src/Pure/Admin/build_log.scala

clarified signature;

/*  Title:      Pure/Admin/build_log.scala
    Author:     Makarius

Management of build log files and database storage.
*/

package isabelle


import java.io.{File => JFile}
import java.time.format.{DateTimeFormatter, DateTimeParseException}
import java.util.Locale

import scala.collection.immutable.SortedMap
import scala.collection.mutable
import scala.util.matching.Regex


object Build_Log
{
  /** content **/

  /* properties */

  object Prop
  {
    val build_tags = SQL.Column.string("build_tags")  // lines
    val build_args = SQL.Column.string("build_args")  // lines
    val build_group_id = SQL.Column.string("build_group_id")
    val build_id = SQL.Column.string("build_id")
    val build_engine = SQL.Column.string("build_engine")
    val build_host = SQL.Column.string("build_host")
    val build_start = SQL.Column.date("build_start")
    val build_end = SQL.Column.date("build_end")
    val isabelle_version = SQL.Column.string("isabelle_version")
    val afp_version = SQL.Column.string("afp_version")

    val all_props: List[SQL.Column] =
      List(build_tags, build_args, build_group_id, build_id, build_engine,
        build_host, build_start, build_end, isabelle_version, afp_version)
  }


  /* settings */

  object Settings
  {
    val ISABELLE_BUILD_OPTIONS = SQL.Column.string("ISABELLE_BUILD_OPTIONS")
    val ML_PLATFORM = SQL.Column.string("ML_PLATFORM")
    val ML_HOME = SQL.Column.string("ML_HOME")
    val ML_SYSTEM = SQL.Column.string("ML_SYSTEM")
    val ML_OPTIONS = SQL.Column.string("ML_OPTIONS")

    val ml_settings = List(ML_PLATFORM, ML_HOME, ML_SYSTEM, ML_OPTIONS)
    val all_settings = ISABELLE_BUILD_OPTIONS :: ml_settings

    type Entry = (String, String)
    type T = List[Entry]

    object Entry
    {
      def unapply(s: String): Option[Entry] =
        s.indexOf('=') match {
          case -1 => None
          case i =>
            val a = s.substring(0, i)
            val b = Library.perhaps_unquote(s.substring(i + 1))
            Some((a, b))
        }
      def apply(a: String, b: String): String = a + "=" + quote(b)
      def getenv(a: String): String = apply(a, Isabelle_System.getenv(a))
    }

    def show(): String =
      cat_lines(
        List(Entry.getenv(ISABELLE_BUILD_OPTIONS.name), "") :::
        ml_settings.map(c => Entry.getenv(c.name)))
  }


  /* file names */

  def log_date(date: Date): String =
    String.format(Locale.ROOT, "%s.%05d",
      DateTimeFormatter.ofPattern("yyyy-MM-dd").format(date.rep),
      new java.lang.Long((date.time - date.midnight.time).ms / 1000))

  def log_subdir(date: Date): Path =
    Path.explode("log") + Path.explode(date.rep.getYear.toString)

  def log_filename(engine: String, date: Date, more: List[String] = Nil): Path =
    Path.explode((engine :: log_date(date) :: more).mkString("", "_", ".log"))



  /** log file **/

  def print_date(date: Date): String = Log_File.Date_Format(date)

  object Log_File
  {
    /* log file */

    def plain_name(name: String): String =
    {
      List(".log", ".log.gz", ".log.xz", ".gz", ".xz").find(name.endsWith(_)) match {
        case Some(s) => Library.try_unsuffix(s, name).get
        case None => name
      }
    }

    def apply(name: String, lines: List[String]): Log_File =
      new Log_File(plain_name(name), lines)

    def apply(name: String, text: String): Log_File =
      Log_File(name, Library.trim_split_lines(text))

    def apply(file: JFile): Log_File =
    {
      val name = file.getName
      val text =
        if (name.endsWith(".gz")) File.read_gzip(file)
        else if (name.endsWith(".xz")) File.read_xz(file)
        else File.read(file)
      apply(name, text)
    }

    def apply(path: Path): Log_File = apply(path.file)


    /* log file collections */

    def is_log(file: JFile,
      prefixes: List[String] =
        List(Build_History.log_prefix, Identify.log_prefix, Identify.log_prefix2,
          Isatest.log_prefix, AFP_Test.log_prefix, Jenkins.log_prefix),
      suffixes: List[String] = List(".log", ".log.gz", ".log.xz")): Boolean =
    {
      val name = file.getName

      prefixes.exists(name.startsWith(_)) &&
      suffixes.exists(name.endsWith(_)) &&
      name != "isatest.log" &&
      name != "afp-test.log" &&
      name != "main.log"
    }


    /* date format */

    val Date_Format =
    {
      val fmts =
        Date.Formatter.variants(
          List("EEE MMM d HH:mm:ss O yyyy", "EEE MMM d HH:mm:ss VV yyyy"),
          List(Locale.ENGLISH, Locale.GERMAN)) :::
        List(
          DateTimeFormatter.RFC_1123_DATE_TIME,
          Date.Formatter.pattern("EEE MMM d HH:mm:ss yyyy").withZone(Date.timezone_berlin))

      def tune_timezone(s: String): String =
        s match {
          case "CET" | "MET" => "GMT+1"
          case "CEST" | "MEST" => "GMT+2"
          case "EST" => "Europe/Berlin"
          case _ => s
        }
      def tune_weekday(s: String): String =
        s match {
          case "Die" => "Di"
          case "Mit" => "Mi"
          case "Don" => "Do"
          case "Fre" => "Fr"
          case "Sam" => "Sa"
          case "Son" => "So"
          case _ => s
        }

      def tune(s: String): String =
        Word.implode(
          Word.explode(s) match {
            case a :: "M\uFFFDr" :: bs => tune_weekday(a) :: "Mär" :: bs.map(tune_timezone(_))
            case a :: bs => tune_weekday(a) :: bs.map(tune_timezone(_))
            case Nil => Nil
          }
        )

