SONAR-6397 Do not read SCM info from db on first analysis

15 files changed, 250 insertions, 21 deletions

diff --git a/server/sonar-server-benchmarks/src/test/java/org/sonar/server/benchmark/PersistFileSourcesStepTest.java b/server/sonar-server-benchmarks/src/test/java/org/sonar/server/benchmark/PersistFileSourcesStepTest.java
index 87ad097dbab..09520d5b788 100644
--- a/server/sonar-server-benchmarks/src/test/java/org/sonar/server/benchmark/PersistFileSourcesStepTest.java
+++ b/server/sonar-server-benchmarks/src/test/java/org/sonar/server/benchmark/PersistFileSourcesStepTest.java
@@ -37,6 +37,7 @@ import org.sonar.batch.protocol.output.BatchReportWriter;
 import org.sonar.core.util.Uuids;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbTester;
+import org.sonar.server.computation.analysis.MutableAnalysisMetadataHolderRule;
 import org.sonar.server.computation.batch.BatchReportDirectoryHolderImpl;
 import org.sonar.server.computation.batch.BatchReportReaderImpl;
 import org.sonar.server.computation.batch.TreeRootHolderRule;
@@ -69,6 +70,9 @@ public class PersistFileSourcesStepTest {
   @Rule
   public TreeRootHolderRule treeRootHolder = new TreeRootHolderRule();
 
+  @Rule
+  public MutableAnalysisMetadataHolderRule analysisMetadataHolder = new MutableAnalysisMetadataHolderRule();
+
   @Test
   public void benchmark() throws Exception {
     File reportDir = prepareReport();
@@ -85,7 +89,8 @@ public class PersistFileSourcesStepTest {
     batchReportDirectoryHolder.setDirectory(reportDir);
     org.sonar.server.computation.batch.BatchReportReader batchReportReader = new BatchReportReaderImpl(batchReportDirectoryHolder);
     SourceService sourceService = new SourceService(dbClient, null);
-    ScmInfoRepositoryImpl scmInfoRepository = new ScmInfoRepositoryImpl(batchReportReader, dbClient, sourceService);
+    analysisMetadataHolder.setIsFirstAnalysis(false);
+    ScmInfoRepositoryImpl scmInfoRepository = new ScmInfoRepositoryImpl(batchReportReader, analysisMetadataHolder, dbClient, sourceService);
     PersistFileSourcesStep step = new PersistFileSourcesStep(dbClient, System2.INSTANCE, treeRootHolder, batchReportReader,
       new SourceLinesRepositoryImpl(batchReportReader), scmInfoRepository);
     step.execute();
diff --git a/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/AnalysisMetadataHolder.java b/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/AnalysisMetadataHolder.java
index 5653e72110f..445fd8a63c8 100644
--- a/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/AnalysisMetadataHolder.java
+++ b/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/AnalysisMetadataHolder.java
@@ -26,4 +26,9 @@ public interface AnalysisMetadataHolder {
    * @throws IllegalStateException if no analysis date has been set
    */
   Date getAnalysisDate();
+
+  /**
+   * @throws IllegalStateException if isFirstAnalysis has not been set
+   */
+  boolean isFirstAnalysis();
 }
diff --git a/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/MutableAnalysisMetadataHolder.java b/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/MutableAnalysisMetadataHolder.java
index aa8736419ea..1733010fc93 100644
--- a/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/MutableAnalysisMetadataHolder.java
+++ b/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/MutableAnalysisMetadataHolder.java
@@ -27,4 +27,9 @@ public interface MutableAnalysisMetadataHolder extends AnalysisMetadataHolder {
    * @throws IllegalStateException if the analysis date has already been set
    */
   void setAnalysisDate(Date date);
+
+  /**
+   * @throws IllegalStateException if isFirstAnalysis has already been set
+   */
+  void setIsFirstAnalysis(boolean isFirstAnalysis);
 }
diff --git a/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/ReportAnalysisMetadataHolder.java b/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/ReportAnalysisMetadataHolder.java
index fa1fdf3754b..64e4c923d0a 100644
--- a/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/ReportAnalysisMetadataHolder.java
+++ b/server/sonar-server/src/main/java/org/sonar/server/computation/analysis/ReportAnalysisMetadataHolder.java
@@ -28,6 +28,9 @@ public class ReportAnalysisMetadataHolder implements MutableAnalysisMetadataHold
   @CheckForNull
   private Long analysisDate;
 
