Allow setting label types in project.config

Project owners can add a label.Label-Name section with keys
corresponding to the existing columns in the ApprovalCategory table:

[label "My-Label"]
  id = MLBL
  abbreviation = L
  function = MaxNoBlock
  copyMinScore = true
  value = -1 Negative label value
  value =  0 Neutral label value
  value = +1 Positive label value.

Providing a label in a child project overrides all configuration and
values for that label in parent projects or in the global DB. Labels
with no values are treated as nonexistent. Thus child projects can
disable labels defined in parent projects by adding an empty section for
that label in the child project.config.

Labels are ordered in the order they appear walking from parent to child
projects, with labels in the database ordered first. Overriding a
label's configuration does not change its ordering.

Adding a label does not imply adding any permissions, so initially new
labels will not be votable. Once a label is added, it will show up in
permission dropdowns in the project access editor, so owners can add
permissions through the web UI.

This applies equally to labels produced dynamically from Prolog rules:
to make such labels votable, a project owner needs to define label
values and permissions for those labels. Since the owner will be editing
rules.pl in refs/meta/config anyway, it should be convenient enough to
also modify project.config in the same commit.

Change-Id: I94d041236d53b1fdcd45a19806df1fb605588ff2

gerrit-server/src/main/java/com/google/gerrit/server/git/ProjectConfig.java

@@ -16,13 +16,20 @@ package com.google.gerrit.server.git;
 
 import static com.google.gerrit.common.data.Permission.isPermission;
 
+import com.google.common.base.CharMatcher;
+import com.google.common.base.Objects;
+import com.google.common.base.Splitter;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
+import com.google.common.primitives.Shorts;
 import com.google.gerrit.common.data.AccessSection;
 import com.google.gerrit.common.data.ContributorAgreement;
 import com.google.gerrit.common.data.GlobalCapability;
 import com.google.gerrit.common.data.GroupDescription;
 import com.google.gerrit.common.data.GroupReference;
+import com.google.gerrit.common.data.LabelType;
+import com.google.gerrit.common.data.LabelValue;
 import com.google.gerrit.common.data.Permission;
 import com.google.gerrit.common.data.PermissionRule;
 import com.google.gerrit.common.data.PermissionRule.Action;
@@ -35,6 +42,7 @@ import com.google.gerrit.reviewdb.client.Project.SubmitType;
 import com.google.gerrit.server.account.GroupBackend;
 import com.google.gerrit.server.config.ConfigUtil;
 import com.google.gerrit.server.mail.Address;
+import com.google.gerrit.server.workflow.CategoryFunction;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.CommitBuilder;
@@ -98,6 +106,13 @@ public class ProjectConfig extends VersionedMetaData {
   private static final String KEY_DEFAULT = "default";
   private static final String KEY_LOCAL_DEFAULT = "local-default";
 
+  private static final String LABEL = "label";
+  private static final String KEY_ID = "id";
+  private static final String KEY_ABBREVIATION = "abbreviation";
+  private static final String KEY_FUNCTION = "function";
+  private static final String KEY_COPY_MIN_SCORE = "copyMinScore";
+  private static final String KEY_VALUE = "value";
+
   private static final SubmitType defaultSubmitAction =
       SubmitType.MERGE_IF_NECESSARY;
   private static final State defaultStateValue =
@@ -110,6 +125,7 @@ public class ProjectConfig extends VersionedMetaData {
   private Map<String, AccessSection> accessSections;
   private Map<String, ContributorAgreement> contributorAgreements;
   private Map<String, NotifyConfig> notifySections;
+  private Map<String, LabelType> labelSections;
   private List<ValidationError> validationErrors;
   private ObjectId rulesId;
 
@@ -208,6 +224,10 @@ public class ProjectConfig extends VersionedMetaData {
     return notifySections.values();
   }
 
+  public Collection<LabelType> getLabelSections() {
+    return labelSections.values();
+  }
+
   public GroupReference resolve(AccountGroup group) {
     return resolve(GroupReference.forGroup(group));
   }
@@ -307,6 +327,7 @@ public class ProjectConfig extends VersionedMetaData {
     loadContributorAgreements(rc, groupsByName);
     loadAccessSections(rc, groupsByName);
     loadNotifySections(rc, groupsByName);
+    loadLabelSections(rc);
   }
 
   private void loadAccountsSection(
@@ -496,6 +517,68 @@ public class ProjectConfig extends VersionedMetaData {
     }
   }
 