      Date.Format.make(fmts, tune)
    }


    /* inlined content */

    def print_props(marker: String, props: Properties.T): String =
      marker + YXML.string_of_body(XML.Encode.properties(Properties.encode_lines(props)))
  }

  class Log_File private(val name: String, val lines: List[String])
  {
    log_file =>

    override def toString: String = name

    def text: String = cat_lines(lines)

    def err(msg: String): Nothing =
      error("Error in log file " + quote(name) + ": " + msg)


    /* date format */

    object Strict_Date
    {
      def unapply(s: String): Some[Date] =
        try { Some(Log_File.Date_Format.parse(s)) }
        catch { case exn: DateTimeParseException => log_file.err(exn.getMessage) }
    }


    /* inlined content */

    def find[A](f: String => Option[A]): Option[A] =
      lines.iterator.map(f).find(_.isDefined).map(_.get)

    def find_line(marker: String): Option[String] =
      find(Library.try_unprefix(marker, _))

    def find_match(regexes: List[Regex]): Option[String] =
      regexes match {
        case Nil => None
        case regex :: rest =>
          lines.iterator.map(regex.unapplySeq(_)).find(res => res.isDefined && res.get.length == 1).
            map(res => res.get.head) orElse find_match(rest)
      }


    /* settings */

    def get_setting(a: String): Option[Settings.Entry] =
      lines.find(_.startsWith(a + "=")) match {
        case Some(line) => Settings.Entry.unapply(line)
        case None => None
      }

    def get_all_settings: Settings.T =
      for { c <- Settings.all_settings; entry <- get_setting(c.name) }
      yield entry


    /* properties (YXML) */

    val xml_cache = XML.make_cache()

    def parse_props(text: String): Properties.T =
      try {
        xml_cache.props(Properties.decode_lines(XML.Decode.properties(YXML.parse_body(text))))
      }
      catch { case _: XML.Error => log_file.err("malformed properties") }

    def filter_lines(marker: String): List[String] =
      for (line <- lines; s <- Library.try_unprefix(marker, line)) yield s

    def filter_props(marker: String): List[Properties.T] =
      for (s <- filter_lines(marker) if YXML.detect(s)) yield parse_props(s)

    def find_props(marker: String): Option[Properties.T] =
      find_line(marker) match {
        case Some(text) if YXML.detect(text) => Some(parse_props(text))
        case _ => None
      }


    /* parse various formats */

    def parse_meta_info(): Meta_Info = Build_Log.parse_meta_info(log_file)

    def parse_build_info(ml_statistics: Boolean = false): Build_Info =
      Build_Log.parse_build_info(log_file, ml_statistics)

    def parse_session_info(
        command_timings: Boolean = false,
        theory_timings: Boolean = false,
        ml_statistics: Boolean = false,
        task_statistics: Boolean = false): Session_Info =
      Build_Log.parse_session_info(
        log_file, command_timings, theory_timings, ml_statistics, task_statistics)
  }



  /** digested meta info: produced by Admin/build_history in log.xz file **/

  object Meta_Info
  {
    val empty: Meta_Info = Meta_Info(Nil, Nil)
  }

  sealed case class Meta_Info(props: Properties.T, settings: Settings.T)
  {
    def is_empty: Boolean = props.isEmpty && settings.isEmpty

    def get(c: SQL.Column): Option[String] =
      Properties.get(props, c.name) orElse
      Properties.get(settings, c.name)

    def get_date(c: SQL.Column): Option[Date] =
      get(c).map(Log_File.Date_Format.parse(_))
  }

  object Identify
  {
    val log_prefix = "isabelle_identify_"
    val log_prefix2 = "plain_identify_"

    def engine(log_file: Log_File): String =
      if (log_file.name.startsWith(Jenkins.log_prefix)) "jenkins_identify"
      else if (log_file.name.startsWith(log_prefix2)) "plain_identify"
      else "identify"

    def content(date: Date, isabelle_version: Option[String], afp_version: Option[String]): String =
      terminate_lines(
        List("isabelle_identify: " + Build_Log.print_date(date), "") :::
        isabelle_version.map("Isabelle version: " + _).toList :::
        afp_version.map("AFP version: " + _).toList)

    val Start = new Regex("""^isabelle_identify: (.+)$""")
    val No_End = new Regex("""$.""")
    val Isabelle_Version = List(new Regex("""^Isabelle version: (\S+)$"""))
    val AFP_Version = List(new Regex("""^AFP version: (\S+)$"""))
  }

  object Isatest
  {
    val log_prefix = "isatest-makeall-"
    val engine = "isatest"
    val Start = new Regex("""^------------------- starting test --- (.+) --- (.+)$""")
    val End = new Regex("""^------------------- test (?:successful|FAILED) --- (.+) --- .*$""")
    val Isabelle_Version = List(new Regex("""^Isabelle version: (\S+)$"""))
  }

  object AFP_Test
  {
    val log_prefix = "afp-test-devel-"
    val engine = "afp-test"
    val Start = new Regex("""^Start test(?: for .+)? at ([^,]+), (.*)$""")
    val Start_Old = new Regex("""^Start test(?: for .+)? at ([^,]+)$""")
    val End = new Regex("""^End test on (.+), .+, elapsed time:.*$""")
    val Isabelle_Version = List(new Regex("""^Isabelle version: .* -- hg id (\S+)$"""))
    val AFP_Version = List(new Regex("""^AFP version: .* -- hg id (\S+)$"""))
    val Bad_Init = new Regex("""^cp:.*: Disc quota exceeded$""")
  }