+  @CheckForNull
+  private Boolean firstAnalysis;
+
   @Override
   public void setAnalysisDate(Date date) {
     checkState(analysisDate == null, "Analysis date has already been set");
@@ -39,4 +42,16 @@ public class ReportAnalysisMetadataHolder implements MutableAnalysisMetadataHold
     checkState(analysisDate != null, "Analysis date has not been set");
     return new Date(this.analysisDate);
   }
+
+  @Override
+  public void setIsFirstAnalysis(boolean firstAnalysis) {
+    checkState(this.firstAnalysis == null, "firstAnalysis flag has already been set");
+    this.firstAnalysis = firstAnalysis;
+  }
+
+  @Override
+  public boolean isFirstAnalysis() {
+    checkState(firstAnalysis != null, "firstAnalysis flag has not been set");
+    return firstAnalysis;
+  }
 }
diff --git a/server/sonar-server/src/main/java/org/sonar/server/computation/scm/ScmInfoRepositoryImpl.java b/server/sonar-server/src/main/java/org/sonar/server/computation/scm/ScmInfoRepositoryImpl.java
index 20a7e1d88b9..b39fc819f20 100644
--- a/server/sonar-server/src/main/java/org/sonar/server/computation/scm/ScmInfoRepositoryImpl.java
+++ b/server/sonar-server/src/main/java/org/sonar/server/computation/scm/ScmInfoRepositoryImpl.java
@@ -28,6 +28,7 @@ import org.sonar.batch.protocol.output.BatchReport;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.protobuf.DbFileSources;
+import org.sonar.server.computation.analysis.AnalysisMetadataHolder;
 import org.sonar.server.computation.batch.BatchReportReader;
 import org.sonar.server.computation.component.Component;
 import org.sonar.server.source.SourceService;
@@ -39,13 +40,15 @@ public class ScmInfoRepositoryImpl implements ScmInfoRepository {
   private static final Logger LOGGER = Loggers.get(ScmInfoRepositoryImpl.class);
 
   private final BatchReportReader batchReportReader;
+  private final AnalysisMetadataHolder analysisMetadataHolder;
   private final DbClient dbClient;
   private final SourceService sourceService;
 
   private final Map<Component, ScmInfo> scmInfoCache = new HashMap<>();
 
-  public ScmInfoRepositoryImpl(BatchReportReader batchReportReader, DbClient dbClient, SourceService sourceService) {
+  public ScmInfoRepositoryImpl(BatchReportReader batchReportReader, AnalysisMetadataHolder analysisMetadataHolder, DbClient dbClient, SourceService sourceService) {
     this.batchReportReader = batchReportReader;
+    this.analysisMetadataHolder = analysisMetadataHolder;
     this.dbClient = dbClient;
     this.sourceService = sourceService;
   }
@@ -68,15 +71,17 @@ public class ScmInfoRepositoryImpl implements ScmInfoRepository {
   private Optional<ScmInfo> getScmInfoForComponent(Component component) {
     BatchReport.Changesets changesets = batchReportReader.readChangesets(component.getReportAttributes().getRef());
     if (changesets == null) {
-      LOGGER.trace("Reading SCM info from db for file '{}'", component);
       return getScmInfoFromDb(component);
-    } else {
-      LOGGER.trace("Reading SCM info from report for file '{}'", component);
-      return Optional.<ScmInfo>of(new ReportScmInfo(changesets));
     }
+    return getScmInfoFromReport(component, changesets);
   }
 
