Introduce merge detection for receive hooks

Here we add a merge detection provider for pre and post receive hooks
and implement this new provider for git.

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+### Added
+- Introduced merge detection for receive hooks ([#1278](https://github.com/scm-manager/scm-manager/pull/1278))
+
 ## [2.3.1] - 2020-08-04
 ### Added
 - New api to resolve SCM-Manager root url ([#1276](https://github.com/scm-manager/scm-manager/pull/1276))

scm-core/src/main/java/sonia/scm/repository/api/HookContext.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.repository.api;
 
 //~--- non-JDK imports --------------------------------------------------------
@@ -33,18 +33,18 @@ import sonia.scm.repository.Changeset;
 import sonia.scm.repository.PreProcessorUtil;
 import sonia.scm.repository.Repository;
 import sonia.scm.repository.spi.HookContextProvider;
+import sonia.scm.repository.spi.HookMergeDetectionProvider;
 
 /**
  * The context for all repository hooks. With the {@link HookContext} class it
  * is able to send messages back to the client, retrieve {@link Changeset}s
- * which are added during this push/commit and gives informations about changed 
+ * which are added during this push/commit and gives informations about changed
  * branches and tags.
  *
  * @author Sebastian Sdorra
  * @since 1.33
  */
-public final class HookContext
-{
+public final class HookContext {
 
   /**
    * the logger for HookContext
@@ -52,8 +52,6 @@ public final class HookContext
   private static final Logger logger =
     LoggerFactory.getLogger(HookContext.class);
 
-  //~--- constructors ---------------------------------------------------------
-
   /**
    * Constructs ...
    *
@@ -62,9 +60,7 @@ public final class HookContext
    * @param repository
    * @param preProcessorUtil
    */
-  HookContext(HookContextProvider provider, Repository repository,
-    PreProcessorUtil preProcessorUtil)
-  {
+  HookContext(HookContextProvider provider, Repository repository, PreProcessorUtil preProcessorUtil) {
     this.provider = provider;
     this.repository = repository;
     this.preProcessorUtil = preProcessorUtil;
@@ -77,41 +73,33 @@ public final class HookContext
    * about changed branches during the current hook.
    *
    * @return {@link HookBranchProvider}
-   * 
-   * @throws HookFeatureIsNotSupportedException if the feature is not supported 
+   *
+   * @throws HookFeatureIsNotSupportedException if the feature is not supported
    *  by the underlying provider
-   * 
+   *
    * @since 1.45
    */
-  public HookBranchProvider getBranchProvider()
-  {
-    if (logger.isDebugEnabled())
-    {
-      logger.debug("create branch provider for repository {}",
-        repository.getName());
-    }
+  public HookBranchProvider getBranchProvider() {
+    logger.debug("create branch provider for repository {}",
+      repository.getName());
 
     return provider.getBranchProvider();
   }
-  
+
  /**
    * Returns a {@link HookTagProvider} which is able to return informations
    * about changed tags during the current hook.
    *
    * @return {@link HookTagProvider}
-   * 
-   * @throws HookFeatureIsNotSupportedException if the feature is not supported 
+   *
+   * @throws HookFeatureIsNotSupportedException if the feature is not supported
    *  by the underlying provider
-   * 
+   *
    * @since 1.50
    */
-  public HookTagProvider getTagProvider()
-  {
-    if (logger.isDebugEnabled())
-    {
-      logger.debug("create tag provider for repository {}",
-        repository.getName());
-    }
+  public HookTagProvider getTagProvider() {
+    logger.debug("create tag provider for repository {}",
+      repository.getName());
 
     return provider.getTagProvider();
   }
@@ -122,25 +110,19 @@ public final class HookContext
    *
    *
    * @return {@link HookChangesetBuilder}
-   * 
-   * @throws HookFeatureIsNotSupportedException if the feature is not supported 
+   *
+   * @throws HookFeatureIsNotSupportedException if the feature is not supported
    *  by the underlying provider
    */
-  public HookChangesetBuilder getChangesetProvider()
-  {
-    if (logger.isDebugEnabled())
-    {
-      logger.debug("create changeset provider for repository {}",
-        repository.getName());
-    }
+  public HookChangesetBuilder getChangesetProvider() {
+    logger.debug("create changeset provider for repository {}",
+      repository.getName());
 
