Move file web_links into the meta_a, meta_b headers

Web links should be part of the metadata for the two halves of a diff.
The protocol uses meta_a and meta_b to represent the halves, with
contained fields for specific values.

Also avoid unnecessary copying of the WebLinkInfo by reusing the
created list from the WebLinks factory.

Change-Id: I2c31cad2a4fed11e513f81cd613742534662a663

Documentation/rest-api-changes.txt

@@ -3366,6 +3366,8 @@ The `DiffFileMetaInfo` entity contains meta information about a file diff.
 |`name`        |The name of the file.
 |`content_type`|The content type of the file.
 |`lines`       |The total number of lines in the file.
+|'web_links'   |Links to the file in external sites as a list of
+link:rest-api-changes.html#web-link-info[WebLinkInfo] entries.
 |==========================
 
 [[diff-info]]
@@ -3389,12 +3391,6 @@ Intraline status (`OK`, `ERROR`, `TIMEOUT`).
 |`diff_header`     ||A list of strings representing the patch set diff header.
 |`content`         ||The content differences in the file as a list of
 link:#diff-content[DiffContent] entities.
-|'web_links_a'     |optional|
-Links to the side A file in external sites as a list of
-link:rest-api-changes.html#web-link-info[WebLinkInfo] entries.
-|'web_links_b'     |optional|
-Links to the side B file in external sites as a list of
-link:rest-api-changes.html#web-link-info[WebLinkInfo] entries.
 |==========================
 
 [[diff-intraline-info]]

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/DiffInfo.java

@@ -28,8 +28,6 @@ public class DiffInfo extends JavaScriptObject {
   public final native FileMeta meta_b() /*-{ return this.meta_b; }-*/;
   public final native JsArrayString diff_header() /*-{ return this.diff_header; }-*/;
   public final native JsArray<Region> content() /*-{ return this.content; }-*/;
-  public final native JsArray<WebLinkInfo> web_links_a() /*-{ return this.web_links_a; }-*/;
-  public final native JsArray<WebLinkInfo> web_links_b() /*-{ return this.web_links_b; }-*/;
 
   public final ChangeType change_type() {
     return ChangeType.valueOf(change_typeRaw());
@@ -103,6 +101,7 @@ public class DiffInfo extends JavaScriptObject {
     public final native String name() /*-{ return this.name; }-*/;
     public final native String content_type() /*-{ return this.content_type; }-*/;
     public final native int lines() /*-{ return this.lines || 0 }-*/;
+    public final native JsArray<WebLinkInfo> web_links() /*-{ return this.web_links; }-*/;
 
     protected FileMeta() {
     }

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/DiffTable.java

@@ -16,7 +16,6 @@ package com.google.gerrit.client.diff;
 
 import com.google.gerrit.client.account.DiffPreferences;
 import com.google.gerrit.client.changes.ChangeInfo.RevisionInfo;
-import com.google.gerrit.client.rpc.Natives;
 import com.google.gerrit.reviewdb.client.Patch.ChangeType;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gwt.core.client.GWT;
@@ -173,10 +172,8 @@ class DiffTable extends Composite {
       boolean editExists, int currentPatchSet) {
     this.changeType = info.change_type();
     this.autoHideHeader = prefs.autoHideDiffTableHeader();
-    patchSetSelectBoxA.setUpPatchSetNav(list, info.meta_a(),
-        Natives.asList(info.web_links_a()), editExists, currentPatchSet);
-    patchSetSelectBoxB.setUpPatchSetNav(list, info.meta_b(),
-        Natives.asList(info.web_links_b()), editExists, currentPatchSet);
+    patchSetSelectBoxA.setUpPatchSetNav(list, info.meta_a(), editExists, currentPatchSet);
+    patchSetSelectBoxB.setUpPatchSetNav(list, info.meta_b(), editExists, currentPatchSet);
 
     JsArrayString hdr = info.diff_header();
     if (hdr != null) {

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PatchSetSelectBox2.java

@@ -22,6 +22,7 @@ import com.google.gerrit.client.changes.ChangeFileApi;
 import com.google.gerrit.client.changes.ChangeInfo.RevisionInfo;
 import com.google.gerrit.client.patches.PatchUtil;
 import com.google.gerrit.client.rpc.GerritCallback;
+import com.google.gerrit.client.rpc.Natives;
 import com.google.gerrit.client.ui.InlineHyperlink;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Patch;
@@ -86,7 +87,7 @@ class PatchSetSelectBox2 extends Composite {
   }
 
   void setUpPatchSetNav(JsArray<RevisionInfo> list, DiffInfo.FileMeta meta,
-      List<WebLinkInfo> webLinks, boolean editExists, int currentPatchSet) {
+      boolean editExists, int currentPatchSet) {
     InlineHyperlink baseLink = null;
     InlineHyperlink selectedLink = null;
     if (sideA) {
@@ -117,6 +118,7 @@ class PatchSetSelectBox2 extends Composite {
         linkPanel.add(createEditIcon());
       }
     }
+    List<WebLinkInfo> webLinks = Natives.asList(meta.web_links());
     if (webLinks != null) {
       for (WebLinkInfo weblink : webLinks) {
         Anchor a = new Anchor();

gerrit-server/src/main/java/com/google/gerrit/server/WebLinks.java

@@ -14,6 +14,7 @@
 
 package com.google.gerrit.server;
 
