From 713faa7a3fcd7d5b541211335d9decd39a8c25f0 Mon Sep 17 00:00:00 2001
From: Robert Hencke <robert.hencke@gmail.com>
Date: Sat, 8 Apr 2017 13:11:41 -0400
Subject: [PATCH] Reduce time spent in JAR/ZIP assembly.

Locally, this reduces a run of kobaltw assemble --noIncremental
on the Kobalt codebase itself from 47 seconds to 25 seconds.

When JarInputStream.nextEntry is invoked, the stream sets its position
and length so that it can directly be used to read the underlying content
associated with the entry.  This avoids the need to call
JarFile(localFile).getInputStream(entry) and the cost associated with it.

addEntry has a slight change of semantics due to this change - it is now
the caller's responsibility to close the associated input stream.  The two
existing calls to the method were adjusted accordingly.
---
 .../kotlin/com/beust/kobalt/misc/JarUtils.kt  | 30 +++++++------------
 1 file changed, 11 insertions(+), 19 deletions(-)

diff --git a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/misc/JarUtils.kt b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/misc/JarUtils.kt
index 0837012d..81f55b8e 100644
--- a/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/misc/JarUtils.kt
+++ b/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/misc/JarUtils.kt
@@ -53,20 +53,22 @@ class JarUtils {
                 } else {
                     if (file.expandJarFiles && foundFile.name.endsWith(".jar") && ! file.from.contains("resources")) {
                         kobaltLog(2, "  Writing contents of jar file $foundFile")
-                        val stream = JarInputStream(FileInputStream(localFile))
-                        var entry = stream.nextEntry
-                        while (entry != null) {
-                            if (!entry.isDirectory && !KFiles.isExcluded(entry.name, DEFAULT_JAR_EXCLUDES)) {
-                                val ins = JarFile(localFile).getInputStream(entry)
-                                addEntry(ins, JarEntry(entry), outputStream, onError)
+                        JarInputStream(FileInputStream(localFile)).use { stream ->
+                            var entry = stream.nextEntry
+                            while (entry != null) {
+                                if (!entry.isDirectory && !KFiles.isExcluded(entry.name, DEFAULT_JAR_EXCLUDES)) {
+                                    addEntry(stream, JarEntry(entry), outputStream, onError)
+                                }
+                                entry = stream.nextEntry
                             }
-                            entry = stream.nextEntry
                         }
                     } else {
                         val entryFileName = KFiles.fixSlashes(file.to(foundFile.path))
                         val entry = JarEntry(entryFileName)
                         entry.time = localFile.lastModified()
-                        addEntry(FileInputStream(localFile), entry, outputStream, onError)
+                        FileInputStream(localFile).use { stream ->
+                            addEntry(stream, entry, outputStream, onError)
+                        }
                     }
                 }
             }
@@ -74,22 +76,12 @@ class JarUtils {
 
         private fun addEntry(inputStream: InputStream, entry: ZipEntry, outputStream: ZipOutputStream,
                 onError: (Exception) -> Unit = DEFAULT_HANDLER) {
-            var bis: BufferedInputStream? = null
             try {
                 outputStream.putNextEntry(entry)
-                bis = BufferedInputStream(inputStream)
-
-                val buffer = ByteArray(50 * 1024)
-                while (true) {
-                    val count = bis.read(buffer)
-                    if (count == -1) break
-                    outputStream.write(buffer, 0, count)
-                }
+                inputStream.copyTo(outputStream, 50 * 1024)
                 outputStream.closeEntry()
             } catch(ex: Exception) {
                 onError(ex)
-            } finally {
-                bis?.close()
             }
         }