diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 553a727..9fe3dda 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -9,9 +9,9 @@
 #
 # For help see docs/tracing.txt
 
-import sys
 import struct
 import re
+import inspect
 
 header_event_id = 0xffffffffffffffff
 header_magic    = 0xf2b177cb0aa429b4
@@ -21,12 +21,8 @@ trace_fmt = '=QQQQQQQQ'
 trace_len = struct.calcsize(trace_fmt)
 event_re  = re.compile(r'(disable\s+)?([a-zA-Z0-9_]+)\(([^)]*)\).*')
 
-def err(msg):
-    sys.stderr.write(msg + '\n')
-    sys.exit(1)
-
 def parse_events(fobj):
-    """Parse a trace-events file."""
+    """Parse a trace-events file into {event_num: (name, arg1, ...)}."""
 
     def get_argnames(args):
         """Extract argument names from a parameter list."""
@@ -45,20 +41,20 @@ def parse_events(fobj):
     return events
 
 def read_record(fobj):
-    """Deserialize a trace record from a file."""
+    """Deserialize a trace record from a file into a tuple (event_num, timestamp, arg1, ..., arg6)."""
     s = fobj.read(trace_len)
     if len(s) != trace_len:
         return None
     return struct.unpack(trace_fmt, s)
 
 def read_trace_file(fobj):
-    """Deserialize trace records from a file."""
+    """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, arg1, ..., arg6)."""
     header = read_record(fobj)
     if header is None or \
        header[0] != header_event_id or \
        header[1] != header_magic or \
        header[2] != header_version:
-        err('not a trace file or incompatible version')
+        raise ValueError('not a trace file or incompatible version')
 
     while True:
         rec = read_record(fobj)
@@ -67,27 +63,88 @@ def read_trace_file(fobj):
 
         yield rec
 
-class Formatter(object):
-    def __init__(self, events):
-        self.events = events
-        self.last_timestamp = None
-
-    def format_record(self, rec):
-        if self.last_timestamp is None:
-            self.last_timestamp = rec[1]
-        delta_ns = rec[1] - self.last_timestamp
-        self.last_timestamp = rec[1]
-
-        event = self.events[rec[0]]
-        fields = [event[0], '%0.3f' % (delta_ns / 1000.0)]
-        for i in xrange(1, len(event)):
-            fields.append('%s=0x%x' % (event[i], rec[i + 1]))
-        return ' '.join(fields)
-
-if len(sys.argv) != 3:
-    err('usage: %s <trace-events> <trace-file>' % sys.argv[0])
-
-events = parse_events(open(sys.argv[1], 'r'))
-formatter = Formatter(events)
-for rec in read_trace_file(open(sys.argv[2], 'rb')):
-    print formatter.format_record(rec)
+class Analyzer(object):
+    """A trace file analyzer which processes trace records.
+
+    An analyzer can be passed to run() or process().  The begin() method is
+    invoked, then each trace record is processed, and finally the end() method
+    is invoked.
+
+    If a method matching a trace event name exists, it is invoked to process
+    that trace record.  Otherwise the catchall() method is invoked."""
+
+    def begin(self):
+        """Called at the start of the trace."""
+        pass
+
+    def catchall(self, event, rec):
+        """Called if no specific method for processing a trace event has been found."""
+        pass
+
+    def end(self):
+        """Called at the end of the trace."""
+        pass
+
+def process(events, log, analyzer):
+    """Invoke an analyzer on each event in a log."""
+    if isinstance(events, str):
+        events = parse_events(open(events, 'r'))
+    if isinstance(log, str):
+        log = open(log, 'rb')
+
+    def build_fn(analyzer, event):
+        fn = getattr(analyzer, event[0], None)
+        if fn is None:
+            return analyzer.catchall
+
+        event_argcount = len(event) - 1
+        fn_argcount = len(inspect.getargspec(fn)[0]) - 1
+        if fn_argcount == event_argcount + 1:
+            # Include timestamp as first argument
+            return lambda _, rec: fn(*rec[1:2 + fn_argcount])
+        else:
+            # Just arguments, no timestamp
+            return lambda _, rec: fn(*rec[2:2 + fn_argcount])
+
+    analyzer.begin()
+    fn_cache = {}
+    for rec in read_trace_file(log):
+        event_num = rec[0]
+        event = events[event_num]
+        if event_num not in fn_cache:
+            fn_cache[event_num] = build_fn(analyzer, event)
+        fn_cache[event_num](event, rec)
+    analyzer.end()
+
+def run(analyzer):
+    """Execute an analyzer on a trace file given on the command-line.
+
+    This function is useful as a driver for simple analysis scripts.  More
+    advanced scripts will want to call process() instead."""
+    import sys
+
+    if len(sys.argv) != 3:
+        sys.stderr.write('usage: %s <trace-events> <trace-file>\n' % sys.argv[0])
+        sys.exit(1)
+
+    events = parse_events(open(sys.argv[1], 'r'))
+    process(events, sys.argv[2], analyzer)
+
+if __name__ == '__main__':
+    class Formatter(Analyzer):
+        def __init__(self):
+            self.last_timestamp = None
+
+        def catchall(self, event, rec):
+            timestamp = rec[1]
+            if self.last_timestamp is None:
+                self.last_timestamp = timestamp
+            delta_ns = timestamp - self.last_timestamp
+            self.last_timestamp = timestamp
+
+            fields = [event[0], '%0.3f' % (delta_ns / 1000.0)]
+            for i in xrange(1, len(event)):
+                fields.append('%s=0x%x' % (event[i], rec[i + 1]))
+            print ' '.join(fields)
+
+    run(Formatter())
