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-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt
index 8e3e60cc..73978990 100644
--- a/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt
+++ b/opendc-trace/opendc-trace-azure/src/main/kotlin/org/opendc/trace/azure/AzureTraceFormat.kt
@@ -81,7 +81,7 @@ public class AzureTraceFormat : TraceFormat {
         }
     }
 
-    override fun newReader(path: Path, table: String): TableReader {
+    override fun newReader(path: Path, table: String, projection: List<TableColumn<*>>?): TableReader {
         return when (table) {
             TABLE_RESOURCES -> {
                 val stream = GZIPInputStream(path.resolve("vmtable/vmtable.csv.gz").inputStream())
diff --git a/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt b/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt
index 56f9a940..263d26ce 100644
--- a/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt
+++ b/opendc-trace/opendc-trace-azure/src/test/kotlin/org/opendc/trace/azure/AzureTraceFormatTest.kt
@@ -57,7 +57,7 @@ class AzureTraceFormatTest {
     @Test
     fun testResources() {
         val path = Paths.get("src/test/resources/trace")
-        val reader = format.newReader(path, TABLE_RESOURCES)
+        val reader = format.newReader(path, TABLE_RESOURCES, null)
         assertAll(
             { assertTrue(reader.nextRow()) },
             { assertEquals("x/XsOfHO4ocsV99i4NluqKDuxctW2MMVmwqOPAlg4wp8mqbBOe3wxBlQo0+Qx+uf", reader.get(RESOURCE_ID)) },
@@ -71,7 +71,7 @@ class AzureTraceFormatTest {
     @Test
     fun testSmoke() {
         val path = Paths.get("src/test/resources/trace")
-        val reader = format.newReader(path, TABLE_RESOURCE_STATES)
+        val reader = format.newReader(path, TABLE_RESOURCE_STATES, null)
 
         assertAll(
             { assertTrue(reader.nextRow()) },