-    //J-
     return new HookChangesetBuilder(
-      repository, 
+      repository,
       preProcessorUtil,
       provider.getChangesetProvider()
     );
-    //J+
   }
 
   /**
@@ -152,21 +134,33 @@ public final class HookContext
    *
    * @return {@link HookMessageProvider} which is able to send message back to
    * the scm client
-   * 
-   * @throws HookFeatureIsNotSupportedException if the feature is not supported 
+   *
+   * @throws HookFeatureIsNotSupportedException if the feature is not supported
    *  by the underlying provider
    */
-  public HookMessageProvider getMessageProvider()
-  {
-    if (logger.isDebugEnabled())
-    {
-      logger.debug("create message provider for repository {}",
-        repository.getName());
-    }
+  public HookMessageProvider getMessageProvider() {
+    logger.debug("create message provider for repository {}",
+      repository.getName());
 
     return provider.getMessageProvider();
   }
 
+  /**
+   * Returns a {@link HookMergeDetectionProvider} which is able to check whether two
+   * branches have been merged with the incoming changesets.
+   *
+   * @return {@link HookMergeDetectionProvider} which is able to detect merges.
+   *
+   * @throws HookFeatureIsNotSupportedException if the feature is not supported
+   *  by the underlying provider
+   */
+  public HookMergeDetectionProvider getMergeDetectionProvider() {
+    logger.debug("create merge detection provider for repository {}",
+      repository.getName());
+
+    return provider.getMergeDetectionProvider();
+  }
+
   /**
    * Returns true if the underlying provider support the requested feature.
    *

scm-core/src/main/java/sonia/scm/repository/api/HookFeature.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.repository.api;
 
 /**
@@ -49,11 +49,18 @@ public enum HookFeature
    * @since 1.45
    */
   BRANCH_PROVIDER,
-  
+
   /**
    * Hook tag provider
-   * 
+   *
    * @since 1.50
    */
-  TAG_PROVIDER;
+  TAG_PROVIDER,
+
+  /**
+   * Provider to detect merges
+   *
+   * @since 2.4.0
+   */
+  MERGE_DETECTION_PROVIDER
 }

scm-core/src/main/java/sonia/scm/repository/spi/HookContextProvider.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.repository.spi;
 
 //~--- non-JDK imports --------------------------------------------------------
@@ -50,7 +50,7 @@ public abstract class HookContextProvider
   /**
    * Return the provider specific {@link HookMessageProvider} or throws a {@link HookFeatureIsNotSupportedException}.
    * The method will throw a {@link HookException} if the client is already disconnected.
-   * 
+   *
    * @return provider specific {@link HookMessageProvider}
    */
   public final HookMessageProvider getMessageProvider()
@@ -86,31 +86,31 @@ public abstract class HookContextProvider
 
   /**
    * Return the provider specific {@link HookBranchProvider} or throws a {@link HookFeatureIsNotSupportedException}.
-   * 
+   *
    * @return provider specific {@link HookBranchProvider}
-   * 
+   *
    * @since 1.45
    */
   public HookBranchProvider getBranchProvider()
   {
     throw new HookFeatureIsNotSupportedException(HookFeature.BRANCH_PROVIDER);
   }
-  
+
   /**
    * Return the provider specific {@link HookTagProvider} or throws a {@link HookFeatureIsNotSupportedException}.
-   * 
+   *
    * @return provider specific {@link HookTagProvider}
-   * 
+   *
    * @since 1.50
    */
-  public HookTagProvider getTagProvider() 
+  public HookTagProvider getTagProvider()
   {
     throw new HookFeatureIsNotSupportedException(HookFeature.TAG_PROVIDER);
   }
 
