Refactor Copier.copyObject(AmazonS3.Client,Bucket,RemoteKey,MD5Hash,RemoteKey) (#137)

* [core] Convert HashService into an effect Hasher

* [core] LocalFileStreamSuite fix prep of test env

* [core] LocalFileStreamSuite Refactor

* [core] Add Hasher.hashObjectChunk

* [core] make MD5HashGenerator private

Moved MD5HashGenerator into package hasher and made it private to that
package, together with the Hasher effect which is the only permitted
user of it. Added hex and digest methods to Hasher.

Similar for the ETageGenerator in [storage-aws], moved into a hasher
package and made private. It can only be accessed using the S3Hasher
effect.

* [domain] Add Monoid

* [domain] Sources use Monoid

* [core] ActionGenerator Refactor

* [core] Use >>= and *> operators

* [config] Refactoring

* [storage-aws] Refactoring

* [domain] Refactoring

* [core] Refactoring

* [config] refactoring

* Refactoring

* [core] PlanBuilder Refactoring

* [core] Make PlanBuilder into an object

* [storate-aws] Copier Reduce the number of parameters

build.sbt

@@ -122,7 +122,7 @@ lazy val config = (project in file("config"))
   .settings(testDependencies)
   .settings(commandLineParsing)
   .settings(assemblyJarName in assembly := "config.jar")
-  .dependsOn(domain)
+  .dependsOn(domain % "compile->compile;test->test")
   .dependsOn(filesystem)
 
 lazy val filesystem = (project in file("filesystem"))

cli/src/main/scala/net/kemitix/thorp/cli/Main.scala

@@ -4,6 +4,7 @@ import net.kemitix.thorp.config.Config
 import net.kemitix.thorp.console.Console
 import net.kemitix.thorp.filesystem.FileSystem
 import net.kemitix.thorp.storage.aws.S3Storage
+import net.kemitix.thorp.storage.aws.hasher.S3Hasher
 import zio.{App, ZIO}
 
 object Main extends App {
@@ -13,6 +14,7 @@ object Main extends App {
       with Console.Live
       with Config.Live
       with FileSystem.Live
+      with S3Hasher.Live
 
   override def run(args: List[String]): ZIO[Environment, Nothing, Int] =
     Program

cli/src/main/scala/net/kemitix/thorp/cli/Program.scala

@@ -5,7 +5,6 @@ import net.kemitix.thorp.console._
 import net.kemitix.thorp.core.CoreTypes.CoreProgram
 import net.kemitix.thorp.core._
 import net.kemitix.thorp.domain.StorageQueueEvent
-import net.kemitix.thorp.storage.aws.S3HashService.defaultHashService
 import zio.ZIO
 
 trait Program {
@@ -27,7 +26,7 @@ trait Program {
 
   private def execute = {
     for {
-      plan    <- PlanBuilder.createPlan(defaultHashService)
+      plan    <- PlanBuilder.createPlan
       archive <- UnversionedMirrorArchive.default(plan.syncTotals)
       events  <- applyPlan(archive, plan)
       _       <- SyncLogging.logRunFinished(events)
@@ -39,7 +38,7 @@ trait Program {
       _ <- Console.putStrLn("There were errors:")
       _ <- throwable match {
         case ConfigValidationException(errors) =>
-          ZIO.foreach(errors)(error => Console.putStrLn(s"- $error"))
+          ZIO.foreach_(errors)(error => Console.putStrLn(s"- $error"))
       }
     } yield ()
 

config/src/main/scala/net/kemitix/thorp/config/ConfigOption.scala

@@ -14,7 +14,7 @@ object ConfigOption {
 
   case class Source(path: Path) extends ConfigOption {
     override def update(config: Configuration): Configuration =
-      sources.modify(_ ++ path)(config)
+      sources.modify(_ + path)(config)
   }
 
   case class Bucket(name: String) extends ConfigOption {

config/src/main/scala/net/kemitix/thorp/config/ConfigValidationException.scala

@@ -1,5 +1,5 @@
 package net.kemitix.thorp.config
 
 final case class ConfigValidationException(
-    errors: List[ConfigValidation]
+    errors: Seq[ConfigValidation]
 ) extends Exception

config/src/main/scala/net/kemitix/thorp/config/ConfigValidator.scala

@@ -22,8 +22,7 @@ sealed trait ConfigValidator {
 
   def validateSources(
       sources: Sources): Either[List[ConfigValidation], Sources] =
-    (for {
+    sources.paths.foldLeft(List[ConfigValidation]()) {
-      x <- sources.paths.foldLeft(List[ConfigValidation]()) {
       (acc: List[ConfigValidation], path) =>
         {
           validateSource(path) match {
@@ -31,8 +30,7 @@ sealed trait ConfigValidator {
             case Right(_)     => acc
           }
         }
-      }
+    } match {
-    } yield x) match {
       case Nil    => Right(sources)
       case errors => Left(errors)
     }

config/src/main/scala/net/kemitix/thorp/config/ConfigurationBuilder.scala

@@ -17,10 +17,8 @@ trait ConfigurationBuilder {
 
   def buildConfig(priorityOpts: ConfigOptions)
     : ZIO[FileSystem, ConfigValidationException, Configuration] =
-    (for {
+    (getConfigOptions(priorityOpts).map(collateOptions) >>=
-      config <- getConfigOptions(priorityOpts).map(collateOptions)
+      ConfigValidator.validateConfig)
-      valid  <- ConfigValidator.validateConfig(config)
-    } yield valid)
       .catchAll(errors => ZIO.fail(ConfigValidationException(errors)))
 
   private def getConfigOptions(priorityOpts: ConfigOptions) =

config/src/main/scala/net/kemitix/thorp/config/ParseConfigFile.scala

@@ -3,24 +3,25 @@ package net.kemitix.thorp.config
 import java.nio.file.Path
 
 import net.kemitix.thorp.filesystem.FileSystem
-import zio.{IO, ZIO}
+import zio.{IO, TaskR, ZIO}
 
 trait ParseConfigFile {
 
   def parseFile(
-      filename: Path): ZIO[FileSystem, List[ConfigValidation], ConfigOptions] =
+      filename: Path): ZIO[FileSystem, Seq[ConfigValidation], ConfigOptions] =
-    readFile(filename)
+    (readFile(filename) >>= ParseConfigLines.parseLines)
-      .map(ParseConfigLines.parseLines)
+      .catchAll(
-      .catchAll(h =>
+        h =>
           IO.fail(
             List(ConfigValidation.ErrorReadingFile(filename, h.getMessage))))
 
   private def readFile(filename: Path) =
-    FileSystem
+    FileSystem.exists(filename.toFile) >>= readLines(filename)
-      .exists(filename.toFile)
+
-      .flatMap(
+  private def readLines(filename: Path)(
-        if (_) FileSystem.lines(filename.toFile)
+      exists: Boolean): TaskR[FileSystem, Seq[String]] =
-        else ZIO.succeed(List.empty))
+    if (exists) FileSystem.lines(filename.toFile)
+    else ZIO.succeed(Seq.empty)
 
 }
 

config/src/main/scala/net/kemitix/thorp/config/ParseConfigLines.scala

@@ -3,22 +3,16 @@ package net.kemitix.thorp.config
 import java.nio.file.Paths
 import java.util.regex.Pattern
 
-import net.kemitix.thorp.config.ConfigOption.{
+import net.kemitix.thorp.config.ConfigOption._
-  Bucket,
+import zio.UIO
-  Debug,
-  Exclude,
-  Include,
-  Prefix,
-  Source
-}
 
 trait ParseConfigLines {
 
   private val pattern = "^\\s*(?<key>\\S*)\\s*=\\s*(?<value>\\S*)\\s*$"
   private val format  = Pattern.compile(pattern)
 
-  def parseLines(lines: List[String]): ConfigOptions =
+  def parseLines(lines: Seq[String]): UIO[ConfigOptions] =
-    ConfigOptions(lines.flatMap(parseLine))
+    UIO(ConfigOptions(lines.flatMap(parseLine).toList))
 
   private def parseLine(str: String) =
     format.matcher(str) match {
@@ -40,7 +34,7 @@ trait ParseConfigLines {
       case _         => None
     }
 
-  def truthy(value: String): Boolean =
+  private def truthy(value: String): Boolean =
     value.toLowerCase match {
       case "true"    => true
       case "yes"     => true

config/src/main/scala/net/kemitix/thorp/config/SourceConfigLoader.scala

@@ -8,24 +8,16 @@ trait SourceConfigLoader {
 
   val thorpConfigFileName = ".thorp.conf"
 
