Refactoring: introduce file attribute utils

idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/ModuleNameFileAttribute.kt

@@ -6,26 +6,15 @@
 package org.jetbrains.kotlin.idea.core.script
 
 import com.intellij.openapi.vfs.VirtualFile
-import com.intellij.openapi.vfs.VirtualFileWithId
+import org.jetbrains.kotlin.idea.core.util.fileAttribute
-import com.intellij.openapi.vfs.newvfs.FileAttribute
+import org.jetbrains.kotlin.idea.core.util.readString
-import kotlin.reflect.KProperty
+import org.jetbrains.kotlin.idea.core.util.writeString
+import java.io.DataInputStream
+import java.io.DataOutputStream
 
-var VirtualFile.scriptRelatedModuleName: String? by ScratchModuleNameProperty()
+var VirtualFile.scriptRelatedModuleName: String? by fileAttribute(
-
+    name = "kotlin-script-moduleName",
-private val moduleNameAttribute = FileAttribute("kotlin-script-moduleName", 1, false)
+    version = 1,
-private class ScratchModuleNameProperty {
+    read = DataInputStream::readString,
-
+    write = DataOutputStream::writeString
-    operator fun getValue(file: VirtualFile, property: KProperty<*>): String? {
+)
-        if (file !is VirtualFileWithId) return null
-
-        return moduleNameAttribute.readAttributeBytes(file)?.let { String(it) }
-    }
-
-    operator fun setValue(file: VirtualFile, property: KProperty<*>, newValue: String?) {
-        if (file !is VirtualFileWithId) return
-
-        if (newValue != null) {
-            moduleNameAttribute.writeAttributeBytes(file, newValue.toByteArray())
-        }
-    }
-}

idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/ScriptDependenciesFileAttribute.kt

@@ -17,75 +17,30 @@
 package org.jetbrains.kotlin.idea.core.script
 
 import com.intellij.openapi.vfs.VirtualFile
-import com.intellij.openapi.vfs.VirtualFileWithId
+import org.jetbrains.kotlin.idea.core.util.*
-import com.intellij.openapi.vfs.newvfs.FileAttribute
-import com.intellij.util.io.DataInputOutputUtil.readSeq
-import com.intellij.util.io.DataInputOutputUtil.writeSeq
-import com.intellij.util.io.IOUtil.readUTF
-import com.intellij.util.io.IOUtil.writeUTF
 import java.io.DataInput
 import java.io.DataOutput
-import java.io.File
-import kotlin.reflect.KProperty
 import kotlin.script.experimental.dependencies.ScriptDependencies
 
-var VirtualFile.scriptDependencies: ScriptDependencies? by ScriptDependenciesProperty()
+var VirtualFile.scriptDependencies: ScriptDependencies? by fileAttribute(
-private val scriptDependencies = FileAttribute("kotlin-script-dependencies", 4, false)
+    name = "kotlin-script-dependencies",
-
+    version = 3,
-private class ScriptDependenciesProperty {
+    read = {
-
+        ScriptDependencies(
-    operator fun setValue(file: VirtualFile, property: KProperty<*>, newValue: ScriptDependencies?) {
+            classpath = readFileList(),
-        if (file !is VirtualFileWithId) return
+            imports = readStringList(),
-
+            javaHome = readNullable(DataInput::readFile),
-        val output = scriptDependencies.writeAttribute(file)
+            scripts = readFileList(),
-        output.use {
+            sources = readFileList()
-            it.writeNullable(newValue) { value ->
+        )
-                with(value) {
+    },
-                    writeFileList(classpath)
+    write = {
-                    writeStringList(imports)
+        with(it) {
-                    writeNullable(javaHome, DataOutput::writeFile)
+            writeFileList(classpath)
-                    writeFileList(scripts)
+            writeStringList(imports)
-                    writeFileList(sources)
+            writeNullable(javaHome, DataOutput::writeFile)
-
+            writeFileList(scripts)
-                }
+            writeFileList(sources)
-            }
         }
     }
-
+)
-    operator fun getValue(file: VirtualFile, property: KProperty<*>): ScriptDependencies? {
-        if (file !is VirtualFileWithId) return null
-
-        val input = scriptDependencies.readAttribute(file)
-        return input?.use {
-            it.readNullable {
-                ScriptDependencies(
-                    classpath = readFileList(),
-                    imports = readStringList(),
-                    javaHome = readNullable(DataInput::readFile),
-                    scripts = readFileList(),
-                    sources = readFileList()
-                )
-            }
-        }
-    }
-}
-
-private fun DataInput.readStringList(): List<String> = readSeq(this) { readString() }
-private fun DataInput.readFileList() = readSeq(this) { readFile() }
-private fun DataInput.readString() = readUTF(this)
-private fun DataInput.readFile() = readUTF(this).let { File(it) }
-
-private fun DataOutput.writeFileList(iterable: Iterable<File>) = writeSeq(this, iterable.toList()) { writeFile(it) }
-private fun DataOutput.writeFile(it: File) = writeString(it.canonicalPath)
-private fun DataOutput.writeString(string: String) = writeUTF(this, string)
-private fun DataOutput.writeStringList(iterable: Iterable<String>) = writeSeq(this, iterable.toList()) { writeString(it) }
-
-private fun <T : Any> DataOutput.writeNullable(nullable: T?, writeT: DataOutput.(T) -> Unit) {
-    writeBoolean(nullable != null)
-    nullable?.let { writeT(it) }
-}
-
-private fun <T : Any> DataInput.readNullable(readT: DataInput.() -> T): T? {
-    val hasValue = readBoolean()
-    return if (hasValue) readT() else null
-}