   /**
    * Return the provider specific {@link HookChangesetProvider} or throws a {@link HookFeatureIsNotSupportedException}.
-   * 
+   *
    * @return provider specific {@link HookChangesetProvider}
    */
   public HookChangesetProvider getChangesetProvider()
@@ -118,11 +118,21 @@ public abstract class HookContextProvider
     throw new HookFeatureIsNotSupportedException(HookFeature.CHANGESET_PROVIDER);
   }
 
+  /**
+   * Return the provider specific {@link HookMergeDetectionProvider} or throws a {@link HookFeatureIsNotSupportedException}.
+   *
+   * @return provider specific {@link HookMergeDetectionProvider}
+   */
+  public HookMergeDetectionProvider getMergeDetectionProvider()
+  {
+    throw new HookFeatureIsNotSupportedException(HookFeature.MERGE_DETECTION_PROVIDER);
+  }
+
   //~--- methods --------------------------------------------------------------
 
   /**
    * Creates a new provider specific {@link HookMessageProvider} or throws a {@link HookFeatureIsNotSupportedException}.
-   * 
+   *
    * @return provider specific {@link HookChangesetProvider}
    */
   protected HookMessageProvider createMessageProvider()

scm-core/src/main/java/sonia/scm/repository/spi/HookMergeDetectionProvider.java

@@ -0,0 +1,42 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.spi;
+
+/**
+ * @since 2.4.0
+ */
+public interface HookMergeDetectionProvider {
+
+  /**
+   * Checks whether <code>branch</code> has been merged into <code>target</code>. So this will also return
+   * <code>true</code>, when <code>branch</code> has been deleted with this change.
+   *
+   * @param target The name of the branch to check, whether the other branch has been merged into.
+   * @param branch The name of the branch to check, whether it has been merged into the other branch.
+   * @return <code>true</code> when <code>branch</code> has been merged into <code>target</code>, <code>false</code>
+   * otherwise.
+   */
+  boolean branchesMerged(String target, String branch);
+}

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.repository;
 
 //~--- non-JDK imports --------------------------------------------------------
@@ -337,6 +337,16 @@ public final class GitUtil
     return Strings.nullToEmpty(refName).startsWith(PREFIX_HEADS);
   }
 
+  public static Ref getBranchIdOrCurrentHead(org.eclipse.jgit.lib.Repository gitRepository, String requestedBranch) throws IOException {
+    if ( Strings.isNullOrEmpty(requestedBranch) ) {
+      logger.trace("no default branch configured, use repository head as default");
+      Optional<Ref> repositoryHeadRef = GitUtil.getRepositoryHeadRef(gitRepository);
+      return repositoryHeadRef.orElse(null);
+    } else {
+      return GitUtil.getBranchId(gitRepository, requestedBranch);
+    }
+  }
+
   /**
    * Method description
    *

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/api/GitPostReceiveHookMergeDetectionProvider.java

@@ -0,0 +1,52 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.api;
+
+import org.eclipse.jgit.lib.Repository;
+import sonia.scm.repository.ChangesetPagingResult;
+import sonia.scm.repository.spi.GitLogComputer;
+import sonia.scm.repository.spi.HookMergeDetectionProvider;
+import sonia.scm.repository.spi.LogCommandRequest;
+
+public class GitPostReceiveHookMergeDetectionProvider implements HookMergeDetectionProvider {
+  private final Repository repository;
+  private final String repositoryId;
+
+  public GitPostReceiveHookMergeDetectionProvider(Repository repository, String repositoryId) {
+    this.repository = repository;
+    this.repositoryId = repositoryId;
+  }
+
+  @Override
+  public boolean branchesMerged(String target, String branch) {
+    LogCommandRequest request = new LogCommandRequest();
+    request.setBranch(branch);
+    request.setAncestorChangeset(target);
+    request.setPagingLimit(1);
+
+    ChangesetPagingResult changesets = new GitLogComputer(repositoryId, repository).compute(request);
+    return changesets.getTotal() == 0;
+  }
+}

