Dissolve gerrit-server top-level directory

Change-Id: I538512dfe0f1bea774c01fdd45fa410a45634011

java/com/google/gerrit/server/project/RefPatternMatcher.java

@@ -0,0 +1,172 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.project;
+
+import static com.google.gerrit.server.project.RefPattern.isRE;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterables;
+import com.google.gerrit.common.data.ParameterizedString;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.RefNames;
+import com.google.gerrit.server.CurrentUser;
+import dk.brics.automaton.Automaton;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.regex.Pattern;
+
+public abstract class RefPatternMatcher {
+  public static RefPatternMatcher getMatcher(String pattern) {
+    if (pattern.contains("${")) {
+      return new ExpandParameters(pattern);
+    } else if (isRE(pattern)) {
+      return new Regexp(pattern);
+    } else if (pattern.endsWith("/*")) {
+      return new Prefix(pattern.substring(0, pattern.length() - 1));
+    } else {
+      return new Exact(pattern);
+    }
+  }
+
+  public abstract boolean match(String ref, CurrentUser user);
+
+  private static class Exact extends RefPatternMatcher {
+    private final String expect;
+
+    Exact(String name) {
+      expect = name;
+    }
+
+    @Override
+    public boolean match(String ref, CurrentUser user) {
+      return expect.equals(ref);
+    }
+  }
+
+  private static class Prefix extends RefPatternMatcher {
+    private final String prefix;
+
+    Prefix(String pfx) {
+      prefix = pfx;
+    }
+
+    @Override
+    public boolean match(String ref, CurrentUser user) {
+      return ref.startsWith(prefix);
+    }
+  }
+
+  private static class Regexp extends RefPatternMatcher {
+    private final Pattern pattern;
+
+    Regexp(String re) {
+      pattern = Pattern.compile(re);
+    }
+
+    @Override
+    public boolean match(String ref, CurrentUser user) {
+      return pattern.matcher(ref).matches();
+    }
+  }
+
+  static class ExpandParameters extends RefPatternMatcher {
+    private final ParameterizedString template;
+    private final String prefix;
+
+    ExpandParameters(String pattern) {
+      template = new ParameterizedString(pattern);
+
+      if (isRE(pattern)) {
+        // Replace ${username} and ${shardeduserid} with ":PLACEHOLDER:"
+        // as : is not legal in a reference and the string :PLACEHOLDER:
+        // is not likely to be a valid part of the regex. This later
+        // allows the pattern prefix to be clipped, saving time on
+        // evaluation.
+        String replacement = ":PLACEHOLDER:";
+        Map<String, String> params =
+            ImmutableMap.of(
+                RefPattern.USERID_SHARDED, replacement,
+                RefPattern.USERNAME, replacement);
+        Automaton am = RefPattern.toRegExp(template.replace(params)).toAutomaton();
+        String rePrefix = am.getCommonPrefix();
+        prefix = rePrefix.substring(0, rePrefix.indexOf(replacement));
+      } else {
+        prefix = pattern.substring(0, pattern.indexOf("${"));
+      }
+    }
+
+    @Override
+    public boolean match(String ref, CurrentUser user) {
+      if (!ref.startsWith(prefix)) {
+        return false;
+      }
+
+      for (String username : getUsernames(user)) {
+        String u;
+        if (isRE(template.getPattern())) {
+          u = Pattern.quote(username);
+        } else {
+          u = username;
+        }
+
+        Account.Id accountId = user.isIdentifiedUser() ? user.getAccountId() : null;
+        RefPatternMatcher next = getMatcher(expand(template, u, accountId));
+        if (next != null && next.match(expand(ref, u, accountId), user)) {
+          return true;
+        }
+      }
+      return false;
+    }
+
+    private Iterable<String> getUsernames(CurrentUser user) {
+      if (user.isIdentifiedUser()) {
+        Set<String> emails = user.asIdentifiedUser().getEmailAddresses();
+        if (user.getUserName() == null) {
+          return emails;
+        } else if (emails.isEmpty()) {
+          return ImmutableSet.of(user.getUserName());
+        }
+        return Iterables.concat(emails, ImmutableSet.of(user.getUserName()));
+      }
+      if (user.getUserName() != null) {
+        return ImmutableSet.of(user.getUserName());
+      }
+      return ImmutableSet.of();
+    }
+
+    boolean matchPrefix(String ref) {
+      return ref.startsWith(prefix);
+    }
+
+    private String expand(String parameterizedRef, String userName, Account.Id accountId) {
+      if (parameterizedRef.contains("${")) {
+        return expand(new ParameterizedString(parameterizedRef), userName, accountId);
+      }
+      return parameterizedRef;
+    }
+
+    private String expand(
+        ParameterizedString parameterizedRef, String userName, Account.Id accountId) {
+      Map<String, String> params = new HashMap<>();
+      params.put(RefPattern.USERNAME, userName);
+      if (accountId != null) {
+        params.put(RefPattern.USERID_SHARDED, RefNames.shard(accountId.get()));
+      }
+      return parameterizedRef.replace(params);
+    }
+  }
+}