Return streams in Lineage search and subkeys methods.

modules/nextflow/src/test/groovy/nextflow/cli/CmdLineageTest.groovy

@@ -279,7 +279,7 @@ class CmdLineageTest extends Specification {
         def entry = new FileOutput("path/to/file",new Checksum("45372qe","nextflow","standard"),
                 "lid://123987/file.bam", "lid://12345", "lid://123987/", 1234, time, time, ['foo', 'bar'])
         def jsonSer = encoder.encode(entry)
-        def expectedOutput = '[\n  "lid://12345"\n]'
+        def expectedOutput = 'lid://12345'
         lidFile.text = jsonSer
         when:
         def lidCmd = new CmdLineage(launcher: launcher, args: ["find", "type=FileOutput", "label=foo"])

modules/nf-lineage/src/main/nextflow/lineage/DefaultLinStore.groovy

@@ -16,11 +16,9 @@
 
 package nextflow.lineage
 
-import java.nio.file.FileVisitResult
-import java.nio.file.FileVisitor
 import java.nio.file.Files
 import java.nio.file.Path
-import java.nio.file.attribute.BasicFileAttributes
+import java.util.stream.Stream
 
 import groovy.transform.CompileStatic
 import groovy.util.logging.Slf4j
@@ -93,70 +91,32 @@ class DefaultLinStore implements LinStore {
     void close() throws IOException {}
 
     @Override
-    Map<String, LinSerializable> search(Map<String, List<String>> params) {
-        final results = new HashMap<String, LinSerializable>()
-
-        Files.walkFileTree(location, new FileVisitor<Path>() {
-
-            @Override
-            FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
-                FileVisitResult.CONTINUE
-            }
-
-            @Override
-            FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
-                if( file.name.startsWith('.data.json') ) {
-                    final lidObject = encoder.decode(file.text)
-                    if( LinUtils.checkParams(lidObject, params) ) {
-                        results.put(location.relativize(file.getParent()).toString(), lidObject as LinSerializable)
-                    }
-                }
-                FileVisitResult.CONTINUE
+    Stream<String> search(Map<String, List<String>> params) {
+        return Files.walk(location)
+            .filter { Path path ->
+                Files.isRegularFile(path) && path.fileName.toString().startsWith('.data.json')
             }
-
-            @Override
-            FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
-                FileVisitResult.CONTINUE
+            .map { Path path ->
+                final obj = encoder.decode(path.text)
+                final key = location.relativize(path.parent).toString()
+                return new AbstractMap.SimpleEntry<String, LinSerializable>(key, obj)
             }
-
-            @Override
-            FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
-                FileVisitResult.CONTINUE
+            .filter { entry ->
+                LinUtils.checkParams(entry.value, params)
             }
-        })
-
-        return results
+            .map {it->  it.key }
     }
 
     @Override
-    List<String> getSubKeys(String parentKey) {
-        final results = new LinkedList<String>()
+    Stream<String> getSubKeys(String parentKey) {
         final startPath = location.resolve(parentKey)
-        Files.walkFileTree(startPath, new FileVisitor<Path>() {
-
-            @Override
-            FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
-                FileVisitResult.CONTINUE
-            }
 
-            @Override
-            FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
-                if( file.name.startsWith('.data.json') && file.parent != startPath ) {
-                    results << location.relativize(file.parent).toString()
-                }
-                FileVisitResult.CONTINUE
+        return Files.walk(startPath)
+            .filter { Path path ->
+                Files.isRegularFile(path) && path.fileName.toString().startsWith('.data.json') && path.parent != startPath
             }
-
-            @Override
-            FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
-                FileVisitResult.CONTINUE
-            }
-
-            @Override
-            FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
-                FileVisitResult.CONTINUE
+            .map { Path path ->
+                location.relativize(path.parent).toString()
             }
-        })
-        return results
     }
-}
+}

modules/nf-lineage/src/main/nextflow/lineage/LinExtensionImpl.groovy

@@ -24,7 +24,6 @@ import nextflow.Session
 import nextflow.extension.LinExtension
 import nextflow.lineage.fs.LinPathFactory
 import nextflow.lineage.model.v1beta1.FileOutput
-import nextflow.lineage.serde.LinSerializable
 
