Bug 951 - Externalize cors definition of restconf

[controller.git] / opendaylight / commons / filter-valve / src / main / java / org / opendaylight / controller / filtervalve / cors / model / UrlMatcher.java

diff --git a/opendaylight/commons/filter-valve/src/main/java/org/opendaylight/controller/filtervalve/cors/model/UrlMatcher.java b/opendaylight/commons/filter-valve/src/main/java/org/opendaylight/controller/filtervalve/cors/model/UrlMatcher.java
new file mode 100644 (file)
index 0000000..9535fb1
--- /dev/null
+++ b/opendaylight/commons/filter-valve/src/main/java/org/opendaylight/controller/filtervalve/cors/model/UrlMatcher.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.opendaylight.controller.filtervalve.cors.model;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.collect.Maps.immutableEntry;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.TreeMap;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Match incoming URL with user defined patterns according to servlet specification.
+ * In the Web application deployment descriptor, the following syntax is used to define mappings:
+ * <ul>
+ * <li>A string beginning with a ‘/’ character and ending with a ‘/*’ suffix is used for path mapping.</li>
+ * <li>A string beginning with a ‘*.’ prefix is used as an extension mapping.</li>
+ * <li>All other strings are used for exact matches only.</li>
+ * </ul>
+ */
+public class UrlMatcher<FILTER> {
+    private static final Logger logger = LoggerFactory.getLogger(UrlMatcher.class);
+    // order index for each FILTER is kept as Entry.value
+    private final Map<String, Entry<FILTER, Integer>> prefixMap = new HashMap<>(); // contains patterns ending with '/*', '*' is stripped from each key
+    private final Map<String, Entry<FILTER, Integer>> suffixMap = new HashMap<>(); // contains patterns starting with '*.' prefix, '*' is stripped from each key
+    private final Map<String, Entry<FILTER, Integer>> exactMatchMap = new HashMap<>(); // contains exact matches only
+
+    /**
+     * @param patternMap order preserving map containing path info pattern as key
+     */
+    public UrlMatcher(LinkedHashMap<String, FILTER> patternMap) {
+        int idx = 0;
+        for (Entry<String, FILTER> entry : patternMap.entrySet()) {
+            idx++;
+            String pattern = checkNotNull(entry.getKey());
+            FILTER value = entry.getValue();
+            Entry<FILTER, Integer> valueWithIdx = immutableEntry(value, idx);
+            if (pattern.startsWith("/") && pattern.endsWith("/*")) {
+                pattern = pattern.substring(0, pattern.length() - 1);
+                prefixMap.put(pattern, valueWithIdx);
+            } else if (pattern.startsWith("*.")) {
+                pattern = pattern.substring(1);
+                suffixMap.put(pattern, valueWithIdx);
+            } else {
+                exactMatchMap.put(pattern, valueWithIdx);
+            }
+        }
+    }
+
+    /**
+     * Find filters matching path
+     *
+     * @param pathInfo as returned by request.getPathInfo()
+     * @return list of matching filters
+     */
+    public List<FILTER> findMatchingFilters(String pathInfo) {
+        checkNotNull(pathInfo);
+        TreeMap<Integer, FILTER> sortedMap = new TreeMap<>();
+        // add matching prefixes
+        for (Entry<String, Entry<FILTER, Integer>> prefixEntry : prefixMap.entrySet()) {
+            if (pathInfo.startsWith(prefixEntry.getKey())) {
+                put(sortedMap, prefixEntry.getValue());
+            }
+        }
+        // add matching suffixes
+        for (Entry<String, Entry<FILTER, Integer>> suffixEntry : suffixMap.entrySet()) {
+            if (pathInfo.endsWith(suffixEntry.getKey())) {
+                put(sortedMap, suffixEntry.getValue());
+            }
+        }
+        // add exact match
+        Entry<FILTER, Integer> exactMatch = exactMatchMap.get(pathInfo);
+        if (exactMatch != null) {
+            put(sortedMap, exactMatch);
+        }
+        ArrayList<FILTER> filters = new ArrayList<>(sortedMap.values());
+        logger.trace("Matching filters for path {} are {}", pathInfo, filters);
+        return filters;
+    }
+
+    private void put(TreeMap<Integer, FILTER> sortedMap, Entry<FILTER, Integer> entry) {
+        sortedMap.put(entry.getValue(), entry.getKey());
+    }
+}