merge: Add support for trace writing

This pull request extends the trace API to support writing new traces.

- Unify columns of different tables 
- Support column lookup via index
- Use index lookup in trace loader 
- Add property for describing partition keys
- Simplify TraceFormat SPI interface
- Add support for writing traces

**Breaking API Changes**

- `TraceFormat` SPI interface has been redesigned.

1 files changed, 29 insertions, 12 deletions

diff --git a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Trace.kt b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Trace.kt
index 0ae45e86..64e8f272 100644
--- a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Trace.kt
+++ b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Trace.kt
@@ -22,9 +22,9 @@
 
 package org.opendc.trace
 
+import org.opendc.trace.internal.TraceImpl
 import org.opendc.trace.spi.TraceFormat
 import java.io.File
-import java.net.URL
 import java.nio.file.Path
 
 /**
@@ -48,31 +48,48 @@ public interface Trace {
 
     public companion object {
         /**
-         * Open a [Trace] at the specified [url] in the given [format].
+         * Open a [Trace] at the specified [path] in the given [format].
          *
+         * @param path The path to the trace.
+         * @param format The format of the trace to open.
          * @throws IllegalArgumentException if [format] is not supported.
          */
-        public fun open(url: URL, format: String): Trace {
-            val provider = requireNotNull(TraceFormat.byName(format)) { "Unknown format $format" }
-            return provider.open(url)
-        }
+        @JvmStatic
+        public fun open(path: File, format: String): Trace = open(path.toPath(), format)
 
         /**
          * Open a [Trace] at the specified [path] in the given [format].
          *
+         * @param path The [Path] to the trace.
+         * @param format The format of the trace to open.
          * @throws IllegalArgumentException if [format] is not supported.
          */
-        public fun open(path: File, format: String): Trace {
-            return open(path.toURI().toURL(), format)
+        @JvmStatic
+        public fun open(path: Path, format: String): Trace {
+            val provider = requireNotNull(TraceFormat.byName(format)) { "Unknown format $format" }
+            return TraceImpl(provider, path)
         }
 
         /**
-         * Open a [Trace] at the specified [path] in the given [format].
+         * Create a [Trace] at the specified [path] in the given [format].
          *
-         * @throws IllegalArgumentException if [format] is not supported.
+         * @param path The [Path] to the trace.
+         * @param format The format of the trace to create.
          */
-        public fun open(path: Path, format: String): Trace {
-            return open(path.toUri().toURL(), format)
+        @JvmStatic
+        public fun create(path: File, format: String): Trace = create(path.toPath(), format)
+
+        /**
+         * Create a [Trace] at the specified [path] in the given [format].
+         *
+         * @param path The [Path] to the trace.
+         * @param format The format of the trace to create.
+         */
+        @JvmStatic
+        public fun create(path: Path, format: String): Trace {
+            val provider = requireNotNull(TraceFormat.byName(format)) { "Unknown format $format" }
+            provider.create(path)
+            return TraceImpl(provider, path)
         }
     }
 }