feat(trace): Add support for writing traces

This change adds a new API for writing traces in a trace format.
Currently, writing is only supported by the OpenDC VM format, but over
time the other formats will also have support for writing added.

5 files changed, 209 insertions, 3 deletions

diff --git a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt
index 031ee269..b0181cbc 100644
--- a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt
+++ b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt
@@ -45,4 +45,11 @@ public interface Table {
      * Open a [TableReader] for this table.
      */
     public fun newReader(): TableReader
+
+    /**
+     * Open a [TableWriter] for this table.
+     *
+     * @throws UnsupportedOperationException if writing is not supported by the table.
+     */
+    public fun newWriter(): TableWriter
 }
diff --git a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/TableWriter.kt b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/TableWriter.kt
new file mode 100644
index 00000000..423ce86a
--- /dev/null
+++ b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/TableWriter.kt
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.trace
+
+/**
+ * Base class for writing workload traces.
+ */
+public interface TableWriter : AutoCloseable {
+    /**
+     * Start a new row in the table.
+     */
+    public fun startRow()
+
+    /**
+     * Flush the current row to the table.
+     */
+    public fun endRow()
+
+    /**
+     * Resolve the index of the specified [column] for this writer.
+     *
+     * @param column The column to lookup.
+     * @return The zero-based index of the column or a negative value if the column is not present in this table.
+     */
+    public fun resolve(column: TableColumn<*>): Int
+
+    /**
+     * Determine whether the [TableReader] supports the specified [column].
+     */
+    public fun hasColumn(column: TableColumn<*>): Boolean = resolve(column) >= 0
+
+    /**
+     * Set [column] to [value].
+     *
+     * @param index The zero-based index of the column to set the value for.
+     * @param value The value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun set(index: Int, value: Any)
+
+    /**
+     * Set [column] to boolean [value].
+     *
+     * @param index The zero-based index of the column to set the value for.
+     * @param value The boolean value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun setBoolean(index: Int, value: Boolean)
+
+    /**
+     * Set [column] to integer [value].
+     *
+     * @param index The zero-based index of the column to set the value for.
+     * @param value The integer value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun setInt(index: Int, value: Int)
+
+    /**
+     * Set [column] to long [value].
+     *
+     * @param index The zero-based index of the column to set the value for.
+     * @param value The long value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun setLong(index: Int, value: Long)
+
+    /**
+     * Set [column] to double [value].
+     *
+     * @param index The zero-based index of the column to set the value for.
+     * @param value The double value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun setDouble(index: Int, value: Double)
+
+    /**
+     * Set [column] to [value].
+     *
+     * @param column The column to set the value for.
+     * @param value The value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun <T : Any> set(column: TableColumn<T>, value: T): Unit = set(resolve(column), value)
+
+    /**
+     * Set [column] to boolean [value].
+     *
+     * @param column The column to set the value for.
+     * @param value The boolean value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun setBoolean(column: TableColumn<Boolean>, value: Boolean): Unit = setBoolean(resolve(column), value)
+
+    /**
+     * Set [column] to integer [value].
+     *
+     * @param column The column to set the value for.
+     * @param value The integer value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun setInt(column: TableColumn<Int>, value: Int): Unit = setInt(resolve(column), value)
+
+    /**
+     * Set [column] to long [value].
+     *
+     * @param column The column to set the value for.
+     * @param value The long value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun setLong(column: TableColumn<Long>, value: Long): Unit = setLong(resolve(column), value)
+
+    /**
+     * Set [column] to double [value].
+     *
+     * @param column The column to set the value for.
+     * @param value The double value to set the column to.
+     * @throws IllegalArgumentException if the column is not valid for this method.
+     */
+    public fun setDouble(column: TableColumn<Double>, value: Double): Unit = setDouble(resolve(column), value)
+
+    /**
+     * Flush any buffered content to the underlying target.
+     */
+    public fun flush()
+
+    /**
+     * Close the writer so that no more rows can be written.
+     */
+    public override fun close()
+}
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 6d0014cb..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
@@ -51,21 +51,45 @@ public interface Trace {
          * 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.toPath(), format)
-        }
+        @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.
          */
+        @JvmStatic
         public fun open(path: Path, format: String): Trace {
             val provider = requireNotNull(TraceFormat.byName(format)) { "Unknown format $format" }
             return TraceImpl(provider, path)
         }
+
+        /**
+         * 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: 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)
+        }
     }
 }
diff --git a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/internal/TableImpl.kt b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/internal/TableImpl.kt
index fd0a0f04..24551edb 100644
--- a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/internal/TableImpl.kt
+++ b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/internal/TableImpl.kt
@@ -25,6 +25,7 @@ package org.opendc.trace.internal
 import org.opendc.trace.Table
 import org.opendc.trace.TableColumn
 import org.opendc.trace.TableReader
+import org.opendc.trace.TableWriter
 import java.util.*
 
 /**
@@ -44,6 +45,8 @@ internal class TableImpl(val trace: TraceImpl, override val name: String) : Tabl
 
     override fun newReader(): TableReader = trace.format.newReader(trace.path, name)
 
+    override fun newWriter(): TableWriter = trace.format.newWriter(trace.path, name)
+
     override fun toString(): String = "Table[name=$name]"
 
     override fun hashCode(): Int = Objects.hash(trace, name)
diff --git a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/spi/TraceFormat.kt b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/spi/TraceFormat.kt
index e04dd948..f2e610db 100644
--- a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/spi/TraceFormat.kt
+++ b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/spi/TraceFormat.kt
@@ -23,6 +23,7 @@
 package org.opendc.trace.spi
 
 import org.opendc.trace.TableReader
+import org.opendc.trace.TableWriter
 import java.nio.file.Path
 import java.util.*
 
@@ -36,6 +37,15 @@ public interface TraceFormat {
     public val name: String
 
     /**
+     * Construct an empty trace at [path].
+     *
+     * @param path The path where to create the empty trace.
+     * @throws IllegalArgumentException If [path] is invalid.
+     * @throws UnsupportedOperationException If the table does not support trace creation.
+     */
+    public fun create(path: Path)
+
+    /**
      * Return the name of the tables available in the trace at the specified [path].
      *
      * @param path The path to the trace.
@@ -64,6 +74,17 @@ public interface TraceFormat {
     public fun newReader(path: Path, table: String): TableReader
 
     /**
+     * Open a [TableWriter] for the specified [table].
+     *
+     * @param path The path to the trace to open.
+     * @param table The name of the table to open a [TableWriter] for.
+     * @throws IllegalArgumentException If [table] does not exist.
+     * @throws UnsupportedOperationException If the format does not support writing.
+     * @return A [TableWriter] instance for the table.
+     */
+    public fun newWriter(path: Path, table: String): TableWriter
+
+    /**
      * A helper object for resolving providers.
      */
     public companion object {