Expose URLYangTextSource
[yangtools.git] / plugin / yang-maven-plugin / src / main / java / org / opendaylight / yangtools / yang2sources / plugin / YangToSourcesProcessor.java
index f180634968d4e477b9c77e5fa9962a83740095a7..8297a392e2e04fe863f52773ff3fa0daf20b3703 100644 (file)
@@ -7,29 +7,30 @@
  */
 package org.opendaylight.yangtools.yang2sources.plugin;
 
-import static com.google.common.base.Preconditions.checkState;
 import static java.util.Objects.requireNonNull;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Stopwatch;
 import com.google.common.base.Throwables;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.ImmutableSet.Builder;
 import com.google.common.collect.Maps;
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Iterator;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.Optional;
+import java.util.NoSuchElementException;
 import java.util.ServiceLoader;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
@@ -38,9 +39,9 @@ import org.eclipse.jdt.annotation.NonNull;
 import org.opendaylight.yangtools.plugin.generator.api.FileGeneratorException;
 import org.opendaylight.yangtools.plugin.generator.api.FileGeneratorFactory;
 import org.opendaylight.yangtools.yang.common.YangConstants;
-import org.opendaylight.yangtools.yang.model.repo.api.YangIRSchemaSource;
-import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
-import org.opendaylight.yangtools.yang.parser.api.YangParser;
+import org.opendaylight.yangtools.yang.model.spi.source.DelegatedYangTextSource;
+import org.opendaylight.yangtools.yang.model.spi.source.YangIRSchemaSource;
+import org.opendaylight.yangtools.yang.model.spi.source.YangTextSource;
 import org.opendaylight.yangtools.yang.parser.api.YangParserConfiguration;
 import org.opendaylight.yangtools.yang.parser.api.YangParserException;
 import org.opendaylight.yangtools.yang.parser.api.YangParserFactory;
@@ -51,32 +52,64 @@ import org.slf4j.LoggerFactory;
 import org.sonatype.plexus.build.incremental.BuildContext;
 import org.sonatype.plexus.build.incremental.DefaultBuildContext;
 
+// FIXME: rename to Execution
+// FIXME: final
 class YangToSourcesProcessor {
     private static final Logger LOG = LoggerFactory.getLogger(YangToSourcesProcessor.class);
     private static final YangParserFactory DEFAULT_PARSER_FACTORY;
 
     static {
-        final Iterator<YangParserFactory> it = ServiceLoader.load(YangParserFactory.class).iterator();
-        checkState(it.hasNext(), "Failed to find a YangParserFactory implementation");
-        DEFAULT_PARSER_FACTORY = it.next();
+        try {
+            DEFAULT_PARSER_FACTORY = ServiceLoader.load(YangParserFactory.class).iterator().next();
+        } catch (NoSuchElementException e) {
+            throw new IllegalStateException("Failed to find a YangParserFactory implementation", e);
+        }
     }
 
-    static final String LOG_PREFIX = "yang-to-sources:";
     private static final String META_INF_STR = "META-INF";
     private static final String YANG_STR = "yang";
 
+    static final String LOG_PREFIX = "yang-to-sources:";
     static final String META_INF_YANG_STRING = META_INF_STR + File.separator + YANG_STR;
     static final String META_INF_YANG_STRING_JAR = META_INF_STR + "/" + YANG_STR;
     static final String META_INF_YANG_SERVICES_STRING_JAR = META_INF_STR + "/" + "services";
 