idea/idea-core/src/org/jetbrains/kotlin/idea/core/util/FileAttributeUtils.kt

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2010-2018 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.idea.core.util
+
+import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.openapi.vfs.VirtualFileWithId
+import com.intellij.openapi.vfs.newvfs.FileAttribute
+import com.intellij.util.io.DataInputOutputUtil.readSeq
+import com.intellij.util.io.DataInputOutputUtil.writeSeq
+import com.intellij.util.io.IOUtil.readUTF
+import com.intellij.util.io.IOUtil.writeUTF
+import java.io.*
+import kotlin.reflect.KProperty
+
+fun <T : Any> fileAttribute(
+    name: String,
+    version: Int,
+    read: DataInputStream.() -> T,
+    write: DataOutputStream.(T) -> Unit
+): FileAttributeProperty<T> {
+    return object : FileAttributeProperty<T>(name, version) {
+        override fun readValue(input: DataInputStream): T = read(input)
+        override fun writeValue(output: DataOutputStream, value: T) = write(output, value)
+    }
+}
+
+abstract class FileAttributeProperty<T : Any>(name: String, version: Int, private val default: T? = null) {
+    abstract fun readValue(input: DataInputStream): T
+    abstract fun writeValue(output: DataOutputStream, value: T)
+
+    private val attribute = FileAttribute(name, version, false)
+
+    operator fun setValue(file: VirtualFile, property: KProperty<*>, newValue: T?) {
+        if (file !is VirtualFileWithId) return
+
+        attribute.writeAttribute(file).use { output ->
+            output.writeNullable(newValue) { value ->
+                writeValue(output, value)
+            }
+        }
+    }
+
+    operator fun getValue(file: VirtualFile, property: KProperty<*>): T? {
+        if (file !is VirtualFileWithId) return null
+
+        return attribute.readAttribute(file)?.use { input ->
+            input.readNullable {
+                readValue(input)
+            }
+        } ?: default
+    }
+}
+
+fun DataInput.readStringList(): List<String> = readSeq(this) { readString() }
+fun DataInput.readFileList(): List<File> = readSeq(this) { readFile() }
+fun DataInput.readString(): String = readUTF(this)
+fun DataInput.readFile() = readUTF(this).let { File(it) }
+
+fun DataOutput.writeFileList(iterable: Iterable<File>) = writeSeq(this, iterable.toList()) { writeFile(it) }
+fun DataOutput.writeFile(it: File) = writeString(it.canonicalPath)
+fun DataOutput.writeString(string: String) = writeUTF(this, string)
+fun DataOutput.writeStringList(iterable: Iterable<String>) = writeSeq(this, iterable.toList()) { writeString(it) }
+
+fun <T : Any> DataOutput.writeNullable(nullable: T?, writeT: DataOutput.(T) -> Unit) {
+    writeBoolean(nullable != null)
+    nullable?.let { writeT(it) }
+}
+
+fun <T : Any> DataInput.readNullable(readT: DataInput.() -> T): T? {
+    val hasValue = readBoolean()
+    return if (hasValue) readT() else null
+}