steal from diodes

copyparty/star.py

@@ -0,0 +1,65 @@
+import os
+import tarfile
+import threading
+
+from .util import Queue
+
+
+class QFile(object):
+    """file-like object which buffers writes into a queue"""
+
+    def __init__(self):
+        self.q = Queue(64)
+
+    def write(self, buf):
+        self.q.put(buf)
+
+
+class StreamTar(object):
+    """construct in-memory tar file from the given path"""
+
+    def __init__(self, top, fgen):
+        self.ci = 0
+        self.co = 0
+        self.qfile = QFile()
+        self.srcfiles = fgen
+
+        # python 3.8 changed to PAX_FORMAT as default,
+        # waste of space and don't care about the new features
+        fmt = tarfile.GNU_FORMAT
+        self.tar = tarfile.open(fileobj=self.qfile, mode="w|", format=fmt)
+
+        w = threading.Thread(target=self._gen)
+        w.daemon = True
+        w.start()
+
+    def gen(self):
+        while True:
+            buf = self.qfile.q.get()
+            if buf is None:
+                break
+
+            self.co += len(buf)
+            yield buf
+
+        yield None
+
+    def _gen(self):
+        for f in self.fgen:
+            src = f["a"]
+            name = f["n"]
+            inf = tarfile.TarInfo(name=name)
+
+            fsi = os.stat(src)
+            inf.mode = fsi.st_mode
+            inf.size = fsi.st_size
+            inf.mtime = fsi.st_mtime
+            inf.uid = 0
+            inf.gid = 0
+
+            self.ci += inf.size
+            with open(src, "rb") as f:
+                self.tar.addfile(inf, f)
+
+        self.tar.close()
+        self.qfile.q.put(None)