improve performance of mercurial log command

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/HgLogCommand.java

@@ -107,9 +107,14 @@ public class HgLogCommand extends AbstractCommand implements LogCommand
   public ChangesetPagingResult getChangesets(LogCommandRequest request)
     throws IOException, RepositoryException
   {
+    ChangesetPagingResult result = null;
+
     com.aragost.javahg.Repository repository = open();
     HgLogChangesetCommand cmd = HgLogChangesetCommand.on(repository);
 
+    if (!Strings.isNullOrEmpty(request.getPath()))
+    {
+
       String startChangeset = request.getStartChangeset();
       String endChangeset = request.getEndChangeset();
 
@@ -127,16 +132,7 @@ public class HgLogCommand extends AbstractCommand implements LogCommand
         cmd.rev(startChangeset.concat(":0"));
       }
 
-    List<Changeset> changesetList = null;
+      List<Changeset> changesetList = cmd.execute(request.getPath());
-
-    if (!Strings.isNullOrEmpty(request.getPath()))
-    {
-      changesetList = cmd.execute(request.getPath());
-    }
-    else
-    {
-      changesetList = cmd.execute();
-    }
 
       int start = request.getPagingStart();
       int limit = request.getPagingLimit();
@@ -160,6 +156,55 @@ public class HgLogCommand extends AbstractCommand implements LogCommand
         changesets = Lists.newArrayList(sublist);
       }
 
-    return new ChangesetPagingResult(changesetList.size(), changesets);
+      result = new ChangesetPagingResult(changesetList.size(), changesets);
+    }
+    else
+    {
+
+      int start = -1;
+      int end = 0;
+
+      String startChangeset = request.getStartChangeset();
+      String endChangeset = request.getEndChangeset();
+
+      if (!Strings.isNullOrEmpty(startChangeset))
+      {
+        start = HgLogChangesetCommand.on(repository).rev(
+          startChangeset).singleRevision();
+      }
+      else if (!Strings.isNullOrEmpty(endChangeset))
+      {
+        end = HgLogChangesetCommand.on(repository).rev(
+          endChangeset).singleRevision();
+      }
+
+      if (start < 0)
+      {
+        start =
+          HgLogChangesetCommand.on(repository).rev("tip").singleRevision();
+      }
+
+      int total = start - end + 1;
+
+      if (request.getPagingStart() > 0)
+      {
+        start -= request.getPagingStart();
+      }
+
+      if (request.getPagingLimit() > 0)
+      {
+        end = start - request.getPagingLimit() + 1;
+      }
+      
+      if ( end < 0 ){
+        end = 0;
+      }
+
+      List<Changeset> changesets = cmd.rev(start + ":" + end).execute();
+
+      result = new ChangesetPagingResult(total, changesets);
+    }
+
+    return result;
   }
 }

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/spi/javahg/HgLogChangesetCommand.java

@@ -191,6 +191,19 @@ public class HgLogChangesetCommand extends AbstractCommand
     return Utils.single(execute(files));
   }
 
+  /**
+   * Method description
+   *
+   *
+   * @param files
+   *
+   * @return
+   */
+  public int singleRevision(String... files)
+  {
+    return Utils.single(loadRevisions(files));
+  }
+
   //~--- get methods ----------------------------------------------------------
 
   /**