Graph viewer on ch4 and25

4 files changed, 18 insertions, 370 deletions

diff --git a/chapter25/src/main/java/com/seaofnodes/simple/print/JSViewer.java b/chapter25/src/main/java/com/seaofnodes/simple/print/JSViewer.java
index 10c07730..03842119 100644
--- a/chapter25/src/main/java/com/seaofnodes/simple/print/JSViewer.java
+++ b/chapter25/src/main/java/com/seaofnodes/simple/print/JSViewer.java
@@ -1,72 +1,20 @@
 package com.seaofnodes.simple.print;
 
-import com.seaofnodes.graph.GraphJson;
-import com.seaofnodes.graph.GraphEvent;
-import com.seaofnodes.graph.GraphSnapshot;
+import com.seaofnodes.graph.*;
 import com.seaofnodes.simple.codegen.CodeGen;
 import java.io.IOException;
-import java.nio.file.Paths;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.net.URI;
 
-public class JSViewer implements AutoCloseable {
-    // Display programs in an endless loop
-    public static void main( String[] args ) throws Exception {
-        try(var js = new JSViewer()) {
-            js.run();
-        }
-    }
-
-    // WebSocket to the browser for display
-    private final SimpleWebSocket _server;
-
-    JSViewer() throws Exception {
-        // Launch server; handshake
-        _server = new SimpleWebSocket(viewerURI(),12345);
-    }
-
-    // The browser application is shared by all chapters. Search upwards so
-    // chapter, repository-root, and linearized checkouts use the same assets.
-    static URI viewerURI() throws IOException {
-        String url = System.getProperty("simple.graph.url");
-        if( url != null ) return URI.create(url);
-        for( Path dir = Paths.get("").toAbsolutePath(); dir != null; dir = dir.getParent() ) {
-            Path page = dir.resolve("graph/web/index.html");
-            if( Files.isRegularFile(page) ) return page.toUri();
-        }
-        throw new IOException("Cannot find graph/web/index.html; run inside the Simple checkout "
-                              + "or set -Dsimple.graph.url=<viewer URL>");
-    }
-
-    void run( ) throws Exception {
-        _server.put("!");
-        while( true ) {
-            String src = _server.get();
-            switch( src ) {
-            case null: return;
-            case "null": return;
-            case "+": break;    // Client requests more frames, but we send them all anyway
-            default:
-                System.out.println(src);
-                try {
-                    compile(src);
-                    // Catch and ignore Parser errors
-                } catch(RuntimeException re) {
-                    System.err.println(re);
-                } finally {
-                    _server.put("#"); // Final frame
-                }
-                break;
-            }
-        }
+public class JSViewer extends GraphViewer {
+    public static void main(String[] args) throws IOException {
+        try( var view = new JSViewer() ) { view.run(); }
     }
+    JSViewer() throws IOException {}
 
-    private void compile(String src) {
+    @Override protected void compile(String src) {
         CodeGen code = new CodeGen(src);
         code._obs = new SimpleGraphObserver(code) {
             @Override protected void frame(GraphSnapshot snap, int pos, GraphEvent evt) throws IOException {
-                _server.put(GraphJson.frame(snap, pos, evt));
+                JSViewer.this.frame(snap, pos, evt);
             }
         };
         try {
@@ -75,6 +23,4 @@ public class JSViewer implements AutoCloseable {
             code._obs = null;
         }
     }
-
-    @Override public void close() throws IOException { _server.close(); }
 }
diff --git a/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java b/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
index 592abb5c..e9b1dc6d 100644
--- a/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
+++ b/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphAdapter.java
@@ -10,6 +10,9 @@ import java.util.ArrayList;
 
 /** Chapter 25's view of the IR, including partially constructed parse-time graphs. */
 public class SimpleGraphAdapter extends GraphAdapter<Node> {
+    @Override protected boolean dead(Node n) { return n.isDead(); }
+    @Override protected int nDeps(Node n) { return n.nDeps(); }
+    @Override protected Node dep(Node n, int idx) { return n.dep(idx); }
     @Override protected int id(Node n) { return n._nid; }
     @Override protected int nIns(Node n) { return n.nIns(); }
     @Override protected Node in(Node n, int idx) { return n.in(idx); }
diff --git a/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java b/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java
index 5d511287..0318b793 100644
--- a/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java
+++ b/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleGraphObserver.java
@@ -1,130 +1,22 @@
 package com.seaofnodes.simple.print;
 
