Added QueryStringDecoder.rawPath() and rawQuery()

Motivation:

Before this commit, it is impossible to access the path component of the
URI before it has been decoded.  This makes it impossible to distinguish
between the following URIs:

/user/title?key=value
/user%2Ftitle?key=value

The user could already access the raw uri value, but they had to calculate
pathEndIdx themselves, even though it might already be cached inside
QueryStringDecoder.

Result:

The user can easily and efficiently access the undecoded path and query.

codec-http/src/main/java/io/netty/handler/codec/http/QueryStringDecoder.java

@@ -182,6 +182,21 @@ public class QueryStringDecoder {
         return params;
     }
 
+    /**
+     * Returns the raw path string of the URI.
+     */
+    public String rawPath() {
+        return uri.substring(0, pathEndIdx());
+    }
+
+    /**
+     * Returns raw query string of the URI.
+     */
+    public String rawQuery() {
+        int start = pathEndIdx() + 1;
+        return start < uri.length() ? uri.substring(start) : EMPTY_STRING;
+    }
+
     private int pathEndIdx() {
         if (pathEndIdx == -1) {
             pathEndIdx = findPathEndIndex(uri);

codec-http/src/test/java/io/netty/handler/codec/http/QueryStringDecoderTest.java

@@ -237,6 +237,8 @@ public class QueryStringDecoderTest {
         URI uri = URI.create("http://localhost:8080/foo?param1=value1&param2=value2&param3=value3");
         QueryStringDecoder decoder = new QueryStringDecoder(uri);
         Assert.assertEquals("/foo", decoder.path());
+        Assert.assertEquals("/foo", decoder.rawPath());
+        Assert.assertEquals("param1=value1&param2=value2&param3=value3", decoder.rawQuery());
         Map<String, List<String>> params =  decoder.parameters();
         Assert.assertEquals(3, params.size());
         Iterator<Entry<String, List<String>>> entries = params.entrySet().iterator();
@@ -265,6 +267,9 @@ public class QueryStringDecoderTest {
         URI uri = URI.create("http://localhost:8080/?param1=value1&param2=value2&param3=value3");
         QueryStringDecoder decoder = new QueryStringDecoder(uri);
         Assert.assertEquals("/", decoder.path());
+        Assert.assertEquals("/", decoder.rawPath());
+        Assert.assertEquals("param1=value1&param2=value2&param3=value3", decoder.rawQuery());
+
         Map<String, List<String>> params =  decoder.parameters();
         Assert.assertEquals(3, params.size());
         Iterator<Entry<String, List<String>>> entries = params.entrySet().iterator();
@@ -293,6 +298,9 @@ public class QueryStringDecoderTest {
         URI uri = URI.create("http://localhost:8080?param1=value1&param2=value2&param3=value3");
         QueryStringDecoder decoder = new QueryStringDecoder(uri);
         Assert.assertEquals("", decoder.path());
+        Assert.assertEquals("", decoder.rawPath());
+        Assert.assertEquals("param1=value1&param2=value2&param3=value3", decoder.rawQuery());
+
         Map<String, List<String>> params =  decoder.parameters();
         Assert.assertEquals(3, params.size());
         Iterator<Entry<String, List<String>>> entries = params.entrySet().iterator();
@@ -321,6 +329,9 @@ public class QueryStringDecoderTest {
         URI uri = URI.create("http://foo.com/images;num=10?query=name;value=123");
         QueryStringDecoder decoder = new QueryStringDecoder(uri);
         Assert.assertEquals("/images;num=10", decoder.path());
+        Assert.assertEquals("/images;num=10", decoder.rawPath());
+        Assert.assertEquals("query=name;value=123", decoder.rawQuery());
+
         Map<String, List<String>> params =  decoder.parameters();
         Assert.assertEquals(2, params.size());
         Iterator<Entry<String, List<String>>> entries = params.entrySet().iterator();
@@ -337,4 +348,17 @@ public class QueryStringDecoderTest {
 
         Assert.assertFalse(entries.hasNext());
     }
+
+    @Test
+    public void testEmptyStrings() {
+        QueryStringDecoder pathSlash = new QueryStringDecoder("path/");
+        Assert.assertEquals("path/", pathSlash.rawPath());
+        Assert.assertEquals("", pathSlash.rawQuery());
+        QueryStringDecoder pathQuestion = new QueryStringDecoder("path?");
+        Assert.assertEquals("path", pathQuestion.rawPath());
+        Assert.assertEquals("", pathQuestion.rawQuery());
+        QueryStringDecoder empty = new QueryStringDecoder("");
+        Assert.assertEquals("", empty.rawPath());
+        Assert.assertEquals("", empty.rawQuery());
+    }
 }