  object Jenkins
  {
    val log_prefix = "jenkins_"
    val engine = "jenkins"
    val Host = new Regex("""^Building remotely on (\S+) \((\S+)\).*$""")
    val Start = new Regex("""^(?:Started by an SCM change|Started from command line by admin|).*$""")
    val Start_Date = new Regex("""^Build started at (.+)$""")
    val No_End = new Regex("""$.""")
    val Isabelle_Version =
      List(new Regex("""^(?:Build for Isabelle id|Isabelle id) (\w+).*$"""),
        new Regex("""^ISABELLE_CI_REPO_ID="(\w+)".*$"""),
        new Regex("""^(\w{12}) tip.*$"""))
    val AFP_Version =
      List(new Regex("""^(?:Build for AFP id|AFP id) (\w+).*$"""),
        new Regex("""^ISABELLE_CI_AFP_ID="(\w+)".*$"""))
    val CONFIGURATION = "=== CONFIGURATION ==="
    val BUILD = "=== BUILD ==="
  }

  private def parse_meta_info(log_file: Log_File): Meta_Info =
  {
    def parse(engine: String, host: String, start: Date,
      End: Regex, Isabelle_Version: List[Regex], AFP_Version: List[Regex]): Meta_Info =
    {
      val build_id =
      {
        val prefix = proper_string(host) orElse proper_string(engine) getOrElse "build"
        prefix + ":" + start.time.ms
      }
      val build_engine = if (engine == "") Nil else List(Prop.build_engine.name -> engine)
      val build_host = if (host == "") Nil else List(Prop.build_host.name -> host)

      val start_date = List(Prop.build_start.name -> print_date(start))
      val end_date =
        log_file.lines.last match {
          case End(log_file.Strict_Date(end_date)) =>
            List(Prop.build_end.name -> print_date(end_date))
          case _ => Nil
        }

      val isabelle_version =
        log_file.find_match(Isabelle_Version).map(Prop.isabelle_version.name -> _)
      val afp_version =
        log_file.find_match(AFP_Version).map(Prop.afp_version.name -> _)

      Meta_Info((Prop.build_id.name -> build_id) :: build_engine ::: build_host :::
          start_date ::: end_date ::: isabelle_version.toList ::: afp_version.toList,
        log_file.get_all_settings)
    }

    log_file.lines match {
      case line :: _ if line.startsWith(Build_History.META_INFO_MARKER) =>
        Meta_Info(log_file.find_props(Build_History.META_INFO_MARKER).get,
          log_file.get_all_settings)

      case Identify.Start(log_file.Strict_Date(start)) :: _ =>
        parse(Identify.engine(log_file), "", start, Identify.No_End,
          Identify.Isabelle_Version, Identify.AFP_Version)

      case Isatest.Start(log_file.Strict_Date(start), host) :: _ =>
        parse(Isatest.engine, host, start, Isatest.End,
          Isatest.Isabelle_Version, Nil)

      case AFP_Test.Start(log_file.Strict_Date(start), host) :: _ =>
        parse(AFP_Test.engine, host, start, AFP_Test.End,
          AFP_Test.Isabelle_Version, AFP_Test.AFP_Version)

      case AFP_Test.Start_Old(log_file.Strict_Date(start)) :: _ =>
        parse(AFP_Test.engine, "", start, AFP_Test.End,
          AFP_Test.Isabelle_Version, AFP_Test.AFP_Version)

      case Jenkins.Start() :: _ =>
        log_file.lines.dropWhile(_ != Jenkins.BUILD) match {
          case Jenkins.BUILD :: _ :: Jenkins.Start_Date(log_file.Strict_Date(start)) :: _ =>
            val host =
              log_file.lines.takeWhile(_ != Jenkins.CONFIGURATION).collectFirst({
                case Jenkins.Host(a, b) => a + "." + b
              }).getOrElse("")
            parse(Jenkins.engine, host, start.to(Date.timezone_berlin), Jenkins.No_End,
              Jenkins.Isabelle_Version, Jenkins.AFP_Version)
          case _ => Meta_Info.empty
        }

      case line :: _ if line.startsWith("\u0000") => Meta_Info.empty
      case List(Isatest.End(_)) => Meta_Info.empty
      case _ :: AFP_Test.Bad_Init() :: _ => Meta_Info.empty
      case Nil => Meta_Info.empty

      case _ => log_file.err("cannot detect log file format")
    }
  }



  /** build info: toplevel output of isabelle build or Admin/build_history **/

  val THEORY_TIMING_MARKER = "\ftheory_timing = "
  val ML_STATISTICS_MARKER = "\fML_statistics = "
  val ERROR_MESSAGE_MARKER = "\ferror_message = "
  val SESSION_NAME = "session_name"

  object Session_Status extends Enumeration
  {
    val existing, finished, failed, cancelled = Value
  }

  sealed case class Session_Entry(
    chapter: String = "",
    groups: List[String] = Nil,
    threads: Option[Int] = None,
    timing: Timing = Timing.zero,
    ml_timing: Timing = Timing.zero,
    sources: Option[String] = None,
    heap_size: Option[Long] = None,
    status: Option[Session_Status.Value] = None,
    errors: List[String] = Nil,
    theory_timings: Map[String, Timing] = Map.empty,
    ml_statistics: List[Properties.T] = Nil)
  {
    def proper_groups: Option[String] = if (groups.isEmpty) None else Some(cat_lines(groups))
    def finished: Boolean = status == Some(Session_Status.finished)
    def failed: Boolean = status == Some(Session_Status.failed)
  }

  object Build_Info
  {
    val sessions_dummy: Map[String, Session_Entry] =
      Map("" -> Session_Entry(theory_timings = Map("" -> Timing.zero)))
  }