-  def loadSourceConfigs
+  def loadSourceConfigs(
-    : Sources => ZIO[FileSystem, List[ConfigValidation], ConfigOptions] =
+      sources: Sources): ZIO[FileSystem, Seq[ConfigValidation], ConfigOptions] =
-    sources => {
-
-      val sourceConfigOptions =
-        ConfigOptions(sources.paths.map(ConfigOption.Source))
-
-      val reduce: List[ConfigOptions] => ConfigOptions =
-        _.foldLeft(sourceConfigOptions) { (acc, co) =>
-          acc ++ co
-        }
-
     ZIO
       .foreach(sources.paths) { path =>
         ParseConfigFile.parseFile(path.resolve(thorpConfigFileName))
       }
-        .map(reduce)
+      .map(_.foldLeft(ConfigOptions(sources.paths.map(ConfigOption.Source))) {
-    }
+        (acc, co) =>
+          acc ++ co
+      })
 
 }
 

config/src/test/scala/net/kemitix/thorp/config/ConfigOptionTest.scala

@@ -1,12 +1,6 @@
-package net.kemitix.thorp.core
+package net.kemitix.thorp.config
 
-import net.kemitix.thorp.config.{
+import net.kemitix.thorp.domain.{Sources, TemporaryFolder}
-  ConfigOption,
-  ConfigOptions,
-  ConfigQuery,
-  ConfigurationBuilder
-}
-import net.kemitix.thorp.domain.Sources
 import net.kemitix.thorp.filesystem.FileSystem
 import org.scalatest.FunSpec
 import zio.DefaultRuntime

config/src/test/scala/net/kemitix/thorp/config/ConfigQueryTest.scala

@@ -1,8 +1,7 @@
-package net.kemitix.thorp.core
+package net.kemitix.thorp.config
 
 import java.nio.file.Paths
 
-import net.kemitix.thorp.config.{ConfigOption, ConfigOptions, ConfigQuery}
 import net.kemitix.thorp.domain.Sources
 import org.scalatest.FreeSpec
 

config/src/test/scala/net/kemitix/thorp/config/ConfigurationBuilderTest.scala

@@ -1,12 +1,7 @@
-package net.kemitix.thorp.core
+package net.kemitix.thorp.config
 
 import java.nio.file.{Path, Paths}
 
-import net.kemitix.thorp.config.{
-  ConfigOption,
-  ConfigOptions,
-  ConfigurationBuilder
-}
 import net.kemitix.thorp.domain.Filter.{Exclude, Include}
 import net.kemitix.thorp.domain._
 import net.kemitix.thorp.filesystem.FileSystem

config/src/test/scala/net/kemitix/thorp/config/ParseConfigFileTest.scala

@@ -1,13 +1,7 @@
-package net.kemitix.thorp.core
+package net.kemitix.thorp.config
 
 import java.nio.file.{Path, Paths}
 
-import net.kemitix.thorp.config.{
-  ConfigOption,
-  ConfigOptions,
-  ParseConfigFile,
-  Resource
-}
 import net.kemitix.thorp.filesystem.FileSystem
 import org.scalatest.FunSpec
 import zio.DefaultRuntime

config/src/test/scala/net/kemitix/thorp/config/ParseConfigLinesTest.scala

@@ -0,0 +1,88 @@
+package net.kemitix.thorp.config
+
+import java.nio.file.Paths
+
+import org.scalatest.FunSpec
+import zio.DefaultRuntime
+
+class ParseConfigLinesTest extends FunSpec {
+
+  describe("parse single lines") {
+    describe("source") {
+      it("should parse") {
+        val expected =
+          Right(
+            ConfigOptions(
+              List(ConfigOption.Source(Paths.get("/path/to/source")))))
+        val result = invoke(List("source = /path/to/source"))
+        assertResult(expected)(result)
+      }
+    }
+    describe("bucket") {
+      it("should parse") {
+        val expected =
+          Right(ConfigOptions(List(ConfigOption.Bucket("bucket-name"))))
+        val result = invoke(List("bucket = bucket-name"))
+        assertResult(expected)(result)
+      }
+    }
+    describe("prefix") {
+      it("should parse") {
+        val expected =
+          Right(ConfigOptions(List(ConfigOption.Prefix("prefix/to/files"))))
+        val result = invoke(List("prefix = prefix/to/files"))
+        assertResult(expected)(result)
+      }
+    }
+    describe("include") {
+      it("should parse") {
+        val expected =
+          Right(ConfigOptions(List(ConfigOption.Include("path/to/include"))))
+        val result = invoke(List("include = path/to/include"))
+        assertResult(expected)(result)
+      }
+    }
+    describe("exclude") {
+      it("should parse") {
+        val expected =
+          Right(ConfigOptions(List(ConfigOption.Exclude("path/to/exclude"))))
+        val result = invoke(List("exclude = path/to/exclude"))
+        assertResult(expected)(result)
+      }
+    }
+    describe("debug - true") {
+      it("should parse") {
+        val expected = Right(ConfigOptions(List(ConfigOption.Debug())))
+        val result   = invoke(List("debug = true"))
+        assertResult(expected)(result)
+      }
+    }
+    describe("debug - false") {
+      it("should parse") {
+        val expected = Right(ConfigOptions())
+        val result   = invoke(List("debug = false"))
+        assertResult(expected)(result)
+      }
+    }
+    describe("comment line") {
+      it("should be ignored") {
+        val expected = Right(ConfigOptions())
+        val result   = invoke(List("# ignore me"))
+        assertResult(expected)(result)
+      }
+    }
+    describe("unrecognised option") {
+      it("should be ignored") {
+        val expected = Right(ConfigOptions())
+        val result   = invoke(List("unsupported = option"))
+        assertResult(expected)(result)
+      }
+    }
+
+    def invoke(lines: List[String]) = {
+      new DefaultRuntime {}.unsafeRunSync {
+        ParseConfigLines.parseLines(lines)
+      }.toEither
+    }
+  }
+}

core/src/main/scala/net/kemitix/thorp/core/ActionGenerator.scala

@@ -13,7 +13,11 @@ object ActionGenerator {
   ): ZIO[Config, Nothing, Stream[Action]] =
     for {
       bucket <- Config.bucket
-    } yield
+    } yield genAction(s3MetaData, previousActions, bucket)
+
+  private def genAction(s3MetaData: S3MetaData,
+                        previousActions: Stream[Action],
+                        bucket: Bucket): Stream[Action] = {
     s3MetaData match {
       // #1 local exists, remote exists, remote matches - do nothing
       case S3MetaData(localFile, _, Some(RemoteMetaData(key, hash, _)))
@@ -28,20 +32,18 @@ object ActionGenerator {
             isUploadAlreadyQueued(previousActions)(localFile) =>
         uploadFile(bucket, localFile)
       // #4 local exists, remote exists, remote no match, other matches - copy
-        case S3MetaData(localFile,
+      case S3MetaData(localFile, matchByHash, Some(RemoteMetaData(_, hash, _)))
-                        matchByHash,
-                        Some(RemoteMetaData(_, hash, _)))
           if !localFile.matches(hash) &&
             matchByHash.nonEmpty =>
         copyFile(bucket, localFile, matchByHash)
       // #5 local exists, remote exists, remote no match, other no matches - upload
-        case S3MetaData(localFile, matchByHash, Some(_))
+      case S3MetaData(localFile, matchByHash, Some(_)) if matchByHash.isEmpty =>
-            if matchByHash.isEmpty =>
         uploadFile(bucket, localFile)
       // fallback
       case S3MetaData(localFile, _, _) =>
         doNothing(bucket, localFile.remoteKey)
     }
+  }
 
   private def key = LocalFile.remoteKey ^|-> RemoteKey.key
 

core/src/main/scala/net/kemitix/thorp/core/CoreTypes.scala

@@ -2,13 +2,14 @@ package net.kemitix.thorp.core
 
 import net.kemitix.thorp.config.Config
 import net.kemitix.thorp.console.Console
+import net.kemitix.thorp.core.hasher.Hasher
 import net.kemitix.thorp.filesystem.FileSystem
 import net.kemitix.thorp.storage.api.Storage
 import zio.ZIO
 
 object CoreTypes {
 
-  type CoreEnv        = Storage with Console with Config with FileSystem
+  type CoreEnv        = Storage with Console with Config with FileSystem with Hasher
   type CoreProgram[A] = ZIO[CoreEnv, Throwable, A]
 
