Move some serialization helpers to metadata/metadata.jvm

core/metadata/src/org/jetbrains/kotlin/metadata/serialization/Interner.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.metadata.serialization
+
+class Interner<T>(private val parent: Interner<T>? = null) {
+    private val firstIndex: Int = parent?.run { interned.size + firstIndex } ?: 0
+    private val interned = hashMapOf<T, Int>()
+
+    val allInternedObjects: List<T>
+        get() = interned.keys.sortedBy(interned::get)
+
+    val isEmpty: Boolean
+        get() = interned.isEmpty() && parent?.isEmpty != false
+
+    private fun find(obj: T): Int? {
+        assert(parent == null || parent.interned.size + parent.firstIndex == firstIndex) {
+            "Parent changed in parallel with child: indexes will be wrong"
+        }
+        return parent?.find(obj) ?: interned[obj]
+    }
+
+    fun intern(obj: T): Int =
+        find(obj) ?: (firstIndex + interned.size).also {
+            interned[obj] = it
+        }
+}

core/metadata/src/org/jetbrains/kotlin/metadata/serialization/MutableTable.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+@file:Suppress("FINITE_BOUNDS_VIOLATION_IN_JAVA")
+package org.jetbrains.kotlin.metadata.serialization
+
+import org.jetbrains.kotlin.metadata.ProtoBuf
+import org.jetbrains.kotlin.protobuf.GeneratedMessageLite
+
+private class TableElementWrapper<Element : GeneratedMessageLite.Builder<*, Element>>(val builder: Element) {
+    // If you'll try to optimize it using structured equals/hashCode, pay attention to extensions present in proto messages
+    private val bytes: ByteArray = builder.build().toByteArray()
+    private val hashCode: Int = bytes.contentHashCode()
+
+    override fun hashCode() = hashCode
+
+    override fun equals(other: Any?) = other is TableElementWrapper<*> && bytes.contentEquals(other.bytes)
+}
+
+abstract class MutableTable<Element, Table, TableBuilder>
+    where Element : GeneratedMessageLite.Builder<*, Element>,
+          Table : GeneratedMessageLite,
+          TableBuilder : GeneratedMessageLite.Builder<Table, TableBuilder> {
+
+    private val interner = Interner<TableElementWrapper<Element>>()
+
+    protected abstract fun createTableBuilder(): TableBuilder
+
+    protected abstract fun addElement(builder: TableBuilder, element: Element)
+
+    operator fun get(type: Element): Int =
+            interner.intern(TableElementWrapper(type))
+
+    @Suppress("UNCHECKED_CAST")
+    fun serialize(): Table? =
+            if (interner.isEmpty) null
+            else createTableBuilder().apply {
+                for (obj in interner.allInternedObjects) {
+                    addElement(this, obj.builder)
+                }
+            }.build() as Table
+}
+
+class MutableTypeTable : MutableTable<ProtoBuf.Type.Builder, ProtoBuf.TypeTable, ProtoBuf.TypeTable.Builder>() {
+    override fun createTableBuilder(): ProtoBuf.TypeTable.Builder = ProtoBuf.TypeTable.newBuilder()
+
+    override fun addElement(builder: ProtoBuf.TypeTable.Builder, element: ProtoBuf.Type.Builder) {
+        builder.addType(element)
+    }
+}
+
+class MutableVersionRequirementTable : MutableTable<ProtoBuf.VersionRequirement.Builder, ProtoBuf.VersionRequirementTable, ProtoBuf.VersionRequirementTable.Builder>() {
+    override fun createTableBuilder(): ProtoBuf.VersionRequirementTable.Builder = ProtoBuf.VersionRequirementTable.newBuilder()
+
+    override fun addElement(builder: ProtoBuf.VersionRequirementTable.Builder, element: ProtoBuf.VersionRequirement.Builder) {
+        builder.addRequirement(element)
+    }
+}

core/metadata/src/org/jetbrains/kotlin/metadata/serialization/StringTable.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.metadata.serialization
+
+import java.io.OutputStream
+
+interface StringTable {
+    fun getStringIndex(string: String): Int
+
+    /**
+     * @param className the fully qualified name of some class in the format: `org/foo/bar/Test.Inner`
+     */
+    fun getQualifiedClassNameIndex(className: String, isLocal: Boolean): Int
+
+    fun serializeTo(output: OutputStream)
+}