   private Optional<ScmInfo> getScmInfoFromDb(Component component) {
+    if (analysisMetadataHolder.isFirstAnalysis()) {
+      return Optional.absent();
+    }
+    LOGGER.trace("Reading SCM info from db for file '{}'", component);
+
     DbSession dbSession = dbClient.openSession(false);
     try {
       Optional<Iterable<DbFileSources.Line>> linesOpt = sourceService.getLines(dbSession, component.getUuid(), 1, Integer.MAX_VALUE);
@@ -88,4 +93,9 @@ public class ScmInfoRepositoryImpl implements ScmInfoRepository {
       dbClient.closeSession(dbSession);
     }
   }
+
+  private static Optional<ScmInfo> getScmInfoFromReport(Component component, BatchReport.Changesets changesets) {
+    LOGGER.trace("Reading SCM info from report for file '{}'", component);
+    return Optional.<ScmInfo>of(new ReportScmInfo(changesets));
+  }
 }
diff --git a/server/sonar-server/src/main/java/org/sonar/server/computation/step/BuildComponentTreeStep.java b/server/sonar-server/src/main/java/org/sonar/server/computation/step/BuildComponentTreeStep.java
index 6e1e2a2fdc5..036bce963f4 100644
--- a/server/sonar-server/src/main/java/org/sonar/server/computation/step/BuildComponentTreeStep.java
+++ b/server/sonar-server/src/main/java/org/sonar/server/computation/step/BuildComponentTreeStep.java
@@ -28,6 +28,7 @@ import javax.annotation.Nullable;
 import org.sonar.batch.protocol.output.BatchReport;
 import org.sonar.core.component.ComponentKeys;
 import org.sonar.db.DbClient;
+import org.sonar.db.DbSession;
 import org.sonar.server.computation.analysis.MutableAnalysisMetadataHolder;
 import org.sonar.server.computation.batch.BatchReportReader;
 import org.sonar.server.computation.component.Component;
@@ -62,7 +63,18 @@ public class BuildComponentTreeStep implements ComputationStep {
     String branch = reportMetadata.hasBranch() ? reportMetadata.getBranch() : null;
     BatchReport.Component reportProject = reportReader.readComponent(reportMetadata.getRootComponentRef());
     UuidFactory uuidFactory = new UuidFactory(dbClient, moduleKey(reportProject, branch));
-    treeRootHolder.setRoot(new ComponentRootBuilder(reportProject, uuidFactory, branch).build());
+    Component project = new ComponentRootBuilder(reportProject, uuidFactory, branch).build();
+    treeRootHolder.setRoot(project);
+    setIsFirstAnalysis(project.getUuid());
+  }
+
+  private void setIsFirstAnalysis(String projectUuid){
+    DbSession dbSession = dbClient.openSession(false);
+    try {
+      analysisMetadataHolder.setIsFirstAnalysis(!dbClient.snapshotDao().hasLastSnapshotByComponentUuid(dbSession, projectUuid));
+    } finally {
+      dbClient.closeSession(dbSession);
+    }
   }
 
   private class ComponentRootBuilder {
diff --git a/server/sonar-server/src/test/java/org/sonar/server/computation/analysis/MutableAnalysisMetadataHolderRule.java b/server/sonar-server/src/test/java/org/sonar/server/computation/analysis/MutableAnalysisMetadataHolderRule.java
index dd06019d1d9..ba6984f58cc 100644
--- a/server/sonar-server/src/test/java/org/sonar/server/computation/analysis/MutableAnalysisMetadataHolderRule.java
+++ b/server/sonar-server/src/test/java/org/sonar/server/computation/analysis/MutableAnalysisMetadataHolderRule.java
@@ -39,4 +39,14 @@ public class MutableAnalysisMetadataHolderRule extends ExternalResource implemen
   public void setAnalysisDate(Date date) {
     delegate.setAnalysisDate(date);
   }
+
+  @Override
+  public boolean isFirstAnalysis() {
+    return delegate.isFirstAnalysis();
+  }
+
+  @Override
+  public void setIsFirstAnalysis(boolean isFirstAnalysis) {
+    delegate.setIsFirstAnalysis(isFirstAnalysis);
+  }
 }
diff --git a/server/sonar-server/src/test/java/org/sonar/server/computation/analysis/ReportAnalysisMetadataHolderTest.java b/server/sonar-server/src/test/java/org/sonar/server/computation/analysis/ReportAnalysisMetadataHolderTest.java
index d9d6cf93c3b..c5b362d9eee 100644
--- a/server/sonar-server/src/test/java/org/sonar/server/computation/analysis/ReportAnalysisMetadataHolderTest.java
+++ b/server/sonar-server/src/test/java/org/sonar/server/computation/analysis/ReportAnalysisMetadataHolderTest.java
@@ -33,14 +33,6 @@ public class ReportAnalysisMetadataHolderTest {
   private Date someDate = new Date();
 
