@@ -30,26 +30,24 @@ def read_header(fobj, hfmt):
hlen = struct.calcsize(hfmt)
hdr = fobj.read(hlen)
if len(hdr) != hlen:
- return None
+ raise ValueError('Error reading header. Wrong filetype provided?')
return struct.unpack(hfmt, hdr)
def get_record(event_mapping, event_id_to_name, rechdr, fobj):
"""Deserialize a trace record from a file into a tuple
(name, timestamp, pid, arg1, ..., arg6)."""
- if rechdr is None:
- return None
- if rechdr[0] != dropped_event_id:
- event_id = rechdr[0]
+ event_id, timestamp_ns, length, pid = rechdr
+ if event_id != dropped_event_id:
name = event_id_to_name[event_id]
- rec = (name, rechdr[1], rechdr[3])
try:
event = event_mapping[name]
except KeyError as e:
- sys.stderr.write('%s event is logged but is not declared ' \
+ sys.stderr.write(f'{e} event is logged but is not declared ' \
'in the trace events file, try using ' \
- 'trace-events-all instead.\n' % str(e))
+ 'trace-events-all instead.\n')
sys.exit(1)
+ rec = (name, timestamp_ns, pid)
for type, name in event.args:
if is_string(type):
l = fobj.read(4)
@@ -60,9 +58,8 @@ def get_record(event_mapping, event_id_to_name, rechdr, fobj):
(value,) = struct.unpack('=Q', fobj.read(8))
rec = rec + (value,)
else:
- rec = ("dropped", rechdr[1], rechdr[3])
- (value,) = struct.unpack('=Q', fobj.read(8))
- rec = rec + (value,)
+ (dropped_count,) = struct.unpack('=Q', fobj.read(8))
+ rec = ("dropped", timestamp_ns, pid, dropped_count)
return rec
def get_mapping(fobj):
@@ -79,22 +76,16 @@ def read_record(event_mapping, event_id_to_name, fobj):
def read_trace_header(fobj):
"""Read and verify trace file header"""
- header = read_header(fobj, log_header_fmt)
- if header is None:
- raise ValueError('Not a valid trace file!')
- if header[0] != header_event_id:
- raise ValueError('Not a valid trace file, header id %d != %d' %
- (header[0], header_event_id))
- if header[1] != header_magic:
- raise ValueError('Not a valid trace file, header magic %d != %d' %
- (header[1], header_magic))
-
- log_version = header[2]
+ _header_event_id, _header_magic, log_version = read_header(fobj, log_header_fmt)
+ if _header_event_id != header_event_id:
+ raise ValueError(f'Not a valid trace file, header id {_header_event_id} != {header_event_id}')
+ if _header_magic != header_magic:
+ raise ValueError(f'Not a valid trace file, header magic {_header_magic} != {header_magic}')
+
if log_version not in [0, 2, 3, 4]:
- raise ValueError('Unknown version of tracelog format!')
+ raise ValueError(f'Unknown version {log_version} of tracelog format!')
if log_version != 4:
- raise ValueError('Log format %d not supported with this QEMU release!'
- % log_version)
+ raise ValueError(f'Log format {log_version} not supported with this QEMU release!')
def read_trace_records(event_mapping, event_id_to_name, fobj):
"""Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6).