Merge pull request #8806 from vespa-engine/smorgrav/path_with_prefix

Add support for an optional prefix to path matching

3 files changed, 47 insertions, 16 deletions

diff --git a/container-core/abi-spec.json b/container-core/abi-spec.json
index d20d5643647..b21a496cd01 100644
--- a/container-core/abi-spec.json
+++ b/container-core/abi-spec.json
@@ -862,6 +862,7 @@
     ],
     "methods": [
       "public void <init>(java.lang.String)",
+      "public void <init>(java.lang.String, java.lang.String)",
       "public boolean matches(java.lang.String)",
       "public java.lang.String get(java.lang.String)",
       "public java.lang.String getRest()",
diff --git a/container-core/src/main/java/com/yahoo/restapi/Path.java b/container-core/src/main/java/com/yahoo/restapi/Path.java
index 7f78572f2d7..3aa23fbc916 100644
--- a/container-core/src/main/java/com/yahoo/restapi/Path.java
+++ b/container-core/src/main/java/com/yahoo/restapi/Path.java
@@ -21,37 +21,36 @@ import java.util.stream.Collectors;
  * 
  * Note that for convenience in common use this has state which changes as a side effect of each matches
  * invocation. It is therefore for single thread use.
- * 
+ *
+ * A optional prefix can be used to match the path spec against an alternative path. This
+ * is used when you have alternative paths mapped to the same resource.
+ *
  * @author bratseth
  */
 public class Path {
 
     // This path
     private final String pathString;
+    private final String optionalPrefix;
     private final String[] elements;
 
     // Info about the last match
     private final Map<String, String> values = new HashMap<>();
     private String rest = "";
-    
+
     public Path(String path) {
+        this.optionalPrefix = "";
         this.pathString = path;
         this.elements = path.split("/");
     }
 
-    /**
-     * Parses the path according to pathSpec - must be called prior to {@link #get}
-     *
-     * Returns whether this path matches the given template string.
-     * If the given template has placeholders, their values (accessible by get) are reset by calling this,
-     * whether or not the path matches the given template.
-     *
-     * This will NOT match empty path elements.
-     *
-     * @param pathSpec the path string to match to this
-     * @return true if the string matches, false otherwise
-     */
-    public boolean matches(String pathSpec) {
+    public Path(String path, String optionalPrefix) {
+        this.optionalPrefix = optionalPrefix;
+        this.pathString = path;
+        this.elements = path.split("/");
+    }
+
+    private boolean matches_inner(String pathSpec) {
         values.clear();
         String[] specElements = pathSpec.split("/");
         boolean matchPrefix = false;
@@ -87,6 +86,24 @@ public class Path {
     }
 
     /**
+     * Parses the path according to pathSpec - must be called prior to {@link #get}
+     *
+     * Returns whether this path matches the given template string.
+     * If the given template has placeholders, their values (accessible by get) are reset by calling this,
+     * whether or not the path matches the given template.
+     *
+     * This will NOT match empty path elements.
+     *
+     * @param pathSpec the path string to match to this
+     * @return true if the string matches, false otherwise
+     */
+    public boolean matches(String pathSpec) {
+        if (matches_inner(pathSpec)) return true;
+        if (optionalPrefix.isEmpty()) return false;
+        return  matches_inner(optionalPrefix + pathSpec);
+    }
+
+    /**
      * Returns the value of the given template variable in the last path matched, or null 
      * if the previous matches call returned false or if this has not matched anything yet.
      */
diff --git a/container-core/src/test/java/com/yahoo/restapi/PathTest.java b/container-core/src/test/java/com/yahoo/restapi/PathTest.java
index 9e77dc7b3f0..886b3ba9c87 100644
--- a/container-core/src/test/java/com/yahoo/restapi/PathTest.java
+++ b/container-core/src/test/java/com/yahoo/restapi/PathTest.java
@@ -11,7 +11,20 @@ import static org.junit.Assert.assertEquals;
  * @author bratseth
  */
 public class PathTest {
-    
+
+    @Test
+    public void testWithPrefix() {
+        // Test that a path with a prefix matches spec without the prefix
+        Path path = new Path("/ball/a/1/bar/fuz", "/ball");
+        assertTrue(path.matches("/a/{foo}/bar/{b}"));
+        assertEquals("1", path.get("foo"));
+        assertEquals("fuz", path.get("b"));
+
+        // Also test that prefix does not cause false matches
+        assertFalse(path.matches("/ball/a/{foo}/zoo/{b}"));
+    }
+
+
     @Test
     public void testPath() {
         assertFalse(new Path("").matches("/a/{foo}/bar/{b}"));