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/api/GitPreReceiveHookMergeDetectionProvider.java

@@ -0,0 +1,63 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.api;
+
+import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.transport.ReceiveCommand;
+import sonia.scm.repository.ChangesetPagingResult;
+import sonia.scm.repository.GitUtil;
+import sonia.scm.repository.spi.GitLogComputer;
+import sonia.scm.repository.spi.HookMergeDetectionProvider;
+import sonia.scm.repository.spi.LogCommandRequest;
+
+import java.util.List;
+
+public class GitPreReceiveHookMergeDetectionProvider implements HookMergeDetectionProvider {
+  private final List<ReceiveCommand> receiveCommands;
+  private final Repository repository;
+  private final String repositoryId;
+
+  public GitPreReceiveHookMergeDetectionProvider(List<ReceiveCommand> receiveCommands, Repository repository, String repositoryId) {
+    this.receiveCommands = receiveCommands;
+    this.repository = repository;
+    this.repositoryId = repositoryId;
+  }
+
+  @Override
+  public boolean branchesMerged(String target, String branch) {
+
+    String sourceToUse = receiveCommands.stream().filter(receiveCommand -> GitUtil.getBranch(receiveCommand.getRef()).equals(branch)).findFirst().map(ReceiveCommand::getNewId).map(AnyObjectId::getName).orElse(branch);
+    String targetToUse = receiveCommands.stream().filter(receiveCommand -> GitUtil.getBranch(receiveCommand.getRef()).equals(target)).findFirst().map(ReceiveCommand::getNewId).map(AnyObjectId::getName).orElse(target);
+
+    LogCommandRequest request = new LogCommandRequest();
+    request.setBranch(sourceToUse);
+    request.setAncestorChangeset(targetToUse);
+    request.setPagingLimit(1);
+
+    ChangesetPagingResult changesets = new GitLogComputer(repositoryId, repository).compute(request);
+    return changesets.getTotal() == 0;
+  }
+}

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/AbstractGitCommand.java

@@ -59,6 +59,7 @@ import static java.util.Optional.empty;
 import static java.util.Optional.of;
 import static sonia.scm.ContextEntry.ContextBuilder.entity;
 import static sonia.scm.NotFoundException.notFound;
+import static sonia.scm.repository.GitUtil.getBranchIdOrCurrentHead;
 
 //~--- JDK imports ------------------------------------------------------------
 
@@ -123,15 +124,9 @@ class AbstractGitCommand
   Ref getBranchOrDefault(Repository gitRepository, String requestedBranch) throws IOException {
     if ( Strings.isNullOrEmpty(requestedBranch) ) {
       String defaultBranchName = context.getConfig().getDefaultBranch();
-      if (!Strings.isNullOrEmpty(defaultBranchName)) {
-        return GitUtil.getBranchId(gitRepository, defaultBranchName);
-      } else {
-        logger.trace("no default branch configured, use repository head as default");
-        Optional<Ref> repositoryHeadRef = GitUtil.getRepositoryHeadRef(gitRepository);
-        return repositoryHeadRef.orElse(null);
-      }
+      return getBranchIdOrCurrentHead(gitRepository, defaultBranchName);
     } else {
-      return GitUtil.getBranchId(gitRepository, requestedBranch);
+      return getBranchIdOrCurrentHead(gitRepository, requestedBranch);
     }
   }
 

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitHookContextProvider.java

@@ -21,27 +21,28 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.repository.spi;
 
