Introduce ScriptDependenciesFileAttribute to persist script dependencies

idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/FileAttributeService.kt

@@ -17,11 +17,13 @@
 package org.jetbrains.kotlin.idea.caches
 
 import com.intellij.openapi.vfs.VirtualFile
+import java.io.DataInput
+import java.io.DataOutput
 
 data class CachedAttributeData<out T>(val value: T, val timeStamp: Long)
 
 interface FileAttributeService {
-    fun register(id: String, version: Int) {}
+    fun register(id: String, version: Int, fixedSize: Boolean = true) {}
 
     fun <T: Enum<T>> writeEnumAttribute(id: String, file: VirtualFile, value: T): CachedAttributeData<T> =
             CachedAttributeData(value, timeStamp = file.timeStamp)
@@ -32,4 +34,8 @@ interface FileAttributeService {
             CachedAttributeData(value, timeStamp = file.timeStamp)
 
     fun readBooleanAttribute(id: String, file: VirtualFile): CachedAttributeData<Boolean>? = null
+
+    fun <T> write(file: VirtualFile, id: String, value: T, writeValueFun: (DataOutput, T) -> Unit): CachedAttributeData<T>
+
+    fun <T> read(file: VirtualFile, id: String, readValueFun: (DataInput) -> T): CachedAttributeData<T>?
 }

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

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.core.script
+
+import com.intellij.openapi.components.service
+import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.openapi.vfs.VirtualFileWithId
+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 org.jetbrains.kotlin.idea.caches.FileAttributeService
+import java.io.DataInput
+import java.io.DataOutput
+import java.io.File
+import kotlin.script.dependencies.KotlinScriptExternalDependencies
+
+// TODO_R: write nullable, write version
+object ScriptDependenciesFileAttribute {
+    private val VERSION = 1
+    private val ID = "kotlin-script-dependencies"
+
+    private val fileAttributeService = service<FileAttributeService>()
+
+    init {
+        fileAttributeService.register(ID, VERSION, false)
+    }
+
+    fun write(virtualFile: VirtualFile, dependencies: KotlinScriptExternalDependencies) {
+        if (virtualFile !is VirtualFileWithId) return
+
+        fileAttributeService.write(virtualFile, ID, dependencies) { output, dep ->
+            with(dep) {
+                output.writeFileList(classpath)
+                output.writeStringList(imports)
+                // TODO: actually read/write nullable
+                output.writeString(javaHome ?: "")
+                output.writeFileList(scripts)
+                output.writeFileList(sources)
+            }
+        }
+    }
+
+    fun read(virtualFile: VirtualFile): KotlinScriptExternalDependencies? {
+        if (virtualFile !is VirtualFileWithId) return null
+
+        return fileAttributeService.read(virtualFile, ID) { input ->
+            SerializedScriptDependencies(
+                    classpath = input.readFileList(),
+                    imports = input.readStringList(),
+                    javaHome = input.readString(),
+                    scripts = input.readFileList(),
+                    sources = input.readFileList()
+            )
+        }?.value
+    }
+}
+
+private fun DataInput.readStringList(): List<String> = readSeq(this) { readString() }
+private fun DataInput.readFileList() = readStringList().map { File(it) }
+private fun DataInput.readString() = readUTF(this)
+
+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 class SerializedScriptDependencies(
+        override val classpath: Iterable<File>,
+        override val imports: Iterable<String>,
+        override val javaHome: String?,
+        override val scripts: Iterable<File>,
+        override val sources: Iterable<File>
+) : KotlinScriptExternalDependencies

idea/src/org/jetbrains/kotlin/idea/caches/FileAttributeServiceImpl.kt

@@ -26,8 +26,8 @@ import java.io.DataOutput
 class FileAttributeServiceImpl : FileAttributeService {
     val attributes: MutableMap<String, FileAttribute> = ContainerUtil.newConcurrentMap()
 
-    override fun register(id: String, version: Int) {
-        attributes[id] = FileAttribute(id, version, true)
+    override fun register(id: String, version: Int, fixedSize: Boolean) {
+        attributes[id] = FileAttribute(id, version, fixedSize)
     }
 
     override fun <T: Enum<T>> writeEnumAttribute(id: String, file: VirtualFile, value: T): CachedAttributeData<T> {
@@ -55,7 +55,7 @@ class FileAttributeServiceImpl : FileAttributeService {
         }
     }
 
-    private inline fun <T> write(file: VirtualFile, id: String, value: T, writeValueFun: (DataOutput, T) -> Unit): CachedAttributeData<T> {
+    override fun <T> write(file: VirtualFile, id: String, value: T, writeValueFun: (DataOutput, T) -> Unit): CachedAttributeData<T> {
         val attribute = attributes[id] ?: throw IllegalArgumentException("Attribute with $id wasn't registered")
 
         val data = CachedAttributeData(value, timeStamp = file.timeStamp)
@@ -68,7 +68,7 @@ class FileAttributeServiceImpl : FileAttributeService {
         return data
     }
 
-    private inline fun <T> read(file: VirtualFile, id: String, readValueFun: (DataInput) -> T): CachedAttributeData<T>? {
+    override fun <T> read(file: VirtualFile, id: String, readValueFun: (DataInput) -> T): CachedAttributeData<T>? {
         val attribute = attributes[id] ?: throw IllegalArgumentException("Attribute with $id wasn't registered")
 
         val stream = attribute.readAttribute(file) ?: return null