From: Tony Mack <tmack@paris.CS.Princeton.EDU>
Date: Mon, 17 Oct 2011 15:01:14 +0000 (-0400)
Subject: initial checkin
X-Git-Tag: sfa-1.1-1~93
X-Git-Url: http://git.onelab.eu/?a=commitdiff_plain;h=ecb052281cdf5f2713eb2f1d5103b2b4e7a5ebd3;p=sfa.git

initial checkin
---

diff --git a/sfa/util/bwlimit.py b/sfa/util/bwlimit.py
new file mode 100644
index 00000000..62d3cca5
--- /dev/null
+++ b/sfa/util/bwlimit.py
@@ -0,0 +1,58 @@
+# Taken from bwlimit.py
+#
+# See tc_util.c and http://physics.nist.gov/cuu/Units/binary.html. Be
+# warned that older versions of tc interpret "kbps", "mbps", "mbit",
+# and "kbit" to mean (in this system) "kibps", "mibps", "mibit", and
+# "kibit" and that if an older version is installed, all rates will
+# be off by a small fraction.
+suffixes = {
+    "":         1,
+    "bit":  1,
+    "kibit":    1024,
+    "kbit": 1000,
+    "mibit":    1024*1024,
+    "mbit": 1000000,
+    "gibit":    1024*1024*1024,
+    "gbit": 1000000000,
+    "tibit":    1024*1024*1024*1024,
+    "tbit": 1000000000000,
+    "bps":  8,
+    "kibps":    8*1024,
+    "kbps": 8000,
+    "mibps":    8*1024*1024,
+    "mbps": 8000000,
+    "gibps":    8*1024*1024*1024,
+    "gbps": 8000000000,
+    "tibps":    8*1024*1024*1024*1024,
+    "tbps": 8000000000000
+}
+
+def get_tc_rate(s):
+    """
+    Parses an integer or a tc rate string (e.g., 1.5mbit) into bits/second
+    """
+
+    if type(s) == int:
+        return s
+    m = re.match(r"([0-9.]+)(\D*)", s)
+    if m is None:
+        return -1
+    suffix = m.group(2).lower()
+    if suffixes.has_key(suffix):
+        return int(float(m.group(1)) * suffixes[suffix])
+    else:
+        return -1
+
+def format_tc_rate(rate):
+    """
+    Formats a bits/second rate into a tc rate string
+    """
+
+    if rate >= 1000000000 and (rate % 1000000000) == 0:
+        return "%.0fgbit" % (rate / 1000000000.)
+    elif rate >= 1000000 and (rate % 1000000) == 0:
+        return "%.0fmbit" % (rate / 1000000.)
+    elif rate >= 1000:
+        return "%.0fkbit" % (rate / 1000.)
+    else:
+        return "%.0fbit" % rate