Merge static blocks, test converting and merging

NeRdTheNed · Nov 9, 2023 · 37a60cf · 37a60cf
1 parent efb5ca7
commit 37a60cf
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Showing 4 changed files with 43 additions and 3 deletions.
diff --git a/deft4j-base/src/main/java/com/github/NeRdTheNed/deft4j/deflate/DeflateBlockHuffman.java b/deft4j-base/src/main/java/com/github/NeRdTheNed/deft4j/deflate/DeflateBlockHuffman.java
@@ -1223,15 +1223,50 @@ public void discard() {
         rlePairs = null;
     }
 
-    // TODO
+    // TODO Merge dynamic blocks
     @Override
     public boolean canMerge(DeflateBlock append) {
-        return false;
+        return (append != null) && ((append.getDeflateBlockType() == DeflateBlockType.FIXED) || (append.getDeflateBlockType() == DeflateBlockType.DYNAMIC));
     }
 
-    // TODO
+    // TODO Merge dynamic blocks
     @Override
     public DeflateBlock merge(DeflateBlock append) {
+        if ((append.getDeflateBlockType() == DeflateBlockType.FIXED) || (append.getDeflateBlockType() == DeflateBlockType.DYNAMIC)) {
+            DeflateBlockHuffman thisFixed;
+
+            if (getDeflateBlockType() == DeflateBlockType.DYNAMIC) {
+                thisFixed = (DeflateBlockHuffman) copy();
+                thisFixed.recodeToFixedHuffman();
+            } else {
+                thisFixed = this;
+            }
+
+            DeflateBlockHuffman otherFixed;
+
+            if (append.getDeflateBlockType() == DeflateBlockType.DYNAMIC) {
+                otherFixed = (DeflateBlockHuffman) append.copy();
+                otherFixed.recodeToFixedHuffman();
+            } else {
+                otherFixed = (DeflateBlockHuffman) append;
+            }
+
+            final DeflateBlockHuffman merged = (DeflateBlockHuffman) thisFixed.copy();
+            merged.decodedData = Util.combine(getUncompressedData(), append.getUncompressedData());
+            merged.ensureDidCopyLitLens();
+            final LitLen eob = merged.litlens.remove(merged.litlens.size() - 1);
+            merged.litlens.addAll(otherFixed.litlens);
+            merged.sizeBits -= merged.litlenSizeBits;
+
+            for (final LitLen litlenThis : otherFixed.litlens) {
+                merged.litlenSizeBits += getLitLenSize(litlenThis, merged.litlenDec, merged.distDec);
+            }
+
+            merged.litlenSizeBits -= getLitLenSize(eob, merged.litlenDec, merged.distDec);
+            merged.sizeBits += merged.litlenSizeBits;
+            return merged;
+        }
+
         return null;
     }
 }
diff --git a/runTestOpt.sh b/runTestOpt.sh
@@ -1,6 +1,7 @@
 gradle build
 
 java -ea -jar ./deft4j-cmd/build/libs/deft4j-cmd-all.jar optimise ./test/deflate-store-2.txt.gz ./test/deflate-store-2-opt.txt.gz | tee ./test/deflate-store-2-opt.txt.gz.txt
+java -ea -jar ./deft4j-cmd/build/libs/deft4j-cmd-all.jar optimise ./test/lz-twice-twice.txt.gz ./test/lz-twice-twice-opt.txt.gz | tee ./test/lz-twice-twice-opt.txt.gz.txt
 java -ea -jar ./deft4j-cmd/build/libs/deft4j-cmd-all.jar optimise ./test/asyoulik/asyoulik-gzip.txt.gz ./test/asyoulik/asyoulik-gzip-opt.txt.gz | tee ./test/asyoulik/asyoulik-gzip-opt.txt.gz.txt
 java -ea -jar ./deft4j-cmd/build/libs/deft4j-cmd-all.jar optimise ./test/asyoulik/asyoulik-zopfli.txt.gz ./test/asyoulik/asyoulik-zopfli-opt.txt.gz | tee ./test/asyoulik/asyoulik-zopfli-opt.txt.gz.txt
 java -ea -jar ./deft4j-cmd/build/libs/deft4j-cmd-all.jar optimise ./test/text.png ./test/text-opt.png | tee ./test/text-opt.png.txt

diff --git a/test/lz-twice-twice-opt.txt.gz b/test/lz-twice-twice-opt.txt.gz
diff --git a/test/lz-twice-twice-opt.txt.gz.txt b/test/lz-twice-twice-opt.txt.gz.txt
@@ -0,0 +1,4 @@
+File type recognised as GZip
+10 bits saved in stream 0 (lz.txt)
+Total bits saved 10
+Saved 10 bits with optimisation