LUCENE-7662: throw CorruptIndexException if index files are missing

lucene/CHANGES.txt

@@ -37,6 +37,10 @@ Improvements
 * LUCENE-7489: Better storage of sparse doc-values fields with the default
   codec. (Adrien Grand)
 
+* LUCENE-7662: If index files are missing, throw CorruptIndexException instead
+  of the less descriptive FileNotFound or NoSuchFileException (Mike Drob via 
+  Mike McCandless, Erick Erickson)
+
 Optimizations
 
 * LUCENE-7416: BooleanQuery optimizes queries that have queries that occur both

lucene/core/src/java/org/apache/lucene/index/SegmentCoreReaders.java

@@ -17,7 +17,10 @@
 package org.apache.lucene.index;
 
 
+import java.io.EOFException;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.nio.file.NoSuchFileException;
 import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.Set;
@@ -133,6 +136,10 @@ final class SegmentCoreReaders {
         pointsReader = null;
       }
       success = true;
+    } catch (EOFException | FileNotFoundException e) {
+      throw new CorruptIndexException("Problem reading index from " + dir, dir.toString(), e);
+    } catch (NoSuchFileException e) {
+      throw new CorruptIndexException("Problem reading index.", e.getFile(), e);
     } finally {
       if (!success) {
         decRef();

lucene/core/src/java/org/apache/lucene/index/SegmentInfos.java

@@ -18,8 +18,10 @@ package org.apache.lucene.index;
 
 
 import java.io.EOFException;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.PrintStream;
+import java.nio.file.NoSuchFileException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -280,8 +282,8 @@ public final class SegmentInfos implements Cloneable, Iterable<SegmentCommitInfo
     try (ChecksumIndexInput input = directory.openChecksumInput(segmentFileName, IOContext.READ)) {
       try {
         return readCommit(directory, input, generation);
-      } catch (EOFException e) {
+      } catch (EOFException | NoSuchFileException | FileNotFoundException e) {
-        throw new CorruptIndexException("Unexpected end of file while reading index.", input, e);
+        throw new CorruptIndexException("Unexpected file read error while reading index.", input, e);
       }
     }
   }

lucene/test-framework/src/java/org/apache/lucene/index/BaseIndexFileFormatTestCase.java

@@ -544,14 +544,9 @@ abstract class BaseIndexFileFormatTestCase extends LuceneTestCase {
           conf.setMergeScheduler(new SerialMergeScheduler());
           conf.setCodec(getCodec());
           iw = new IndexWriter(dir, conf);            
-        } catch (Exception e) {
+        } catch (IOException e) {
-          if (e.getMessage() != null && e.getMessage().startsWith("a random IOException")) {
+          handleFakeIOException(e, exceptionStream);
-            exceptionStream.println("\nTEST: got expected fake exc:" + e.getMessage());
+          allowAlreadyClosed = true;
-            e.printStackTrace(exceptionStream);
-            allowAlreadyClosed = true;
-          } else {
-            Rethrow.rethrow(e);
-          }
         }
         
         if (random().nextInt(10) == 0) {
@@ -585,14 +580,9 @@ abstract class BaseIndexFileFormatTestCase extends LuceneTestCase {
             conf.setMergeScheduler(new SerialMergeScheduler());
             conf.setCodec(getCodec());
             iw = new IndexWriter(dir, conf);            
-          } catch (Exception e) {
+          } catch (IOException e) {
-            if (e.getMessage() != null && e.getMessage().startsWith("a random IOException")) {
+            handleFakeIOException(e, exceptionStream);
-              exceptionStream.println("\nTEST: got expected fake exc:" + e.getMessage());
+            allowAlreadyClosed = true;
-              e.printStackTrace(exceptionStream);
-              allowAlreadyClosed = true;
-            } else {
-              Rethrow.rethrow(e);
-            }
           }
         }
       }
@@ -601,16 +591,11 @@ abstract class BaseIndexFileFormatTestCase extends LuceneTestCase {
         dir.setRandomIOExceptionRateOnOpen(0.0); // disable exceptions on openInput until next iteration: 
                                                  // or we make slowExists angry and trip a scarier assert!
         iw.close();
-      } catch (Exception e) {
+      } catch (IOException e) {
-        if (e.getMessage() != null && e.getMessage().startsWith("a random IOException")) {
+        handleFakeIOException(e, exceptionStream);
-          exceptionStream.println("\nTEST: got expected fake exc:" + e.getMessage());
+        try {
-          e.printStackTrace(exceptionStream);
+          iw.rollback();
-          try {
+        } catch (Throwable t) {}
-            iw.rollback();
-          } catch (Throwable t) {}
-        } else {
-          Rethrow.rethrow(e);
-        }
       }
       dir.close();
     } catch (Throwable t) {
@@ -626,4 +611,18 @@ abstract class BaseIndexFileFormatTestCase extends LuceneTestCase {
       System.out.println(exceptionLog.toString("UTF-8"));
     }
   }
+  
+  private void handleFakeIOException(IOException e, PrintStream exceptionStream) {
+    Throwable ex = e;
+    while (ex != null) {
+      if (ex.getMessage() != null && ex.getMessage().startsWith("a random IOException")) {
+        exceptionStream.println("\nTEST: got expected fake exc:" + ex.getMessage());
+        ex.printStackTrace(exceptionStream);
+        return;
+      }
+      ex = ex.getCause();
+    }
+    
+    Rethrow.rethrow(e);
+  }
 }