* Replaced TreeMap with custom linked hash map for storing HTTP headers

* Added HttpMessage.getHeaders() and HttpChunkTrailer.getHeaders()

src/main/java/org/jboss/netty/handler/codec/http/DefaultHttpChunkTrailer.java

@@ -15,17 +15,12 @@
  */
 package org.jboss.netty.handler.codec.http;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.TreeMap;
 
 import org.jboss.netty.buffer.ChannelBuffer;
 import org.jboss.netty.buffer.ChannelBuffers;
-import org.jboss.netty.util.internal.CaseIgnoringComparator;
 
 /**
  * The default {@link HttpChunkTrailer} implementation.
@@ -36,95 +31,61 @@ import org.jboss.netty.util.internal.CaseIgnoringComparator;
  */
 public class DefaultHttpChunkTrailer implements HttpChunkTrailer {
 
-    // FIXME Lots of code duplication with DefaultHttpMessage
+    private final HttpHeaders headers = new HttpHeaders() {
-    private final Map<String, List<String>> headers = new TreeMap<String, List<String>>(CaseIgnoringComparator.INSTANCE);
+        @Override
+        void validateHeaderName(String name) {
+            super.validateHeaderName(name);
+            if (name.equalsIgnoreCase(HttpHeaders.Names.CONTENT_LENGTH) ||
+                name.equalsIgnoreCase(HttpHeaders.Names.TRANSFER_ENCODING) ||
+                name.equalsIgnoreCase(HttpHeaders.Names.TRAILER)) {
+                throw new IllegalArgumentException(
+                        "prohibited trailing header: " + name);
+            }
+        }
+    };
 
     public boolean isLast() {
         return true;
     }
 
     public void addHeader(final String name, final String value) {
-        validateHeaderName(name);
+        headers.addHeader(name, value);
-        HttpCodecUtil.validateHeaderValue(value);
-        if (headers.get(name) == null) {
-            headers.put(name, new ArrayList<String>(1));
-        }
-        headers.get(name).add(value);
     }
 
     public void setHeader(final String name, final String value) {
-        validateHeaderName(name);
+        headers.setHeader(name, value);
-        HttpCodecUtil.validateHeaderValue(value);
-        List<String> values = new ArrayList<String>(1);
-        values.add(value);
-        headers.put(name, values);
     }
 
     public void setHeader(final String name, final Iterable<String> values) {
-        validateHeaderName(name);
+        headers.setHeader(name, values);
-        if (values == null) {
-            throw new NullPointerException("values");
-        }
-
-        int nValues = 0;
-        for (String v: values) {
-            HttpCodecUtil.validateHeaderValue(v);
-            nValues ++;
-        }
-
-        if (nValues == 0) {
-            throw new IllegalArgumentException("values is empty.");
-        }
-
-        if (values instanceof List<?>) {
-            headers.put(name, (List<String>) values);
-        } else {
-            List<String> valueList = new LinkedList<String>();
-            for (String v: values) {
-                valueList.add(v);
-            }
-            headers.put(name, valueList);
-        }
-    }
-
-    private static void validateHeaderName(String name) {
-        HttpCodecUtil.validateHeaderName(name);
-        if (name.equalsIgnoreCase(HttpHeaders.Names.CONTENT_LENGTH) ||
-            name.equalsIgnoreCase(HttpHeaders.Names.TRANSFER_ENCODING) ||
-            name.equalsIgnoreCase(HttpHeaders.Names.TRAILER)) {
-            throw new IllegalArgumentException(
-                    "prohibited trailing header: " + name);
-        }
     }
 
     public void removeHeader(final String name) {
-        headers.remove(name);
+        headers.removeHeader(name);
     }
 
     public void clearHeaders() {
-        headers.clear();
+        headers.clearHeaders();
     }
 
     public String getHeader(final String name) {
-        List<String> header = headers.get(name);
+        return headers.getHeader(name);
-        return header != null && header.size() > 0 ? headers.get(name).get(0) : null;
     }
 