   @Test
-  public void getAnalysisDate_throws_ISE_when_not_holder_is_not_initialized() {
-    expectedException.expect(IllegalStateException.class);
-    expectedException.expectMessage("Analysis date has not been set");
-
-    new ReportAnalysisMetadataHolder().getAnalysisDate();
-  }
-
-  @Test
   public void getAnalysisDate_returns_date_with_same_time_as_the_one_set_with_setAnalysisDate() throws InterruptedException {
     ReportAnalysisMetadataHolder underTest = new ReportAnalysisMetadataHolder();
 
@@ -54,6 +46,14 @@ public class ReportAnalysisMetadataHolderTest {
   }
 
   @Test
+  public void getAnalysisDate_throws_ISE_when_holder_is_not_initialized() {
+    expectedException.expect(IllegalStateException.class);
+    expectedException.expectMessage("Analysis date has not been set");
+
+    new ReportAnalysisMetadataHolder().getAnalysisDate();
+  }
+
+  @Test
   public void setAnalysisDate_throws_ISE_when_called_twice() {
     expectedException.expect(IllegalStateException.class);
     expectedException.expectMessage("Analysis date has already been set");
@@ -63,4 +63,39 @@ public class ReportAnalysisMetadataHolderTest {
     underTest.setAnalysisDate(someDate);
     underTest.setAnalysisDate(someDate);
   }
+
+  @Test
+  public void isFirstAnalysis_return_true() throws Exception {
+    ReportAnalysisMetadataHolder underTest = new ReportAnalysisMetadataHolder();
+
+    underTest.setIsFirstAnalysis(true);
+    assertThat(underTest.isFirstAnalysis()).isTrue();
+  }
+
+  @Test
+  public void isFirstAnalysis_return_false() throws Exception {
+    ReportAnalysisMetadataHolder underTest = new ReportAnalysisMetadataHolder();
+
+    underTest.setIsFirstAnalysis(false);
+    assertThat(underTest.isFirstAnalysis()).isFalse();
+  }
+
+  @Test
+  public void isFirstAnalysis_throws_ISE_when_holder_is_not_initialized() {
+    expectedException.expect(IllegalStateException.class);
+    expectedException.expectMessage("firstAnalysis flag has not been set");
+
+    new ReportAnalysisMetadataHolder().isFirstAnalysis();
+  }
+
+  @Test
+  public void setIsFirstAnalysis_throws_ISE_when_called_twice() {
+    expectedException.expect(IllegalStateException.class);
+    expectedException.expectMessage("firstAnalysis flag has already been set");
+
+    ReportAnalysisMetadataHolder underTest = new ReportAnalysisMetadataHolder();
+
+    underTest.setIsFirstAnalysis(true);
+    underTest.setIsFirstAnalysis(true);
+  }
 }
diff --git a/server/sonar-server/src/test/java/org/sonar/server/computation/scm/ScmInfoRepositoryImplTest.java b/server/sonar-server/src/test/java/org/sonar/server/computation/scm/ScmInfoRepositoryImplTest.java
index 6108f9f640d..6380d274b2c 100644
--- a/server/sonar-server/src/test/java/org/sonar/server/computation/scm/ScmInfoRepositoryImplTest.java
+++ b/server/sonar-server/src/test/java/org/sonar/server/computation/scm/ScmInfoRepositoryImplTest.java
@@ -30,6 +30,7 @@ import org.sonar.db.DbClient;
 import org.sonar.db.DbTester;
 import org.sonar.db.protobuf.DbFileSources;
 import org.sonar.db.source.FileSourceDto;
+import org.sonar.server.computation.analysis.MutableAnalysisMetadataHolderRule;
 import org.sonar.server.computation.batch.BatchReportReaderRule;
 import org.sonar.server.computation.component.Component;
 import org.sonar.server.source.SourceService;
@@ -41,27 +42,32 @@ import static org.sonar.server.computation.component.ReportComponent.builder;
 
 public class ScmInfoRepositoryImplTest {
 
-  @Rule
-  public LogTester logTester = new LogTester();
+  static final int FILE_REF = 1;
+
+  static final Component FILE = builder(Component.Type.FILE, FILE_REF).setKey("FILE_KEY").setUuid("FILE_UUID").build();
 