 }

core/src/main/scala/net/kemitix/thorp/core/HashService.scala

@@ -1,16 +0,0 @@
-package net.kemitix.thorp.core
-
-import java.nio.file.Path
-
-import net.kemitix.thorp.domain.{HashType, MD5Hash}
-import net.kemitix.thorp.filesystem.FileSystem
-import zio.TaskR
-
-/**
-  * Creates one, or more, hashes for local objects.
-  */
-trait HashService {
-
-  def hashLocalObject(path: Path): TaskR[FileSystem, Map[HashType, MD5Hash]]
-
-}

core/src/main/scala/net/kemitix/thorp/core/LocalFileStream.scala

@@ -1,48 +1,43 @@
 package net.kemitix.thorp.core
 
+import java.io.File
 import java.nio.file.Path
 
 import net.kemitix.thorp.config.Config
 import net.kemitix.thorp.core.KeyGenerator.generateKey
+import net.kemitix.thorp.core.hasher.Hasher
 import net.kemitix.thorp.domain._
 import net.kemitix.thorp.filesystem.FileSystem
 import zio.{Task, TaskR, ZIO}
 
 object LocalFileStream {
 
-  def findFiles(hashService: HashService)(
+  def findFiles(
       source: Path
-  ): TaskR[Config with FileSystem, LocalFiles] = {
+  ): TaskR[Config with FileSystem with Hasher, LocalFiles] = {
 
     def recurseIntoSubDirectories(
-        path: Path): TaskR[Config with FileSystem, LocalFiles] =
+        path: Path): TaskR[Config with FileSystem with Hasher, LocalFiles] =
       path.toFile match {
         case f if f.isDirectory => loop(path)
-        case _                  => pathToLocalFile(hashService)(path)
+        case _                  => localFile(path)
       }
 
-    def recurse(
+    def recurse(paths: Stream[Path])
-        paths: Stream[Path]): TaskR[Config with FileSystem, LocalFiles] =
+      : TaskR[Config with FileSystem with Hasher, LocalFiles] =
       for {
         recursed <- ZIO.foreach(paths)(path => recurseIntoSubDirectories(path))
       } yield LocalFiles.reduce(recursed.toStream)
 
-    def loop(path: Path): TaskR[Config with FileSystem, LocalFiles] = {
+    def loop(
-
+        path: Path): TaskR[Config with FileSystem with Hasher, LocalFiles] =
-      for {
+      dirPaths(path) >>= recurse
-        paths      <- dirPaths(path)
-        localFiles <- recurse(paths)
-      } yield localFiles
-    }
 
     loop(source)
   }
 
   private def dirPaths(path: Path) =
-    for {
+    listFiles(path) >>= includedDirPaths
-      paths    <- listFiles(path)
-      filtered <- includedDirPaths(paths)
-    } yield filtered
 
   private def includedDirPaths(paths: Stream[Path]) =
     for {
@@ -53,12 +48,12 @@ object LocalFileStream {
         .filter({ case (_, included) => included })
         .map({ case (path, _) => path })
 
-  private def localFile(hashService: HashService)(path: Path) = {
+  private def localFile(path: Path) = {
     val file = path.toFile
     for {
       sources <- Config.sources
       prefix  <- Config.prefix
-      hash    <- hashService.hashLocalObject(path)
+      hash    <- Hasher.hashObject(path)
       localFile = LocalFile(file,
                             sources.forPath(path).toFile,
                             hash,
@@ -72,16 +67,17 @@ object LocalFileStream {
   private def listFiles(path: Path) =
     for {
       files <- Task(path.toFile.listFiles)
-      _ <- Task.when(files == null)(
+      _     <- filesMustExist(path, files)
-        Task.fail(new IllegalArgumentException(s"Directory not found $path")))
     } yield Stream(files: _*).map(_.toPath)
 
+  private def filesMustExist(path: Path, files: Array[File]) = {
+    Task.when(files == null)(
+      Task.fail(new IllegalArgumentException(s"Directory not found $path")))
+  }
+
   private def isIncluded(path: Path) =
     for {
       filters <- Config.filters
-    } yield Filter.isIncluded(filters)(path)
+    } yield Filter.isIncluded(path)(filters)
-
-  private def pathToLocalFile(hashService: HashService)(path: Path) =
-    localFile(hashService)(path)
 
 }

core/src/main/scala/net/kemitix/thorp/core/PlanBuilder.scala

@@ -3,30 +3,36 @@ package net.kemitix.thorp.core
 import net.kemitix.thorp.config.Config
 import net.kemitix.thorp.console._
 import net.kemitix.thorp.core.Action._
+import net.kemitix.thorp.core.hasher.Hasher
 import net.kemitix.thorp.domain._
 import net.kemitix.thorp.filesystem.FileSystem
 import net.kemitix.thorp.storage.api.Storage
 import zio.{TaskR, ZIO}
 
-trait PlanBuilder {
+object PlanBuilder {
 
-  def createPlan(hashService: HashService)
+  def createPlan
-    : TaskR[Storage with Console with Config with FileSystem, SyncPlan] =
+    : TaskR[Storage with Console with Config with FileSystem with Hasher,
-    for {
+            SyncPlan] =
-      _       <- SyncLogging.logRunStart
+    SyncLogging.logRunStart *> buildPlan
-      actions <- buildPlan(hashService)
-    } yield actions
 
-  private def buildPlan(hashService: HashService) =
+  private def buildPlan =
+    gatherMetadata >>= assemblePlan
+
+  private def gatherMetadata =
+    fetchRemoteData &&& findLocalFiles
+
+  private def fetchRemoteData =
     for {
-      metadata <- gatherMetadata(hashService)
+      bucket  <- Config.bucket
-      plan     <- assemblePlan(metadata)
+      prefix  <- Config.prefix
-    } yield plan
+      objects <- Storage.list(bucket, prefix)
+    } yield objects
 
   private def assemblePlan(metadata: (S3ObjectsData, LocalFiles)) =
     metadata match {
       case (remoteData, localData) =>
-        createActions(remoteData, localData)
+        createActions(remoteData, localData.localFiles)
           .map(_.filter(doesSomething).sortBy(SequencePlan.order))
           .map(
             SyncPlan(_, SyncTotals(localData.count, localData.totalSizeBytes)))
@@ -34,11 +40,11 @@ trait PlanBuilder {
 
   private def createActions(
       remoteData: S3ObjectsData,
-      localData: LocalFiles
+      localFiles: Stream[LocalFile]
   ) =
     for {
-      fileActions   <- actionsForLocalFiles(remoteData, localData)
+      fileActions   <- actionsForLocalFiles(remoteData, localFiles)
-      remoteActions <- actionsForRemoteKeys(remoteData)
+      remoteActions <- actionsForRemoteKeys(remoteData.byKey.keys)
     } yield fileActions ++ remoteActions
 
   private def doesSomething: Action => Boolean = {
@@ -48,12 +54,10 @@ trait PlanBuilder {
 
   private def actionsForLocalFiles(
       remoteData: S3ObjectsData,
-      localData: LocalFiles
+      localFiles: Stream[LocalFile]
   ) =
-    ZIO.foldLeft(localData.localFiles)(Stream.empty[Action])(
+    ZIO.foldLeft(localFiles)(Stream.empty[Action])((acc, localFile) =>
-      (acc, localFile) =>
+      createActionFromLocalFile(remoteData, acc, localFile).map(_ ++ acc))
-        createActionFromLocalFile(remoteData, acc, localFile)
-          .map(actions => actions ++ acc))
 
   private def createActionFromLocalFile(
       remoteData: S3ObjectsData,
@@ -64,11 +68,9 @@ trait PlanBuilder {
       S3MetaDataEnricher.getMetadata(localFile, remoteData),
       previousActions)
 
-  private def actionsForRemoteKeys(remoteData: S3ObjectsData) =
+  private def actionsForRemoteKeys(remoteKeys: Iterable[RemoteKey]) =
-    ZIO.foldLeft(remoteData.byKey.keys)(Stream.empty[Action]) {
+    ZIO.foldLeft(remoteKeys)(Stream.empty[Action])((acc, remoteKey) =>
-      (acc, remoteKey) =>
+      createActionFromRemoteKey(remoteKey).map(_ #:: acc))
-        createActionFromRemoteKey(remoteKey).map(action => action #:: acc)
-    }
 
   private def createActionFromRemoteKey(remoteKey: RemoteKey) =
     for {
@@ -80,33 +82,13 @@ trait PlanBuilder {
       if (needsDeleted) ToDelete(bucket, remoteKey, 0L)
       else DoNothing(bucket, remoteKey, 0L)
 
-  private def gatherMetadata(hashService: HashService) =
+  private def findLocalFiles =
-    for {
+    SyncLogging.logFileScan *> findFiles
-      remoteData <- fetchRemoteData
-      localData  <- findLocalFiles(hashService)
-    } yield (remoteData, localData)
 
-  private def fetchRemoteData =
+  private def findFiles =
-    for {
-      bucket  <- Config.bucket
-      prefix  <- Config.prefix
-      objects <- Storage.list(bucket, prefix)
-    } yield objects
-
-  private def findLocalFiles(hashService: HashService) =
-    for {
-      _          <- SyncLogging.logFileScan
-      localFiles <- findFiles(hashService)
-    } yield localFiles
-
-  private def findFiles(hashService: HashService) =
     for {
       sources <- Config.sources
-      paths = sources.paths
+      found   <- ZIO.foreach(sources.paths)(LocalFileStream.findFiles)
-      found <- ZIO.foreach(paths)(path =>
-        LocalFileStream.findFiles(hashService)(path))
     } yield LocalFiles.reduce(found.toStream)
 