+  private static LabelValue parseLabelValue(String src) {
+    List<String> parts = ImmutableList.copyOf(
+        Splitter.on(CharMatcher.WHITESPACE).omitEmptyStrings().limit(2)
+        .split(src));
+    if (parts.isEmpty()) {
+      throw new IllegalArgumentException("empty value");
+    }
+    return new LabelValue(
+        Shorts.checkedCast(PermissionRule.parseInt(parts.get(0))),
+        parts.get(1));
+  }
+
+  private void loadLabelSections(Config rc) throws IOException {
+    labelSections = Maps.newLinkedHashMap();
+    for (String name : rc.getSubsections(LABEL)) {
+      List<LabelValue> values = Lists.newArrayList();
+      for (String value : rc.getStringList(LABEL, name, KEY_VALUE)) {
+        try {
+          values.add(parseLabelValue(value));
+        } catch (IllegalArgumentException notValue) {
+          error(new ValidationError(PROJECT_CONFIG, String.format(
+              "Invalid %s \"%s\" for label \"%s\": %s",
+              KEY_VALUE, value, name, notValue.getMessage())));
+        }
+      }
+
+      LabelType label;
+      String id = rc.getString(LABEL, name, KEY_ID);
+      if (id == null || id.length() > 4) {
+        error(new ValidationError(PROJECT_CONFIG, String.format(
+            "Invalid label ID \"%s\" for label \"%s\": "
+           + "Label ID may have at most 4 characters", id, name)));
+        continue;
+      }
+      try {
+        label = new LabelType(id, name, values);
+      } catch (IllegalArgumentException badName) {
+        error(new ValidationError(PROJECT_CONFIG, String.format(
+            "Invalid label \"%s\"", name)));
+        continue;
+      }
+
+      String abbr = rc.getString(LABEL, name, KEY_ABBREVIATION);
+      if (abbr != null) {
+        label.setAbbreviatedName(abbr);
+      }
+
+      String functionName = Objects.firstNonNull(
+          rc.getString(LABEL, name, KEY_FUNCTION), "MaxWithBlock");
+      if (CategoryFunction.forName(functionName) != null) {
+        label.setFunctionName(functionName);
+      } else {
+        error(new ValidationError(PROJECT_CONFIG, String.format(
+            "Invalid %s for label \"%s\"", KEY_FUNCTION, name)));
+        label.setFunctionName(null);
+      }
+      label.setCopyMinScore(
+          rc.getBoolean(LABEL, name, KEY_COPY_MIN_SCORE, false));
+      labelSections.put(name, label);
+    }
+  }
+
   private Map<String, GroupReference> readGroupList() throws IOException {
     groupsByUUID = new HashMap<AccountGroup.UUID, GroupReference>();
     Map<String, GroupReference> groupsByName =

gerrit-server/src/main/java/com/google/gerrit/server/project/ProjectControl.java

@@ -122,10 +122,10 @@ public class ProjectControl {
 
   private List<SectionMatcher> allSections;
   private List<SectionMatcher> localSections;
+  private LabelTypes labelTypes;
   private Map<String, RefControl> refControls;
   private Boolean declaredOwner;
 
-
   @Inject
   ProjectControl(@GitUploadPackGroups Set<AccountGroup.UUID> uploadGroups,
       @GitReceivePackGroups Set<AccountGroup.UUID> receiveGroups,
@@ -183,7 +183,10 @@ public class ProjectControl {
   }
 
   public LabelTypes getLabelTypes() {
-    return state.getLabelTypes();
+    if (labelTypes == null) {
+      labelTypes = state.getLabelTypes();
+    }
+    return labelTypes;
   }
 
   private boolean isHidden() {

gerrit-server/src/main/java/com/google/gerrit/server/project/ProjectState.java

@@ -18,8 +18,10 @@ import com.google.common.base.Function;
 import com.google.common.base.Predicate;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
 import com.google.gerrit.common.data.AccessSection;
 import com.google.gerrit.common.data.GroupReference;
+import com.google.gerrit.common.data.LabelType;
 import com.google.gerrit.common.data.LabelTypes;
 import com.google.gerrit.common.data.Permission;
 import com.google.gerrit.common.data.PermissionRule;
@@ -51,6 +53,7 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 /** Cached information on a project. */
@@ -66,7 +69,7 @@ public class ProjectState {
   private final PrologEnvironment.Factory envFactory;
   private final GitRepositoryManager gitMgr;
   private final RulesCache rulesCache;
-  private final LabelTypes labelTypes;
+  private final LabelTypes dbLabelTypes;
 
   private final ProjectConfig config;
   private final Set<AccountGroup.UUID> localOwners;
@@ -104,7 +107,7 @@ public class ProjectState {
     this.capabilities = isAllProjects
       ? new CapabilityCollection(config.getAccessSection(AccessSection.GLOBAL_CAPABILITIES))
       : null;
-    this.labelTypes = labelTypes;
+    this.dbLabelTypes = labelTypes;
 
     if (isAllProjects && !Permission.canBeOnAllProjects(AccessSection.ALL, Permission.OWNER)) {
       localOwners = Collections.emptySet();
@@ -342,7 +345,24 @@ public class ProjectState {
   }
 
   public LabelTypes getLabelTypes() {
-    return labelTypes;
+    Map<String, LabelType> types = Maps.newLinkedHashMap();
+    for (LabelType type : dbLabelTypes.getLabelTypes()) {
+      types.put(type.getName(), type);
+    }
+    List<ProjectState> projects = Lists.newArrayList(tree());
+    Collections.reverse(projects);
+    for (ProjectState s : projects) {
+      for (LabelType type : s.getConfig().getLabelSections()) {
+        types.put(type.getName(), type);
+      }
+    }
+    List<LabelType> all = Lists.newArrayListWithCapacity(types.size());
+    for (LabelType type : types.values()) {
+      if (!type.getValues().isEmpty()) {
+        all.add(type);
+      }
+    }
+    return new LabelTypes(Collections.unmodifiableList(all));
   }
 
   private boolean getInheritableBoolean(Function<Project, InheritableBoolean> func) {