   @Rule
   public ExpectedException thrown = ExpectedException.none();
 
-  static final int FILE_REF = 1;
-  static final Component FILE = builder(Component.Type.FILE, FILE_REF).setKey("FILE_KEY").setUuid("FILE_UUID").build();
+  @Rule
+  public LogTester logTester = new LogTester();
 
   @Rule
   public BatchReportReaderRule reportReader = new BatchReportReaderRule();
 
   @Rule
+  public MutableAnalysisMetadataHolderRule analysisMetadataHolder = new MutableAnalysisMetadataHolderRule();
+
+  @Rule
   public DbTester dbTester = DbTester.create(System2.INSTANCE);
 
   DbClient dbClient = dbTester.getDbClient();
 
-  ScmInfoRepositoryImpl underTest = new ScmInfoRepositoryImpl(reportReader, dbClient, new SourceService(dbClient, null));
+  ScmInfoRepositoryImpl underTest = new ScmInfoRepositoryImpl(reportReader, analysisMetadataHolder, dbClient, new SourceService(dbClient, null));
 
   @Test
   public void read_from_report() throws Exception {
+    analysisMetadataHolder.setIsFirstAnalysis(false);
     addChangesetInReport("john", 123456789L, "rev-1");
 
     ScmInfo scmInfo = underTest.getScmInfo(FILE).get();
@@ -72,6 +78,7 @@ public class ScmInfoRepositoryImplTest {
 
   @Test
   public void read_from_db() throws Exception {
+    analysisMetadataHolder.setIsFirstAnalysis(false);
     addChangesetInDb("henry", 123456789L, "rev-1");
 
     ScmInfo scmInfo = underTest.getScmInfo(FILE).get();
@@ -82,6 +89,7 @@ public class ScmInfoRepositoryImplTest {
 
   @Test
   public void read_from_report_even_if_data_in_db_exists() throws Exception {
+    analysisMetadataHolder.setIsFirstAnalysis(false);
     addChangesetInDb("henry", 123456789L, "rev-1");
 
     addChangesetInReport("john", 1234567810L, "rev-2");
@@ -96,11 +104,13 @@ public class ScmInfoRepositoryImplTest {
 
   @Test
   public void return_nothing_when_no_data_in_report_and_db() throws Exception {
+    analysisMetadataHolder.setIsFirstAnalysis(false);
     assertThat(underTest.getScmInfo(FILE)).isAbsent();
   }
 
   @Test
-  public void return_nothing_when_nothing_in_erpot_and_db_has_no_scm() throws Exception {
+  public void return_nothing_when_nothing_in_report_and_db_has_no_scm() throws Exception {
+    analysisMetadataHolder.setIsFirstAnalysis(false);
     DbFileSources.Data.Builder fileDataBuilder = DbFileSources.Data.newBuilder();
     fileDataBuilder.addLinesBuilder()
       .setLine(1);
@@ -114,6 +124,8 @@ public class ScmInfoRepositoryImplTest {
 
   @Test
   public void fail_with_NPE_when_component_is_null() throws Exception {
+    analysisMetadataHolder.setIsFirstAnalysis(false);
+
     thrown.expect(NullPointerException.class);
     thrown.expectMessage("Component cannot be bull");
 
@@ -122,6 +134,7 @@ public class ScmInfoRepositoryImplTest {
 
   @Test
   public void load_scm_info_from_cache_when_already_read() throws Exception {
+    analysisMetadataHolder.setIsFirstAnalysis(false);
     addChangesetInReport("john", 123456789L, "rev-1");
     ScmInfo scmInfo = underTest.getScmInfo(FILE).get();
     assertThat(scmInfo.getAllChangesets()).hasSize(1);
@@ -133,6 +146,15 @@ public class ScmInfoRepositoryImplTest {
     assertThat(logTester.logs(TRACE)).isEmpty();
   }
 
