feat(trace/api): Add support for projecting tables

This change adds support for projecting certain columns of a table. This
enables faster reading for tables with high number of columns.
Currently, we support projection in the Parquet-based workload formats.
Other formats are text-based and will probably not benefit much from
projection.

2 files changed, 3 insertions, 3 deletions

diff --git a/opendc-trace/opendc-trace-wfformat/src/main/kotlin/org/opendc/trace/wfformat/WfFormatTraceFormat.kt b/opendc-trace/opendc-trace-wfformat/src/main/kotlin/org/opendc/trace/wfformat/WfFormatTraceFormat.kt
index bc175b58..8db4c169 100644
--- a/opendc-trace/opendc-trace-wfformat/src/main/kotlin/org/opendc/trace/wfformat/WfFormatTraceFormat.kt
+++ b/opendc-trace/opendc-trace-wfformat/src/main/kotlin/org/opendc/trace/wfformat/WfFormatTraceFormat.kt
@@ -63,7 +63,7 @@ public class WfFormatTraceFormat : TraceFormat {
         }
     }
 
-    override fun newReader(path: Path, table: String): TableReader {
+    override fun newReader(path: Path, table: String, projection: List<TableColumn<*>>?): TableReader {
         return when (table) {
             TABLE_TASKS -> WfFormatTaskTableReader(factory.createParser(path.toFile()))
             else -> throw IllegalArgumentException("Table $table not supported")
diff --git a/opendc-trace/opendc-trace-wfformat/src/test/kotlin/org/opendc/trace/wfformat/WfFormatTraceFormatTest.kt b/opendc-trace/opendc-trace-wfformat/src/test/kotlin/org/opendc/trace/wfformat/WfFormatTraceFormatTest.kt
index 710de88e..4a8b2792 100644
--- a/opendc-trace/opendc-trace-wfformat/src/test/kotlin/org/opendc/trace/wfformat/WfFormatTraceFormatTest.kt
+++ b/opendc-trace/opendc-trace-wfformat/src/test/kotlin/org/opendc/trace/wfformat/WfFormatTraceFormatTest.kt
@@ -62,7 +62,7 @@ class WfFormatTraceFormatTest {
     @Test
     fun testTableReader() {
         val path = Paths.get("src/test/resources/trace.json")
-        val reader = format.newReader(path, TABLE_TASKS)
+        val reader = format.newReader(path, TABLE_TASKS, null)
 
         assertAll(
             { assertTrue(reader.nextRow()) },
@@ -89,7 +89,7 @@ class WfFormatTraceFormatTest {
     @Test
     fun testTableReaderFull() {
         val path = Paths.get("src/test/resources/trace.json")
-        val reader = format.newReader(path, TABLE_TASKS)
+        val reader = format.newReader(path, TABLE_TASKS, null)
 
         assertDoesNotThrow {
             while (reader.nextRow()) {