Avoid generating a JSON string before writing to file

This solve a crash when considering a huge amount of queries.

4 files changed, 41 insertions, 19 deletions

diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 336f052..8341b8d 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -5,7 +5,7 @@ object Dependencies {
   lazy val scalatestVersion = "3.2.3"
   lazy val owlapiVersion = "5.1.17"
   lazy val scalagraphVersion = "1.13.2"
-  lazy val ujsonVersion = "1.4.1"
+  lazy val ujsonVersion = "1.4.2"
   lazy val oslibVersion = "0.7.8"
 
   // Libraries
diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/Main.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/Main.scala
index 7eb39e8..fe88b4f 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/Main.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/Main.scala
@@ -41,6 +41,10 @@ object RSAComb extends App {
   if (config.contains('logger))
     Logger.level = config('logger).get[Logger.Level]
 
+  /* Set answers output file */
+  if (config.contains('answers))
+    Logger.answers = config('answers).get[os.Path]
+
   /* Load original ontology and normalize it */
   val ontopath = config('ontology).get[os.Path]
   val data = config('data).get[List[os.Path]]
@@ -61,12 +65,7 @@ object RSAComb extends App {
     val answers = rsa ask queries
 
     /* Write answers to output file */
-    os.write(
-      config('answers).get[os.Path],
-      ujson.write(ujson.Arr(answers.map(_.toJSON)), indent = 2),
-      createFolders = true
-    )
-
+    Logger write answers
     /* Generate simulation script */
     Logger.generateSimulationScripts(data, queries)
   }
diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/RSAConfig.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/RSAConfig.scala
index f3039b3..4d96850 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/RSAConfig.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/RSAConfig.scala
@@ -149,8 +149,6 @@ object RSAConfig {
       exit("The following flag is mandatory: '-o' or '--ontology'.")
     if (!config.contains('data))
       config += ('data -> List.empty[os.Path])
-    if (!config.contains('answers))
-      config += ('answers -> Logger.dir / "answers.json")
     config
   }
 }
diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/util/Logger.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/util/Logger.scala
index f3b0232..20fd4c3 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/util/Logger.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/util/Logger.scala
@@ -19,23 +19,25 @@ package uk.ac.ox.cs.rsacomb.util
 import java.util.Calendar
 import java.text.SimpleDateFormat
 import java.io.PrintStream
-import uk.ac.ox.cs.rsacomb.sparql.ConjunctiveQuery
+import uk.ac.ox.cs.rsacomb.sparql.{ConjunctiveQuery, ConjunctiveQueryAnswers}
 
 /** Simple logger */
 object Logger {
 
-  lazy val dir = {
+  /** Main directory for logger output for the current run */
+  val dir = {
     val timestamp = (new SimpleDateFormat("yyyyMMddHHmmss")).format(
       Calendar.getInstance().getTime
     )
-    val dir = os.pwd / s"rsacomb-$timestamp"
-    os.makeDir(dir)
-    dir
+    os.pwd / s"rsacomb-$timestamp"
   }
 
   /** Output stream for the logger. */
   var output: PrintStream = System.out
 
+  /** Path to answers output file */
+  var answers: os.Path = dir / "answers.json"
+
   /** Logger levels (i.e., verbosity of output) */
   sealed abstract class Level(val level: Int, val name: String)
       extends Ordered[Level] {
@@ -67,8 +69,29 @@ object Logger {
     */
   def write(content: => os.Source, file: String, lvl: Level = VERBOSE): Unit =
     if (lvl <= level)
-      os.write.append(dir / file, content)
+      os.write.append(dir / file, content, createFolders = true)
+
+  /** Write answers to queries to output file in JSON format.
+    * 
+    * @param ans the set of answers to be written.
+    */
+  def write(ans: Seq[ConjunctiveQueryAnswers]): Unit = {
+    ujson.writeToOutputStream(
+      ujson.Arr(ans.map(_.toJSON)),
+      os.write.outputStream(answers, createFolders = true),
+      indent = 2
+    )
+  }
 
+  /** Timed evaluation of an expression.
+    *
+    * Records and outputs additional information about evaluation time.
+    *
+    * @param expr expression to be evaluated.
+    * @param desc short description of the expression.
+    * @param lvl minimum require logger level for output
+    * @return the result of the evaluation.
+    */
   def timed[A](expr: => A, desc: String = "", lvl: Level = NORMAL): A = {
     val t0 = System.currentTimeMillis()
     print(s"$desc (START)", lvl)
@@ -92,7 +115,6 @@ object Logger {
     if (lvl <= level) {
       /* Create script folder */
       val sim = os.rel / 'sim
-      os.makeDir(dir / sim)
       /* Generate main script */
       os.write.append(
         dir / "simulate.rdfox",
@@ -121,14 +143,16 @@ echo "\\n[Load canonical model program]"
 import "canonical_model.dlog"
 
 exec "$sim/filter_query_$$(1).rdfox"
-"""
+""",
+        createFolders = true
       )
       /* Generate query scripts */
       queries.map(q => {
         val id = q.id
         os.write.append(
           dir / sim / "filter_query_all.rdfox",
-          s"exec $sim/filter_query_$id.rdfox\n"
+          s"exec $sim/filter_query_$id.rdfox\n",
+          createFolders = true
         )
         os.write.append(
           dir / sim / s"filter_query_$id.rdfox",
@@ -136,7 +160,8 @@ exec "$sim/filter_query_$$(1).rdfox"
 echo "\\n[Load filtering program for query $id]"
 tupletable create rsacomb:Filter$id type "named-graph"
 import "filter_query_$id.dlog"
-"""
+""",
+          createFolders = true
         )
       })
     }