+  @Test
+  public void not_read_in_db_on_first_analysis() throws Exception {
+    analysisMetadataHolder.setIsFirstAnalysis(true);
+    addChangesetInDb("henry", 123456789L, "rev-1");
+
+    assertThat(underTest.getScmInfo(FILE)).isAbsent();
+    assertThat(logTester.logs(TRACE)).isEmpty();
+  }
+
   private void addChangesetInDb(String author, Long date, String revision) {
     DbFileSources.Data.Builder fileDataBuilder = DbFileSources.Data.newBuilder();
     fileDataBuilder.addLinesBuilder()
diff --git a/server/sonar-server/src/test/java/org/sonar/server/computation/step/BuildComponentTreeStepTest.java b/server/sonar-server/src/test/java/org/sonar/server/computation/step/BuildComponentTreeStepTest.java
index 788507d9197..c085483ace5 100644
--- a/server/sonar-server/src/test/java/org/sonar/server/computation/step/BuildComponentTreeStepTest.java
+++ b/server/sonar-server/src/test/java/org/sonar/server/computation/step/BuildComponentTreeStepTest.java
@@ -38,6 +38,7 @@ import org.sonar.batch.protocol.output.BatchReport.Metadata;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbTester;
 import org.sonar.db.component.ComponentDto;
+import org.sonar.db.component.SnapshotDto;
 import org.sonar.server.computation.analysis.MutableAnalysisMetadataHolderRule;
 import org.sonar.server.computation.batch.BatchReportReaderRule;
 import org.sonar.server.computation.component.Component;
@@ -53,6 +54,7 @@ import static org.sonar.db.component.ComponentTesting.newDirectory;
 import static org.sonar.db.component.ComponentTesting.newFileDto;
 import static org.sonar.db.component.ComponentTesting.newModuleDto;
 import static org.sonar.db.component.ComponentTesting.newProjectDto;
+import static org.sonar.db.component.SnapshotTesting.newSnapshotForProject;
 
 @Category(DbTests.class)
 @RunWith(DataProviderRunner.class)
@@ -274,6 +276,36 @@ public class BuildComponentTreeStepTest {
     verifyComponent(FILE_1_REF, REPORT_MODULE_KEY + ":" + REPORT_FILE_KEY_1, "DEFG");
   }
 
+  @Test
+  public void set_first_analysis_to_true_when_no_snapshot() throws Exception {
+    reportReader.putComponent(componentWithKey(ROOT_REF, PROJECT, REPORT_PROJECT_KEY));
+    underTest.execute();
+
+    assertThat(analysisMetadataHolder.isFirstAnalysis()).isTrue();
+  }
+
+  @Test
+  public void set_first_analysis_to_true_when_no_last_snapshot() throws Exception {
+    ComponentDto project = insertComponent(newProjectDto("ABCD").setKey(REPORT_PROJECT_KEY));
+    insertSnapshot(newSnapshotForProject(project).setLast(false));
+
+    reportReader.putComponent(componentWithKey(ROOT_REF, PROJECT, REPORT_PROJECT_KEY));
+    underTest.execute();
+
+    assertThat(analysisMetadataHolder.isFirstAnalysis()).isTrue();
+  }
+
+  @Test
+  public void set_first_analysis_to_false_when_last_snapshot_exist() throws Exception {
+    ComponentDto project = insertComponent(newProjectDto("ABCD").setKey(REPORT_PROJECT_KEY));
+    insertSnapshot(newSnapshotForProject(project).setLast(true));
+
+    reportReader.putComponent(componentWithKey(ROOT_REF, PROJECT, REPORT_PROJECT_KEY));
+    underTest.execute();
+
+    assertThat(analysisMetadataHolder.isFirstAnalysis()).isFalse();
+  }
+
   private void verifyComponent(Component component, Component.Type type, int componentRef, int size) {
     assertThat(component.getType()).isEqualTo(type);
     assertThat(component.getReportAttributes().getRef()).isEqualTo(componentRef);
@@ -342,4 +374,10 @@ public class BuildComponentTreeStepTest {
     return component;
   }
 