 }
-
-object PlanBuilder extends PlanBuilder

core/src/main/scala/net/kemitix/thorp/core/SimpleHashService.scala

@@ -1,19 +0,0 @@
-package net.kemitix.thorp.core
-
-import java.nio.file.Path
-
-import net.kemitix.thorp.domain.HashType.MD5
-import net.kemitix.thorp.domain.{HashType, MD5Hash}
-import net.kemitix.thorp.filesystem.FileSystem
-import zio.TaskR
-
-case class SimpleHashService() extends HashService {
-
-  override def hashLocalObject(
-      path: Path
-  ): TaskR[FileSystem, Map[HashType, MD5Hash]] =
-    for {
-      md5 <- MD5HashGenerator.md5File(path)
-    } yield Map(MD5 -> md5)
-
-}

core/src/main/scala/net/kemitix/thorp/core/SyncLogging.scala

@@ -33,13 +33,11 @@ trait SyncLogging {
       actions: Stream[StorageQueueEvent]
   ): ZIO[Console, Nothing, Unit] = {
     val counters = actions.foldLeft(Counters())(countActivities)
-    for {
+    Console.putStrLn(eraseToEndOfScreen) *>
-      _ <- Console.putStrLn(eraseToEndOfScreen)
+      Console.putStrLn(s"Uploaded ${counters.uploaded} files") *>
-      _ <- Console.putStrLn(s"Uploaded ${counters.uploaded} files")
+      Console.putStrLn(s"Copied   ${counters.copied} files") *>
-      _ <- Console.putStrLn(s"Copied   ${counters.copied} files")
+      Console.putStrLn(s"Deleted  ${counters.deleted} files") *>
-      _ <- Console.putStrLn(s"Deleted  ${counters.deleted} files")
+      Console.putStrLn(s"Errors   ${counters.errors}")
-      _ <- Console.putStrLn(s"Errors   ${counters.errors}")
-    } yield ()
   }
 
   private def countActivities: (Counters, StorageQueueEvent) => Counters =

core/src/main/scala/net/kemitix/thorp/core/ThorpArchive.scala

@@ -27,7 +27,7 @@ trait ThorpArchive {
 
   def logEvent(
       event: StorageQueueEvent
-  ): TaskR[Console with Config, Unit] =
+  ): TaskR[Console with Config, StorageQueueEvent] =
     event match {
       case UploadQueueEvent(remoteKey, _) =>
         for {
@@ -37,7 +37,7 @@ trait ThorpArchive {
           _ <- TaskR.when(!batchMode)(
             Console.putStrLn(
               s"${GREEN}Uploaded:$RESET ${remoteKey.key}$eraseToEndOfScreen"))
-        } yield ()
+        } yield event
       case CopyQueueEvent(sourceKey, targetKey) =>
         for {
           batchMode <- Config.batchMode
@@ -47,7 +47,7 @@ trait ThorpArchive {
             Console.putStrLn(
               s"${GREEN}Copied:$RESET ${sourceKey.key} => ${targetKey.key}$eraseToEndOfScreen")
           )
-        } yield ()
+        } yield event
       case DeleteQueueEvent(remoteKey) =>
         for {
           batchMode <- Config.batchMode
@@ -55,7 +55,7 @@ trait ThorpArchive {
           _ <- TaskR.when(!batchMode)(
             Console.putStrLn(
               s"${GREEN}Deleted:$RESET ${remoteKey.key}$eraseToEndOfScreen"))
-        } yield ()
+        } yield event
       case ErrorQueueEvent(action, _, e) =>
         for {
           batchMode <- Config.batchMode
@@ -64,9 +64,9 @@ trait ThorpArchive {
               s"${action.name} failed: ${action.keys}: ${e.getMessage}"))
           _ <- TaskR.when(!batchMode)(Console.putStrLn(
             s"${RED}ERROR:$RESET ${action.name} ${action.keys}: ${e.getMessage}$eraseToEndOfScreen"))
-        } yield ()
+        } yield event
-      case DoNothingQueueEvent(_) => TaskR(())
+      case DoNothingQueueEvent(_) => TaskR(event)
-      case ShutdownQueueEvent()   => TaskR(())
+      case ShutdownQueueEvent()   => TaskR(event)
     }
 
 }

core/src/main/scala/net/kemitix/thorp/core/UnversionedMirrorArchive.scala

@@ -18,20 +18,11 @@ case class UnversionedMirrorArchive(syncTotals: SyncTotals)
   ): TaskR[Storage with Console with Config, StorageQueueEvent] =
     action match {
       case ToUpload(bucket, localFile, _) =>
-        for {
+        doUpload(index, totalBytesSoFar, bucket, localFile) >>= logEvent
-          event <- doUpload(index, totalBytesSoFar, bucket, localFile)
-          _     <- logEvent(event)
-        } yield event
       case ToCopy(bucket, sourceKey, hash, targetKey, _) =>
-        for {
+        Storage.copy(bucket, sourceKey, hash, targetKey) >>= logEvent
-          event <- Storage.copy(bucket, sourceKey, hash, targetKey)
-          _     <- logEvent(event)
-        } yield event
       case ToDelete(bucket, remoteKey, _) =>
-        for {
+        Storage.delete(bucket, remoteKey) >>= logEvent
-          event <- Storage.delete(bucket, remoteKey)
-          _     <- logEvent(event)
-        } yield event
       case DoNothing(_, remoteKey, _) =>
         Task(DoNothingQueueEvent(remoteKey))
     }

core/src/main/scala/net/kemitix/thorp/core/hasher/Hasher.scala

@@ -0,0 +1,96 @@
+package net.kemitix.thorp.core.hasher
+
+import java.nio.file.Path
+import java.util.concurrent.atomic.AtomicReference
+
+import net.kemitix.thorp.domain.HashType.MD5
+import net.kemitix.thorp.domain.{HashType, MD5Hash}
+import net.kemitix.thorp.filesystem.FileSystem
+import zio.{TaskR, ZIO}
+
+/**
+  * Creates one, or more, hashes for local objects.
+  */
+trait Hasher {
+  val hasher: Hasher.Service
+}
+object Hasher {
+  trait Service {
+    def hashObject(
+        path: Path): TaskR[Hasher with FileSystem, Map[HashType, MD5Hash]]
+    def hashObjectChunk(
+        path: Path,
+        chunkNumber: Long,
+        chunkSize: Long): TaskR[Hasher with FileSystem, Map[HashType, MD5Hash]]
+    def hex(in: Array[Byte]): TaskR[Hasher, String]
+    def digest(in: String): TaskR[Hasher, Array[Byte]]
+  }
+  trait Live extends Hasher {
+    val hasher: Service = new Service {
+      override def hashObject(
+          path: Path): TaskR[FileSystem, Map[HashType, MD5Hash]] =
+        for {
+          md5 <- MD5HashGenerator.md5File(path)
+        } yield Map(MD5 -> md5)
+
+      override def hashObjectChunk(path: Path,
+                                   chunkNumber: Long,
+                                   chunkSize: Long)
+        : TaskR[Hasher with FileSystem, Map[HashType, MD5Hash]] =
+        for {
+          md5 <- MD5HashGenerator.md5FileChunk(path,
+                                               chunkNumber * chunkSize,
+                                               chunkSize)
+        } yield Map(MD5 -> md5)
+
+      override def hex(in: Array[Byte]): TaskR[Hasher, String] =
+        ZIO(MD5HashGenerator.hex(in))
+
+      override def digest(in: String): TaskR[Hasher, Array[Byte]] =
+        ZIO(MD5HashGenerator.digest(in))
+    }
+  }
+  object Live extends Live
+
+  trait Test extends Hasher {
+    val hashes: AtomicReference[Map[Path, Map[HashType, MD5Hash]]] =
+      new AtomicReference(Map.empty)
+    val hashChunks
+      : AtomicReference[Map[Path, Map[Long, Map[HashType, MD5Hash]]]] =
+      new AtomicReference(Map.empty)
+    val hasher: Service = new Service {
+      override def hashObject(
+          path: Path): TaskR[Hasher with FileSystem, Map[HashType, MD5Hash]] =
+        ZIO(hashes.get()(path))
+
+      override def hashObjectChunk(path: Path,
+                                   chunkNumber: Long,
+                                   chunkSize: Long)
+        : TaskR[Hasher with FileSystem, Map[HashType, MD5Hash]] =
+        ZIO(hashChunks.get()(path)(chunkNumber))
+
+      override def hex(in: Array[Byte]): TaskR[Hasher, String] =
+        ZIO(MD5HashGenerator.hex(in))
+
+      override def digest(in: String): TaskR[Hasher, Array[Byte]] =
+        ZIO(MD5HashGenerator.digest(in))
+    }
+  }
+  object Test extends Test
+
+  final def hashObject(
+      path: Path): TaskR[Hasher with FileSystem, Map[HashType, MD5Hash]] =
+    ZIO.accessM(_.hasher hashObject path)
+
+  final def hashObjectChunk(
+      path: Path,
+      chunkNumber: Long,
+      chunkSize: Long): TaskR[Hasher with FileSystem, Map[HashType, MD5Hash]] =
+    ZIO.accessM(_.hasher hashObjectChunk (path, chunkNumber, chunkSize))
+
+  final def hex(in: Array[Byte]): TaskR[Hasher, String] =
+    ZIO.accessM(_.hasher hex in)
+
+  final def digest(in: String): TaskR[Hasher, Array[Byte]] =
+    ZIO.accessM(_.hasher digest in)
+}