  sealed case class Build_Info(sessions: Map[String, Session_Entry])
  {
    def finished_sessions: List[String] = for ((a, b) <- sessions.toList if b.finished) yield a
    def failed_sessions: List[String] = for ((a, b) <- sessions.toList if b.failed) yield a
  }

  private def parse_build_info(log_file: Log_File, parse_ml_statistics: Boolean): Build_Info =
  {
    object Chapter_Name
    {
      def unapply(s: String): Some[(String, String)] =
        space_explode('/', s) match {
          case List(chapter, name) => Some((chapter, name))
          case _ => Some(("", s))
        }
    }

    val Session_No_Groups = new Regex("""^Session (\S+)$""")
    val Session_Groups = new Regex("""^Session (\S+) \((.*)\)$""")
    val Session_Finished1 =
      new Regex("""^Finished (\S+) \((\d+):(\d+):(\d+) elapsed time, (\d+):(\d+):(\d+) cpu time.*$""")
    val Session_Finished2 =
      new Regex("""^Finished (\S+) \((\d+):(\d+):(\d+) elapsed time.*$""")
    val Session_Timing =
      new Regex("""^Timing (\S+) \((\d+) threads, (\d+\.\d+)s elapsed time, (\d+\.\d+)s cpu time, (\d+\.\d+)s GC time.*$""")
    val Session_Started = new Regex("""^(?:Running|Building) (\S+) \.\.\.$""")
    val Session_Failed = new Regex("""^(\S+) FAILED""")
    val Session_Cancelled = new Regex("""^(\S+) CANCELLED""")
    val Sources = new Regex("""^Sources (\S+) (\S{""" + SHA1.digest_length + """})$""")
    val Heap = new Regex("""^Heap (\S+) \((\d+) bytes\)$""")

    object Theory_Timing
    {
      def unapply(line: String): Option[(String, (String, Timing))] =
      {
        val line1 = line.replace('~', '-')
        Library.try_unprefix(THEORY_TIMING_MARKER, line1).map(log_file.parse_props(_)) match {
          case Some((SESSION_NAME, name) :: props) =>
            (props, props) match {
              case (Markup.Name(thy), Markup.Timing_Properties(t)) => Some((name, thy -> t))
              case _ => None
            }
          case _ => None
        }
      }
    }

    var chapter = Map.empty[String, String]
    var groups = Map.empty[String, List[String]]
    var threads = Map.empty[String, Int]
    var timing = Map.empty[String, Timing]
    var ml_timing = Map.empty[String, Timing]
    var started = Set.empty[String]
    var failed = Set.empty[String]
    var cancelled = Set.empty[String]
    var sources = Map.empty[String, String]
    var heap_sizes = Map.empty[String, Long]
    var theory_timings = Map.empty[String, Map[String, Timing]]
    var ml_statistics = Map.empty[String, List[Properties.T]]
    var errors = Map.empty[String, List[String]]

    def all_sessions: Set[String] =
      chapter.keySet ++ groups.keySet ++ threads.keySet ++ timing.keySet ++ ml_timing.keySet ++
      failed ++ cancelled ++ started ++ sources.keySet ++ heap_sizes.keySet ++
      theory_timings.keySet ++ ml_statistics.keySet


    for (line <- log_file.lines) {
      line match {
        case Session_No_Groups(Chapter_Name(chapt, name)) =>
          chapter += (name -> chapt)
          groups += (name -> Nil)

        case Session_Groups(Chapter_Name(chapt, name), grps) =>
          chapter += (name -> chapt)
          groups += (name -> Word.explode(grps))

        case Session_Started(name) =>
          started += name

        case Session_Finished1(name,
            Value.Int(e1), Value.Int(e2), Value.Int(e3),
            Value.Int(c1), Value.Int(c2), Value.Int(c3)) =>
          val elapsed = Time.hms(e1, e2, e3)
          val cpu = Time.hms(c1, c2, c3)
          timing += (name -> Timing(elapsed, cpu, Time.zero))

        case Session_Finished2(name,
            Value.Int(e1), Value.Int(e2), Value.Int(e3)) =>
          val elapsed = Time.hms(e1, e2, e3)
          timing += (name -> Timing(elapsed, Time.zero, Time.zero))

        case Session_Timing(name,
            Value.Int(t), Value.Double(e), Value.Double(c), Value.Double(g)) =>
          val elapsed = Time.seconds(e)
          val cpu = Time.seconds(c)
          val gc = Time.seconds(g)
          ml_timing += (name -> Timing(elapsed, cpu, gc))
          threads += (name -> t)

        case Sources(name, s) =>
          sources += (name -> s)

        case Heap(name, Value.Long(size)) =>
          heap_sizes += (name -> size)

        case _ if line.startsWith(THEORY_TIMING_MARKER) && YXML.detect(line) =>
          line match {
            case Theory_Timing(name, theory_timing) =>
              theory_timings += (name -> (theory_timings.getOrElse(name, Map.empty) + theory_timing))
            case _ => log_file.err("malformed theory_timing " + quote(line))
          }

        case _ if parse_ml_statistics && line.startsWith(ML_STATISTICS_MARKER) && YXML.detect(line) =>
          Library.try_unprefix(ML_STATISTICS_MARKER, line).map(log_file.parse_props(_)) match {
            case Some((SESSION_NAME, name) :: props) =>
              ml_statistics += (name -> (props :: ml_statistics.getOrElse(name, Nil)))
            case _ => log_file.err("malformed ML_statistics " + quote(line))
          }