     public List<String> getHeaders(final String name) {
-        List<String> values = headers.get(name);
+        return headers.getHeaders(name);
-        if (values == null) {
+    }
-            return Collections.emptyList();
+
-        } else {
+    public List<Map.Entry<String, String>> getHeaders() {
-            return values;
+        return headers.getHeaders();
-        }
     }
 
     public boolean containsHeader(final String name) {
-        return headers.containsKey(name);
+        return headers.containsHeader(name);
     }
 
     public Set<String> getHeaderNames() {
-        return headers.keySet();
+        return headers.getHeaderNames();
     }
 
     public ChannelBuffer getContent() {

src/main/java/org/jboss/netty/handler/codec/http/DefaultHttpMessage.java

@@ -15,17 +15,12 @@
  */
 package org.jboss.netty.handler.codec.http;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.TreeMap;
 
 import org.jboss.netty.buffer.ChannelBuffer;
 import org.jboss.netty.buffer.ChannelBuffers;
-import org.jboss.netty.util.internal.CaseIgnoringComparator;
 
 /**
  * The default {@link HttpMessage} implementation.
@@ -37,7 +32,7 @@ import org.jboss.netty.util.internal.CaseIgnoringComparator;
  */
 public class DefaultHttpMessage implements HttpMessage {
 
-    private final Map<String, List<String>> headers = new TreeMap<String, List<String>>(CaseIgnoringComparator.INSTANCE);
+    private final HttpHeaders headers = new HttpHeaders();
     private HttpVersion version;
     private ChannelBuffer content = ChannelBuffers.EMPTY_BUFFER;
     private boolean chunked;
@@ -50,51 +45,19 @@ public class DefaultHttpMessage implements HttpMessage {
     }
 
     public void addHeader(final String name, final String value) {
-        HttpCodecUtil.validateHeaderName(name);
+        headers.addHeader(name, value);
-        HttpCodecUtil.validateHeaderValue(value);
-        if (headers.get(name) == null) {
-            headers.put(name, new ArrayList<String>(1));
-        }
-        headers.get(name).add(value);
     }
 
     public void setHeader(final String name, final String value) {
-        HttpCodecUtil.validateHeaderName(name);
+        headers.setHeader(name, value);
-        HttpCodecUtil.validateHeaderValue(value);
-        List<String> values = new ArrayList<String>(1);
-        values.add(value);
-        headers.put(name, values);
     }
 
     public void setHeader(final String name, final Iterable<String> values) {
-        HttpCodecUtil.validateHeaderName(name);
+        headers.setHeader(name, values);
-        if (values == null) {
-            throw new NullPointerException("values");
-        }
-
-        int nValues = 0;
-        for (String v: values) {
-            HttpCodecUtil.validateHeaderValue(v);
-            nValues ++;
-        }
-
-        if (nValues == 0) {
-            throw new IllegalArgumentException("values is empty.");
-        }
-
-        if (values instanceof List<?>) {
-            headers.put(name, (List<String>) values);
-        } else {
-            List<String> valueList = new LinkedList<String>();
-            for (String v: values) {
-                valueList.add(v);
-            }
-            headers.put(name, valueList);
-        }
     }
 
     public void removeHeader(final String name) {
-        headers.remove(name);
+        headers.removeHeader(name);
     }
 
     public long getContentLength() {
@@ -102,7 +65,7 @@ public class DefaultHttpMessage implements HttpMessage {
     }
 
     public long getContentLength(long defaultValue) {
-        List<String> contentLength = headers.get(HttpHeaders.Names.CONTENT_LENGTH);
+        List<String> contentLength = getHeaders(HttpHeaders.Names.CONTENT_LENGTH);
         if (contentLength != null && contentLength.size() > 0) {
             return Long.parseLong(contentLength.get(0));
         }
@@ -137,7 +100,7 @@ public class DefaultHttpMessage implements HttpMessage {
     }
 
     public void clearHeaders() {
-        headers.clear();
+        headers.clearHeaders();
     }
 
     public void setContent(ChannelBuffer content) {
@@ -152,25 +115,24 @@ public class DefaultHttpMessage implements HttpMessage {
     }
 