core/src/main/scala/net/kemitix/thorp/core/hasher/MD5HashGenerator.scala

@@ -1,4 +1,4 @@
-package net.kemitix.thorp.core
+package net.kemitix.thorp.core.hasher
 
 import java.io.{File, FileInputStream}
 import java.nio.file.Path
@@ -10,7 +10,7 @@ import zio.{Task, TaskR}
 
 import scala.collection.immutable.NumericRange
 
-object MD5HashGenerator {
+private object MD5HashGenerator {
 
   val maxBufferSize = 8048
   val defaultBuffer = new Array[Byte](maxBufferSize)
@@ -48,9 +48,7 @@ object MD5HashGenerator {
       offset: Long,
       endOffset: Long
   ) =
-    FileSystem
+    FileSystem.open(file, offset) >>= { managedFileInputStream =>
-      .open(file, offset)
-      .flatMap { managedFileInputStream =>
       managedFileInputStream.use { fileInputStream =>
         digestFile(fileInputStream, offset, endOffset)
       }

core/src/test/scala/net/kemitix/thorp/core/DummyHashService.scala

@@ -1,14 +0,0 @@
-package net.kemitix.thorp.core
-
-import java.nio.file.Path
-
-import net.kemitix.thorp.domain.{HashType, MD5Hash}
-import zio.Task
-
-case class DummyHashService(hashes: Map[Path, Map[HashType, MD5Hash]])
-    extends HashService {
-
-  override def hashLocalObject(path: Path): Task[Map[HashType, MD5Hash]] =
-    Task(hashes(path))
-
-}

core/src/test/scala/net/kemitix/thorp/core/LocalFileStreamSuite.scala

@@ -10,6 +10,7 @@ import net.kemitix.thorp.config.{
   Resource
 }
 import net.kemitix.thorp.console._
+import net.kemitix.thorp.core.hasher.Hasher
 import net.kemitix.thorp.domain.HashType.MD5
 import net.kemitix.thorp.domain._
 import net.kemitix.thorp.filesystem.FileSystem
@@ -21,30 +22,17 @@ class LocalFileStreamSuite extends FunSpec {
 
   private val source     = Resource(this, "upload")
   private val sourcePath = source.toPath
-  private val hashService: HashService = DummyHashService(
-    Map(
-      file("root-file")        -> Map(MD5 -> MD5HashData.Root.hash),
-      file("subdir/leaf-file") -> Map(MD5 -> MD5HashData.Leaf.hash)
-    ))
 
   private def file(filename: String) =
     sourcePath.resolve(Paths.get(filename))
 
-  private val configOptions = ConfigOptions(
-    List(
-      ConfigOption.IgnoreGlobalOptions,
-      ConfigOption.IgnoreUserOptions,
-      ConfigOption.Source(sourcePath),
-      ConfigOption.Bucket("aBucket")
-    ))
-
   describe("findFiles") {
     it("should find all files") {
       val expected = Right(Set("subdir/leaf-file", "root-file"))
       val result =
         invoke()
           .map(_.localFiles)
-          .map(localFiles => localFiles.map(_.relative.toString))
+          .map(_.map(_.relative.toString))
           .map(_.toSet)
       assertResult(expected)(result)
     }
@@ -61,9 +49,13 @@ class LocalFileStreamSuite extends FunSpec {
   }
 
   private def invoke() = {
-    type TestEnv = Storage with Console with Config with FileSystem
+    type TestEnv = Storage
+      with Console
+      with Config
+      with FileSystem
+      with Hasher.Test
     val testEnv: TestEnv = new Storage.Test with Console.Test with Config.Live
-    with FileSystem.Live {
+    with FileSystem.Live with Hasher.Test {
       override def listResult: Task[S3ObjectsData] =
         Task.die(new NotImplementedError)
       override def uploadResult: UIO[StorageQueueEvent] =
@@ -75,12 +67,23 @@ class LocalFileStreamSuite extends FunSpec {
       override def shutdownResult: UIO[StorageQueueEvent] =
         Task.die(new NotImplementedError)
     }
-
+    testEnv.hashes.set(
+      Map(
+        file("root-file")        -> Map(MD5 -> MD5HashData.Root.hash),
+        file("subdir/leaf-file") -> Map(MD5 -> MD5HashData.Leaf.hash)
+      ))
+    val configOptions = ConfigOptions(
+      List(
+        ConfigOption.IgnoreGlobalOptions,
+        ConfigOption.IgnoreUserOptions,
+        ConfigOption.Source(sourcePath),
+        ConfigOption.Bucket("aBucket")
+      ))
     def testProgram =
       for {
         config <- ConfigurationBuilder.buildConfig(configOptions)
         _      <- Config.set(config)
-        files  <- LocalFileStream.findFiles(hashService)(sourcePath)
+        files  <- LocalFileStream.findFiles(sourcePath)
       } yield files
 
     new DefaultRuntime {}.unsafeRunSync {

core/src/test/scala/net/kemitix/thorp/core/ParseConfigLinesTest.scala

@@ -1,83 +0,0 @@
-package net.kemitix.thorp.core
-
-import java.nio.file.Paths
-
-import net.kemitix.thorp.config.{ConfigOption, ConfigOptions, ParseConfigLines}
-import org.scalatest.FunSpec
-
-class ParseConfigLinesTest extends FunSpec {
-
-  describe("parse single lines") {
-    describe("source") {
-      it("should parse") {
-        val expected =
-          ConfigOptions(List(ConfigOption.Source(Paths.get("/path/to/source"))))
-        val result =
-          ParseConfigLines.parseLines(List("source = /path/to/source"))
-        assertResult(expected)(result)
-      }
-    }
-    describe("bucket") {
-      it("should parse") {
-        val expected = ConfigOptions(List(ConfigOption.Bucket("bucket-name")))
-        val result   = ParseConfigLines.parseLines(List("bucket = bucket-name"))
-        assertResult(expected)(result)
-      }
-    }
-    describe("prefix") {
-      it("should parse") {
-        val expected =
-          ConfigOptions(List(ConfigOption.Prefix("prefix/to/files")))
-        val result =
-          ParseConfigLines.parseLines(List("prefix = prefix/to/files"))
-        assertResult(expected)(result)
-      }
-    }
-    describe("include") {
-      it("should parse") {
-        val expected =
-          ConfigOptions(List(ConfigOption.Include("path/to/include")))
-        val result =
-          ParseConfigLines.parseLines(List("include = path/to/include"))
-        assertResult(expected)(result)
-      }
-    }
-    describe("exclude") {
-      it("should parse") {
-        val expected =
-          ConfigOptions(List(ConfigOption.Exclude("path/to/exclude")))
-        val result =
-          ParseConfigLines.parseLines(List("exclude = path/to/exclude"))
-        assertResult(expected)(result)
-      }
-    }
-    describe("debug - true") {
-      it("should parse") {
-        val expected = ConfigOptions(List(ConfigOption.Debug()))
-        val result   = ParseConfigLines.parseLines(List("debug = true"))
-        assertResult(expected)(result)
-      }
-    }
-    describe("debug - false") {
-      it("should parse") {
-        val expected = ConfigOptions()
-        val result   = ParseConfigLines.parseLines(List("debug = false"))
-        assertResult(expected)(result)
-      }
-    }
-    describe("comment line") {
-      it("should be ignored") {
-        val expected = ConfigOptions()
-        val result   = ParseConfigLines.parseLines(List("# ignore me"))
-        assertResult(expected)(result)
-      }
-    }
-    describe("unrecognised option") {
-      it("should be ignored") {
-        val expected = ConfigOptions()
-        val result   = ParseConfigLines.parseLines(List("unsupported = option"))
-        assertResult(expected)(result)
-      }
-    }
-  }
-}

core/src/test/scala/net/kemitix/thorp/core/PlanBuilderTest.scala

@@ -11,6 +11,7 @@ import net.kemitix.thorp.config.{
 }
 import net.kemitix.thorp.console._
 import net.kemitix.thorp.core.Action.{DoNothing, ToCopy, ToDelete, ToUpload}
+import net.kemitix.thorp.core.hasher.Hasher
 import net.kemitix.thorp.domain.HashType.MD5
 import net.kemitix.thorp.domain._
 import net.kemitix.thorp.filesystem._
@@ -25,8 +26,6 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
 