+    private static final YangProvider YANG_PROVIDER = (project, modelsInProject) -> {
+        final var generatedYangDir =
+            // FIXME: why are we generating these in "generated-sources"? At the end of the day YANG files are more
+            //        resources (except we do not them to be subject to filtering)
+            new File(new File(project.getBuild().getDirectory(), "generated-sources"), "yang");
+        LOG.debug("Generated dir {}", generatedYangDir);
+
+        // copy project's src/main/yang/*.yang to ${project.builddir}/generated-sources/yang/META-INF/yang/
+        // This honors setups like a Eclipse-profile derived one
+        final var withMetaInf = new File(generatedYangDir, YangToSourcesProcessor.META_INF_YANG_STRING);
+        Files.createDirectories(withMetaInf.toPath());
+
+        final var stateListBuilder = ImmutableList.<FileState>builderWithExpectedSize(modelsInProject.size());
+        for (var source : modelsInProject) {
+            final File file = new File(withMetaInf, source.sourceId().toYangFilename());
+            stateListBuilder.add(FileState.ofWrittenFile(file,
+                out -> source.asByteSource(StandardCharsets.UTF_8).copyTo(out)));
+            LOG.debug("Created file {} for {}", file, source.sourceId());
+        }
+
+        ProjectFileAccess.addResourceDir(project, generatedYangDir);
+        LOG.debug("{} YANG files marked as resources: {}", YangToSourcesProcessor.LOG_PREFIX, generatedYangDir);
+
+        return stateListBuilder.build();
+    };
+
     private final YangParserFactory parserFactory;
     private final File yangFilesRootDir;
     private final Set<File> excludedFiles;
-    private final Map<String, FileGeneratorArg> fileGeneratorArgs;
+    private final ImmutableMap<String, FileGeneratorArg> fileGeneratorArgs;
     private final @NonNull MavenProject project;
     private final boolean inspectDependencies;
-    private final BuildContext buildContext;
+    private final @NonNull BuildContext buildContext;
     private final YangProvider yangProvider;
+    private final StateStorage stateStorage;
+    private final String projectBuildDirectory;
 
     private YangToSourcesProcessor(final BuildContext buildContext, final File yangFilesRootDir,
             final Collection<File> excludedFiles, final List<FileGeneratorArg> fileGeneratorsArgs,
@@ -89,34 +122,38 @@ class YangToSourcesProcessor {
         this.project = requireNonNull(project);
         this.inspectDependencies = inspectDependencies;
         this.yangProvider = requireNonNull(yangProvider);
+        projectBuildDirectory = project.getBuild().getDirectory();
+        stateStorage = StateStorage.of(buildContext, stateFilePath(projectBuildDirectory));
         parserFactory = DEFAULT_PARSER_FACTORY;
     }
 
     @VisibleForTesting
-    YangToSourcesProcessor(final File yangFilesRootDir, final Collection<File> excludedFiles,
-            final List<FileGeneratorArg> fileGenerators, final MavenProject project, final boolean inspectDependencies,
-            final YangProvider yangProvider) {
-        this(new DefaultBuildContext(), yangFilesRootDir, excludedFiles, ImmutableList.of(),
-            project, inspectDependencies, yangProvider);
+    YangToSourcesProcessor(final File yangFilesRootDir, final List<FileGeneratorArg> fileGenerators,
+            final MavenProject project, final YangProvider yangProvider) {
+        this(new DefaultBuildContext(), yangFilesRootDir, List.of(), List.of(), project, false, yangProvider);
     }
 
     YangToSourcesProcessor(final BuildContext buildContext, final File yangFilesRootDir,
             final Collection<File> excludedFiles, final List<FileGeneratorArg> fileGenerators,
             final MavenProject project, final boolean inspectDependencies) {
         this(buildContext, yangFilesRootDir, excludedFiles, fileGenerators, project, inspectDependencies,
-            YangProvider.getInstance());
+            YANG_PROVIDER);
     }
 
-    public void execute() throws MojoExecutionException, MojoFailureException {
-        conditionalExecute(false);
-    }
+    void execute() throws MojoExecutionException, MojoFailureException {
+        YangToSourcesState prevState;
+        try {
+            prevState = stateStorage.loadState();
+        } catch (IOException e) {
+            throw new MojoFailureException("Failed to restore execution state", e);
+        }
+        if (prevState == null) {
+            LOG.debug("{} no previous execution state present", LOG_PREFIX);
+            prevState = new YangToSourcesState(ImmutableMap.of(),
+                    FileStateSet.empty(), FileStateSet.empty(), FileStateSet.empty());
+        }
 