+import com.google.common.base.Strings;
 import com.google.common.collect.Lists;
 import com.google.gerrit.extensions.common.WebLinkInfo;
 import com.google.gerrit.extensions.registration.DynamicSet;
@@ -57,14 +58,18 @@ public class WebLinks {
     return links;
   }
 
-  public Iterable<WebLinkInfo> getFileLinks(String project, String revision,
+  public List<WebLinkInfo> getFileLinks(String project, String revision,
       String file) {
-    List<WebLinkInfo> links = Lists.newArrayList();
+    List<WebLinkInfo> links = new ArrayList<>(4);
     for (FileWebLink webLink : fileLinks) {
-      links.add(new WebLinkInfo(webLink.getLinkName(),
-          webLink.getImageUrl(),
-          webLink.getFileUrl(project, revision, file),
-          webLink.getTarget()));
+      String name = webLink.getLinkName();
+      String url = webLink.getFileUrl(project, revision, file);
+      if (!Strings.isNullOrEmpty(name) && !Strings.isNullOrEmpty(url)) {
+        links.add(new WebLinkInfo(name,
+            webLink.getImageUrl(),
+            url,
+            webLink.getTarget()));
+      }
     }
     return links;
   }

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

@@ -17,7 +17,6 @@ package com.google.gerrit.server.change;
 import static com.google.common.base.Preconditions.checkState;
 
 import com.google.common.base.MoreObjects;
-import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 import com.google.gerrit.common.data.PatchScript;
@@ -47,6 +46,7 @@ import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectState;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+
 import org.eclipse.jgit.diff.Edit;
 import org.eclipse.jgit.diff.ReplaceEdit;
 import org.kohsuke.args4j.CmdLineException;
@@ -59,7 +59,6 @@ import org.kohsuke.args4j.spi.Parameters;
 import org.kohsuke.args4j.spi.Setter;
 
 import java.io.IOException;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 
@@ -160,7 +159,7 @@ public class GetDiff implements RestReadView<FileResource> {
         String rev = basePatchSet != null
             ? basePatchSet.getRefName()
             : resource.getRevision().getPatchSet().getRefName() + "^1";
-        result.webLinksA =
+        result.metaA.webLinks =
             getFileWebLinks(state.getProject(), rev, result.metaA.name);
       }
 
@@ -169,7 +168,7 @@ public class GetDiff implements RestReadView<FileResource> {
         result.metaB.name = ps.getNewName();
         setContentType(result.metaB, state, ps.getFileModeB(), ps.getMimeTypeB());
         result.metaB.lines = ps.getB().size();
-        result.webLinksB = getFileWebLinks(state.getProject(),
+        result.metaB.webLinks = getFileWebLinks(state.getProject(),
             resource.getRevision().getPatchSet().getRefName(),
             result.metaB.name);
       }
@@ -203,14 +202,9 @@ public class GetDiff implements RestReadView<FileResource> {
 
   private List<WebLinkInfo> getFileWebLinks(Project project, String rev,
       String file) {
-    List<WebLinkInfo> fileWebLinks = new ArrayList<>();
-    for (WebLinkInfo link : webLinks.getFileLinks(project.getName(),
-        rev, file)) {
-      if (!Strings.isNullOrEmpty(link.name) && !Strings.isNullOrEmpty(link.url)) {
-        fileWebLinks.add(link);
-      }
-    }
-    return fileWebLinks;
+    List<WebLinkInfo> links =
+        webLinks.getFileLinks(project.getName(), rev, file);
+    return !links.isEmpty() ? links : null;
   }
 
   static class Result {
@@ -220,14 +214,13 @@ public class GetDiff implements RestReadView<FileResource> {
     ChangeType changeType;
     List<String> diffHeader;
     List<ContentEntry> content;
-    List<WebLinkInfo> webLinksA;
-    List<WebLinkInfo> webLinksB;
   }
 
   static class FileMeta {
     String name;
     String contentType;
     Integer lines;
+    List<WebLinkInfo> webLinks;
   }
 
   private void setContentType(FileMeta meta, ProjectState project,