McQuad -- Version 1.2.2

Added filtering of "Spurious Regions".
- initial cut at McaDump for analyzing region files.
- added timeStampAt() to RegionFile, so we can retrieve chunk timestamps.
    (to be used later in chunk-resolution heatmap generation)

core/src/main/java/com/meowster/mcquad/McQuad.java

@@ -23,7 +23,7 @@
 public class McQuad {
 
     /* This version is displayed in the masthead of the web app */
-    private static final String MCQUAD_VERSION = "1.2.1";
+    private static final String MCQUAD_VERSION = "1.2.2";
 
     private final ParsedArgs parsedArgs;
     private final OutputUtils outputUtils;

core/src/main/java/com/meowster/mcquad/McaDump.java

@@ -0,0 +1,56 @@
+package com.meowster.mcquad;
+
+import java.io.File;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import static com.meowster.util.StringUtils.printErr;
+import static java.lang.System.exit;
+
+/**
+ * Command-line based region file analysis program, for dumping information
+ * about MCA (Minecraft Anvil format) files.
+ * <pre>
+ *  Usage: com.meowster.mcquad.McaDump {region file}.
+ * </pre>
+ */
+public class McaDump {
+
+    private static final Pattern RE_REGION_FILE =
+            Pattern.compile("^r\\.(-?\\d+)\\.(-?\\d+)\\.mca$");
+
+    private McaDump(File mca) {
+        Matcher m = RE_REGION_FILE.matcher(mca.getName());
+        if (m.matches()) {
+            int x = Integer.parseInt(m.group(1));
+            int z = Integer.parseInt(m.group(2));
+            Region region = new Region(x, z, mca);
+            RegionDataDump.analyze(region);
+        } else {
+            printErr("No match?? {}", mca.getName());
+            exit(1);
+        }
+    }
+
+    private static int usage() {
+        System.out.println("Usage: McaDump {region file}");
+        return 2;
+    }
+
+    /**
+     * Main entry point.
+     *
+     * @param args command line arguments.
+     */
+    public static void main(String[] args) {
+        if (args.length != 1) {
+            exit(usage());
+        }
+        File mca = new File(args[0]);
+        if (!mca.canRead()) {
+            printErr("Unable to read file: {}", args[0]);
+            exit(usage());
+        }
+        new McaDump(mca);
+    }
+}

core/src/main/java/com/meowster/mcquad/Region.java

@@ -33,7 +33,7 @@ class Region {
      * @param f    the region file
      * @param mock file is a mock
      */
-    public Region(int x, int z, File f, boolean mock) {
+    Region(int x, int z, File f, boolean mock) {
         this.coord = new Coord(x, z);
         this.f = f;
         this.mock = mock;
@@ -51,6 +51,17 @@ public Region(int x, int z, File f, boolean mock) {
         this(x, z, null, true);
     }
 
+    /**
+     * Constructor for creating region file (not a mock).
+     *
+     * @param x    the x-coord
+     * @param z    the z-coord
+     * @param f    the region file
+     */
+    Region(int x, int z, File f) {
+        this(x, z, f, false);
+    }
+
     @Override
     public String toString() {
         return "Region{" + coord + ", mock=" + mock + ", f=" + f + '}';
@@ -79,6 +90,15 @@ File regionFile() {
         return f;
     }
 
+    /**
+     * Returns true if this is a mock (test) region.
+     *
+     * @return true if mock; false otherwise
+     */
+    boolean isMock() {
+        return mock;
+    }
+
     /**
      * Returns the last modified timestamp for the backing region file.
      * If there is no backing file (for example, unit tests running in
@@ -123,12 +143,20 @@ DataInputStream getChunkDataStream(int cx, int cz) {
         return rf == null ? null : rf.getChunkDataStream(cx, cz);
     }
 
+    /**
+     * Returns the number of chunks contained in this region.
+     *
+     * @return the number of chunks in the region
+     */
+    int chunkCount() {
+        return rf == null ? 0 : rf.chunkCount();
+    }
+
     /**
      * Instructs the region to release any resources used to hold region data,
      * since we have generated the image and the data is no longer required.
      */
     void releaseResources() {
         rf = null;
     }
-
 }

core/src/main/java/com/meowster/mcquad/RegionData.java

@@ -48,6 +48,18 @@ void load(Set<Region> regions) {
      * @param r the region to load
      */
     private void loadRegion(Region r) {
+        /*
+         * NOTE:
+         *  There is a bug in the Minecraft server (observed in 1.10.2) that
+         *  sometimes outputs region files containing a single chunk, with no
+         *  bearing to where players have explored. We need to filter out these
+         *  spurious regions.
+         */
+        if (!r.isMock() && r.chunkCount() < 2) {
+            printErr("Spurious region detected: {}", r);
+            return;
+        }
+
         bounds.add(r.coord());
         regionMap.put(r.coord(), r);
     }