-    void conditionalExecute(final boolean skip) throws MojoExecutionException, MojoFailureException {
-        /*
-         * Collect all files which affect YANG context. This includes all
-         * files in current project and optionally any jars/files in the
-         * dependencies.
-         */
+        // Collect all files in the current project.
         final List<File> yangFilesInProject;
         try {
             yangFilesInProject = listFiles(yangFilesRootDir, excludedFiles);
@@ -127,55 +164,90 @@ class YangToSourcesProcessor {
         if (yangFilesInProject.isEmpty()) {
             // No files to process, skip.
             LOG.info("{} No input files found", LOG_PREFIX);
+            wipeAllState(prevState);
             return;
         }
 
         // We need to instantiate all code generators to determine required import resolution mode
-        final List<GeneratorTaskFactory> codeGenerators = instantiateGenerators();
+        final var codeGenerators = instantiateGenerators();
         if (codeGenerators.isEmpty()) {
             LOG.warn("{} No code generators provided", LOG_PREFIX);
+            wipeAllState(prevState);
             return;
         }
 
-        final Set<YangParserConfiguration> parserConfigs = codeGenerators.stream()
-            .map(GeneratorTaskFactory::parserConfig)
-            .collect(Collectors.toUnmodifiableSet());
-
         LOG.info("{} Inspecting {}", LOG_PREFIX, yangFilesRootDir);
 
-        final Collection<File> allFiles = new ArrayList<>(yangFilesInProject);
-        final Collection<ScannedDependency> dependencies;
+        // All files which affect YANG context. This minimally includes all files in the current project, but optionally
+        // may include any YANG files in the dependencies.
+        final List<ScannedDependency> dependencies;
         if (inspectDependencies) {
-            dependencies = new ArrayList<>();
             final Stopwatch watch = Stopwatch.createStarted();
-
             try {
-                ScannedDependency.scanDependencies(project).forEach(dep -> {
-                    allFiles.add(dep.file());
-                    dependencies.add(dep);
-                });
+                dependencies = ScannedDependency.scanDependencies(project);
             } catch (IOException e) {
                 LOG.error("{} Failed to scan dependencies", LOG_PREFIX, e);
                 throw new MojoExecutionException(LOG_PREFIX + " Failed to scan dependencies ", e);
             }
             LOG.info("{} Found {} dependencies in {}", LOG_PREFIX, dependencies.size(), watch);
         } else {
-            dependencies = ImmutableList.of();
+            dependencies = List.of();
         }
 