     public String getHeader(final String name) {
-        List<String> header = headers.get(name);
+        List<String> values = getHeaders(name);
-        return header != null && header.size() > 0 ? headers.get(name).get(0) : null;
+        return values.size() > 0 ? values.get(0) : null;
     }
 
     public List<String> getHeaders(final String name) {
-        List<String> values = headers.get(name);
+        return headers.getHeaders(name);
-        if (values == null) {
+    }
-            return Collections.emptyList();
+
-        } else {
+    public List<Map.Entry<String, String>> getHeaders() {
-            return values;
+        return headers.getHeaders();
-        }
     }
 
     public boolean containsHeader(final String name) {
-        return headers.containsKey(name);
+        return headers.containsHeader(name);
     }
 
     public Set<String> getHeaderNames() {
-        return headers.keySet();
+        return headers.getHeaderNames();
     }
 
     public HttpVersion getProtocolVersion() {

src/main/java/org/jboss/netty/handler/codec/http/HttpChunk.java

@@ -17,6 +17,7 @@ package org.jboss.netty.handler.codec.http;
 
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 import org.jboss.netty.buffer.ChannelBuffer;
@@ -79,6 +80,10 @@ public interface HttpChunk {
             return Collections.emptyList();
         }
 
+        public List<Map.Entry<String, String>> getHeaders() {
+            return Collections.emptyList();
+        }
+
         public void removeHeader(String name) {
             // NOOP
         }

src/main/java/org/jboss/netty/handler/codec/http/HttpChunkTrailer.java

@@ -16,6 +16,7 @@
 package org.jboss.netty.handler.codec.http;
 
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 /**
@@ -50,6 +51,14 @@ public interface HttpChunkTrailer extends HttpChunk {
      */
     List<String> getHeaders(String name);
 
+    /**
+     * Returns the all header names and values that this trailer contains.
+     *
+     * @return the {@link List} of the header name-value pairs.  An empty list
+     *         if there is no header in this trailer.
+     */
+    List<Map.Entry<String, String>> getHeaders();
+
     /**
      * Returns {@code true} if and only if there is a trailing header with
      * the specified header name.

src/main/java/org/jboss/netty/handler/codec/http/HttpHeaders.java

@@ -15,6 +15,14 @@
  */
 package org.jboss.netty.handler.codec.http;
 
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.jboss.netty.util.internal.CaseIgnoringComparator;
+
 /**
  * Standard HTTP header names and values.
  *
@@ -24,7 +32,7 @@ package org.jboss.netty.handler.codec.http;
  *
  * @apiviz.stereotype static
  */
-public final class HttpHeaders {
+public class HttpHeaders {
 
     /**
      * Standard HTTP header names.
@@ -384,6 +392,10 @@ public final class HttpHeaders {
          * {@code "trailers"}
          */
         public static final String TRAILERS = "trailers";
+        /**
+         * {@code "Upgrade"}
+         */
+        public static final String UPGRADE = "Upgrade";
         /**
          * {@code "WebSocket"}
          */
@@ -394,7 +406,273 @@ public final class HttpHeaders {
         }
     }
 
