Update (#852)

* Update

 * comments and clarifications in block_splitter
 * power-of-2 aligned allocations for Hasher
 * refresh decode.js from Java sources
 * disable JS build

5 files changed, 35 insertions, 21 deletions

diff --git a/java/org/brotli/dec/BitReader.java b/java/org/brotli/dec/BitReader.java
index 6dfeedc..0fb4bfa 100644
--- a/java/org/brotli/dec/BitReader.java
+++ b/java/org/brotli/dec/BitReader.java
@@ -211,7 +211,7 @@ final class BitReader {
     return limit - s.halfOffset;
   }
 
-  static void copyBytes(State s, byte[] data, int offset, int length) {
+  static void copyRawBytes(State s, byte[] data, int offset, int length) {
     if ((s.bitOffset & 7) != 0) {
       throw new BrotliRuntimeException("Unaligned copyBytes");
     }
diff --git a/java/org/brotli/dec/Decode.java b/java/org/brotli/dec/Decode.java
index 8395f04..da7c453 100644
--- a/java/org/brotli/dec/Decode.java
+++ b/java/org/brotli/dec/Decode.java
@@ -903,7 +903,7 @@ final class Decode {
     }
 
     int chunkLength = Math.min(s.ringBufferSize - s.pos, s.metaBlockLength);
-    BitReader.copyBytes(s, ringBuffer, s.pos, chunkLength);
+    BitReader.copyRawBytes(s, ringBuffer, s.pos, chunkLength);
     s.metaBlockLength -= chunkLength;
     s.pos += chunkLength;
     if (s.pos == s.ringBufferSize) {
diff --git a/java/org/brotli/dec/Dictionary.java b/java/org/brotli/dec/Dictionary.java
index 043572f..458e597 100644
--- a/java/org/brotli/dec/Dictionary.java
+++ b/java/org/brotli/dec/Dictionary.java
@@ -21,7 +21,7 @@ public final class Dictionary {
   static final int MIN_DICTIONARY_WORD_LENGTH = 4;
   static final int MAX_DICTIONARY_WORD_LENGTH = 31;
 
-  private static ByteBuffer data;
+  private static ByteBuffer data = null;
   static final int[] offsets = new int[32];
   static final int[] sizeBits = new int[32];
 
@@ -39,45 +39,45 @@ public final class Dictionary {
     }
   }
 
-  public static void setData(ByteBuffer data, int[] sizeBits) {
-    if (!data.isDirect() || !data.isReadOnly()) {
-      throw new BrotliRuntimeException("data must be a direct read-only byte buffer");
+  public static void setData(ByteBuffer newData, int[] newSizeBits) {
+    if ((Utils.isDirect(newData) == 0) || (Utils.isReadOnly(newData) == 0)) {
+      throw new BrotliRuntimeException("newData must be a direct read-only byte buffer");
     }
     // TODO: is that so?
-    if (sizeBits.length > MAX_DICTIONARY_WORD_LENGTH) {
+    if (newSizeBits.length > MAX_DICTIONARY_WORD_LENGTH) {
       throw new BrotliRuntimeException(
           "sizeBits length must be at most " + MAX_DICTIONARY_WORD_LENGTH);
     }
     for (int i = 0; i < MIN_DICTIONARY_WORD_LENGTH; ++i) {
-      if (sizeBits[i] != 0) {
+      if (newSizeBits[i] != 0) {
         throw new BrotliRuntimeException("first " + MIN_DICTIONARY_WORD_LENGTH + " must be 0");
       }
     }
     int[] dictionaryOffsets = Dictionary.offsets;
     int[] dictionarySizeBits = Dictionary.sizeBits;
-    System.arraycopy(sizeBits, 0, dictionarySizeBits, 0, sizeBits.length);
+    System.arraycopy(newSizeBits, 0, dictionarySizeBits, 0, newSizeBits.length);
     int pos = 0;
-    int limit = data.capacity();
-    for (int i = 0; i < sizeBits.length; ++i) {
+    int limit = newData.capacity();
+    for (int i = 0; i < newSizeBits.length; ++i) {
       dictionaryOffsets[i] = pos;
       int bits = dictionarySizeBits[i];
       if (bits != 0) {
         if (bits >= 31) {
-          throw new BrotliRuntimeException("sizeBits values must be less than 31");
+          throw new BrotliRuntimeException("newSizeBits values must be less than 31");
         }
         pos += i << bits;
         if (pos <= 0 || pos > limit) {
-          throw new BrotliRuntimeException("sizeBits is inconsistent: overflow");
+          throw new BrotliRuntimeException("newSizeBits is inconsistent: overflow");
         }
       }
     }
-    for (int i = sizeBits.length; i < 32; ++i) {
+    for (int i = newSizeBits.length; i < 32; ++i) {
       dictionaryOffsets[i] = pos;
     }
     if (pos != limit) {
-      throw new BrotliRuntimeException("sizeBits is inconsistent: underflow");
+      throw new BrotliRuntimeException("newSizeBits is inconsistent: underflow");
     }
-    Dictionary.data = data;
+    Dictionary.data = newData;
   }
 
   public static ByteBuffer getData() {
diff --git a/java/org/brotli/dec/DictionaryData.java b/java/org/brotli/dec/DictionaryData.java
index db281e3..4a8450c 100644
--- a/java/org/brotli/dec/DictionaryData.java
+++ b/java/org/brotli/dec/DictionaryData.java
@@ -62,10 +62,11 @@ final class DictionaryData {
   }
 
   static {
-    ByteBuffer dictionary = ByteBuffer.allocateDirect(122784);
-    int[] sizeBits = new int[25];
-    unpackDictionaryData(dictionary, DATA0, DATA1, SKIP_FLIP, sizeBits, SIZE_BITS_DATA);
-    Utils.flipBuffer(dictionary);
-    Dictionary.setData(dictionary.asReadOnlyBuffer(), sizeBits);
+    ByteBuffer dictionaryData = ByteBuffer.allocateDirect(122784);
+    int[] dictionarySizeBits = new int[25];
+    unpackDictionaryData(
+        dictionaryData, DATA0, DATA1, SKIP_FLIP, dictionarySizeBits, SIZE_BITS_DATA);
+    Utils.flipBuffer(dictionaryData);
+    Dictionary.setData(Utils.asReadOnlyBuffer(dictionaryData), dictionarySizeBits);
   }
 }
diff --git a/java/org/brotli/dec/Utils.java b/java/org/brotli/dec/Utils.java
index 3fb2bfa..cc4a9f0 100644
--- a/java/org/brotli/dec/Utils.java
+++ b/java/org/brotli/dec/Utils.java
@@ -10,6 +10,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.UnsupportedEncodingException;
 import java.nio.Buffer;
+import java.nio.ByteBuffer;
 
 /**
  * A set of utility methods.
@@ -88,6 +89,18 @@ final class Utils {
     }
   }
 
+  static ByteBuffer asReadOnlyBuffer(ByteBuffer src) {
+    return src.asReadOnlyBuffer();
+  }
+
+  static int isReadOnly(ByteBuffer src) {
+    return src.isReadOnly() ? 1 : 0;
+  }
+
+  static int isDirect(ByteBuffer src) {
+    return src.isDirect() ? 1 : 0;
+  }
+
   // Crazy pills factory: code compiled for JDK8 does not work on JRE9.
   static void flipBuffer(Buffer buffer) {
     buffer.flip();