 //~--- non-JDK imports --------------------------------------------------------
 
+import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.transport.ReceiveCommand;
 import org.eclipse.jgit.transport.ReceivePack;
-
+import sonia.scm.repository.RepositoryHookType;
 import sonia.scm.repository.api.GitHookBranchProvider;
 import sonia.scm.repository.api.GitHookMessageProvider;
+import sonia.scm.repository.api.GitHookTagProvider;
+import sonia.scm.repository.api.GitPostReceiveHookMergeDetectionProvider;
+import sonia.scm.repository.api.GitPreReceiveHookMergeDetectionProvider;
 import sonia.scm.repository.api.HookBranchProvider;
 import sonia.scm.repository.api.HookFeature;
 import sonia.scm.repository.api.HookMessageProvider;
-
-//~--- JDK imports ------------------------------------------------------------
+import sonia.scm.repository.api.HookTagProvider;
 
 import java.util.EnumSet;
 import java.util.List;
 import java.util.Set;
-import sonia.scm.repository.api.GitHookTagProvider;
-import sonia.scm.repository.api.HookTagProvider;
 
 /**
  *
@@ -50,24 +51,37 @@ import sonia.scm.repository.api.HookTagProvider;
 public class GitHookContextProvider extends HookContextProvider
 {
 
-  /** Field description */
-  private static final Set<HookFeature> SUPPORTED_FEATURES =
-    EnumSet.of(HookFeature.MESSAGE_PROVIDER, HookFeature.CHANGESET_PROVIDER,
-      HookFeature.BRANCH_PROVIDER, HookFeature.TAG_PROVIDER);
+  /**
+   * Field description
+   */
+  private static final Set<HookFeature> SUPPORTED_FEATURES = EnumSet.of(
+    HookFeature.MESSAGE_PROVIDER,
+    HookFeature.CHANGESET_PROVIDER,
+    HookFeature.BRANCH_PROVIDER,
+    HookFeature.TAG_PROVIDER,
+    HookFeature.MERGE_DETECTION_PROVIDER
+  );
 
   //~--- constructors ---------------------------------------------------------
 
   /**
    * Constructs a new instance
-   *
-   * @param receivePack git receive pack
+   *  @param receivePack git receive pack
    * @param receiveCommands received commands
+   * @param type
    */
-  public GitHookContextProvider(ReceivePack receivePack,
-    List<ReceiveCommand> receiveCommands)
-  {
+  public GitHookContextProvider(
+    ReceivePack receivePack,
+    List<ReceiveCommand> receiveCommands,
+    RepositoryHookType type,
+    Repository repository,
+    String repositoryId
+  ) {
     this.receivePack = receivePack;
     this.receiveCommands = receiveCommands;
+    this.type = type;
+    this.repository = repository;
+    this.repositoryId = repositoryId;
     this.changesetProvider = new GitHookChangesetProvider(receivePack,
       receiveCommands);
   }
@@ -99,20 +113,25 @@ public class GitHookContextProvider extends HookContextProvider
     return changesetProvider;
   }
 
+  @Override
+  public HookMergeDetectionProvider getMergeDetectionProvider() {
+    if (type == RepositoryHookType.POST_RECEIVE) {
+      return new GitPostReceiveHookMergeDetectionProvider(repository, repositoryId);
+    } else {
+      return new GitPreReceiveHookMergeDetectionProvider(receiveCommands, repository, repositoryId);
+    }
+  }
+
   @Override
   public Set<HookFeature> getSupportedFeatures()
   {
     return SUPPORTED_FEATURES;
   }
 
-  //~--- fields ---------------------------------------------------------------
-
-  /** Field description */
   private final GitHookChangesetProvider changesetProvider;
-
-  /** Field description */
   private final List<ReceiveCommand> receiveCommands;
-
-  /** Field description */
   private final ReceivePack receivePack;
+  private final RepositoryHookType type;
+  private final Repository repository;
+  private final String repositoryId;
 }

