From 5cbe58f22c71cfe3f6d21b4661914c255ac80e3d Mon Sep 17 00:00:00 2001
From: Adrien Grand <jpountz@gmail.com>
Date: Fri, 14 Feb 2020 10:37:06 +0100
Subject: [PATCH] Add back assertions removed by LUCENE-9187. (#1236)

This time they would only apply to TestFastLZ4/TestHighLZ4 and avoid slowing
down all tests.
---
 .../org/apache/lucene/util/compress/LZ4.java  | 16 ++++++++++
 .../lucene/util/compress/LZ4TestCase.java     | 31 +++++++++++++++++++
 .../lucene/util/compress/TestFastLZ4.java     |  3 +-
 .../lucene/util/compress/TestHighLZ4.java     |  3 +-
 4 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/lucene/core/src/java/org/apache/lucene/util/compress/LZ4.java b/lucene/core/src/java/org/apache/lucene/util/compress/LZ4.java
index 0b2945efc79..0b7f5d85a29 100644
--- a/lucene/core/src/java/org/apache/lucene/util/compress/LZ4.java
+++ b/lucene/core/src/java/org/apache/lucene/util/compress/LZ4.java
@@ -202,6 +202,9 @@ static abstract class HashTable {
      * offsets. A return value of {@code -1} indicates that no other index could
      * be found. */
     abstract int previous(int off);
+
+    // For testing
+    abstract boolean assertReset();
   }
 
   /**
@@ -263,6 +266,11 @@ public int previous(int off) {
       return -1;
     }
 
+    @Override
+    boolean assertReset() {
+      return true;
+    }
+
   }
 
   /**
@@ -369,6 +377,14 @@ int previous(int off) {
       }
       return -1;
     }
+
+    @Override
+    boolean assertReset() {
+      for (int i = 0; i < chainTable.length; ++i) {
+        assert chainTable[i] == (short) 0xFFFF : i;
+      }
+      return true;
+    }
   }
 
   /**
diff --git a/lucene/core/src/test/org/apache/lucene/util/compress/LZ4TestCase.java b/lucene/core/src/test/org/apache/lucene/util/compress/LZ4TestCase.java
index e49cf4803e1..81f84e47e78 100644
--- a/lucene/core/src/test/org/apache/lucene/util/compress/LZ4TestCase.java
+++ b/lucene/core/src/test/org/apache/lucene/util/compress/LZ4TestCase.java
@@ -30,6 +30,37 @@ public abstract class LZ4TestCase extends LuceneTestCase {
 
   protected abstract LZ4.HashTable newHashTable();
 
+  protected static class AssertingHashTable extends LZ4.HashTable {
+
+    private final LZ4.HashTable in;
+
+    AssertingHashTable(LZ4.HashTable in) {
+      this.in = in;
+    }
+
+    @Override
+    void reset(byte[] b, int off, int len) {
+      in.reset(b, off, len);
+      assertTrue(in.assertReset());
+    }
+
+    @Override
+    int get(int off) {
+      return in.get(off);
+    }
+
+    @Override
+    int previous(int off) {
+      return in.previous(off);
+    }
+
+    @Override
+    boolean assertReset() {
+      throw new UnsupportedOperationException();
+    }
+
+  }
+
   private void doTest(byte[] data, LZ4.HashTable hashTable) throws IOException {
     int offset = random().nextBoolean()
         ? random().nextInt(10)
diff --git a/lucene/core/src/test/org/apache/lucene/util/compress/TestFastLZ4.java b/lucene/core/src/test/org/apache/lucene/util/compress/TestFastLZ4.java
index 076d04c6635..58709523802 100644
--- a/lucene/core/src/test/org/apache/lucene/util/compress/TestFastLZ4.java
+++ b/lucene/core/src/test/org/apache/lucene/util/compress/TestFastLZ4.java
@@ -22,7 +22,8 @@ public class TestFastLZ4 extends LZ4TestCase {
 
   @Override
   protected HashTable newHashTable() {
-    return new LZ4.FastCompressionHashTable();
+    LZ4.HashTable hashTable = new LZ4.FastCompressionHashTable();
+    return new AssertingHashTable(hashTable);
   }
 
 }
diff --git a/lucene/core/src/test/org/apache/lucene/util/compress/TestHighLZ4.java b/lucene/core/src/test/org/apache/lucene/util/compress/TestHighLZ4.java
index b118f947384..207940a0dc2 100644
--- a/lucene/core/src/test/org/apache/lucene/util/compress/TestHighLZ4.java
+++ b/lucene/core/src/test/org/apache/lucene/util/compress/TestHighLZ4.java
@@ -22,7 +22,8 @@ public class TestHighLZ4 extends LZ4TestCase {
 
   @Override
   protected HashTable newHashTable() {
-    return new LZ4.HighCompressionHashTable();
+    LZ4.HashTable hashTable =  new LZ4.HighCompressionHashTable();
+    return new AssertingHashTable(hashTable);
   }
 
 }