        case _ if line.startsWith(ERROR_MESSAGE_MARKER) && YXML.detect(line) =>
          Library.try_unprefix(ERROR_MESSAGE_MARKER, line).map(log_file.parse_props(_)) match {
            case Some(List((SESSION_NAME, name), (Markup.CONTENT, msg))) =>
              errors += (name -> (Library.decode_lines(msg) :: errors.getOrElse(name, Nil)))
            case _ => log_file.err("malformed error message " + quote(line))
          }

        case _ =>
      }
    }

    val sessions =
      Map(
        (for (name <- all_sessions.toList) yield {
          val status =
            if (failed(name)) Session_Status.failed
            else if (cancelled(name)) Session_Status.cancelled
            else if (timing.isDefinedAt(name) || ml_timing.isDefinedAt(name))
              Session_Status.finished
            else if (started(name)) Session_Status.failed
            else Session_Status.existing
          val entry =
            Session_Entry(
              chapter = chapter.getOrElse(name, ""),
              groups = groups.getOrElse(name, Nil),
              threads = threads.get(name),
              timing = timing.getOrElse(name, Timing.zero),
              ml_timing = ml_timing.getOrElse(name, Timing.zero),
              sources = sources.get(name),
              heap_size = heap_sizes.get(name),
              status = Some(status),
              errors = errors.getOrElse(name, Nil).reverse,
              theory_timings = theory_timings.getOrElse(name, Map.empty),
              ml_statistics = ml_statistics.getOrElse(name, Nil).reverse)
          (name -> entry)
        }):_*)
    Build_Info(sessions)
  }



  /** session info: produced by isabelle build as session log.gz file **/

  sealed case class Session_Info(
    session_timing: Properties.T,
    command_timings: List[Properties.T],
    theory_timings: List[Properties.T],
    ml_statistics: List[Properties.T],
    task_statistics: List[Properties.T],
    errors: List[String])
  {
    def error(s: String): Session_Info =
      copy(errors = errors ::: List(s))
  }

  private def parse_session_info(
    log_file: Log_File,
    command_timings: Boolean,
    theory_timings: Boolean,
    ml_statistics: Boolean,
    task_statistics: Boolean): Session_Info =
  {
    Session_Info(
      session_timing = log_file.find_props("\fTiming = ") getOrElse Nil,
      command_timings = if (command_timings) log_file.filter_props("\fcommand_timing = ") else Nil,
      theory_timings = if (theory_timings) log_file.filter_props(THEORY_TIMING_MARKER) else Nil,
      ml_statistics = if (ml_statistics) log_file.filter_props(ML_STATISTICS_MARKER) else Nil,
      task_statistics = if (task_statistics) log_file.filter_props("\ftask_statistics = ") else Nil,
      errors = log_file.filter_lines(ERROR_MESSAGE_MARKER).map(Library.decode_lines(_)))
  }

  def compress_errors(errors: List[String], cache: XZ.Cache = XZ.cache()): Option[Bytes] =
    if (errors.isEmpty) None
    else {
      Some(Bytes(YXML.string_of_body(XML.Encode.list(XML.Encode.string)(errors))).
        compress(cache = cache))
    }

  def uncompress_errors(bytes: Bytes, cache: XZ.Cache = XZ.cache()): List[String] =
    if (bytes.isEmpty) Nil
    else {
      XML.Decode.list(YXML.string_of_body(_))(YXML.parse_body(bytes.uncompress(cache = cache).text))
    }



  /** persistent store **/

  /* SQL data model */

  object Data
  {
    def build_log_table(name: String, columns: List[SQL.Column], body: String = ""): SQL.Table =
      SQL.Table("isabelle_build_log_" + name, columns, body)


    /* main content */

    val log_name = SQL.Column.string("log_name").make_primary_key
    val session_name = SQL.Column.string("session_name").make_primary_key
    val theory_name = SQL.Column.string("theory_name").make_primary_key
    val chapter = SQL.Column.string("chapter")
    val groups = SQL.Column.string("groups")
    val threads = SQL.Column.int("threads")
    val timing_elapsed = SQL.Column.long("timing_elapsed")
    val timing_cpu = SQL.Column.long("timing_cpu")
    val timing_gc = SQL.Column.long("timing_gc")
    val timing_factor = SQL.Column.double("timing_factor")
    val ml_timing_elapsed = SQL.Column.long("ml_timing_elapsed")
    val ml_timing_cpu = SQL.Column.long("ml_timing_cpu")
    val ml_timing_gc = SQL.Column.long("ml_timing_gc")
    val ml_timing_factor = SQL.Column.double("ml_timing_factor")
    val theory_timing_elapsed = SQL.Column.long("theory_timing_elapsed")
    val theory_timing_cpu = SQL.Column.long("theory_timing_cpu")
    val theory_timing_gc = SQL.Column.long("theory_timing_gc")
    val heap_size = SQL.Column.long("heap_size")
    val status = SQL.Column.string("status")
    val errors = SQL.Column.bytes("errors")
    val sources = SQL.Column.string("sources")
    val ml_statistics = SQL.Column.bytes("ml_statistics")
    val known = SQL.Column.bool("known")

    val meta_info_table =
      build_log_table("meta_info", log_name :: Prop.all_props ::: Settings.all_settings)

    val sessions_table =
      build_log_table("sessions",
        List(log_name, session_name, chapter, groups, threads, timing_elapsed, timing_cpu,
          timing_gc, timing_factor, ml_timing_elapsed, ml_timing_cpu, ml_timing_gc, ml_timing_factor,
          heap_size, status, errors, sources))

    val theories_table =
      build_log_table("theories",
        List(log_name, session_name, theory_name, theory_timing_elapsed, theory_timing_cpu,
          theory_timing_gc))

    val ml_statistics_table =
      build_log_table("ml_statistics", List(log_name, session_name, ml_statistics))