-        /*
-         * Check if any of the listed files changed. If no changes occurred, simply return empty, which indicates
-         * end of execution.
-         */
-        if (!allFiles.stream().anyMatch(buildContext::hasDelta)) {
-            LOG.info("{} None of {} input files changed", LOG_PREFIX, allFiles.size());
-            return;
+        // Determine hash/size of YANG input files and dependencies in parallel
+        final var hashTimer = Stopwatch.createStarted();
+        final var projectYangs = new FileStateSet(yangFilesInProject.parallelStream()
+            .map(file -> {
+                try {
+                    return FileState.ofFile(file);
+                } catch (IOException e) {
+                    throw new IllegalStateException("Failed to read " + file, e);
+                }
+            })
+            .collect(ImmutableMap.toImmutableMap(FileState::path, Function.identity())));
+        // TODO: this produces false positives for Jar files -- there we want to capture the contents of the YANG files,
+        //       not the entire file
+        final var dependencyYangs = new FileStateSet(dependencies.parallelStream()
+            .map(ScannedDependency::file)
+            .map(file -> {
+                try {
+                    return FileState.ofFile(file);
+                } catch (IOException e) {
+                    throw new IllegalStateException("Failed to read " + file, e);
+                }
+            })
+            .collect(ImmutableMap.toImmutableMap(FileState::path, Function.identity())));
+        LOG.debug("{} Input state determined in {}", LOG_PREFIX, hashTimer);
+
+        // We have collected our current inputs and previous state. Instantiate a support object which will guide us for
+        // the rest of the way.
+        final var buildSupport = new IncrementalBuildSupport(prevState,
+            codeGenerators.stream()
+                .collect(ImmutableMap.toImmutableMap(GeneratorTask::getIdentifier, GeneratorTask::arg)),
+            projectYangs, dependencyYangs);
+
+        // Check if any inputs changed, which is supposed to be fast. If they did not, we need to also validate our
+        // our previous are also up-to-date.
+        if (!buildSupport.inputsChanged()) {
+            final boolean outputsChanged;
+            try {
+                outputsChanged = buildSupport.outputsChanged(projectBuildDirectory);
+            } catch (IOException e) {
+                throw new MojoFailureException("Failed to reconcile generation outputs", e);
+            }
+
+            if (!outputsChanged) {
+                // FIXME: YANGTOOLS-745: still need to add all resources/directories to maven project
+                LOG.info("{}: Everything is up to date, nothing to do", LOG_PREFIX);
+                return;
+            }
         }
 
         final Stopwatch watch = Stopwatch.createStarted();
-        final List<Entry<YangTextSchemaSource, YangIRSchemaSource>> parsed = yangFilesInProject.parallelStream()
+
+        final List<Entry<YangTextSource, YangIRSchemaSource>> parsed = yangFilesInProject.parallelStream()
             .map(file -> {
-                final YangTextSchemaSource textSource = YangTextSchemaSource.forPath(file.toPath());
+                final var textSource = YangTextSource.forPath(file.toPath());
                 try {
                     return Map.entry(textSource, TextToIRTransformer.transformText(textSource));
                 } catch (YangSyntaxErrorException | IOException e) {
@@ -186,72 +258,119 @@ class YangToSourcesProcessor {
         LOG.debug("Found project files: {}", yangFilesInProject);
         LOG.info("{} Project model files found: {} in {}", LOG_PREFIX, yangFilesInProject.size(), watch);
 
-        // FIXME: store these files into state, so that we can verify/clean up
-        final Builder<File> files = ImmutableSet.builder();
-        for (YangParserConfiguration parserConfig : parserConfigs) {
-            final Optional<ProcessorModuleReactor> optReactor = createReactor(yangFilesInProject,
-                parserConfig, dependencies, parsed);
-            if (optReactor.isPresent()) {
-                final ProcessorModuleReactor reactor = optReactor.orElseThrow();
-
-                if (!skip) {
-                    final Stopwatch sw = Stopwatch.createStarted();
-                    final ContextHolder holder;
-
-                    try {
-                        holder = reactor.toContext();
-                    } catch (YangParserException e) {
-                        throw new MojoFailureException("Failed to process reactor " + reactor, e);
-                    } catch (IOException e) {
-                        throw new MojoExecutionException("Failed to read reactor " + reactor, e);
-                    }
-
-                    LOG.info("{} {} YANG models processed in {}", LOG_PREFIX, holder.getContext().getModules().size(),
-                        sw);
-                    files.addAll(generateSources(holder, codeGenerators, parserConfig));
-                } else {
-                    LOG.info("{} Skipping YANG code generation because property yang.skip is true", LOG_PREFIX);
+        final var outputFiles = ImmutableList.<FileState>builder();
+        Collection<YangTextSource> modelsInProject = null;
+        for (var parserConfig : codeGenerators.stream().map(GeneratorTask::parserConfig).collect(Collectors.toSet())) {
+            final var moduleReactor = createReactor(yangFilesInProject, parserConfig, dependencies, parsed);
+            final var yangSw = Stopwatch.createStarted();
+
+            final ContextHolder holder;
+            try {
+                holder = moduleReactor.toContext();
+            } catch (YangParserException e) {
+                throw new MojoFailureException("Failed to process reactor " + moduleReactor, e);
+            } catch (IOException e) {
+                throw new MojoExecutionException("Failed to read reactor " + moduleReactor, e);
+            }
+            LOG.info("{} {} YANG models processed in {}", LOG_PREFIX, holder.getContext().getModules().size(), yangSw);
+
+            for (var factory : codeGenerators) {
+                if (!parserConfig.equals(factory.parserConfig())) {
+                    continue;
                 }
 