core/src/main/java/com/meowster/mcquad/RegionDataDump.java

@@ -0,0 +1,88 @@
+package com.meowster.mcquad;
+
+import java.io.DataInputStream;
+
+import static com.meowster.util.StringUtils.EOL;
+import static com.meowster.util.StringUtils.printOut;
+
+/**
+ * Analysis of a region file.
+ */
+class RegionDataDump {
+
+    private static final String HASH = " #";
+    private static final String DOT = " .";
+
+    private static final int NCHUNKS = 32;  // chunk dimension of region
+    private static final int NBLOCKS = 16;  // block dimension of chunk
+
+    private static final int CHUNKS_PER_REGION = NCHUNKS * NCHUNKS;
+
+
+    private static Region region;
+    private static int totalChunks;
+    private static ChunkStuff[][] data;
+    private static int singleX;
+    private static int singleZ;
+
+    /**
+     * Analyze the region and output results.
+     *
+     * @param r the region to analyze
+     */
+    static void analyze(Region r) {
+        region = r;
+        totalChunks = 0;
+        data = new ChunkStuff[NCHUNKS][NCHUNKS];
+
+        // iterate over the chunks in the region...
+        for (int cz = 0; cz < NCHUNKS; cz++) {
+            for (int cx = 0; cx < NCHUNKS; cx++) {
+                DataInputStream dis = region.getChunkDataStream(cx, cz);
+                if (dis == null)
+                    continue;
+
+                totalChunks++;
+                singleX = cx;
+                singleZ = cz;
+
+//                Chunk chunk = new Chunk(dis);
+                data[cz][cx] = new ChunkStuff(null);
+            }
+        }
+
+        outputResults();
+    }
+
+
+    private static void outputResults() {
+        printOut("Region: {}; Chunks: {}/{}",
+                region.regionFile().getName(),
+                totalChunks,
+                CHUNKS_PER_REGION
+        );
+        if (totalChunks == 1) {
+            printOut("  Chunk coords [{}, {}]", singleX, singleZ);
+        }
+//        printOut(createMap());
+    }
+
+    private static String createMap() {
+        StringBuilder sb = new StringBuilder();
+        for (int cz = 0; cz < NCHUNKS; cz++) {
+            for (int cx = 0; cx < NCHUNKS; cx++) {
+                sb.append(data[cz][cx] != null ? HASH : DOT);
+            }
+            sb.append(EOL);
+        }
+        return sb.toString();
+    }
+
+
+    // retains info about a chunk
+    private static class ChunkStuff {
+        ChunkStuff(Chunk chunk) {
+            // capture any data we need for dumping...
+        }
+    }
+}

core/src/main/java/com/meowster/mcquad/RegionFile.java

@@ -186,6 +186,54 @@ else if (version == VERSION_DEFLATE)
         }
     }
 
+    /**
+     * Returns the number of chunks available in this region.
+     *
+     * @return the chunk count
+     */
+    int chunkCount() {
+        int nChunks = 0;
+        for (int cz = 0; cz < NCHUNKS; cz++) {
+            for (int cx = 0; cx < NCHUNKS; cx++) {
+                if (chunkAvailableAt(cx, cz)) {
+                    nChunks++;
+                }
+            }
+        }
+        return nChunks;
+    }
+
+    /**
+     * Returns true if there is chunk data at the specified coordinates.
+     *
+     * @param x chunk x-coord
+     * @param z chunk z-coord
+     * @return true if chunk data is here; false otherwise
+     */
+    boolean chunkAvailableAt(int x, int z) {
+        if (outOfBounds(x, z))
+            return false;
+
+        int offset = getOffset(x, z);
+        if (offset == 0)
+            return false;
+
+        final int sectorNumber = offset >> 8;
+        final int numSectors = offset & 0xff;
+
+        return sectorNumber + numSectors <= nSectors;
+    }
+
+    /**
+     * Returns the chunk timestamp for the specified coordinates.
+     *
+     * @param x chunk x-coord
+     * @param z chunk z-coord
+     * @return true if chunk data is here; false otherwise
+     */
+    int timeStampAt(int x, int z) {
+        return outOfBounds(x, z) ? 0 : chunkTimestamps[x + z * 32];
+    }
 
     private boolean outOfBounds(int x, int z) {
         return x < 0 || x >= NCHUNKS || z < 0 || z >= NCHUNKS;

pom.xml

@@ -13,7 +13,7 @@
     <modelVersion>4.0.0</modelVersion>
 
     <properties>
-        <mcquad.version>1.2.1</mcquad.version>
+        <mcquad.version>1.2.2</mcquad.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 

tools/src/bin/mcquad-config.sh

@@ -36,5 +36,5 @@ export MCMAPS_CONTEXT=/mcmaps
 ##
 
 # MCQUAD_VERSION should be set to correct version to pull out of maven repo
-export MCQUAD_VERSION=1.2.1
+export MCQUAD_VERSION=1.2.2
 

tools/src/dev/cpwww.sh

@@ -3,7 +3,7 @@
 
 BACK=$PWD
 TARBALL=static.tar.gz
-VERSION=1.2.1
+VERSION=1.2.2
 
 cd ../../../web/target/mcquad-web-${VERSION}/
 echo BUILD TAR

tools/src/dev/mcadump.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+MCQUAD_VERSION=1.2.2
+
+MAIN=com.meowster.mcquad.McaDump
+
+CP="/Users/simonh/dev/mcquad/McQuad/core/target/classes"
+
+MCSAVES="/Users/simonh/dev/mcquad/tmp"
+
+ls "$MCSAVES"
+
+JAVA=/usr/bin/java
+
+
+for FILE in $(ls "$MCSAVES");
+do
+    $JAVA -cp $CP $MAIN "$MCSAVES/$FILE"
+done
+
+