+  private SnapshotDto insertSnapshot(SnapshotDto snapshot) {
+    dbClient.snapshotDao().insert(dbTester.getSession(), snapshot);
+    dbTester.getSession().commit();
+    return snapshot;
+  }
+
 }
diff --git a/sonar-db/src/main/java/org/sonar/db/component/SnapshotDao.java b/sonar-db/src/main/java/org/sonar/db/component/SnapshotDao.java
index 46306bf9a04..55d3fbbb630 100644
--- a/sonar-db/src/main/java/org/sonar/db/component/SnapshotDao.java
+++ b/sonar-db/src/main/java/org/sonar/db/component/SnapshotDao.java
@@ -53,6 +53,10 @@ public class SnapshotDao implements Dao {
     return mapper(session).selectLastSnapshot(componentId);
   }
 
+  public boolean hasLastSnapshotByComponentUuid(DbSession session, String componentUUid) {
+    return mapper(session).countLastSnapshotByComponentUuid(componentUUid) > 0;
+  }
+
   public List<SnapshotDto> selectSnapshotsByComponentId(DbSession session, long componentId) {
     return mapper(session).selectSnapshotsByQuery(new SnapshotQuery().setComponentId(componentId));
   }
diff --git a/sonar-db/src/main/java/org/sonar/db/component/SnapshotMapper.java b/sonar-db/src/main/java/org/sonar/db/component/SnapshotMapper.java
index 49fe34a0ee0..a77633f7d1a 100644
--- a/sonar-db/src/main/java/org/sonar/db/component/SnapshotMapper.java
+++ b/sonar-db/src/main/java/org/sonar/db/component/SnapshotMapper.java
@@ -34,6 +34,8 @@ public interface SnapshotMapper {
   @CheckForNull
   SnapshotDto selectLastSnapshot(Long resourceId);
 
+  int countLastSnapshotByComponentUuid(String componentUuid);
+
   List<SnapshotDto> selectSnapshotsByQuery(@Param("query") SnapshotQuery query);
 
   List<SnapshotDto> selectPreviousVersionSnapshots(@Param(value = "componentId") Long componentId, @Param(value = "lastVersion") String lastVersion);
diff --git a/sonar-db/src/main/resources/org/sonar/db/component/SnapshotMapper.xml b/sonar-db/src/main/resources/org/sonar/db/component/SnapshotMapper.xml
index 6892b27e3b6..01b89c7e1aa 100644
--- a/sonar-db/src/main/resources/org/sonar/db/component/SnapshotMapper.xml
+++ b/sonar-db/src/main/resources/org/sonar/db/component/SnapshotMapper.xml
@@ -56,6 +56,15 @@
     where s.islast=${_true} and s.project_id = #{resource}
   </select>
 
+  <select id="countLastSnapshotByComponentUuid" resultType="Integer">
+    SELECT count(s.id)
+    FROM snapshots s
+    INNER JOIN projects p ON p.id=s.project_id AND p.uuid=#{componentUuid}
+    <where>
+      AND s.islast=${_true}
+    </where>
+  </select>
+
   <select id="selectSnapshotsByQuery" parameterType="map" resultType="Snapshot">
     SELECT
     <include refid="snapshotColumns"/>
diff --git a/sonar-db/src/test/java/org/sonar/db/component/SnapshotDaoTest.java b/sonar-db/src/test/java/org/sonar/db/component/SnapshotDaoTest.java
index 4377a7d45ca..9768a52e1c6 100644
--- a/sonar-db/src/test/java/org/sonar/db/component/SnapshotDaoTest.java
+++ b/sonar-db/src/test/java/org/sonar/db/component/SnapshotDaoTest.java
@@ -261,6 +261,15 @@ public class SnapshotDaoTest {
     assertThat(isLast).isFalse();
   }
 
