--- /dev/null	2017-10-28 22:49:55.551349757 -0700
+++ new/src/jdk.incubator.httpclient/share/classes/jdk/incubator/http/internal/hpack/HPACK.java	2017-11-30 04:05:51.737908415 -0800
@@ -0,0 +1,174 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package jdk.incubator.http.internal.hpack;
+
+import jdk.incubator.http.internal.common.Utils;
+import jdk.incubator.http.internal.hpack.HPACK.Logger.Level;
+
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.util.Map;
+import java.util.ResourceBundle;
+import java.util.function.Supplier;
+
+import static java.lang.String.format;
+import static java.util.stream.Collectors.joining;
+import static jdk.incubator.http.internal.hpack.HPACK.Logger.Level.EXTRA;
+import static jdk.incubator.http.internal.hpack.HPACK.Logger.Level.NONE;
+import static jdk.incubator.http.internal.hpack.HPACK.Logger.Level.NORMAL;
+
+/**
+ * Internal utilities and stuff.
+ */
+public final class HPACK {
+
+    private static final RootLogger LOGGER;
+    private static final Map<String, Level> logLevels =
+            Map.of("NORMAL", NORMAL, "EXTRA", EXTRA);
+
+    static {
+        String PROPERTY = "jdk.internal.httpclient.hpack.log.level";
+
+        String value = AccessController.doPrivileged(
+                (PrivilegedAction<String>) () -> System.getProperty(PROPERTY));
+
+        if (value == null) {
+            LOGGER = new RootLogger(NONE);
+        } else {
+            String upperCasedValue = value.toUpperCase();
+            Level l = logLevels.get(upperCasedValue);
+            if (l == null) {
+                LOGGER = new RootLogger(NONE);
+                LOGGER.log(System.Logger.Level.INFO,
+                        () -> format("%s value '%s' not recognized (use %s); logging disabled",
+                                     PROPERTY, value, logLevels.keySet().stream().collect(joining(", "))));
+            } else {
+                LOGGER = new RootLogger(l);
+                LOGGER.log(System.Logger.Level.DEBUG,
+                        () -> format("logging level %s", l));
+            }
+        }
+    }
+
+    public static Logger getLogger() {
+        return LOGGER;
+    }
+
+    private HPACK() { }
+
+    /**
+     * The purpose of this logger is to provide means of diagnosing issues _in
+     * the HPACK implementation_. It's not a general purpose logger.
+     */
+    // implements System.Logger to make it possible to skip this class
+    // when looking for the Caller.
+    public static class Logger implements System.Logger {
+
+        /**
+         * Log detail level.
+         */
+        public enum Level {
+
+            NONE(0, System.Logger.Level.OFF),
+            NORMAL(1, System.Logger.Level.DEBUG),
+            EXTRA(2, System.Logger.Level.TRACE);
+
+            private final int level;
+            final System.Logger.Level systemLevel;
+
+            Level(int i, System.Logger.Level system) {
+                level = i;
+                systemLevel = system;
+            }
+
+            public final boolean implies(Level other) {
+                return this.level >= other.level;
+            }
+        }
+
+        private final String name;
+        private final Level level;
+        private final String path;
+        private final System.Logger logger;
+
+        private Logger(String path, String name, Level level) {
+            this(path, name, level, null);
+        }
+
+        private Logger(String p, String name, Level level, System.Logger logger) {
+            this.path = p;
+            this.name = name;
+            this.level = level;
+            this.logger = Utils.getHpackLogger(path::toString, level.systemLevel);
+        }
+
+        public final String getName() {
+            return name;
+        }
+
+        @Override
+        public boolean isLoggable(System.Logger.Level level) {
+            return logger.isLoggable(level);
+        }
+
+        @Override
+        public void log(System.Logger.Level level, ResourceBundle bundle, String msg, Throwable thrown) {
+            logger.log(level, bundle, msg,thrown);
+        }
+
+        @Override
+        public void log(System.Logger.Level level, ResourceBundle bundle, String format, Object... params) {
+            logger.log(level, bundle, format, params);
+        }
+
+        /*
+         * Usual performance trick for logging, reducing performance overhead in
+         * the case where logging with the specified level is a NOP.
+         */
+
+        public boolean isLoggable(Level level) {
+            return this.level.implies(level);
+        }
+
+        public void log(Level level, Supplier<String> s) {
+            if (this.level.implies(level)) {
+                logger.log(level.systemLevel, s);
+            }
+        }
+
+        public Logger subLogger(String name) {
+            return new Logger(path + "/" + name, name, level);
+        }
+
+    }
+
+    private static final class RootLogger extends Logger {
+
+        protected RootLogger(Level level) {
+            super("hpack", "hpack", level);
+        }
+
+    }
+}