   "create a plan" - {
 
-    val hashService = SimpleHashService()
-
     "one source" - {
       val options: Path => ConfigOptions =
         source =>
@@ -46,8 +45,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                 val expected =
                   Right(List(toUpload(remoteKey, hash, source, file)))
                 val result =
-                  invoke(hashService,
+                  invoke(options(source),
-                         options(source),
                          UIO.succeed(emptyS3ObjectData),
                          UIO.succeed(Map(file.toPath -> file)))
                 assertResult(expected)(result)
@@ -70,8 +68,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                   byKey = Map(anOtherKey -> HashModified(aHash, lastModified))
                 )
                 val result =
-                  invoke(hashService,
+                  invoke(options(source),
-                         options(source),
                          UIO.succeed(s3ObjectsData),
                          UIO.succeed(Map(aFile.toPath       -> aFile,
                                          anOtherFile.toPath -> anOtherFile)))
@@ -94,8 +91,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                   byKey = Map(remoteKey -> HashModified(hash, lastModified))
                 )
                 val result =
-                  invoke(hashService,
+                  invoke(options(source),
-                         options(source),
                          UIO.succeed(s3ObjectsData),
                          UIO.succeed(Map(file.toPath -> file)))
                 assertResult(expected)(result)
@@ -118,8 +114,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                       Map(remoteKey -> HashModified(originalHash, lastModified))
                   )
                   val result =
-                    invoke(hashService,
+                    invoke(options(source),
-                           options(source),
                            UIO.succeed(s3ObjectsData),
                            UIO.succeed(Map(file.toPath -> file)))
                   assertResult(expected)(result)
@@ -139,8 +134,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                     byKey = Map()
                   )
                   val result =
-                    invoke(hashService,
+                    invoke(options(source),
-                           options(source),
                            UIO.succeed(s3ObjectsData),
                            UIO.succeed(Map(file.toPath -> file)))
                   assertResult(expected)(result)
@@ -165,8 +159,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                 byKey = Map(remoteKey -> HashModified(hash, lastModified))
               )
               val result =
-                invoke(hashService,
+                invoke(options(source),
-                       options(source),
                        UIO.succeed(s3ObjectsData),
                        UIO.succeed(Map(file.toPath -> file)))
               assertResult(expected)(result)
@@ -183,8 +176,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                 byKey = Map(remoteKey -> HashModified(hash, lastModified))
               )
               val result =
-                invoke(hashService,
+                invoke(options(source),
-                       options(source),
                        UIO.succeed(s3ObjectsData),
                        UIO.succeed(Map.empty))
               assertResult(expected)(result)
@@ -222,7 +214,6 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                 ))
               val result =
                 invoke(
-                  hashService,
                   options(firstSource)(secondSource),
                   UIO.succeed(emptyS3ObjectData),
                   UIO.succeed(
@@ -248,7 +239,6 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                 toUpload(remoteKey1, hash1, firstSource, fileInFirstSource)))
               val result =
                 invoke(
-                  hashService,
                   options(firstSource)(secondSource),
                   UIO.succeed(emptyS3ObjectData),
                   UIO.succeed(
@@ -273,8 +263,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                   Map(hash2            -> Set(KeyModified(remoteKey2, lastModified))),
                 byKey = Map(remoteKey2 -> HashModified(hash2, lastModified)))
               val result =
-                invoke(hashService,
+                invoke(options(firstSource)(secondSource),
-                       options(firstSource)(secondSource),
                        UIO.succeed(s3ObjectData),
                        UIO.succeed(
                          Map(fileInSecondSource.toPath -> fileInSecondSource)))
@@ -296,8 +285,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
                   Map(hash1            -> Set(KeyModified(remoteKey1, lastModified))),
                 byKey = Map(remoteKey1 -> HashModified(hash1, lastModified)))
               val result =
-                invoke(hashService,
+                invoke(options(firstSource)(secondSource),
-                       options(firstSource)(secondSource),
                        UIO.succeed(s3ObjectData),
                        UIO.succeed(
                          Map(fileInFirstSource.toPath -> fileInFirstSource)))
@@ -314,8 +302,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
               val s3ObjectData = S3ObjectsData(byKey =
                 Map(remoteKey1 -> HashModified(MD5Hash(""), lastModified)))
               val result =
-                invoke(hashService,
+                invoke(options(firstSource)(secondSource),
-                       options(firstSource)(secondSource),
                        UIO.succeed(s3ObjectData),
                        UIO.succeed(Map.empty))
               assertResult(expected)(result)
@@ -326,12 +313,13 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
     }
 
     def md5Hash(file: File): MD5Hash = {
+      object TestEnv extends Hasher.Live with FileSystem.Live
       new DefaultRuntime {}
         .unsafeRunSync {
-          hashService
+          Hasher
-            .hashLocalObject(file.toPath)
+            .hashObject(file.toPath)
             .map(_.get(MD5))
-            .provide(FileSystem.Live)
+            .provide(TestEnv)
         }
         .toEither
         .toOption
@@ -361,14 +349,13 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
     ConfigOptions(List(configOptions: _*))
 
   private def invoke(
-      hashService: HashService,
       configOptions: ConfigOptions,
       result: Task[S3ObjectsData],
       files: Task[Map[Path, File]]
   ) = {
-    type TestEnv = Storage with Console with Config with FileSystem
+    type TestEnv = Storage with Console with Config with FileSystem with Hasher
     val testEnv: TestEnv = new Storage.Test with Console.Test with Config.Live
-    with FileSystem.Live {
+    with FileSystem.Live with Hasher.Live {
       override def listResult: Task[S3ObjectsData] = result
       override def uploadResult: UIO[StorageQueueEvent] =
         Task.die(new NotImplementedError)
@@ -384,7 +371,7 @@ class PlanBuilderTest extends FreeSpec with TemporaryFolder {
       for {
         config <- ConfigurationBuilder.buildConfig(configOptions)
         _      <- Config.set(config)
-        plan   <- PlanBuilder.createPlan(hashService)
+        plan   <- PlanBuilder.createPlan
       } yield plan
 
     new DefaultRuntime {}

core/src/test/scala/net/kemitix/thorp/core/hasher/MD5HashGeneratorTest.scala

@@ -1,4 +1,4 @@
-package net.kemitix.thorp.core
+package net.kemitix.thorp.core.hasher
 
 import java.nio.file.Path
 
@@ -12,7 +12,7 @@ class MD5HashGeneratorTest extends FunSpec {
 
   describe("md5File()") {
     describe("read a small file (smaller than buffer)") {
-      val path = Resource(this, "upload/root-file").toPath
+      val path = Resource(this, "../upload/root-file").toPath
       it("should generate the correct hash") {
         val expected = Right(Root.hash)
         val result   = invoke(path)
@@ -21,7 +21,7 @@ class MD5HashGeneratorTest extends FunSpec {
     }
 
     describe("read a large file (bigger than buffer)") {
-      val path = Resource(this, "big-file").toPath
+      val path = Resource(this, "../big-file").toPath
       it("should generate the correct hash") {
         val expected = Right(BigFile.hash)
         val result   = invoke(path)
@@ -39,7 +39,7 @@ class MD5HashGeneratorTest extends FunSpec {
 
   describe("md5FileChunk") {
     describe("read chunks of file") {
-      val path = Resource(this, "big-file").toPath
+      val path = Resource(this, "../big-file").toPath
       it("should generate the correct hash for first chunk of the file") {
         val part1    = BigFile.Part1
         val expected = Right(part1.hash.hash)

domain/src/main/scala/net/kemitix/thorp/domain/Filter.scala

@@ -7,7 +7,7 @@ sealed trait Filter
 
 object Filter {
 
-  def isIncluded(filters: List[Filter])(p: Path): Boolean = {
+  def isIncluded(p: Path)(filters: List[Filter]): Boolean = {
     sealed trait State
     case class Unknown()   extends State
     case class Accepted()  extends State

domain/src/main/scala/net/kemitix/thorp/domain/Monoid.scala

@@ -0,0 +1,6 @@
+package net.kemitix.thorp.domain
+
+trait Monoid[T] {
+  def zero: T
+  def op(t1: T, t2: T): T
+}

domain/src/main/scala/net/kemitix/thorp/domain/Sources.scala

@@ -15,12 +15,9 @@ import java.nio.file.Path
 case class Sources(
     paths: List[Path]
 ) {
-  def ++(path: Path): Sources = this ++ List(path)
+  def +(path: Path)(implicit m: Monoid[Sources]): Sources = this ++ List(path)
-  def ++(otherPaths: List[Path]): Sources =
+  def ++(otherPaths: List[Path])(implicit m: Monoid[Sources]): Sources =
-    Sources(otherPaths.foldLeft(paths) { (acc, path) =>
+    m.op(this, Sources(otherPaths))
-      if (acc.contains(path)) acc
-      else acc ++ List(path)
-    })
 