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitLogCommand.java

@@ -27,19 +27,12 @@ package sonia.scm.repository.spi;
 //~--- non-JDK imports --------------------------------------------------------
 
 import com.google.common.base.Strings;
-import com.google.common.collect.Lists;
-import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
-import org.eclipse.jgit.treewalk.filter.AndTreeFilter;
-import org.eclipse.jgit.treewalk.filter.PathFilter;
-import org.eclipse.jgit.treewalk.filter.TreeFilter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import sonia.scm.NotFoundException;
 import sonia.scm.repository.Changeset;
 import sonia.scm.repository.ChangesetPagingResult;
 import sonia.scm.repository.GitChangesetConverter;
@@ -48,9 +41,6 @@ import sonia.scm.repository.InternalRepositoryException;
 import sonia.scm.util.IOUtil;
 
 import java.io.IOException;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.List;
 
 import static sonia.scm.ContextEntry.ContextBuilder.entity;
 import static sonia.scm.NotFoundException.notFound;
@@ -183,123 +173,14 @@ public class GitLogCommand extends AbstractGitCommand implements LogCommand
   @Override
   @SuppressWarnings("unchecked")
   public ChangesetPagingResult getChangesets(LogCommandRequest request) {
-    if (logger.isDebugEnabled()) {
-      logger.debug("fetch changesets for request: {}", request);
-    }
-
-    ChangesetPagingResult changesets = null;
-    GitChangesetConverter converter = null;
-    RevWalk revWalk = null;
-
-    try (org.eclipse.jgit.lib.Repository repository = open()) {
-      if (!repository.getAllRefs().isEmpty()) {
-        int counter = 0;
-        int start = request.getPagingStart();
-
-        if (start < 0) {
-          if (logger.isErrorEnabled()) {
-            logger.error("start parameter is negative, reset to 0");
-          }
-
-          start = 0;
-        }
-
-        List<Changeset> changesetList = Lists.newArrayList();
-        int limit = request.getPagingLimit();
-        ObjectId startId = null;
-
-        if (!Strings.isNullOrEmpty(request.getStartChangeset())) {
-          startId = repository.resolve(request.getStartChangeset());
-        }
-
-        ObjectId endId = null;
-
-        if (!Strings.isNullOrEmpty(request.getEndChangeset())) {
-          endId = repository.resolve(request.getEndChangeset());
-        }
-
-        Ref branch = getBranchOrDefault(repository,request.getBranch());
-
-        ObjectId ancestorId = null;
-
-        if (!Strings.isNullOrEmpty(request.getAncestorChangeset())) {
-          ancestorId = repository.resolve(request.getAncestorChangeset());
-          if (ancestorId == null) {
-            throw notFound(entity(REVISION, request.getAncestorChangeset()).in(this.repository));
-          }
-        }
-
-        revWalk = new RevWalk(repository);
-
-        converter = new GitChangesetConverter(repository, revWalk);
-
-        if (!Strings.isNullOrEmpty(request.getPath())) {
-          revWalk.setTreeFilter(
-            AndTreeFilter.create(
-              PathFilter.create(request.getPath()), TreeFilter.ANY_DIFF));
-        }
-
-        if (branch != null) {
-          if (startId != null) {
-            revWalk.markStart(revWalk.lookupCommit(startId));
-          } else {
-            revWalk.markStart(revWalk.lookupCommit(branch.getObjectId()));
-          }
-
-          if (ancestorId != null) {
-            revWalk.markUninteresting(revWalk.lookupCommit(ancestorId));
-          }
-
-          Iterator<RevCommit> iterator = revWalk.iterator();
-
-          while (iterator.hasNext()) {
-            RevCommit commit = iterator.next();
-
-            if ((counter >= start)
-              && ((limit < 0) || (counter < start + limit))) {
-              changesetList.add(converter.createChangeset(commit));
-            }
-
-            counter++;
-
-            if (commit.getId().equals(endId)) {
-              break;
-            }
-          }
-        } else if (ancestorId != null) {
-          throw notFound(entity(REVISION, request.getBranch()).in(this.repository));
-        }
-
-        if (branch != null) {
-          changesets = new ChangesetPagingResult(counter, changesetList, GitUtil.getBranch(branch.getName()));
-        } else {
-          changesets = new ChangesetPagingResult(counter, changesetList);
-        }
-      } else if (logger.isWarnEnabled()) {
-        logger.warn("the repository {} seems to be empty",
-          this.repository.getName());
-
-        changesets = new ChangesetPagingResult(0, Collections.EMPTY_LIST);
+    try (org.eclipse.jgit.lib.Repository gitRepository = open()) {
+      if (Strings.isNullOrEmpty(request.getBranch())) {
+        request.setBranch(context.getConfig().getDefaultBranch());
       }
+      return new GitLogComputer(this.repository.getId(), gitRepository).compute(request);
+    } catch (IOException e) {
+      throw new InternalRepositoryException(repository, "could not create change log", e);
     }
-    catch (MissingObjectException e)
-    {
-      throw notFound(entity(REVISION, e.getObjectId().getName()).in(repository));
-    }
-    catch (NotFoundException e)
-    {
-      throw e;
-    }
-    catch (Exception ex)
-    {
-      throw new InternalRepositoryException(repository, "could not create change log", ex);
-    }
-    finally
-    {
-      IOUtil.close(converter);
-      GitUtil.release(revWalk);
-    }
-
-    return changesets;
   }
+
 }