-import com.seaofnodes.graph.GraphEvent;
-import com.seaofnodes.graph.GraphObserver;
-import com.seaofnodes.graph.GraphSnapshot;
+import com.seaofnodes.graph.GraphCapture;
 import com.seaofnodes.simple.codegen.CodeGen;
 import com.seaofnodes.simple.node.Node;
-import java.io.IOException;
 import java.util.ArrayList;
-import java.util.BitSet;
-import java.util.UUID;
 
-/** Capture events and neighborhoods on the compiler thread. Transport is supplied by the viewer. */
-public abstract class SimpleGraphObserver extends GraphObserver<Node> {
+/** Chapter 25's compilation context; capture and event bookkeeping are shared. */
+public abstract class SimpleGraphObserver extends GraphCapture<Node> {
     private final CodeGen _code;
-    private final SimpleGraphAdapter _graph = new SimpleGraphAdapter();
-    private final String _comp = UUID.randomUUID().toString();
-    private final ArrayList<Peep> _peeps = new ArrayList<>();
-    private long _next, _step;
-    private boolean _off;
-
-    protected SimpleGraphObserver(CodeGen code) { _code = code; }
-
-    protected abstract void frame(GraphSnapshot snap, int pos, GraphEvent evt) throws IOException;
-
-    private static class Peep {
-        final Node node;
-        final long id, up;
-        final String phase;
-        final int pos;
-        final BitSet near = new BitSet();
-        GraphSnapshot pre;
-        boolean sent;
-
-        Peep(Node n, long id, long up, String phase, int pos) {
-            node = n; this.id = id; this.up = up; this.phase = phase; this.pos = pos;
-        }
-    }
-
-    @Override public void before(Node n) {
-        if( _off ) return;
-        var p = new Peep(n, ++_next, _peeps.isEmpty() ? 0 : _peeps.getLast().id,
-                         _code._phase.name(), pos());
-        _peeps.add(p);
-        near(p, n);
-        // Buffer until we know that this attempt (or a nested one) made progress.
-        // Include n explicitly: parse-time nodes need not have any uses yet.
-        p.pre = snap(n);
-    }
-
-    @Override public void after(Node n, Node repl, boolean applied) {
-        if( _off ) return;
-        Peep p = _peeps.getLast();
-        assert p.node == n;
-        near(p, n);
-        near(p, repl);
-        for( Peep up : _peeps ) up.near.or(p.near);
-        if( repl != null || p.sent ) {
-            // Emit ancestors first so a nested rewrite always has its context.
-            for( Peep up : _peeps ) {
-                if( up.sent ) continue;
-                emit(up.pre, up.pos, evt(up, GraphEvent.Kind.BEFORE, 0));
-                if( _off ) return;
-                up.pre = null;
-                up.sent = true;
-            }
-            Node rez = repl == null ? n : repl;
-            emit(snap(rez.isDead() ? null : rez), pos(),
-                 evt(p, applied ? GraphEvent.Kind.APPLY : GraphEvent.Kind.RETURN,
-                     rez.isDead() ? 0 : rez._nid));
-        }
-        _peeps.removeLast();
-    }
-
-    @Override public void dep(Node n, Node def) {
-        if( _off || _peeps.isEmpty() ) return;
-        Peep p = _peeps.getLast();
-        add(p, n);
-        add(p, def);
-    }
-
-    @Override public void phase(String phase) {
-        if( _off ) return;
-        emit(snap(null), pos(), new GraphEvent(GraphEvent.Kind.PHASE, 0, 0, phase, 0, 0, new int[0]));
-    }
-
-    private GraphEvent evt(Peep p, GraphEvent.Kind kind, int repl) {
-        return new GraphEvent(kind, p.id, p.up, p.phase, p.node._nid, repl, p.near.stream().toArray());
-    }
-
-    private void add(Peep p, Node n) { if( n != null ) p.near.set(n._nid); }
-
-    private void near(Peep p, Node n) {
-        if( n == null ) return;
-        add(p, n);
-        for( Node def : n._inputs  ) add(p, def);
-        for( Node use : n._outputs ) add(p, use);
-        // These are wake-up dependents, not all nodes inspected by a rule.
-        // Read before the compiler drains the list; never move/clear it here.
-        for( int i = 0; i < n.nDeps(); i++ ) add(p, n.dep(i));
-    }
-
-    private int pos() { return _code._phase == CodeGen.Phase.Parse ? _code.P.pos() : -1; }
-
-    private GraphSnapshot snap(Node extra) {
-        var roots = new ArrayList<Node>();
+    protected SimpleGraphObserver(CodeGen code) { super(new SimpleGraphAdapter()); _code = code; }
+    @Override protected String phase() { return _code._phase.name(); }
+    @Override protected int pos() { return _code._phase == CodeGen.Phase.Parse ? _code.P.pos() : -1; }