    /* AFP versions */

    val isabelle_afp_versions_table: SQL.Table =
    {
      val version1 = Prop.isabelle_version
      val version2 = Prop.afp_version
      build_log_table("isabelle_afp_versions", List(version1.make_primary_key, version2),
        SQL.select(List(version1, version2), distinct = true) + meta_info_table +
        " WHERE " + version1.defined + " AND " + version2.defined)
    }


    /* earliest pull date for repository version (PostgreSQL queries) */

    def pull_date(afp: Boolean = false) =
      if (afp) SQL.Column.date("afp_pull_date")
      else SQL.Column.date("pull_date")

    def pull_date_table(afp: Boolean = false): SQL.Table =
    {
      val (name, versions) =
        if (afp) ("afp_pull_date", List(Prop.isabelle_version, Prop.afp_version))
        else ("pull_date", List(Prop.isabelle_version))

      build_log_table(name, versions.map(_.make_primary_key) ::: List(pull_date(afp)),
        "SELECT " + versions.mkString(", ") +
          ", min(" + Prop.build_start + ") AS " + pull_date(afp) +
        " FROM " + meta_info_table +
        " WHERE " + (versions ::: List(Prop.build_start)).map(_.defined).mkString(" AND ") +
        " GROUP BY " + versions.mkString(", "))
    }


    /* recent entries */

    def recent_time(days: Int): SQL.Source =
      "now() - INTERVAL '" + days.max(0) + " days'"

    def recent_pull_date_table(
      days: Int, rev: String = "", afp_rev: Option[String] = None): SQL.Table =
    {
      val afp = afp_rev.isDefined
      val rev2 = afp_rev.getOrElse("")
      val table = pull_date_table(afp)

      val version1 = Prop.isabelle_version
      val version2 = Prop.afp_version
      val eq1 = version1(table) + " = " + SQL.string(rev)
      val eq2 = version2(table) + " = " + SQL.string(rev2)

      SQL.Table("recent_pull_date", table.columns,
        table.select(table.columns,
          "WHERE " + pull_date(afp)(table) + " > " + recent_time(days) +
          (if (rev != "" && rev2 == "") " OR " + eq1
           else if (rev == "" && rev2 != "") " OR " + eq2
           else if (rev != "" && rev2 != "") " OR (" + eq1 + " AND " + eq2 + ")"
           else "")))
    }

    def select_recent_log_names(days: Int): SQL.Source =
    {
      val table1 = meta_info_table
      val table2 = recent_pull_date_table(days)
      table1.select(List(log_name), distinct = true) + SQL.join_inner + table2.query_named +
        " ON " + Prop.isabelle_version(table1) + " = " + Prop.isabelle_version(table2)
    }

    def select_recent_versions(days: Int,
      rev: String = "", afp_rev: Option[String] = None, sql: SQL.Source = ""): SQL.Source =
    {
      val afp = afp_rev.isDefined
      val version = Prop.isabelle_version
      val table1 = recent_pull_date_table(days, rev = rev, afp_rev = afp_rev)
      val table2 = meta_info_table
      val aux_table = SQL.Table("aux", table2.columns, table2.select(sql = sql))

      val columns =
        table1.columns.map(c => c(table1)) :::
          List(known.copy(expr = log_name(aux_table).defined))
      SQL.select(columns, distinct = true) +
        table1.query_named + SQL.join_outer + aux_table.query_named +
        " ON " + version(table1) + " = " + version(aux_table) +
        " ORDER BY " + pull_date(afp)(table1) + " DESC"
    }


    /* universal view on main data */

    val universal_table: SQL.Table =
    {
      val afp_pull_date = pull_date(afp = true)
      val version1 = Prop.isabelle_version
      val version2 = Prop.afp_version
      val table1 = meta_info_table
      val table2 = pull_date_table(afp = true)
      val table3 = pull_date_table()

      val a_columns = log_name :: afp_pull_date :: table1.columns.tail
      val a_table =
        SQL.Table("a", a_columns,
          SQL.select(List(log_name, afp_pull_date) ::: table1.columns.tail.map(_.apply(table1))) +
          table1 + SQL.join_outer + table2 +
          " ON " + version1(table1) + " = " + version1(table2) +
          " AND " + version2(table1) + " = " + version2(table2))

      val b_columns = log_name :: pull_date() :: a_columns.tail
      val b_table =
        SQL.Table("b", b_columns,
          SQL.select(
            List(log_name(a_table), pull_date()(table3)) ::: a_columns.tail.map(_.apply(a_table))) +
          a_table.query_named + SQL.join_outer + table3 +
          " ON " + version1(a_table) + " = " + version1(table3))

      val c_columns = b_columns ::: sessions_table.columns.tail
      val c_table =
        SQL.Table("c", c_columns,
          SQL.select(log_name(b_table) :: c_columns.tail) +
          b_table.query_named + SQL.join_inner + sessions_table +
          " ON " + log_name(b_table) + " = " + log_name(sessions_table))

      SQL.Table("isabelle_build_log", c_columns ::: List(ml_statistics),
        {
          SQL.select(c_columns.map(_.apply(c_table)) ::: List(ml_statistics)) +
          c_table.query_named + SQL.join_outer + ml_statistics_table +
          " ON " + log_name(c_table) + " = " + log_name(ml_statistics_table) +
          " AND " + session_name(c_table) + " = " + session_name(ml_statistics_table)
        })
    }
  }