 import static nextflow.lineage.fs.LinPath.*
 
@@ -43,7 +42,9 @@ class LinExtensionImpl implements LinExtension {
         log.trace("Querying lineage with params: $queryParams")
         new LinPropertyValidator().validateQueryParams(queryParams.keySet())
         final store = getStore(session)
-        emitSearchResults(channel, store.search(queryParams))
+        try( def stream = store.search(queryParams) ){
+            stream.forEach { channel.bind( LinPathFactory.create( asUriString(it) ) ) }
+        }
         channel.bind(Channel.STOP)
     }
 
@@ -62,19 +63,11 @@ class LinExtensionImpl implements LinExtension {
         return queryParams
     }
 
-
     protected LinStore getStore(Session session) {
         final store = LinStoreFactory.getOrCreate(session)
         if( !store ) {
             throw new Exception("Lineage store not found - Check Nextflow configuration")
         }
         return store
     }
-
-    private void emitSearchResults(DataflowWriteChannel channel, Map<String, LinSerializable> results) {
-        if( !results ) {
-            return
-        }
-        results.keySet().forEach { channel.bind( LinPathFactory.create( asUriString(it) ) ) }
-    }
 }

modules/nf-lineage/src/main/nextflow/lineage/LinStore.groovy

@@ -18,6 +18,7 @@ package nextflow.lineage
 
 import com.google.common.annotations.Beta
 import groovy.transform.CompileStatic
+import java.util.stream.Stream
 import nextflow.lineage.config.LineageConfig
 import nextflow.lineage.serde.LinSerializable
 /**
@@ -58,18 +59,18 @@ interface LinStore extends Closeable {
     /**
      * Search for lineage entries.
      * @param params Map of query params
-     * @return Key-lineage entry pairs fulfilling the query params
+     * @return Stream with keys fulfilling the query params
      */
-    Map<String,LinSerializable> search(Map<String, List<String>> params)
+    Stream<String> search(Map<String, List<String>> params)
 
     /**
      * Search for keys starting with a parent key.
      * For example, if a LinStore contains the following keys: '123abc', '123abc/samples/file1.txt' and '123abc/summary',
-     * The execution of the function with parentKey='123abc' will return a list with '123abc/samples/file1.txt' and '123abc/summary'.
+     * The execution of the function with parentKey='123abc' will return a stream with '123abc/samples/file1.txt' and '123abc/summary'.
      * Similarly, the execution of the function with parentKey='123abc/samples' will just return '123abc/samples/file1.txt"
      *
      * @param parentKey
-     * @return list of keys
+     * @return Stream of keys starting with parentKey
      */
-    List<String> getSubKeys(String parentKey)
+    Stream<String> getSubKeys(String parentKey)
 }

modules/nf-lineage/src/main/nextflow/lineage/cli/LinCommandImpl.groovy

@@ -184,7 +184,9 @@ class LinCommandImpl implements CmdLineage.LinCommand {
         try {
             final params = parseFindArgs(args)
             new LinPropertyValidator().validateQueryParams(params.keySet())
-            println LinUtils.encodeSearchOutputs( store.search(params).keySet().collect { asUriString(it) }, true )
+            try (def stream = store.search(params) ) {
+                stream.forEach { println asUriString(it) }
+            }
         } catch (Throwable e){
             println "Error searching for ${args[0]}. ${e.message}"
         }

modules/nf-lineage/src/main/nextflow/lineage/fs/LinFileSystemProvider.groovy

@@ -39,7 +39,6 @@ import java.nio.file.spi.FileSystemProvider
 import groovy.transform.CompileStatic
 import nextflow.lineage.config.LineageConfig
 import nextflow.util.TestOnly
-
 /**
  * File System Provider for LID Paths
  *
@@ -216,16 +215,19 @@ class LinFileSystemProvider extends FileSystemProvider {
             return getDirectoryStreamFromSubPath(lid)
         return getDirectoryStreamFromRealPath(real, lid)
     }
+
     private static DirectoryStream<Path> getDirectoryStreamFromSubPath(LinPath lid){
-        List<Path> paths = lid.getSubPaths()
+        final paths = lid.getSubPaths()
         if( !paths )
             throw new FileNotFoundException("Sub paths for '$lid' do not exist")
         return new DirectoryStream<Path>() {
             Iterator<Path> iterator() {
                 return paths.iterator()
             }
 