+    @Override protected void detach() { _code._obs = null; }
+    @Override protected void roots(ArrayList<Node> roots) {
         roots.add(_code._stop);
         if( _code._phase == CodeGen.Phase.Parse ) {
             roots.add(_code.P._scope);
             roots.addAll(_code.P._xScopes);
         }
-        for( Peep p : _peeps ) if( !p.node.isDead() ) roots.add(p.node);
-        roots.add(extra);
-        return _graph.snap(_comp, 0, roots.toArray(Node[]::new));
-    }
-
-    private void emit(GraphSnapshot snap, int pos, GraphEvent evt) {
-        if( _off ) return;
-        // Assign steps on emission; attempts without progress do not consume frames.
-        snap = new GraphSnapshot(snap.ver(), _comp, _step++, snap.roots(), snap.nodes());
-        try {
-            frame(snap, pos, evt);
-        } catch( IOException e ) {
-            // A disconnected display must not interrupt optimization.
-            _off = true;
-            _code._obs = null;
-            System.err.println("Graph viewer disconnected: " + e.getMessage());
-        }
     }
 }
diff --git a/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleWebSocket.java b/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleWebSocket.java
deleted file mode 100644
index ae500879..00000000
--- a/chapter25/src/main/java/com/seaofnodes/simple/print/SimpleWebSocket.java
+++ /dev/null
@@ -1,193 +0,0 @@
-package com.seaofnodes.simple.print;
-
-import com.seaofnodes.simple.util.Utils;
-import java.io.*;
-import java.net.ServerSocket;
-import java.net.Socket;
-import java.net.URI;
-import java.nio.charset.StandardCharsets;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-import java.util.Base64;
-import java.net.InetSocketAddress;
-import java.nio.file.Path;
-import com.sun.net.httpserver.HttpServer;
-import com.sun.net.httpserver.SimpleFileServer;
-
-// Why-Oh-Why is this needed?
-
-// Pass in a URI and a port.
-// Opens the client; client has to open a websocket at the given port.
-// Connects, handshakes.
-// Thereafter you can call get/put to swap frames with client.
-
-class SimpleWebSocket extends ServerSocket {
-    final  InputStream _in;
-    final OutputStream _out;
-    private HttpServer _http;
-    private Socket _client;
-
-    SimpleWebSocket(URI uri, int port) throws IOException, NoSuchAlgorithmException {
-        super(port);
-        try {
-            // Use an ordinary web URL; desktop dispatch of file: URLs can silently
-            // raise the browser without opening the page.
-            if( "file".equals(uri.getScheme()) ) {
-                Path page = Path.of(uri);
-                _http = SimpleFileServer.createFileServer(
-                    new InetSocketAddress("127.0.0.1",0), page.getParent(),
-                    SimpleFileServer.OutputLevel.NONE);
-                _http.start();
-                uri = URI.create("http://127.0.0.1:" + _http.getAddress().getPort()
-                                 + "/" + page.getFileName());
-            }
-            // Print the address even if the desktop silently fails to open a tab.
-            System.out.println("Graph viewer: " + uri);
-            if( Boolean.parseBoolean(System.getProperty("simple.graph.open", "true")) )
-                java.awt.Desktop.getDesktop().browse(uri);
-            // Look for client; get in/out streams
-            Socket sock = accept();
-            _client = sock;
-            _in  = sock. getInputStream();
-            _out = sock.getOutputStream();
-
-
-            // Establish web socket with handshake; easier with a buffered reader
-            BufferedReader br = new BufferedReader(new InputStreamReader(_in, StandardCharsets.US_ASCII));
-            String key = null;
-            // TCP can deliver the request in several chunks. ready() is not an
-            // end-of-headers test; wait for the terminating empty line.
-            String line;
-            while( (line = br.readLine()) != null && !line.isEmpty() ) {
-                if( line.startsWith("Sec-WebSocket-Key: ") )
-                    key = line.substring(19);
-            }
-            if( key==null || line==null ) {
-                sock.close();
-                super.close();
-                throw new IOException("Incomplete WebSocket upgrade request");
-            }
-            // Magic handshake
-            byte[] response = ("HTTP/1.1 101 Switching Protocols\r\n"
-                               + "Connection: Upgrade\r\n"
-                               + "Upgrade: websocket\r\n"
