Cleanups, Renamings

apps/desktop/desktop/src/main/java/bisq/desktop/components/cathash/Configuration.java → apps/desktop/desktop/src/main/java/bisq/desktop/components/cathash/BucketConfig.java

@@ -17,11 +17,12 @@
 
 package bisq.desktop.components.cathash;
 
+import bisq.common.util.MathUtils;
 import lombok.extern.slf4j.Slf4j;
 
 @Slf4j
-public class Configuration {
-    private static final String ROOT = "";
+public class BucketConfig {
+    static final String DIGIT = "#";
 
     private static final int BG0_COUNT = 16;
     private static final int BG1_COUNT = 16;
@@ -33,42 +34,42 @@ public class Configuration {
     private static final int NOSE0_COUNT = 6;
     private static final int WHISKERS0_COUNT = 7;
 
-    private static final int BUCKET_COUNT = 9;
-    private static final int FACET_COUNT = 9;
-
     private static final int[] BUCKET_SIZES = new int[]{BG0_COUNT, BG1_COUNT, EARS0_COUNT, EARS1_COUNT, FACE0_COUNT,
             FACE1_COUNT, EYES0_COUNT, NOSE0_COUNT, WHISKERS0_COUNT};
 
-    private static final String[] FACET_PATH_TEMPLATES;
+    private static final String[] PATH_TEMPLATES;
 
     static {
         String postFix = ".png";
-        FACET_PATH_TEMPLATES = new String[]{
-                ROOT + "bg0/NUM" + postFix,
-                ROOT + "bg1/NUM" + postFix,
-                ROOT + "ears0/NUM" + postFix,
-                ROOT + "ears1/NUM" + postFix,
-                ROOT + "face0/NUM" + postFix,
-                ROOT + "face1/NUM" + postFix,
-                ROOT + "eyes0/NUM" + postFix,
-                ROOT + "nose0/NUM" + postFix,
-                ROOT + "whiskers0/NUM" + postFix,
+        PATH_TEMPLATES = new String[]{
+                "bg0/" + DIGIT + postFix,
+                "bg1/" + DIGIT + postFix,
+                "ears0/" + DIGIT + postFix,
+                "ears1/" + DIGIT + postFix,
+                "face0/" + DIGIT + postFix,
+                "face1/" + DIGIT + postFix,
+                "eyes0/" + DIGIT + postFix,
+                "nose0/" + DIGIT + postFix,
+                "whiskers0/" + DIGIT + postFix
         };
-    }
-
-    static int getBucketCount() {
-        return BUCKET_COUNT;
-    }
 
-    static int getFacetCount() {
-        return FACET_COUNT;
+        long numCombinations = getNumCombinations();
+        log.info("Number of combinations: 2^{} = {}", MathUtils.getLog2(numCombinations), numCombinations);
     }
 
     static int[] getBucketSizes() {
         return BUCKET_SIZES;
     }
 
-    static String[] getFacetPathTemplates() {
-        return FACET_PATH_TEMPLATES;
+    static String[] getPathTemplates() {
+        return PATH_TEMPLATES;
+    }
+
+    static long getNumCombinations() {
+        long result = 1;
+        for (int bucketSize : BUCKET_SIZES) {
+            result *= bucketSize;
+        }
+        return result;
     }
 }

apps/desktop/desktop/src/main/java/bisq/desktop/components/cathash/BucketEncoder.java

@@ -0,0 +1,53 @@
+/*
+ * This file is part of Bisq.
+ *
+ * Bisq is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Bisq is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Bisq. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bisq.desktop.components.cathash;
+
+import java.math.BigInteger;
+
+public class BucketEncoder {
+    /**
+     * @param input A BigInteger input that is to be split up deterministically in buckets according to the bucketSizes array.
+     * @return buckets
+     */
+    static int[] encode(BigInteger input, int[] bucketSizes) {
+        int currentBucket = 0;
+        int[] result = new int[bucketSizes.length];
+        while (currentBucket < bucketSizes.length) {
+            int bucketSize = bucketSizes[currentBucket];
+            BigInteger[] divisorReminder = input.divideAndRemainder(BigInteger.valueOf(bucketSize));
+            input = divisorReminder[0];
+            long reminder = divisorReminder[1].longValue();
+            result[currentBucket] = (int) Math.abs(reminder % bucketSize);
+            currentBucket++;
+        }
+        return result;
+    }
+
+    static String[] toPaths(int[] buckets, String[] pathTemplates) {
+        String[] paths = new String[buckets.length];
+        for (int facet = 0; facet < buckets.length; facet++) {
+            int bucketValue = buckets[facet];
+            paths[facet] = generatePath(pathTemplates[facet], bucketValue);
+        }
+        return paths;
+    }
+
+    private static String generatePath(String pathTemplate, int index) {
+        return pathTemplate.replaceAll(BucketConfig.DIGIT, String.format("%02d", index));
+    }
+}

apps/desktop/desktop/src/main/java/bisq/desktop/components/cathash/CatHash.java

@@ -26,7 +26,6 @@
 import java.util.concurrent.ConcurrentHashMap;
 
 // Derived from https://github.com/neuhalje/android-robohash
-// Number of combinations: 3 * 15 * 15 * 15 * 15 * 15 * 15  = 34171875 (2 ^ 25)
 @Slf4j
 public class CatHash {
     private static final int SIZE = 300;
@@ -45,21 +44,13 @@ private static Image getImage(ByteArray pubKeyHash, boolean useCache) {
         if (useCache && CACHE.containsKey(pubKeyHash)) {
             return CACHE.get(pubKeyHash);
         }
-        BigInteger bigInteger = new BigInteger(pubKeyHash.getBytes());
-        int[] buckets = BucketGenerator.createBuckets(bigInteger, Configuration.getBucketSizes());
-        Image image = imageFromBuckets(buckets);
+        BigInteger input = new BigInteger(pubKeyHash.getBytes());
+        int[] buckets = BucketEncoder.encode(input, BucketConfig.getBucketSizes());
+        String[] paths = BucketEncoder.toPaths(buckets, BucketConfig.getPathTemplates());
+        Image image = ImageUtil.composeImage(paths, SIZE, SIZE);
         if (useCache && CACHE.size() < MAX_CACHE_SIZE) {
             CACHE.put(pubKeyHash, image);
         }
         return image;
     }
-
-
-    private static Image imageFromBuckets(int[] integerBuckets) {
-        String[] paths = BucketGenerator.integerBucketsToPaths(integerBuckets,
-                Configuration.getBucketCount(),
-                Configuration.getFacetCount(),
-                Configuration.getFacetPathTemplates());
-        return ImageUtil.composeImage(paths, SIZE, SIZE);
-    }
 }

common/src/main/java/bisq/common/util/MathUtils.java

@@ -108,4 +108,8 @@ public static long bounded(long lowerBound, long upperBound, long value) {
                 "lowerBound must not be larger than upperBound");
         return Math.min(Math.max(value, lowerBound), upperBound);
     }
+
+    public static double getLog2(long value) {
+        return Math.log(value) / Math.log(2);
+    }
 }