  /* database access */

  def store(options: Options): Store = new Store(options)

  class Store private[Build_Log](options: Options)
  {
    val xml_cache: XML.Cache = XML.make_cache()
    val xz_cache: XZ.Cache = XZ.make_cache()

    def open_database(
      user: String = options.string("build_log_database_user"),
      password: String = options.string("build_log_database_password"),
      database: String = options.string("build_log_database_name"),
      host: String = options.string("build_log_database_host"),
      port: Int = options.int("build_log_database_port"),
      ssh_host: String = options.string("build_log_ssh_host"),
      ssh_user: String = options.string("build_log_ssh_user"),
      ssh_port: Int = options.int("build_log_ssh_port")): PostgreSQL.Database =
    {
      PostgreSQL.open_database(
        user = user, password = password, database = database, host = host, port = port,
        ssh =
          if (ssh_host == "") None
          else Some(SSH.open_session(options, host = ssh_host, user = ssh_user, port = port)),
        ssh_close = true)
    }

    def update_database(db: PostgreSQL.Database, dirs: List[Path], ml_statistics: Boolean = false)
    {
      val log_files =
        dirs.flatMap(dir =>
          File.find_files(dir.file, pred = Log_File.is_log(_), follow_links = true))
      write_info(db, log_files, ml_statistics = ml_statistics)

      db.create_view(Data.pull_date_table())
      db.create_view(Data.pull_date_table(afp = true))
      db.create_view(Data.universal_table)
    }

    def snapshot_database(db: PostgreSQL.Database, sqlite_database: Path,
      days: Int = 100, ml_statistics: Boolean = false)
    {
      Isabelle_System.mkdirs(sqlite_database.dir)
      sqlite_database.file.delete

      using(SQLite.open_database(sqlite_database))(db2 =>
      {
        db.transaction {
          db2.transaction {
            // main content
            db2.create_table(Data.meta_info_table)
            db2.create_table(Data.sessions_table)
            db2.create_table(Data.theories_table)
            db2.create_table(Data.ml_statistics_table)

            val recent_log_names =
              db.using_statement(Data.select_recent_log_names(days))(stmt =>
                stmt.execute_query().iterator(_.string(Data.log_name)).toList)

            for (log_name <- recent_log_names) {
              read_meta_info(db, log_name).foreach(meta_info =>
                update_meta_info(db2, log_name, meta_info))

              update_sessions(db2, log_name, read_build_info(db, log_name))

              if (ml_statistics) {
                update_ml_statistics(db2, log_name,
                  read_build_info(db, log_name, ml_statistics = true))
              }
            }

            // pull_date
            for (afp <- List(false, true))
            {
              val afp_rev = if (afp) Some("") else None
              val table = Data.pull_date_table(afp)
              db2.create_table(table)
              db2.using_statement(table.insert())(stmt2 =>
              {
                db.using_statement(
                  Data.recent_pull_date_table(days, afp_rev = afp_rev).query)(stmt =>
                {
                  val res = stmt.execute_query()
                  while (res.next()) {
                    for ((c, i) <- table.columns.zipWithIndex) {
                      stmt2.string(i + 1) = res.get_string(c)
                    }
                    stmt2.execute()
                  }
                })
              })
            }

            // full view
            db2.create_view(Data.universal_table)
          }
        }
        db2.rebuild
      })
    }

    def domain(db: SQL.Database, table: SQL.Table, column: SQL.Column): Set[String] =
      db.using_statement(table.select(List(column), distinct = true))(stmt =>
        stmt.execute_query().iterator(_.string(column)).toSet)

    def update_meta_info(db: SQL.Database, log_name: String, meta_info: Meta_Info)
    {
      val table = Data.meta_info_table
      db.using_statement(db.insert_permissive(table))(stmt =>
      {
        stmt.string(1) = log_name
        for ((c, i) <- table.columns.tail.zipWithIndex) {
          if (c.T == SQL.Type.Date)
            stmt.date(i + 2) = meta_info.get_date(c)
          else
            stmt.string(i + 2) = meta_info.get(c)
        }
        stmt.execute()
      })
    }

    def update_sessions(db: SQL.Database, log_name: String, build_info: Build_Info)
    {
      val table = Data.sessions_table
      db.using_statement(db.insert_permissive(table))(stmt =>
      {
        val sessions =
          if (build_info.sessions.isEmpty) Build_Info.sessions_dummy
          else build_info.sessions
        for ((session_name, session) <- sessions) {
          stmt.string(1) = log_name
          stmt.string(2) = session_name
          stmt.string(3) = proper_string(session.chapter)
          stmt.string(4) = session.proper_groups
          stmt.int(5) = session.threads
          stmt.long(6) = session.timing.elapsed.proper_ms
          stmt.long(7) = session.timing.cpu.proper_ms
          stmt.long(8) = session.timing.gc.proper_ms
          stmt.double(9) = session.timing.factor
          stmt.long(10) = session.ml_timing.elapsed.proper_ms
          stmt.long(11) = session.ml_timing.cpu.proper_ms
          stmt.long(12) = session.ml_timing.gc.proper_ms
          stmt.double(13) = session.ml_timing.factor
          stmt.long(14) = session.heap_size
          stmt.string(15) = session.status.map(_.toString)
          stmt.bytes(16) = compress_errors(session.errors, cache = xz_cache)
          stmt.string(17) = session.sources
          stmt.execute()
        }
      })
    }

    def update_theories(db: SQL.Database, log_name: String, build_info: Build_Info)
    {
      val table = Data.theories_table
      db.using_statement(db.insert_permissive(table))(stmt =>
      {
        val sessions =
          if (build_info.sessions.forall({ case (_, session) => session.theory_timings.isEmpty }))
            Build_Info.sessions_dummy
          else build_info.sessions
        for {
          (session_name, session) <- sessions
          (theory_name, timing) <- session.theory_timings
        } {
          stmt.string(1) = log_name
          stmt.string(2) = session_name
          stmt.string(3) = theory_name
          stmt.long(4) = timing.elapsed.ms
          stmt.long(5) = timing.cpu.ms
          stmt.long(6) = timing.gc.ms
          stmt.execute()
        }
      })
    }