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitLogComputer.java

@@ -0,0 +1,187 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.spi;
+
+import com.google.common.base.Strings;
+import com.google.common.collect.Lists;
+import org.eclipse.jgit.errors.InvalidObjectIdException;
+import org.eclipse.jgit.errors.MissingObjectException;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.treewalk.filter.AndTreeFilter;
+import org.eclipse.jgit.treewalk.filter.PathFilter;
+import org.eclipse.jgit.treewalk.filter.TreeFilter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import sonia.scm.ContextEntry;
+import sonia.scm.NotFoundException;
+import sonia.scm.repository.Changeset;
+import sonia.scm.repository.ChangesetPagingResult;
+import sonia.scm.repository.GitChangesetConverter;
+import sonia.scm.repository.GitUtil;
+import sonia.scm.repository.InternalRepositoryException;
+import sonia.scm.util.IOUtil;
+
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+
+import static sonia.scm.ContextEntry.ContextBuilder.entity;
+import static sonia.scm.NotFoundException.notFound;
+
+public class GitLogComputer {
+
+  private static final Logger LOG = LoggerFactory.getLogger(GitLogComputer.class);
+
+  private final String repositoryId;
+  private final Repository gitRepository;
+
+  public GitLogComputer(String repositoryId, Repository repository) {
+    this.repositoryId = repositoryId;
+    this.gitRepository = repository;
+  }
+
+  public ChangesetPagingResult compute(LogCommandRequest request) {
+    LOG.debug("fetch changesets for request: {}", request);
+
+    GitChangesetConverter converter = null;
+    RevWalk revWalk = null;
+
+    try {
+      if (!gitRepository.getAllRefs().isEmpty()) {
+        int counter = 0;
+        int start = request.getPagingStart();
+
+        if (start < 0) {
+          LOG.error("start parameter is negative, reset to 0");
+
+          start = 0;
+        }
+
+        List<Changeset> changesetList = Lists.newArrayList();
+        int limit = request.getPagingLimit();
+        ObjectId startId = null;
+
+        if (!Strings.isNullOrEmpty(request.getStartChangeset())) {
+          startId = gitRepository.resolve(request.getStartChangeset());
+        }
+
+        ObjectId endId = null;
+
+        if (!Strings.isNullOrEmpty(request.getEndChangeset())) {
+          endId = gitRepository.resolve(request.getEndChangeset());
+        }
+
+        Ref branch = GitUtil.getBranchIdOrCurrentHead(gitRepository, request.getBranch());
+        ObjectId branchId;
+        if (branch == null) {
+          if (request.getBranch() != null) {
+            try {
+              branchId = ObjectId.fromString(request.getBranch());
+            } catch (InvalidObjectIdException e) {
+              throw notFound(entity(GitLogCommand.REVISION, request.getBranch()).in(sonia.scm.repository.Repository.class, repositoryId));
+            }
+          } else {
+            branchId = null;
+          }
+        } else {
+          branchId = branch.getObjectId();
+        }
+
+        ObjectId ancestorId = null;
+
+        if (!Strings.isNullOrEmpty(request.getAncestorChangeset())) {
+          ancestorId = gitRepository.resolve(request.getAncestorChangeset());