-            void close() {}
+            void close() {
+                paths.close()
+            }
         }
     }
     private DirectoryStream<Path> getDirectoryStreamFromRealPath(Path real, LinPath lid) {

modules/nf-lineage/src/main/nextflow/lineage/fs/LinPath.groovy

@@ -27,6 +27,7 @@ import java.nio.file.WatchEvent
 import java.nio.file.WatchKey
 import java.nio.file.WatchService
 import java.time.OffsetDateTime
+import java.util.stream.Stream
 
 import groovy.transform.CompileStatic
 import groovy.transform.EqualsAndHashCode
@@ -156,15 +157,15 @@ class LinPath implements Path, LogicalDataPath {
     @TestOnly
     protected String getFilePath() { this.filePath }
 
-    protected List<Path> getSubPaths(){
+    protected Stream<Path> getSubPaths(){
         if( !fileSystem )
             throw new IllegalArgumentException("Cannot get sub-paths for a relative lineage path")
         if( filePath.isEmpty() || filePath == SEPARATOR )
             throw new IllegalArgumentException("Cannot get sub-paths for an empty lineage path (lid:///)")
         final store = fileSystem.getStore()
         if( !store )
             throw new Exception("Lineage store not found - Check Nextflow configuration")
-        return store.getSubKeys(filePath).collect {new LinPath(fileSystem as LinFileSystem, it)} as List<Path>
+        return store.getSubKeys(filePath).map {new LinPath(fileSystem as LinFileSystem, it) as Path }
     }
 
     /**

modules/nf-lineage/src/test/nextflow/lineage/DefaultLinStoreTest.groovy

@@ -123,12 +123,10 @@ class DefaultLinStoreTest extends Specification {
         lidStore.save(key4, value4)
 
         when:
-        def results = lidStore.search( [type:['FileOutput'], labels:['value2']])
+        def results = lidStore.search( [type:['FileOutput'], labels:['value2']]).toList()
         then:
         results.size() == 2
-        results.keySet().containsAll([key2,key3])
-        results[key2] == value2
-        results[key3] == value3
+        results.containsAll([key2,key3])
     }
 
     def 'should search subkeys' () {
@@ -154,7 +152,7 @@ class DefaultLinStoreTest extends Specification {
          lidStore.save(key4, value4)
 
          when:
-         def results = lidStore.getSubKeys("testKey")
+         def results = lidStore.getSubKeys("testKey").toList()
          then:
          results.size() == 2
          results.containsAll([key2, key3])

modules/nf-lineage/src/test/nextflow/lineage/cli/LinCommandImplTest.groovy

@@ -488,8 +488,8 @@ class LinCommandImplTest extends Specification{
             "lid://123987/file2.bam", "lid://123987/", null, 1235, time, time, ["experiment=test"])
         def entry3 = new FileOutput("path/to/file3",new Checksum("42472qet","nextflow","standard"),
             "lid://123987/file2.bam", "lid://123987/", null, 1235, time, time, null)
-        def expectedOutput1 = '[\n  "lid://123987/file.bam",\n  "lid://123987/file2.bam"\n]'
-        def expectedOutput2 = '[\n  "lid://123987/file2.bam",\n  "lid://123987/file.bam"\n]'
+        def expectedOutput1 = 'lid://123987/file.bam\nlid://123987/file2.bam'
+        def expectedOutput2 = 'lid://123987/file2.bam\nlid://123987/file.bam'
         lidFile.text = encoder.encode(entry)
         lidFile2.text = encoder.encode(entry2)
         lidFile3.text = encoder.encode(entry3)