-    private HttpHeaders() {
+    private static int hash(String name) {
-        super();
+        int h = 0;
+        for (int i = name.length() - 1; i >= 0; i --) {
+            char c = name.charAt(i);
+            if (c >= 'A' && c <= 'Z') {
+                c += 32;
+            }
+            h = 31 * h + c;
+        }
+
+        if (h > 0) {
+            return h;
+        } else if (h == Integer.MIN_VALUE) {
+            return Integer.MAX_VALUE;
+        } else {
+            return -h;
+        }
+    }
+
+    private static boolean eq(String name1, String name2) {
+        int nameLen = name1.length();
+        if (nameLen != name2.length()) {
+            return false;
+        }
+
+        for (int i = nameLen - 1; i >= 0; i --) {
+            char c1 = name1.charAt(i);
+            char c2 = name2.charAt(i);
+            if (c1 != c2) {
+                if (c1 >= 'A' && c1 <= 'Z') {
+                    c1 += 32;
+                }
+                if (c2 >= 'A' && c2 <= 'Z') {
+                    c2 += 32;
+                }
+                if (c1 != c2) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    private final Entry[] entries = new Entry[17];
+    private final Entry head = new Entry(-1, null, null);
+
+    HttpHeaders() {
+        head.before = head.after = head;
+    }
+
+    private int index(int hash) {
+        return hash % entries.length;
+    }
+
+    void validateHeaderName(String name) {
+        HttpCodecUtil.validateHeaderName(name);
+    }
+
+    void addHeader(final String name, final String value) {
+        validateHeaderName(name);
+        HttpCodecUtil.validateHeaderValue(value);
+        int h = hash(name);
+        int i = index(h);
+        addHeader0(h, i, name, value);
+    }
+
+    private void addHeader0(int h, int i, final String name, final String value) {
+        // Update the hash table.
+        Entry e = entries[i];
+        Entry newEntry;
+        if (e == null) {
+            entries[i] = newEntry = new Entry(h, name, value);
+        } else {
+            entries[i] = newEntry = new Entry(h, name, value);
+            newEntry.next = e;
+        }
+
+        // Update the linked list.
+        newEntry.addBefore(head);
+    }
+
+    void removeHeader(final String name) {
+        int h = hash(name);
+        int i = index(h);
+        removeHeader0(h, i, name);
+    }
+
+    private void removeHeader0(int h, int i, String name) {
+        Entry e = entries[i];
+        if (e == null) {
+            return;
+        }
+
+        for (;;) {
+            if (e.hash == h && eq(name, e.key)) {
+                Entry next = e.next;
+                if (next != null) {
+                    entries[i] = next;
+                    e = next;
+                } else {
+                    entries[i] = null;
+                    return;
+                }
+            } else {
+                break;
+            }
+        }
+
+        for (;;) {
+            Entry next = e.next;
+            if (next == null) {
+                break;
+            }
+            if (next.hash == h && eq(name, next.key)) {
+                e.next = next.next;
+                next.remove();
+            } else {
+                e = next;
+            }
+        }
+    }
+
+    void setHeader(final String name, final String value) {
+        validateHeaderName(name);
+        HttpCodecUtil.validateHeaderValue(value);
+        int h = hash(name);
+        int i = index(h);
+        removeHeader0(h, i, name);
+        addHeader0(h, i, name, value);
+    }
+
+    void setHeader(final String name, final Iterable<String> values) {
+        validateHeaderName(name);
+        if (values == null) {
+            throw new NullPointerException("values");
+        }
+
+        boolean empty = true;
+        for (String v: values) {
+            if (v == null) {
+                break;
+            }
+            HttpCodecUtil.validateHeaderValue(v);
+            empty = false;
+        }
+
+        int h = hash(name);
+        int i = index(h);
+
+        removeHeader0(h, i, name);
+        if (empty) {
+            return;
+        }
+
+        for (String v: values) {
+            if (v == null) {
+                break;
+            }
+            addHeader0(h, i, name, v);
+        }
+    }
+
+    void clearHeaders() {
+        for (int i = 0; i < entries.length; i ++) {
+            entries[i] = null;
+        }
+        head.before = head.after = head;
+    }
+
+    String getHeader(final String name) {
+        int h = hash(name);
+        int i = index(h);
+        Entry e = entries[i];
+        while (e != null) {
+            if (e.hash == h && eq(name, e.key)) {
+                return e.value;
+            }
+
+            e = e.next;
+        }
+        return null;
+    }
+
+    List<String> getHeaders(final String name) {
+        LinkedList<String> values = new LinkedList<String>();
+
+        int h = hash(name);
+        int i = index(h);
+        Entry e = entries[i];
+        while (e != null) {
+            if (e.hash == h && eq(name, e.key)) {
+                values.addFirst(e.value);
+            }
+            e = e.next;
+        }
+        return values;
+    }
+
+    List<Map.Entry<String, String>> getHeaders() {
+        List<Map.Entry<String, String>> all =
+            new LinkedList<Map.Entry<String, String>>();
+
+        Entry e = head.after;
+        while (e != head) {
+            all.add(e);
+            e = e.after;
+        }
+        return all;
+    }
+
+    boolean containsHeader(String name) {
+        return getHeader(name) != null;
+    }
+
+    Set<String> getHeaderNames() {
+        Set<String> names =
+            new TreeSet<String>(CaseIgnoringComparator.INSTANCE);
+
+        Entry e = head.after;
+        while (e != head) {
+            names.add(e.key);
+            e = e.after;
+        }
+        return names;
+    }
+
+    private static final class Entry implements Map.Entry<String, String> {
+        final int hash;
+        final String key;
+        String value;
+        Entry next;
+        Entry before, after;
+
+        Entry(int hash, String key, String value) {
+            this.hash = hash;
+            this.key = key;
+            this.value = value;
+        }
+
+        void remove() {
+            before.after = after;
+            after.before = before;
+        }
+
+        void addBefore(Entry e) {
+            after  = e;
+            before = e.before;
+            before.after = this;
+            after.before = this;
+        }
+
+        public String getKey() {
+            return key;
+        }
+
+        public String getValue() {
+            return value;
+        }
+
+        public String setValue(String value) {
+            if (value == null) {
+                throw new NullPointerException("value");
+            }
+            HttpCodecUtil.validateHeaderValue(value);
+            String oldValue = this.value;
+            this.value = value;
+            return oldValue;
+        }
     }
 }

