Create a util.py Python module for common functions

Extracting these functions helps avoid circular dependencies,
and make them easier to find/reuse.

python/servo/util.py

@@ -0,0 +1,151 @@
+# Copyright 2013 The Servo Project Developers. See the COPYRIGHT
+# file at the top-level directory of this distribution.
+#
+# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+# option. This file may not be copied, modified, or distributed
+# except according to those terms.
+
+from __future__ import absolute_import, print_function, unicode_literals
+
+import os
+import os.path as path
+import platform
+import sys
+from socket import error as socket_error
+import StringIO
+import tarfile
+import zipfile
+import urllib2
+
+
+def host_triple():
+    os_type = platform.system().lower()
+    if os_type == "linux":
+        os_type = "unknown-linux-gnu"
+    elif os_type == "darwin":
+        os_type = "apple-darwin"
+    elif os_type == "android":
+        os_type = "linux-androideabi"
+    elif os_type == "windows":
+        # If we are in a Visual Studio environment, use msvc
+        if os.getenv("PLATFORM") is not None:
+            os_type = "pc-windows-msvc"
+        elif os.getenv("MSYSTEM") is not None:
+            os_type = "pc-windows-gnu"
+        else:
+            os_type = "unknown"
+    elif os_type.startswith("mingw64_nt-") or os_type.startswith("cygwin_nt-"):
+        os_type = "pc-windows-gnu"
+    elif os_type == "freebsd":
+        os_type = "unknown-freebsd"
+    else:
+        os_type = "unknown"
+
+    cpu_type = platform.machine().lower()
+    if os_type.endswith("-msvc"):
+        # vcvars*.bat should set it properly
+        platform_env = os.environ.get("PLATFORM")
+        if platform_env == "X86":
+            cpu_type = "i686"
+        elif platform_env == "X64":
+            cpu_type = "x86_64"
+        else:
+            cpu_type = "unknown"
+    elif cpu_type in ["i386", "i486", "i686", "i768", "x86"]:
+        cpu_type = "i686"
+    elif cpu_type in ["x86_64", "x86-64", "x64", "amd64"]:
+        cpu_type = "x86_64"
+    elif cpu_type == "arm":
+        cpu_type = "arm"
+    else:
+        cpu_type = "unknown"
+
+    return "{}-{}".format(cpu_type, os_type)
+
+
+def download(desc, src, writer, start_byte=0):
+    if start_byte:
+        print("Resuming download of %s..." % desc)
+    else:
+        print("Downloading %s..." % desc)
+    dumb = (os.environ.get("TERM") == "dumb") or (not sys.stdout.isatty())
+
+    try:
+        req = urllib2.Request(src)
+        if start_byte:
+            req = urllib2.Request(src, headers={'Range': 'bytes={}-'.format(start_byte)})
+        resp = urllib2.urlopen(req)
+
+        fsize = None
+        if resp.info().getheader('Content-Length'):
+            fsize = int(resp.info().getheader('Content-Length').strip()) + start_byte
+
+        recved = start_byte
+        chunk_size = 8192
+
+        while True:
+            chunk = resp.read(chunk_size)
+            if not chunk:
+                break
+            recved += len(chunk)
+            if not dumb:
+                if fsize is not None:
+                    pct = recved * 100.0 / fsize
+                    print("\rDownloading %s: %5.1f%%" % (desc, pct), end="")
+
+                sys.stdout.flush()
+            writer.write(chunk)
+
+        if not dumb:
+            print()
+    except urllib2.HTTPError, e:
+        print("Download failed (%d): %s - %s" % (e.code, e.reason, src))
+        if e.code == 403:
+            print("No Rust compiler binary available for this platform. "
+                  "Please see https://github.com/servo/servo/#prerequisites")
+        sys.exit(1)
+    except urllib2.URLError, e:
+        print("Error downloading Rust compiler: %s. The failing URL was: %s" % (e.reason, src))
+        sys.exit(1)
+    except socket_error, e:
+        print("Looks like there's a connectivity issue, check your Internet connection. %s" % (e))
+        sys.exit(1)
+    except KeyboardInterrupt:
+        writer.flush()
+        raise
+
+
+def download_bytes(desc, src):
+    content_writer = StringIO.StringIO()
+    download(desc, src, content_writer)
+    return content_writer.getvalue()
+
+
+def download_file(desc, src, dst):
+    tmp_path = dst + ".part"
+    try:
+        start_byte = path.getsize(tmp_path)
+        with open(tmp_path, 'ab') as fd:
+            download(desc, src, fd, start_byte=start_byte)
+    except os.error:
+        with open(tmp_path, 'wb') as fd:
+            download(desc, src, fd)
+    os.rename(tmp_path, dst)
+
+
+def extract(src, dst, movedir=None):
+    if src.endswith(".zip"):
+        zipfile.ZipFile(src).extractall(dst)
+    else:
+        tarfile.open(src).extractall(dst)
+
+    if movedir:
+        for f in os.listdir(movedir):
+            frm = path.join(movedir, f)
+            to = path.join(dst, f)
+            os.rename(frm, to)
+        os.rmdir(movedir)
+
+    os.remove(src)