    def update_ml_statistics(db: SQL.Database, log_name: String, build_info: Build_Info)
    {
      val table = Data.ml_statistics_table
      db.using_statement(db.insert_permissive(table))(stmt =>
      {
        val ml_stats: List[(String, Option[Bytes])] =
          Par_List.map[(String, Session_Entry), (String, Option[Bytes])](
            { case (a, b) => (a, Properties.compress(b.ml_statistics, cache = xz_cache).proper) },
            build_info.sessions.iterator.filter(p => p._2.ml_statistics.nonEmpty).toList)
        val entries = if (ml_stats.nonEmpty) ml_stats else List("" -> None)
        for ((session_name, ml_statistics) <- entries) {
          stmt.string(1) = log_name
          stmt.string(2) = session_name
          stmt.bytes(3) = ml_statistics
          stmt.execute()
        }
      })
    }

    def write_info(db: SQL.Database, files: List[JFile], ml_statistics: Boolean = false)
    {
      abstract class Table_Status(table: SQL.Table)
      {
        db.create_table(table)
        private var known: Set[String] = domain(db, table, Data.log_name)

        def required(file: JFile): Boolean = !known(Log_File.plain_name(file.getName))

        def update_db(db: SQL.Database, log_file: Log_File): Unit
        def update(log_file: Log_File)
        {
          if (!known(log_file.name)) {
            update_db(db, log_file)
            known += log_file.name
          }
        }
      }
      val status =
        List(
          new Table_Status(Data.meta_info_table) {
            override def update_db(db: SQL.Database, log_file: Log_File): Unit =
              update_meta_info(db, log_file.name, log_file.parse_meta_info())
          },
          new Table_Status(Data.sessions_table) {
            override def update_db(db: SQL.Database, log_file: Log_File): Unit =
              update_sessions(db, log_file.name, log_file.parse_build_info())
          },
          new Table_Status(Data.theories_table) {
            override def update_db(db: SQL.Database, log_file: Log_File): Unit =
              update_theories(db, log_file.name, log_file.parse_build_info())
          },
          new Table_Status(Data.ml_statistics_table) {
            override def update_db(db: SQL.Database, log_file: Log_File): Unit =
            if (ml_statistics) {
              update_ml_statistics(db, log_file.name,
                log_file.parse_build_info(ml_statistics = true))
            }
          })

      for (file_group <-
            files.filter(file => status.exists(_.required(file))).
              grouped(options.int("build_log_transaction_size") max 1))
      {
        val log_files = Par_List.map[JFile, Log_File](Log_File.apply _, file_group)
        db.transaction { log_files.foreach(log_file => status.foreach(_.update(log_file))) }
      }
    }

    def read_meta_info(db: SQL.Database, log_name: String): Option[Meta_Info] =
    {
      val table = Data.meta_info_table
      val columns = table.columns.tail
      db.using_statement(table.select(columns, Data.log_name.where_equal(log_name)))(stmt =>
      {
        val res = stmt.execute_query()
        if (!res.next) None
        else {
          val results =
            columns.map(c => c.name ->
              (if (c.T == SQL.Type.Date)
                res.get_date(c).map(Log_File.Date_Format(_))
               else
                res.get_string(c)))
          val n = Prop.all_props.length
          val props = for ((x, Some(y)) <- results.take(n)) yield (x, y)
          val settings = for ((x, Some(y)) <- results.drop(n)) yield (x, y)
          Some(Meta_Info(props, settings))
        }
      })
    }

    def read_build_info(
      db: SQL.Database,
      log_name: String,
      session_names: List[String] = Nil,
      ml_statistics: Boolean = false): Build_Info =
    {
      val table1 = Data.sessions_table
      val table2 = Data.ml_statistics_table

      val where_log_name =
        Data.log_name(table1).where_equal(log_name) + " AND " +
        Data.session_name(table1) + " <> ''"
      val where =
        if (session_names.isEmpty) where_log_name
        else where_log_name + " AND " + SQL.member(Data.session_name(table1).ident, session_names)

      val columns1 = table1.columns.tail.map(_.apply(table1))
      val (columns, from) =
        if (ml_statistics) {
          val columns = columns1 ::: List(Data.ml_statistics(table2))
          val join =
            table1 + SQL.join_outer + table2 + " ON " +
            Data.log_name(table1) + " = " + Data.log_name(table2) + " AND " +
            Data.session_name(table1) + " = " + Data.session_name(table2)
          (columns, SQL.enclose(join))
        }
        else (columns1, table1.ident)

      val sessions =
        db.using_statement(SQL.select(columns) + from + " " + where)(stmt =>
        {
          stmt.execute_query().iterator(res =>
          {
            val session_name = res.string(Data.session_name)
            val session_entry =
              Session_Entry(
                chapter = res.string(Data.chapter),
                groups = split_lines(res.string(Data.groups)),
                threads = res.get_int(Data.threads),
                timing = res.timing(Data.timing_elapsed, Data.timing_cpu, Data.timing_gc),
                ml_timing =
                  res.timing(Data.ml_timing_elapsed, Data.ml_timing_cpu, Data.ml_timing_gc),
                sources = res.get_string(Data.sources),
                heap_size = res.get_long(Data.heap_size),
                status = res.get_string(Data.status).map(Session_Status.withName(_)),
                errors = uncompress_errors(res.bytes(Data.errors), cache = xz_cache),
                ml_statistics =
                  if (ml_statistics) {
                    Properties.uncompress(
                      res.bytes(Data.ml_statistics), cache = xz_cache, Some(xml_cache))
                  }
                  else Nil)
            session_name -> session_entry
          }).toMap
        })
      Build_Info(sessions)
    }
  }
}