+          if (ancestorId == null) {
+            throw notFound(entity(GitLogCommand.REVISION, request.getAncestorChangeset()).in(sonia.scm.repository.Repository.class, repositoryId));
+          }
+        }
+
+        revWalk = new RevWalk(gitRepository);
+
+        converter = new GitChangesetConverter(gitRepository, revWalk);
+
+        if (!Strings.isNullOrEmpty(request.getPath())) {
+          revWalk.setTreeFilter(
+            AndTreeFilter.create(
+              PathFilter.create(request.getPath()), TreeFilter.ANY_DIFF));
+        }
+
+        if (branchId != null) {
+          if (startId != null) {
+            revWalk.markStart(revWalk.lookupCommit(startId));
+          } else {
+            revWalk.markStart(revWalk.lookupCommit(branchId));
+          }
+
+          if (ancestorId != null) {
+            revWalk.markUninteresting(revWalk.lookupCommit(ancestorId));
+          }
+
+          Iterator<RevCommit> iterator = revWalk.iterator();
+
+          while (iterator.hasNext()) {
+            RevCommit commit = iterator.next();
+
+            if ((counter >= start)
+              && ((limit < 0) || (counter < start + limit))) {
+              changesetList.add(converter.createChangeset(commit));
+            }
+
+            counter++;
+
+            if (commit.getId().equals(endId)) {
+              break;
+            }
+          }
+        } else if (ancestorId != null) {
+          throw notFound(entity(GitLogCommand.REVISION, request.getBranch()).in(sonia.scm.repository.Repository.class, repositoryId));
+        }
+
+        if (branch != null) {
+          return new ChangesetPagingResult(counter, changesetList, GitUtil.getBranch(branch.getName()));
+        } else {
+          return new ChangesetPagingResult(counter, changesetList);
+        }
+      } else {
+        LOG.debug("the repository with id {} seems to be empty", this.repositoryId);
+
+        return new ChangesetPagingResult(0, Collections.EMPTY_LIST);
+      }
+    } catch (MissingObjectException e) {
+      throw notFound(entity(GitLogCommand.REVISION, e.getObjectId().getName()).in(sonia.scm.repository.Repository.class, repositoryId));
+    } catch (NotFoundException e) {
+      throw e;
+    } catch (Exception ex) {
+      throw new InternalRepositoryException(entity(sonia.scm.repository.Repository.class, repositoryId).build(), "could not create change log", ex);
+    } finally {
+      IOUtil.close(converter);
+      GitUtil.release(revWalk);
+    }
+  }
+}

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/web/GitReceiveHook.java

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.web;
 
 //~--- non-JDK imports --------------------------------------------------------
@@ -122,8 +122,7 @@ public class GitReceiveHook implements PreReceiveHook, PostReceiveHook
 
       logger.trace("resolved repository to {}", repositoryId);
 
-      GitHookContextProvider context = new GitHookContextProvider(rpack,
-                                         receiveCommands);
+      GitHookContextProvider context = new GitHookContextProvider(rpack, receiveCommands, type, repository, repositoryId);
 
       hookEventFacade.handle(repositoryId).fireHookEvent(type, context);