-                // FIXME: this is not right: we should be generating the models exactly once!
-                // add META_INF/yang
-                final Collection<YangTextSchemaSource> models = reactor.getModelsInProject();
+                final var genSw = Stopwatch.createStarted();
+                final List<FileState> files;
                 try {
-                    yangProvider.addYangsToMetaInf(project, models);
-                } catch (IOException e) {
-                    throw new MojoExecutionException("Failed write model files for " + models, e);
+                    files = factory.execute(project, buildContext, holder);
+                } catch (FileGeneratorException e) {
+                    throw new MojoFailureException(LOG_PREFIX + " Generator " + factory + " failed", e);
                 }
+
+                outputFiles.addAll(files);
+                LOG.info("{} Sources generated by {}: {} in {}", LOG_PREFIX, factory.generatorName(), files.size(),
+                    genSw);
             }
+
+            if (modelsInProject == null) {
+                // FIXME: this is an invariant, we should prepare these separately
+                modelsInProject = moduleReactor.getModelsInProject();
+            }
+        }
+
+        // add META_INF/yang once
+        try {
+            outputFiles.addAll(yangProvider.addYangsToMetaInf(project, modelsInProject));
+        } catch (IOException e) {
+            throw new MojoExecutionException("Failed write model files for " + modelsInProject, e);
         }
 
         // add META_INF/services
-        File generatedServicesDir = new GeneratedDirectories(project).getYangServicesDir();
-        YangProvider.setResource(generatedServicesDir, project);
+        File generatedServicesDir = new File(new File(projectBuildDirectory, "generated-sources"), "spi");
+        ProjectFileAccess.addResourceDir(project, generatedServicesDir);
         LOG.debug("{} Yang services files from: {} marked as resources: {}", LOG_PREFIX, generatedServicesDir,
             META_INF_YANG_SERVICES_STRING_JAR);
+
+        final var uniqueOutputFiles = new LinkedHashMap<String, FileState>();
+        for (var fileHash : outputFiles.build()) {
+            final var prev = uniqueOutputFiles.putIfAbsent(fileHash.path(), fileHash);
+            if (prev != null) {
+                throw new MojoFailureException("Duplicate files " + prev + " and " + fileHash);
+            }
+        }
+
+        // Reconcile push output files into project directory and acquire the execution state
+        final YangToSourcesState outputState;
+        try {
+            outputState = buildSupport.reconcileOutputFiles(buildContext, projectBuildDirectory, uniqueOutputFiles);
+        } catch (IOException e) {
+            throw new MojoFailureException("Failed to reconcile output files", e);
+        }
+
+        // Store execution state
+        try {
+            stateStorage.storeState(outputState);
+        } catch (IOException e) {
+            throw new MojoFailureException("Failed to store execution state", e);
+        }
+    }
+
+    private void wipeAllState(final YangToSourcesState prevState) throws MojoExecutionException {
+        try {
+            prevState.deleteOutputFiles();
+        } catch (IOException e) {
+            throw new MojoExecutionException("Failed to delete output files", e);
+        }
+        try {
+            stateStorage.deleteState();
+        } catch (IOException e) {
+            throw new MojoExecutionException("Failed to remove execution state", e);
+        }
     }
 
