Issue #3888 - Fixing for truncated long to int

+ Allowing CachedHttpContent._contentLengthValue actually hold
  the `long` resource size (for the 4G variant on test)
+ Allowing BufferUtil to not throw Exception if resource length
  is a positive value, but exceeds Integer.MAX_VALUE, opting instead
  to return a null to prevent excessive memory usage. (fixes the 10G
  variant of test)

Signed-off-by: Joakim Erdfelt <joakim.erdfelt@gmail.com>

jetty-server/src/main/java/org/eclipse/jetty/server/CachedContentFactory.java

@@ -386,7 +386,7 @@ public class CachedContentFactory implements HttpContent.ContentFactory
     {
         private final String _key;
         private final Resource _resource;
-        private final int _contentLengthValue;
+        private final long _contentLengthValue;
         private final HttpField _contentType;
         private final String _characterEncoding;
         private final MimeTypes.Type _mimeType;
@@ -415,7 +415,7 @@ public class CachedContentFactory implements HttpContent.ContentFactory
             _lastModified = _lastModifiedValue == -1 ? null
                 : new PreEncodedHttpField(HttpHeader.LAST_MODIFIED, DateGenerator.formatDate(_lastModifiedValue));
 
-            _contentLengthValue = exists ? (int)resource.length() : 0;
+            _contentLengthValue = exists ? resource.length() : 0;
             _contentLength = new PreEncodedHttpField(HttpHeader.CONTENT_LENGTH, Long.toString(_contentLengthValue));
 
             if (_cachedFiles.incrementAndGet() > _maxCachedFiles)
@@ -558,7 +558,7 @@ public class CachedContentFactory implements HttpContent.ContentFactory
                 ByteBuffer buffer2 = CachedContentFactory.this.getIndirectBuffer(_resource);
 
                 if (buffer2 == null)
-                    LOG.warn("Could not load " + this);
+                    LOG.warn("Could not load indirect buffer from " + this);
                 else if (_indirectBuffer.compareAndSet(null, buffer2))
                 {
                     buffer = buffer2;

jetty-util/src/main/java/org/eclipse/jetty/util/BufferUtil.java

@@ -971,11 +971,19 @@ public class BufferUtil
 
     public static ByteBuffer toBuffer(Resource resource, boolean direct) throws IOException
     {
-        int len = (int)resource.length();
+        long len = resource.length();
         if (len < 0)
             throw new IllegalArgumentException("invalid resource: " + resource + " len=" + len);
 
-        ByteBuffer buffer = direct ? BufferUtil.allocateDirect(len) : BufferUtil.allocate(len);
+        if (len > Integer.MAX_VALUE)
+        {
+            // This method cannot handle resources of this size.
+            return null;
+        }
+
+        int ilen = (int)len;
+
+        ByteBuffer buffer = direct ? BufferUtil.allocateDirect(ilen) : BufferUtil.allocate(ilen);
 
         int pos = BufferUtil.flipToFill(buffer);
         if (resource.getFile() != null)
@@ -984,7 +992,7 @@ public class BufferUtil
         {
             try (InputStream is = resource.getInputStream())
             {
-                BufferUtil.readFrom(is, len, buffer);
+                BufferUtil.readFrom(is, ilen, buffer);
             }
         }
         BufferUtil.flipToFlush(buffer, pos);

jetty-webapp/src/test/java/org/eclipse/jetty/webapp/HugeResourceTest.java

@@ -160,6 +160,8 @@ public class HugeResourceTest
         HttpURLConnection http = (HttpURLConnection)destUri.toURL().openConnection();
         assertThat("HTTP Response Code", http.getResponseCode(), is(200));
 
+        dumpResponseHeaders(http);
+
         // if a Content-Length is provided, test it
         String contentLength = http.getHeaderField("Content-Length");
         if (contentLength != null)
@@ -186,4 +188,16 @@ public class HugeResourceTest
         // Verify the file download size
         assertThat("Downloaded Files Size: " + filename, Files.size(outputFile), is(expectedSize));
     }
+
+    private void dumpResponseHeaders(HttpURLConnection http)
+    {
+        int i = 0;
+        String value;
+        while ((value = http.getHeaderField(i)) != null)
+        {
+            String key = http.getHeaderFieldKey(i);
+            System.err.printf("  %s: %s%n", key, value);
+            i++;
+        }
+    }
 }