+  @Test
+  public void has_last_snapshot_by_component_uuid() throws Exception {
+    db.prepareDbUnit(getClass(), "has_last_snapshot_by_component_uuid.xml");
+
+    assertThat(underTest.hasLastSnapshotByComponentUuid(db.getSession(), "ABCD")).isTrue();
+    assertThat(underTest.hasLastSnapshotByComponentUuid(db.getSession(), "EFGH")).isFalse();
+    assertThat(underTest.hasLastSnapshotByComponentUuid(db.getSession(), "FGHI")).isFalse();
+  }
+
   private static SnapshotDto defaultSnapshot() {
     return new SnapshotDto()
       .setComponentId(3L)
diff --git a/sonar-db/src/test/resources/org/sonar/db/component/SnapshotDaoTest/has_last_snapshot_by_component_uuid.xml b/sonar-db/src/test/resources/org/sonar/db/component/SnapshotDaoTest/has_last_snapshot_by_component_uuid.xml
new file mode 100644
index 00000000000..16f7fe75471
--- /dev/null
+++ b/sonar-db/src/test/resources/org/sonar/db/component/SnapshotDaoTest/has_last_snapshot_by_component_uuid.xml
@@ -0,0 +1,48 @@
+<dataset>
+
+  <!-- Has last snapshot -->
+  <projects id="1" root_id="[null]" scope="PRJ" qualifier="TRK" kee="org.struts:struts" name="Struts"
+            uuid="ABCD" project_uuid="ABCD" module_uuid="[null]" module_uuid_path="."
+            description="the description" long_name="Apache Struts"
+            enabled="[true]" language="[null]" copy_resource_id="[null]" person_id="[null]" path="[null]" authorization_updated_at="[null]" />
+  <snapshots id="1" project_id="1" parent_snapshot_id="[null]" root_project_id="1" root_snapshot_id="[null]"
+             status="P" islast="[true]" purge_status="[null]"
+             period1_mode="[null]" period1_param="[null]" period1_date="[null]"
+             period2_mode="[null]" period2_param="[null]" period2_date="[null]"
+             period3_mode="[null]" period3_param="[null]" period3_date="[null]"
+             period4_mode="[null]" period4_param="[null]" period4_date="[null]"
+             period5_mode="[null]" period5_param="[null]" period5_date="[null]"
+             depth="[null]" scope="PRJ" qualifier="TRK" created_at="1228222680000" build_date="1228222680000"
+             version="[null]" path=""/>
+  <snapshots id="10" project_id="1" parent_snapshot_id="[null]" root_project_id="1" root_snapshot_id="[null]"
+             status="P" islast="[false]" purge_status="[null]"
+             period1_mode="[null]" period1_param="[null]" period1_date="[null]"
+             period2_mode="[null]" period2_param="[null]" period2_date="[null]"
+             period3_mode="[null]" period3_param="[null]" period3_date="[null]"
+             period4_mode="[null]" period4_param="[null]" period4_date="[null]"
+             period5_mode="[null]" period5_param="[null]" period5_date="[null]"
+             depth="[null]" scope="PRJ" qualifier="TRK" created_at="1228136280000" build_date="1228136280000"
+             version="[null]" path=""/>
+
+  <!-- No snapshot -->
+  <projects id="2" root_id="1" kee="org.struts:struts-core" name="Struts Core"
+            uuid="EFGH" project_uuid="ABCD" module_uuid="[null]" module_uuid_path=".ABCD."
+            scope="PRJ" qualifier="BRC" long_name="Struts Core"
+            description="[null]" enabled="[true]" language="[null]" copy_resource_id="[null]" person_id="[null]" authorization_updated_at="[null]" />
+
+  <!-- No last snapshot -->
+  <projects id="3" root_id="1" kee="org.struts:struts-data" name="Struts Data"
+            uuid="FGHI" project_uuid="ABCD" module_uuid="EFGH" module_uuid_path=".ABCD.EFGH."
+            scope="PRJ" qualifier="BRC" long_name="Struts Data"
+            description="[null]" enabled="[true]" language="[null]" copy_resource_id="[null]" person_id="[null]" authorization_updated_at="[null]" />
+  <snapshots id="3" project_id="3" parent_snapshot_id="2" root_project_id="1" root_snapshot_id="1"
+             status="P" islast="[false]" purge_status="[null]"
+             period1_mode="[null]" period1_param="[null]" period1_date="[null]"
+             period2_mode="[null]" period2_param="[null]" period2_date="[null]"
+             period3_mode="[null]" period3_param="[null]" period3_date="[null]"
+             period4_mode="[null]" period4_param="[null]" period4_date="[null]"
+             period5_mode="[null]" period5_param="[null]" period5_date="[null]"
+             depth="[null]" scope="PRJ" qualifier="BRC" created_at="1228222680000" build_date="1228222680000"
+             version="[null]" path="1.2."/>
+
+</dataset>