Consolidate parsing and formatting for label votes

We currently support two styles of parsing, Label-Value and
Label=Value. Consolidate these into a single LabelVote class.
(Unfortunately for backwards-compatibility reasons we can't just
eliminate Label=Value in ReviewCommand.)

Change-Id: I9e5255b184d786226e6b11fe059001608c00673d

gerrit-server/src/main/java/com/google/gerrit/server/change/PostReview.java

@@ -49,6 +49,7 @@ import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.account.AccountsCollection;
 import com.google.gerrit.server.index.ChangeIndexer;
 import com.google.gerrit.server.project.ChangeControl;
+import com.google.gerrit.server.util.LabelVote;
 import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
@@ -387,7 +388,7 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
         // User requested delete of this label.
         if (c != null) {
           if (c.getValue() != 0) {
-            labelDelta.add("-" + normName);
+            addLabelDelta(normName, (short) 0);
           }
           del.add(c);
         }
@@ -395,7 +396,7 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
         c.setValue(ent.getValue());
         c.setGranted(timestamp);
         upd.add(c);
-        labelDelta.add(format(normName, c.getValue()));
+        addLabelDelta(normName, c.getValue());
         categories.put(normName, c.getValue());
       } else if (c != null && c.getValue() == ent.getValue()) {
         current.put(normName, c);
@@ -407,7 +408,7 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
             ent.getValue(), TimeUtil.nowTs());
         c.setGranted(timestamp);
         ins.add(c);
-        labelDelta.add(format(normName, c.getValue()));
+        addLabelDelta(normName, c.getValue());
         categories.put(normName, c.getValue());
       }
     }
@@ -467,14 +468,8 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
     return current;
   }
 
-  private static String format(String name, short value) {
-    StringBuilder sb = new StringBuilder(name.length() + 2);
-    sb.append(name);
-    if (value >= 0) {
-      sb.append('+');
-    }
-    sb.append(value);
-    return sb.toString();
+  private void addLabelDelta(String name, short value) {
+    labelDelta.add(new LabelVote(name, value).format());
   }
 
   private boolean insertMessage(RevisionResource rsrc, String msg)

gerrit-server/src/main/java/com/google/gerrit/server/query/change/LabelPredicate.java

@@ -23,6 +23,7 @@ import com.google.gerrit.server.project.ChangeControl;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.query.OrPredicate;
 import com.google.gerrit.server.query.Predicate;
+import com.google.gerrit.server.util.LabelVote;
 import com.google.inject.Provider;
 
 import java.util.List;
@@ -75,25 +76,39 @@ public class LabelPredicate extends OrPredicate<ChangeData> {
       ProjectCache projectCache, ChangeControl.GenericFactory ccFactory,
       IdentifiedUser.GenericFactory userFactory, Provider<ReviewDb> dbProvider,
       String value, Set<Account.Id> accounts, AccountGroup.UUID group) {
-    String label;
-    Test test;
-    int expVal;
-    Matcher m1 = Pattern.compile("(=|>=|<=)([+-]?\\d+)$").matcher(value);
-    Matcher m2 = Pattern.compile("([+-]\\d+)$").matcher(value);
-    if (m1.find()) {
-      label = value.substring(0, m1.start());
-      test = Test.op(m1.group(1));
-      expVal = value(m1.group(2));
+    String label = null;
+    Test test = null;
+    int expVal = 0;
 
-    } else if (m2.find()) {
-      label = value.substring(0, m2.start());
+    try {
+      LabelVote v = LabelVote.parse(value);
       test = Test.EQ;
-      expVal = value(m2.group(1));
+      label = v.getLabel();
+      expVal = v.getValue();
+    } catch (IllegalArgumentException e) {
+      // Try next format.
+    }
 
-    } else {
-      label = value;
+    try {
+      LabelVote v = LabelVote.parseWithEquals(value);
       test = Test.EQ;
-      expVal = 1;
+      label = v.getLabel();
+      expVal = v.getValue();
+    } catch (IllegalArgumentException e) {
+      // Try next format.
+    }
+
+    if (label == null) {
+      Matcher m = Pattern.compile("(>=|<=)([+-]?\\d+)$").matcher(value);
+      if (m.find()) {
+        label = value.substring(0, m.start());
+        test = Test.op(m.group(1));
+        expVal = value(m.group(2));
+      } else {
+        label = value;
+        test = Test.EQ;
+        expVal = 1;
+      }
     }
 
     List<Predicate<ChangeData>> r = Lists.newArrayListWithCapacity(2 * MAX_LABEL_VALUE);

gerrit-server/src/main/java/com/google/gerrit/server/util/LabelVote.java

@@ -0,0 +1,109 @@
+// 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.util;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.base.Objects;
+import com.google.common.base.Strings;
+import com.google.gerrit.common.data.LabelType;
+
+/** A single vote on a label, consisting of a label name and a value. */
+public class LabelVote {
+  public static LabelVote parse(String text) {
+    checkArgument(!Strings.isNullOrEmpty(text), "Empty label vote");
+    if (text.charAt(0) == '-') {
+      return new LabelVote(text.substring(1), (short) 0);
+    }
+    short sign = 0;
+    int i;
+    for (i = text.length() - 1; i >= 0; i--) {
+      int c = text.charAt(i);
+      if (c == '-') {
+        sign = (short) -1;
+        break;
+      } else if (c == '+') {
+        sign = (short) 1;
+        break;
+      } else if (!('0' <= c && c <= '9')) {
+        break;
+      }
+    }
+    if (sign == 0) {
+      return new LabelVote(text, (short) 1);
+    }
+    return new LabelVote(text.substring(0, i),
+        (short)(sign * Short.parseShort(text.substring(i + 1))));
+  }
+
+  public static LabelVote parseWithEquals(String text) {
+    checkArgument(!Strings.isNullOrEmpty(text), "Empty label vote");
+    int e = text.lastIndexOf('=');
+    checkArgument(e >= 0, "Label vote missing '=': %s", text);
+    return new LabelVote(text.substring(0, e),
+        Short.parseShort(text.substring(e + 1), text.length()));
+  }
+
+  private final String name;
+  private final short value;
+
+  public LabelVote(String name, short value) {
+    this.name = LabelType.checkName(name);
+    this.value = value;
+  }
+
+  public String getLabel() {
+    return name;
+  }
+
+  public short getValue() {
+    return value;
+  }
+
+  public String format() {
+    if (value == (short) 0) {
+      return '-' + name;
+    } else if (value == (short) 1) {
+      return name;
+    } else if (value < 0) {
+      return name + value;
+    } else {
+      return name + '+' + value;
+    }
+  }
+
+  public String formatWithEquals() {
+    if (value <= (short) 0) {
+      return name + '=' + value;
+    } else {
+      return name + "=+" + value;
+    }
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (o instanceof LabelVote) {
+      LabelVote l = (LabelVote) o;
+      return Objects.equal(name, l.name)
+          && value == l.value;
+    }
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    return format();
+  }
+}