-    private List<GeneratorTaskFactory> instantiateGenerators() throws MojoExecutionException {
+    private ImmutableList<@NonNull GeneratorTask> instantiateGenerators() throws MojoExecutionException {
         // Search for available FileGenerator implementations
-        final Map<String, FileGeneratorFactory> factories = Maps.uniqueIndex(
+        final var factories = Maps.uniqueIndex(
             ServiceLoader.load(FileGeneratorFactory.class), FileGeneratorFactory::getIdentifier);
 
         // FIXME: iterate over fileGeneratorArg instances (configuration), not factories (environment)
         // Assign instantiate FileGenerators with appropriate configuration
-        final List<GeneratorTaskFactory> generators = new ArrayList<>(factories.size());
-        for (Entry<String, FileGeneratorFactory> entry : factories.entrySet()) {
-            final String id = entry.getKey();
-            FileGeneratorArg arg = fileGeneratorArgs.get(id);
+        final var builder = ImmutableList.<@NonNull GeneratorTask>builderWithExpectedSize(factories.size());
+        for (var entry : factories.entrySet()) {
+            final var id = entry.getKey();
+            var arg = fileGeneratorArgs.get(id);
             if (arg == null) {
                 LOG.debug("{} No configuration for {}, using empty", LOG_PREFIX, id);
                 arg = new FileGeneratorArg(id);
             }
 
+            final GeneratorTask task;
             try {
-                generators.add(GeneratorTaskFactory.of(entry.getValue(), arg));
+                task = new GeneratorTask(entry.getValue(), arg);
             } catch (FileGeneratorException e) {
                 throw new MojoExecutionException("File generator " + id + " failed", e);
             }
+            builder.add(task);
             LOG.info("{} Code generator {} instantiated", LOG_PREFIX, id);
         }
 
@@ -264,94 +383,65 @@ class YangToSourcesProcessor {
             }
         );
 
-        return generators;
+        return builder.build();
     }
 
     @SuppressWarnings("checkstyle:illegalCatch")
-    private Optional<ProcessorModuleReactor> createReactor(final List<File> yangFilesInProject,
+    private @NonNull ProcessorModuleReactor createReactor(final List<File> yangFilesInProject,
             final YangParserConfiguration parserConfig, final Collection<ScannedDependency> dependencies,
-            final List<Entry<YangTextSchemaSource, YangIRSchemaSource>> parsed) throws MojoExecutionException {
+            final List<Entry<YangTextSource, YangIRSchemaSource>> parsed) throws MojoExecutionException {
 
         try {
-            final List<YangTextSchemaSource> sourcesInProject = new ArrayList<>(yangFilesInProject.size());
-            final YangParser parser = parserFactory.createParser(parserConfig);
-            for (final Entry<YangTextSchemaSource, YangIRSchemaSource> entry : parsed) {
-                final YangTextSchemaSource textSource = entry.getKey();
-                final YangIRSchemaSource astSource = entry.getValue();
+            final var sourcesInProject = new ArrayList<YangTextSource>(yangFilesInProject.size());
+            final var parser = parserFactory.createParser(parserConfig);
+            for (var entry : parsed) {
+                final var textSource = entry.getKey();
+                final var astSource = entry.getValue();
                 parser.addSource(astSource);
 
-                if (!astSource.getIdentifier().equals(textSource.getIdentifier())) {
+                if (!astSource.sourceId().equals(textSource.sourceId())) {
                     // AST indicates a different source identifier, make sure we use that
-                    sourcesInProject.add(YangTextSchemaSource.delegateForByteSource(astSource.getIdentifier(),
-                        textSource));
+                    sourcesInProject.add(new DelegatedYangTextSource(astSource.sourceId(), textSource));
                 } else {
                     sourcesInProject.add(textSource);
                 }
             }
 