-                               + "Sec-WebSocket-Accept: "
-                               + Base64.getEncoder().encodeToString(MessageDigest.getInstance("SHA-1").digest((key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11").getBytes( StandardCharsets.UTF_8 )))
-                               + "\r\n\r\n").getBytes( StandardCharsets.UTF_8 );
-            _out.write(response,0,response.length);
-            _out.flush();
-        } catch( IOException | NoSuchAlgorithmException | RuntimeException | Error failure ) {
-            if( _http != null ) _http.stop(0);
-            if( _client != null ) {
-                try { _client.close(); } catch( IOException ignored ) {}
-            }
-            try { super.close(); } catch( IOException ignored ) {}
-            throw failure;
-        }
-    }
-
-    final byte[] _ins = new byte[1024];
-    final byte[] _str = new byte[1024];
-    final byte[] _key = new byte[4];
-    int _x, _len;
-    private int rawget() { assert _x<_len; return _ins[_x++]&0xFF; }
-
-    // TODO: Flip to Direct Byte Buffer, this is just a poor-mans version
-    private void flipRead() throws IOException {
-        // Move _x to _len to offset 0
-        System.arraycopy(_ins,_x,_ins,0,(_len-_x));
-        _len = _len-_x;
-        _x=0;
-        // Read more
-        int len = _in.read(_ins,_len,_ins.length-_len);
-        if( len == -1 )
-            throw Utils.TODO(); // EOF
-        _len += len;
-    }
-    // Block until you read at least len
-    private void atLeast(int len) throws IOException {
-        if( _x+len <= _len ) return;
-        flipRead();
-    }
-
-
-    // Classic read from browser client.  Encoded, so decoded here
-    public String get() throws IOException {
-        atLeast(1);             // Need 1 byte for opcode
-        int op = rawget();
-        if( (op&0x80)!=0x80 )   // FIN bit not set?
-            throw Utils.TODO( "Multi-part from client: " + op ); // Multipart message
-        op &= 0x7F;             // Strip FIN bit
-        switch( op&15) {
-        case 1: {
-            atLeast(5);         // Min message length
-            // Message length
-            int len = rawget()-128;
-            if( len > 125 ) {
-                if( len > 126 )
-                    throw Utils.TODO(); // Multi-byte length
-                len = (rawget()<<8) | rawget();
-            }
-            atLeast(len+4);     // Rest of message
-            // Encoding key
-            _key[0] = (byte)rawget();
-            _key[1] = (byte)rawget();
-            _key[2] = (byte)rawget();
-            _key[3] = (byte)rawget();
-
-            // Decode bytes
-            for( int i=0; i<len; i++ )
-                _str[i] = (byte)(rawget() ^ _key[i & 3]);
-
-            return new String(_str,0,len,StandardCharsets.UTF_8);
-        }
-            // Client closes
-        case 8: return null;
-            // Ping
-        case 9:
-            // Send a PONG back.  TODO: echo PING data in the PONG
-            _out.write(0x8A); // FIN + PONG
-            _out.write(0x00); // LENGTH==0
-            return get();
-            // Not (yet) implemented: continuation frames, ping/pong
-        default:
-            throw Utils.TODO("Unexpected op from client: "+op); // Multi-part message
-        }
-    }
-
-    // Server text frames are UTF-8 and unmasked.
-    public void put(String msg) throws IOException {
-        byte[] bytes = msg.getBytes(StandardCharsets.UTF_8);
-        int len = bytes.length;
-        _out.write(129); // FIN, opcode 1 - whole text message
-        if( len <= 125 ) {
-            _out.write(len);
-        } else if( len <= 65535 ) {
-            _out.write(126);
-            _out.write(len>>>8);
-            _out.write(len&255);
-        } else {
-            _out.write(127);
-            for( int shift = 56; shift >= 0; shift -= 8 )
-                _out.write((int)((long)len >>> shift) & 255);
-        }
-        _out.write(bytes);
-        _out.flush();
-    }
-
-    @Override public void close() throws IOException {
-        try {
-            if( _out != null ) {
-                _out.write(new byte[]{(byte)0x88, 0}); // Complete, empty close frame
-                _out.flush();
-            }
-        } finally {
-            if( _http != null ) _http.stop(0);
-            try {
-                if( _client != null ) _client.close();
-            } finally {
-                super.close();
-            }
-        }
-    }
-}