src/main/java/org/jboss/netty/handler/codec/http/HttpMessage.java

@@ -16,6 +16,7 @@
 package org.jboss.netty.handler.codec.http;
 
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 import org.jboss.netty.buffer.ChannelBuffer;
@@ -55,6 +56,14 @@ public interface HttpMessage {
      */
     List<String> getHeaders(String name);
 
+    /**
+     * Returns the all header names and values that this message contains.
+     *
+     * @return the {@link List} of the header name-value pairs.  An empty list
+     *         if there is no header in this message.
+     */
+    List<Map.Entry<String, String>> getHeaders();
+
     /**
      * Returns {@code true} if and only if there is a header with the specified
      * header name.

src/main/java/org/jboss/netty/handler/codec/http/HttpMessageEncoder.java

@@ -19,8 +19,7 @@ import static org.jboss.netty.buffer.ChannelBuffers.*;
 import static org.jboss.netty.handler.codec.http.HttpCodecUtil.*;
 
 import java.io.UnsupportedEncodingException;
-import java.util.List;
+import java.util.Map;
-import java.util.Set;
 
 import org.jboss.netty.buffer.ChannelBuffer;
 import org.jboss.netty.buffer.ChannelBuffers;
@@ -131,13 +130,9 @@ public abstract class HttpMessageEncoder extends OneToOneEncoder {
     }
 
     private void encodeHeaders(ChannelBuffer buf, HttpMessage message) {
-        Set<String> headers = message.getHeaderNames();
         try {
-            for (String header : headers) {
+            for (Map.Entry<String, String> h: message.getHeaders()) {
-                List<String> values = message.getHeaders(header);
+                encodeHeader(buf, h.getKey(), h.getValue());
-                for (String value : values) {
-                    encodeHeader(buf, header, value);
-                }
             }
         } catch (UnsupportedEncodingException e) {
             throw (Error) new Error().initCause(e);
@@ -145,13 +140,9 @@ public abstract class HttpMessageEncoder extends OneToOneEncoder {
     }
 
     private void encodeTrailingHeaders(ChannelBuffer buf, HttpChunkTrailer trailer) {
-        Set<String> headers = trailer.getHeaderNames();
         try {
-            for (String header : headers) {
+            for (Map.Entry<String, String> h: trailer.getHeaders()) {
-                List<String> values = trailer.getHeaders(header);
+                encodeHeader(buf, h.getKey(), h.getValue());
-                for (String value : values) {
-                    encodeHeader(buf, header, value);
-                }
             }
         } catch (UnsupportedEncodingException e) {
             throw (Error) new Error().initCause(e);