-            final ProcessorModuleReactor reactor = new ProcessorModuleReactor(parser, sourcesInProject, dependencies);
-            LOG.debug("Initialized reactor {} with {}", reactor, yangFilesInProject);
-            return Optional.of(reactor);
+            final var moduleReactor = new ProcessorModuleReactor(parser, sourcesInProject, dependencies);
+            LOG.debug("Initialized reactor {} with {}", moduleReactor, yangFilesInProject);
+            return moduleReactor;
         } catch (IOException | YangSyntaxErrorException | RuntimeException e) {
             // MojoExecutionException is thrown since execution cannot continue
             LOG.error("{} Unable to parse YANG files from {}", LOG_PREFIX, yangFilesRootDir, e);
-            Throwable rootCause = Throwables.getRootCause(e);
             throw new MojoExecutionException(LOG_PREFIX + " Unable to parse YANG files from " + yangFilesRootDir,
-                rootCause);
+                Throwables.getRootCause(e));
         }
     }
 
-    private static List<File> listFiles(final File root, final Collection<File> excludedFiles)
+    private static ImmutableList<File> listFiles(final File root, final Collection<File> excludedFiles)
             throws IOException {
         if (!root.isDirectory()) {
             LOG.warn("{} YANG source directory {} not found. No code will be generated.", LOG_PREFIX, root);
             return ImmutableList.of();
         }
 
-        return Files.walk(root.toPath()).map(Path::toFile).filter(File::isFile).filter(f -> {
-            if (excludedFiles.contains(f)) {
-                LOG.info("{} YANG file excluded {}", LOG_PREFIX, f);
-                return false;
-            }
-            return true;
-        }).filter(f -> f.getName().endsWith(YangConstants.RFC6020_YANG_FILE_EXTENSION)).collect(Collectors.toList());
+        return Files.walk(root.toPath())
+            .map(Path::toFile)
+            .filter(File::isFile)
+            .filter(f -> {
+                if (excludedFiles.contains(f)) {
+                    LOG.info("{} YANG file excluded {}", LOG_PREFIX, f);
+                    return false;
+                }
+                return true;
+            })
+            .filter(f -> f.getName().endsWith(YangConstants.RFC6020_YANG_FILE_EXTENSION))
+            .collect(ImmutableList.toImmutableList());
     }
 
-    /**
-     * Call generate on every generator from plugin configuration.
-     */
-    private Set<File> generateSources(final ContextHolder context, final Collection<GeneratorTaskFactory> generators,
-            final YangParserConfiguration parserConfig) throws MojoFailureException {
-        final Builder<File> allFiles = ImmutableSet.builder();
-        for (GeneratorTaskFactory factory : generators) {
-            if (!parserConfig.equals(factory.parserConfig())) {
-                continue;
-            }
-
-            final Stopwatch sw = Stopwatch.createStarted();
-            final GeneratorTask task = factory.createTask(project, context);
-            LOG.debug("{} Task {} initialized in {}", LOG_PREFIX, task, sw);
-
-            final Collection<File> files;
-            try {
-                files = task.execute(buildContext);
-            } catch (FileGeneratorException | IOException e) {
-                throw new MojoFailureException(LOG_PREFIX + " Generator " + factory + " failed", e);
-            }
-
-            LOG.debug("{} Sources generated by {}: {}", LOG_PREFIX, factory.generatorName(), files);
-
-            final int fileCount;
-            if (files != null) {
-                fileCount = files.size();
-                allFiles.addAll(files);
-            } else {
-                fileCount = 0;
-            }
-
-            LOG.info("{} Sources generated by {}: {} in {}", LOG_PREFIX, factory.generatorName(), fileCount, sw);
-        }
-
-        return allFiles.build();
+    @VisibleForTesting
+    static @NonNull Path stateFilePath(final String projectBuildDirectory) {
+        // ${project.build.directory}/maven-status/yang-maven-plugin/execution.state
+        return Path.of(projectBuildDirectory, "maven-status", "yang-maven-plugin", "execution.state");
     }
 }