1 files changed, 135 insertions, 0 deletions

diff --git a/tracecmd.py b/tracecmd.py
new file mode 100644
index 0000000..6520a48
--- /dev/null
+++ b/tracecmd.py
@@ -0,0 +1,135 @@
+#
+# Copyright (C) International Business Machines  Corp., 2009
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+#
+# 2009-Dec-17:  Initial version by Darren Hart <dvhltc@us.ibm.com>
+#
+
+from ctracecmd import *
+
+"""
+Python interface to the tracecmd library for parsing ftrace traces
+
+Python tracecmd applications should be written to this interface. It will be
+updated as the tracecmd C API changes and try to minimze the impact to python
+applications. The ctracecmd Python module is automatically generated using SWIG
+and it is recommended applications not use it directly.
+
+TODO: consider a complete class hierarchy of ftrace events...
+"""
+
+def _pevent_read_number_field(field, data):
+    ret,hi,lo = pevent_read_number_field_32(field, data)
+    if ret == 0:
+        return ret,long(long(hi).__lshift__(32)+lo)
+    return ret,None
+
+
+class Event(object):
+    def __init__(self, trace, record):
+        self.trace = trace
+        self.rec = record
+        type = pevent_data_type(trace.pe, record)
+        self.ec = pevent_data_event_from_type(trace.pe, type)
+
+    def __str__(self):
+        return "%f %s: pid=%d comm=%s type=%d" % \
+               (self.ts, self.name, self.num_field("common_pid"), self.comm, self.type)
+
+
+    # TODO: consider caching the results of the properties
+    @property
+    def comm(self):
+        return self.trace.comm_from_pid(self.pid)
+
+    @property
+    def name(self):
+        return event_name_get(self.ec)
+
+    @property
+    def pid(self):
+        return pevent_data_pid(self.trace.pe, self.rec)
+
+    @property
+    def ts(self):
+        # FIXME: this currently returns a float instead of a 64bit nsec value
+        return record_ts_get(self.rec)
+
+    @property
+    def type(self):
+        return pevent_data_type(self.trace.pe, self.rec)
+
+    def num_field(self, name):
+        # FIXME: need to find an elegant way to handle 64bit fields
+        f = pevent_find_any_field(self.ec, name)
+        ret,val = _pevent_read_number_field(f, record_data_get(self.rec))
+        return val
+
+
+class Trace(object):
+    """
+    Trace object represents the trace file it is created with.
+
+    The Trace object aggregates the tracecmd structures and functions that are
+    used to manage the trace and extract events from it.
+    """
+    def __init__(self, filename):
+        self.handle = None
+        self.pe = None
+
+        try:
+            file = open(filename)
+            self.handle = tracecmd_open(file.fileno())
+            print "self.handle: ", self.handle
+            #FIXME: check if these throw exceptions automatically or if we have
+            #       to check return codes manually
+            tracecmd_read_headers(self.handle)
+            tracecmd_init_data(self.handle)
+            self.pe = tracecmd_get_pevent(self.handle)
+        except:
+            return None
+
+    @property
+    def cpus(self):
+        return tracecmd_cpus(self.handle)
+
+    def read_event(self, cpu):
+        rec = tracecmd_read_data(self.handle, cpu)
+        if rec:
+            return Event(self, rec)
+        return None
+
+    def peek_event(self, cpu):
+        pass
+
+    def comm_from_pid(self, pid):
+        return pevent_data_comm_from_pid(self.pe, pid)
+
+
+# Basic builtin test, execute module directly
+if __name__ == "__main__":
+    t = Trace("trace.dat")
+    print "Trace contains data for %d cpus" % (t.cpus)
+
+    for cpu in range(0, t.cpus):
+        print "CPU %d" % (cpu)
+        ev = t.read_event(cpu)
+        while ev:
+            print "\t%s" % (ev)
+            ev = t.read_event(cpu)
+
+
+