizable {
 	private static final long serialVersionUID = -8013997214978715606L;
 	
 	public String 	topicID;
@@ -17,18 +18,6 @@ public class ReconCandidate implements Serializable, HasFields {
 	public String[] typeIDs;
 	public double	score;
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
-		JSONObject o = new JSONObject();
-		
-		o.put("id", topicID);
-		o.put("guid", topicGUID);
-		o.put("name", topicName);
-		o.put("types", typeIDs);
-		o.put("score", score);
-		
-		return o;
-	}
-
 	@Override
 	public Object getField(String name, Properties bindings) {
 		if ("id".equals(name)) {
@@ -44,4 +33,23 @@ public class ReconCandidate implements Serializable, HasFields {
 		}
 		return null;
 	}
+
+	@Override
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
+		
+		writer.object();
+		writer.key("id"); writer.value(topicID);
+		writer.key("guid"); writer.value(topicGUID);
+		writer.key("name"); writer.value(topicName);
+		writer.key("score"); writer.value(score);
+		
+		writer.key("types"); writer.array();
+		for (String typeID : typeIDs) {
+			writer.value(typeID);
+		}
+		writer.endArray();
+		
+		writer.endObject();
+	}
 }

src/main/java/com/metaweb/gridlock/model/Row.java

@@ -6,11 +6,12 @@ import java.util.List;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
+import com.metaweb.gridlock.Jsonizable;
 import com.metaweb.gridlock.expr.HasFields;
 
-public class Row implements Serializable, HasFields {
+public class Row implements Serializable, HasFields, Jsonizable {
 	private static final long serialVersionUID = -689264211730915507L;
 	
 	public boolean		flagged;
@@ -21,20 +22,6 @@ public class Row implements Serializable, HasFields {
 		cells = new ArrayList<Cell>(cellCount);
 	}
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
-		JSONObject o = new JSONObject();
-		
-		List<JSONObject> a = new ArrayList<JSONObject>(cells.size());
-		for (Cell cell : cells) {
-			a.add(cell.getJSON(options));
-		}
-		o.put("cells", a);
-		o.put("flagged", flagged);
-		o.put("starred", starred);
-		
-		return o;
-	}
-
 	@Override
 	public Object getField(String name, Properties bindings) {
 		if ("flagged".equals(name)) {
@@ -61,4 +48,25 @@ public class Row implements Serializable, HasFields {
 		}
 		
 	}
+
+	@Override
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
+		
+		writer.object();
+		writer.key("flagged"); writer.value(flagged);
+		writer.key("starred"); writer.value(starred);
+		
+		writer.key("cells"); writer.array();
+		for (Cell cell : cells) {
+			cell.write(writer, options);
+		}
+		writer.endArray();
+		
+		if (options.containsKey("rowIndex")) {
+			writer.key("i"); writer.value(options.get("rowIndex"));
+		}
+		
+		writer.endObject();
+	}
 }

src/main/java/com/metaweb/gridlock/process/LongRunningProcess.java

@@ -3,7 +3,7 @@ package com.metaweb.gridlock.process;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
 abstract public class LongRunningProcess extends Process {
 	final protected String 		_description;
@@ -25,16 +25,15 @@ abstract public class LongRunningProcess extends Process {
 	}
 	
 	@Override
-	public
+	public void write(JSONWriter writer, Properties options)
-	JSONObject getJSON(Properties options) throws JSONException {
+			throws JSONException {
-		JSONObject o = new JSONObject();
 		
-		o.put("description", _description);
+		writer.object();
-		o.put("immediate", false);
+		writer.key("description"); writer.value(_description);
-		o.put("status", _thread == null ? "pending" : (_thread.isAlive() ? "running" : "done"));
+		writer.key("immediate"); writer.value(false);
-		o.put("progress", _progress);
+		writer.key("status"); writer.value(_thread == null ? "pending" : (_thread.isAlive() ? "running" : "done"));
-		
+		writer.key("progress"); writer.value(_progress);
-		return o;
+		writer.endObject();
 	}
 
 	@Override

src/main/java/com/metaweb/gridlock/process/Process.java

@@ -1,11 +1,8 @@
 package com.metaweb.gridlock.process;
 
-import java.util.Properties;
+import com.metaweb.gridlock.Jsonizable;
 
-import org.json.JSONException;
+public abstract class Process implements Jsonizable {
-import org.json.JSONObject;
-
-public abstract class Process {
 	abstract public boolean isImmediate();
 	
 	abstract public boolean isRunning();
@@ -15,6 +12,4 @@ public abstract class Process {
 	
 	abstract public void startPerforming(ProcessManager manager);
 	abstract public void cancel();
-	
-	public abstract JSONObject getJSON(Properties options) throws JSONException;
 }

src/main/java/com/metaweb/gridlock/process/ProcessManager.java

@@ -1,30 +1,34 @@
 package com.metaweb.gridlock.process;
 
-import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
-public class ProcessManager {
+import com.metaweb.gridlock.Jsonizable;
+
+public class ProcessManager implements Jsonizable {
 	protected List<Process> _processes = new LinkedList<Process>();
 	
 	public ProcessManager() {
 		
 	}
 	
-	public JSONObject getJSON(Properties options) throws JSONException {
-		JSONObject o = new JSONObject();
 
-		List<JSONObject> a = new ArrayList<JSONObject>(_processes.size());
+	@Override
+	public void write(JSONWriter writer, Properties options)
+			throws JSONException {
+		
+		writer.object();
+		writer.key("processes"); writer.array();
 		for (Process p : _processes) {
-			a.add(p.getJSON(options));
+			p.write(writer, options);
 		}
-		o.put("processes", a);
+		writer.endArray();
 		
-		return o;
+		writer.endObject();
 	}
 
 	public boolean queueProcess(Process process) {

src/main/java/com/metaweb/gridlock/process/QuickHistoryEntryProcess.java

@@ -3,7 +3,7 @@ package com.metaweb.gridlock.process;
 import java.util.Properties;
 
 import org.json.JSONException;
-import org.json.JSONObject;
+import org.json.JSONWriter;
 
 import com.metaweb.gridlock.history.HistoryEntry;
 import com.metaweb.gridlock.model.Project;
@@ -45,17 +45,17 @@ public class QuickHistoryEntryProcess extends Process {
 	}
 
 	@Override
-	public
+	public void write(JSONWriter writer, Properties options)
-	JSONObject getJSON(Properties options) throws JSONException {
+			throws JSONException {
-		JSONObject o = new JSONObject();
 		
-		o.put("description", _historyEntry.description);
+		writer.object();
-		o.put("immediate", true);
+		writer.key("description"); writer.value(_historyEntry.description);
-		o.put("status", _done ? "done" : "pending");
+		writer.key("immediate"); writer.value(true);
-		
+		writer.key("status"); writer.value(_done ? "done" : "pending");
-		return o;
+		writer.endObject();
 	}
 
+
 	@Override
 	public boolean isDone() {
 		return _done;

src/main/webapp/styles/history.css

@@ -25,7 +25,7 @@
 
 .history-past {
     padding-bottom: 3px;
-    border-bottom: 2px solid #aaa;
+    border-bottom: 2px solid #f88;
 }
 .history-future {
     padding-top: 3px;
@@ -33,9 +33,12 @@
 a.history-entry {
     display: block;
     padding: 3px 5px;
-    border-bottom: 1px solid #eee;
     text-decoration: none;
     color: black;
+    border-top: 1px solid #eee;
+}
+a.history-entry:first-child {
+    border-top: none;
 }
 a.history-entry:hover {
     background: #eee;