Extract archives by writing .tar.gz to temp file on Windows.

utils/pub/io.dart

Index: utils/pub/io.dart
diff --git a/utils/pub/io.dart b/utils/pub/io.dart
index 38a4c48680f66438fb67489d0e2b7032ec028ef0..4098f4ce8d557cc312fbd45463c3eb8d59dcedb9 100644
--- a/utils/pub/io.dart
+++ b/utils/pub/io.dart
@@ -140,6 +140,27 @@ Future<File> deleteFile(file) {
   return new File(_getPath(file)).delete();
 }
 
+/// Writes [stream] to a new file at [path], which may be a [String] or a
+/// [File]. Will replace any file already at that path. Completes when the file
+/// is done being written.
+Future<File> createFileFromStream(InputStream stream, path) {
+  path = _getPath(path);
+
+  var completer = new Completer<File>();
+  var file = new File(path);
+  var outputStream = file.openOutputStream();
+  stream.pipe(outputStream);
+
+  outputStream.onClosed = () {
+    completer.complete(file);
+  };
+
+  stream.onError = completer.completeException;
+  outputStream.onError = completer.completeException;

[nweiz, 2012/10/02 01:04:13]

It's possible that both streams could throw errors. It might be better to ensure
that only the first one invokes the completer.

[Bob Nystrom, 2012/10/02 01:36:37]

Done.

+
+  return completer.future;
+}
+
 /**
  * Creates a directory [dir]. Returns a [Future] that completes when the
  * directory is created.
@@ -634,6 +655,69 @@ Future<bool> _extractTarGzWindows(InputStream stream, String destination) {
   // Note: This line of code gets munged by create_sdk.py to be the correct
   // relative path to 7zip in the SDK.
   var pathTo7zip = '../../third_party/7zip/7za.exe';
+  var command = scriptDir.append(pathTo7zip).canonicalize().toNativePath();
+
+  var tempDir;
+
+  return createTempDir().chain((temp) {
+    // Write the archive to a temp file.
+    tempDir = temp;
+    return createFileFromStream(stream, join(tempDir, 'data.tar.gz'));
+  }).chain((tarGz) {
+    // 7zip can't unarchive from gzip -> tar -> destination all in one step
+    // first we un-gzip it to a tar file.
+    // TODO(rnystrom): Setting the working directory instead of passing in

[nweiz, 2012/10/02 01:04:13]

I don't know if this is really a TODO, since you can't do anything about it.

[Bob Nystrom, 2012/10/02 01:36:37]

Done.

+    // a full file path because 7zip says "A full path is not allowed here."
+    return runProcess(command, ['e', 'data.tar.gz'], workingDir: tempDir);
+  }).chain((result) {
+    if (result.exitCode != 0) {
+      throw 'Could not un-gzip (exit code ${result.exitCode}). Error:\n'
+          '${Strings.join(result.stderr, "\n")}';
+    }
+
+    // Find the tar file we just created since we don't know its name.
+    return listDir(tempDir);
+  }).chain((files) {
+    var tarFile;
+    for (var file in files) {
+      if (new Path(file).extension == 'tar') {
+        tarFile = file;
+        break;
+      }
+    }
+
+    if (tarFile == null) throw 'The gzip file did not contain a tar file.';
+
+    // Untar the archive into the destination directory.
+    return runProcess(command, ['x', '-o"$destination"', tarFile],
+        workingDir: tempDir);
+  }).chain((result) {
+    if (result.exitCode != 0) {
+      throw 'Could not un-tar (exit code ${result.exitCode}). Error:\n'
+          '${Strings.join(result.stderr, "\n")}';
+    }
+
+    // Clean up the temp directory.
+    // TODO(rnystrom): Should also delete this if anything fails.
+    return deleteDir(tempDir);
+  }).transform((_) => true);
+}
+
+// TODO(rnystrom): The following is a cleaner way of extracting archives on
+// Windows. It does everything in memory by piping streams directly together
+// instead of writing out temp files. Unfortunately, 7zip seems to periodically
+// fail when we invoke it from Dart and tell it to read from stdin instead of
+// a file. Leaving this code here since it's otherwise cleaner, and maybe we
+// can resurrect it at some point.
+/*

[nweiz, 2012/10/02 01:04:13]

I don't like checking in commented-out code. I feel like source control is
supposed to handle keeping track of dead code.

[Bob Nystrom, 2012/10/02 01:36:37]

Done.

+Future<bool> _extractTarGzWindows(InputStream stream, String destination) {
+  // Find 7zip.
+  var scriptPath = new File(new Options().script).fullPathSync();
+  var scriptDir = new Path.fromNative(scriptPath).directoryPath;
+
+  // Note: This line of code gets munged by create_sdk.py to be the correct
+  // relative path to 7zip in the SDK.
+  var pathTo7zip = '../../third_party/7zip/7za.exe';
 
   var command = scriptDir.append(pathTo7zip).canonicalize().toNativePath();
 
@@ -682,6 +766,7 @@ Future<bool> _extractTarGzWindows(InputStream stream, String destination) {
 
   return completer.future;
 }
+*/
 
 /**
  * Exception thrown when an HTTP operation fails.