   /**
     * Returns the source path for the given path.
@@ -28,3 +25,17 @@ case class Sources(
   def forPath(path: Path): Path =
     paths.find(source => path.startsWith(source)).get
 }
+
+object Sources {
+
+  final val emptySources = Sources(List.empty)
+
+  implicit def sourcesAppendMonoid: Monoid[Sources] = new Monoid[Sources] {
+    override def zero: Sources = emptySources
+    override def op(t1: Sources, t2: Sources): Sources =
+      Sources(t2.paths.foldLeft(t1.paths) { (acc, path) =>
+        if (acc.contains(path)) acc
+        else acc ++ List(path)
+      })
+  }
+}

domain/src/test/scala/net/kemitix/thorp/domain/FiltersSuite.scala

@@ -86,7 +86,7 @@ class FiltersSuite extends FunSpec {
   }
   describe("isIncluded") {
     def invoke(filters: List[Filter]) = {
-      paths.filter(path => Filter.isIncluded(filters)(path))
+      paths.filter(path => Filter.isIncluded(path)(filters))
     }
 
     describe("when there are no filters") {

domain/src/test/scala/net/kemitix/thorp/domain/TemporaryFolder.scala

@@ -1,4 +1,4 @@
-package net.kemitix.thorp.core
+package net.kemitix.thorp.domain
 
 import java.io.{File, IOException, PrintWriter}
 import java.nio.file.attribute.BasicFileAttributes

filesystem/src/main/scala/net/kemitix/thorp/filesystem/FileSystem.scala

@@ -18,7 +18,7 @@ object FileSystem {
     def fileExists(file: File): ZIO[FileSystem, Throwable, Boolean]
     def openManagedFileInputStream(file: File, offset: Long = 0L)
       : TaskR[FileSystem, ZManaged[Any, Throwable, FileInputStream]]
-    def fileLines(file: File): TaskR[FileSystem, List[String]]
+    def fileLines(file: File): TaskR[FileSystem, Seq[String]]
   }
   trait Live extends FileSystem {
     override val filesystem: Service = new Service {
@@ -42,17 +42,11 @@ object FileSystem {
         ZIO(ZManaged.make(acquire)(release))
       }
 
-      override def fileLines(file: File): TaskR[FileSystem, List[String]] = {
+      override def fileLines(file: File): TaskR[FileSystem, Seq[String]] = {
-
         def acquire = ZIO(Files.lines(file.toPath))
-
-        def release(lines: stream.Stream[String]) =
-          ZIO.effectTotal(lines.close())
-
         def use(lines: stream.Stream[String]) =
           ZIO.effectTotal(lines.iterator.asScala.toList)
-
+        acquire.bracketAuto(use)
-        ZIO.bracket(acquire)(release)(use)
       }
     }
   }
@@ -84,6 +78,6 @@ object FileSystem {
     : TaskR[FileSystem, ZManaged[FileSystem, Throwable, FileInputStream]] =
     ZIO.accessM(_.filesystem openManagedFileInputStream (file, offset))
 
-  final def lines(file: File): TaskR[FileSystem, List[String]] =
+  final def lines(file: File): TaskR[FileSystem, Seq[String]] =
     ZIO.accessM(_.filesystem fileLines (file))
 }

storage-aws/src/main/scala/net/kemitix/thorp/storage/aws/Copier.scala

@@ -14,48 +14,34 @@ import zio.{IO, Task, UIO}
 trait Copier {
 
   def copy(amazonS3: AmazonS3.Client)(
+      request: Request): UIO[StorageQueueEvent] =
+    copyObject(amazonS3)(request)
+      .fold(foldFailure(request.sourceKey, request.targetKey),
+            foldSuccess(request.sourceKey, request.targetKey))
+
+  case class Request(
       bucket: Bucket,
       sourceKey: RemoteKey,
       hash: MD5Hash,
       targetKey: RemoteKey
-  ): UIO[StorageQueueEvent] =
+  )
-    copyObject(amazonS3)(bucket, sourceKey, hash, targetKey)
-      .fold(foldFailure(sourceKey, targetKey),
-            foldSuccess(sourceKey, targetKey))
 
-  private def copyObject(amazonS3: AmazonS3.Client)(
+  private def copyObject(amazonS3: AmazonS3.Client)(request: Request) =
-      bucket: Bucket,
-      sourceKey: RemoteKey,
-      hash: MD5Hash,
-      targetKey: RemoteKey
-  ): IO[S3ClientException, CopyObjectResult] = {
-
-    def handleResult
-      : Option[CopyObjectResult] => IO[S3ClientException, CopyObjectResult] =
-      maybeResult =>
-        IO.fromEither {
-          maybeResult
-            .toRight(HashError)
-      }
-
-    def handleError: Throwable => IO[S3ClientException, CopyObjectResult] =
-      error =>
-        Task.fail {
-          CopyError(error)
-      }
-
-    val request =
-      new CopyObjectRequest(
-        bucket.name,
-        sourceKey.key,
-        bucket.name,
-        targetKey.key
-      ).withMatchingETagConstraint(hash.hash)
     amazonS3
-      .copyObject(request)
+      .copyObject(copyObjectRequest(request))
-      .fold(handleError, handleResult)
+      .fold(
+        error => Task.fail(CopyError(error)),
+        result => IO.fromEither(result.toRight(HashError))
+      )
       .flatten
-  }
+
+  private def copyObjectRequest(copyRequest: Request) =
+    new CopyObjectRequest(
+      copyRequest.bucket.name,
+      copyRequest.sourceKey.key,
+      copyRequest.bucket.name,
+      copyRequest.targetKey.key
+    ).withMatchingETagConstraint(copyRequest.hash.hash)
 
   private def foldFailure(
       sourceKey: RemoteKey,

storage-aws/src/main/scala/net/kemitix/thorp/storage/aws/Lister.scala

@@ -32,11 +32,7 @@ trait Lister {
       token => request.withContinuationToken(token)
 
     def fetchBatch: ListObjectsV2Request => TaskR[Console, Batch] =
-      request =>
+      request => ListerLogger.logFetchBatch *> tryFetchBatch(amazonS3)(request)
-        for {
-          _     <- ListerLogger.logFetchBatch
-          batch <- tryFetchBatch(amazonS3)(request)
-        } yield batch
 
     def fetchMore: Option[Token] => TaskR[Console, Stream[S3ObjectSummary]] = {
       case None        => TaskR.succeed(Stream.empty)

storage-aws/src/main/scala/net/kemitix/thorp/storage/aws/S3HashService.scala

@@ -1,35 +0,0 @@
-package net.kemitix.thorp.storage.aws
-
-import java.nio.file.Path
-
-import net.kemitix.thorp.core.{HashService, MD5HashGenerator}
-import net.kemitix.thorp.domain.HashType.MD5
-import net.kemitix.thorp.domain.{HashType, MD5Hash}
-import net.kemitix.thorp.filesystem.FileSystem
-import zio.TaskR
-
-trait S3HashService extends HashService {
-
-  /**
-    * Generates an MD5 Hash and an multi-part ETag
-    *
-    * @param path the local path to scan
-    * @return a set of hash values
-    */
-  override def hashLocalObject(
-      path: Path
-  ): TaskR[FileSystem, Map[HashType, MD5Hash]] =
-    for {
-      md5  <- MD5HashGenerator.md5File(path)
-      etag <- ETagGenerator.eTag(path).map(MD5Hash(_))
-    } yield
-      Map(
-        MD5  -> md5,
-        ETag -> etag
-      )
-
-}
-
-object S3HashService extends S3HashService {
-  lazy val defaultHashService: HashService = S3HashService
-}

storage-aws/src/main/scala/net/kemitix/thorp/storage/aws/S3Storage.scala

@@ -38,7 +38,7 @@ object S3Storage {
                         sourceKey: RemoteKey,
                         hash: MD5Hash,
                         targetKey: RemoteKey): UIO[StorageQueueEvent] =
-        Copier.copy(client)(bucket, sourceKey, hash, targetKey)
+        Copier.copy(client)(Copier.Request(bucket, sourceKey, hash, targetKey))
 
       override def delete(bucket: Bucket,
                           remoteKey: RemoteKey): UIO[StorageQueueEvent] =

storage-aws/src/main/scala/net/kemitix/thorp/storage/aws/Uploader.scala

@@ -28,22 +28,17 @@ trait Uploader {
       .catchAll(handleError(localFile.remoteKey))
 
   private def handleError(remoteKey: RemoteKey)(e: Throwable) =
-    UIO.succeed(ErrorQueueEvent(Action.Upload(remoteKey.key), remoteKey, e))
+    UIO(ErrorQueueEvent(Action.Upload(remoteKey.key), remoteKey, e))
 
   private def transfer(transferManager: => AmazonTransferManager)(
       localFile: LocalFile,
       bucket: Bucket,
       uploadEventListener: UploadEventListener
-  ) = {
+  ) =
-    val listener = progressListener(uploadEventListener)
+    request(localFile, bucket, progressListener(uploadEventListener)) >>=
-    for {
+      dispatch(transferManager)
-      putObjectRequest <- request(localFile, bucket, listener)
-      event            <- dispatch(transferManager, putObjectRequest)
-    } yield event
-  }
 
-  private def dispatch(
+  private def dispatch(transferManager: AmazonTransferManager)(
-      transferManager: AmazonTransferManager,
       putObjectRequest: PutObjectRequest
   ) = {
     transferManager

storage-aws/src/main/scala/net/kemitix/thorp/storage/aws/hasher/ETagGenerator.scala

@@ -1,29 +1,31 @@
-package net.kemitix.thorp.storage.aws
+package net.kemitix.thorp.storage.aws.hasher
 
 import java.nio.file.Path
 
 import com.amazonaws.services.s3.model.PutObjectRequest
 import com.amazonaws.services.s3.transfer.TransferManagerConfiguration
 import com.amazonaws.services.s3.transfer.internal.TransferManagerUtils
-import net.kemitix.thorp.core.MD5HashGenerator
+import net.kemitix.thorp.core.hasher.Hasher
-import net.kemitix.thorp.domain.MD5Hash
+import net.kemitix.thorp.domain.HashType.MD5
 import net.kemitix.thorp.filesystem.FileSystem
 import zio.{TaskR, ZIO}
 
-trait ETagGenerator {
+private trait ETagGenerator {
 
   def eTag(
       path: Path
-  ): TaskR[FileSystem, String] = {
+  ): TaskR[Hasher with FileSystem, String] = {
     val partSize = calculatePartSize(path)
     val parts    = numParts(path.toFile.length, partSize)
-    ZIO
+    eTagHex(path, partSize, parts)
-      .foreach(partsIndex(parts))(digestChunk(path, partSize))
-      .map(concatenateDigests)
-      .map(MD5HashGenerator.hex)
       .map(hash => s"$hash-$parts")
   }
 
+  private def eTagHex(path: Path, partSize: Long, parts: Long) =
+    ZIO
+      .foreach(partsIndex(parts))(digestChunk(path, partSize))
+      .map(concatenateDigests) >>= Hasher.hex
+
   private def partsIndex(parts: Long) =
     Range.Long(0, parts, 1).toList
 
@@ -51,14 +53,10 @@ trait ETagGenerator {
       path: Path,
       chunkSize: Long
   )(chunkNumber: Long) =
-    hashChunk(path, chunkNumber, chunkSize).map(_.digest)
+    Hasher
-
+      .hashObjectChunk(path, chunkNumber, chunkSize)
-  def hashChunk(
+      .map(_(MD5))
-      path: Path,
+      .map(_.digest)
-      chunkNumber: Long,
-      chunkSize: Long
-  ): TaskR[FileSystem, MD5Hash] =
-    MD5HashGenerator.md5FileChunk(path, chunkNumber * chunkSize, chunkSize)
 
   def offsets(
       totalFileSizeBytes: Long,
@@ -67,4 +65,4 @@ trait ETagGenerator {
     Range.Long(0, totalFileSizeBytes, optimalPartSize).toList
 }
 
-object ETagGenerator extends ETagGenerator
+private object ETagGenerator extends ETagGenerator

storage-aws/src/main/scala/net/kemitix/thorp/storage/aws/hasher/S3Hasher.scala

@@ -0,0 +1,45 @@
+package net.kemitix.thorp.storage.aws.hasher
+
+import java.nio.file.Path
+
+import net.kemitix.thorp.core.hasher.Hasher
+import net.kemitix.thorp.core.hasher.Hasher.Live.{hasher => CoreHasher}
+import net.kemitix.thorp.core.hasher.Hasher.Service
+import net.kemitix.thorp.domain.{HashType, MD5Hash}
+import net.kemitix.thorp.filesystem.FileSystem
+import net.kemitix.thorp.storage.aws.ETag
+import zio.TaskR
+
+object S3Hasher {
+
+  trait Live extends Hasher {
+    val hasher: Service = new Service {
+
+      /**
+        * Generates an MD5 Hash and an multi-part ETag
+        *
+        * @param path the local path to scan
+        * @return a set of hash values
+        */
+      override def hashObject(
+          path: Path): TaskR[Hasher with FileSystem, Map[HashType, MD5Hash]] =
+        for {
+          base <- CoreHasher.hashObject(path)
+          etag <- ETagGenerator.eTag(path).map(MD5Hash(_))
+        } yield base + (ETag -> etag)
+
+      override def hashObjectChunk(path: Path,
+                                   chunkNumber: Long,
+                                   chunkSize: Long)
+        : TaskR[Hasher with FileSystem, Map[HashType, MD5Hash]] =
+        CoreHasher.hashObjectChunk(path, chunkNumber, chunkSize)
+
+      override def hex(in: Array[Byte]): TaskR[Hasher, String] =
+        CoreHasher.hex(in)
+
+      override def digest(in: String): TaskR[Hasher, Array[Byte]] =
+        CoreHasher.digest(in)
+    }
+
+  }
+}

storage-aws/src/test/scala/net/kemitix/thorp/storage/aws/AmazonS3ClientTestFixture.scala

@@ -42,7 +42,8 @@ trait AmazonS3ClientTestFixture extends MockFactory {
                           sourceKey: RemoteKey,
                           hash: MD5Hash,
                           targetKey: RemoteKey): UIO[StorageQueueEvent] =
-          Copier.copy(client)(bucket, sourceKey, hash, targetKey)
+          Copier.copy(client)(
+            Copier.Request(bucket, sourceKey, hash, targetKey))
 
         override def delete(bucket: Bucket,
                             remoteKey: RemoteKey): UIO[StorageQueueEvent] =

storage-aws/src/test/scala/net/kemitix/thorp/storage/aws/CopierTest.scala

@@ -88,7 +88,8 @@ class CopierTest extends FreeSpec {
         amazonS3Client: AmazonS3.Client
     ) =
       runtime.unsafeRunSync {
-        Copier.copy(amazonS3Client)(bucket, sourceKey, hash, targetKey)
+        Copier.copy(amazonS3Client)(
+          Copier.Request(bucket, sourceKey, hash, targetKey))
       }.toEither
   }
 

storage-aws/src/test/scala/net/kemitix/thorp/storage/aws/hasher/ETagGeneratorTest.scala

@@ -1,18 +1,20 @@
-package net.kemitix.thorp.storage.aws
+package net.kemitix.thorp.storage.aws.hasher
 
 import java.nio.file.Path
 
 import com.amazonaws.services.s3.transfer.TransferManagerConfiguration
 import net.kemitix.thorp.config.Resource
+import net.kemitix.thorp.core.hasher.Hasher
+import net.kemitix.thorp.domain.HashType.MD5
 import net.kemitix.thorp.filesystem.FileSystem
 import org.scalatest.FunSpec
 import zio.DefaultRuntime
 
 class ETagGeneratorTest extends FunSpec {
 
-  private val runtime = new DefaultRuntime {}
+  object TestEnv extends Hasher.Live with FileSystem.Live
 
-  private val bigFile       = Resource(this, "big-file")
+  private val bigFile       = Resource(this, "../big-file")
   private val bigFilePath   = bigFile.toPath
   private val configuration = new TransferManagerConfiguration
   private val chunkSize     = 1200000
@@ -41,14 +43,16 @@ class ETagGeneratorTest extends FunSpec {
       md5Hashes.foreach {
         case (hash, index) =>
           assertResult(Right(hash))(
-            invoke(bigFilePath, index, chunkSize).map(_.hash))
+            invoke(bigFilePath, index, chunkSize)
+              .map(_(MD5))
+              .map(_.hash))
       }
     }
     def invoke(path: Path, index: Long, size: Long) =
       new DefaultRuntime {}.unsafeRunSync {
-        ETagGenerator
+        Hasher
-          .hashChunk(path, index, size)
+          .hashObjectChunk(path, index, size)
-          .provide(FileSystem.Live)
+          .provide(TestEnv)
       }.toEither
   }
 
@@ -58,12 +62,13 @@ class ETagGeneratorTest extends FunSpec {
       val result = invoke(bigFilePath)
       assertResult(Right(expected))(result)
     }
-    def invoke(path: Path) =
+    def invoke(path: Path) = {
       new DefaultRuntime {}.unsafeRunSync {
         ETagGenerator
           .eTag(path)
-          .provide(FileSystem.Live)
+          .provide(TestEnv)
       }.toEither
     }
+  }
 
 }