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| author | Brendan Jackman <brendan.jackman@arm.com> | 2017-06-14 15:03:23 +0100 |
|---|---|---|
| committer | KP Singh <kpsingh@google.com> | 2017-06-29 22:52:38 +0200 |
| commit | 3fdf6872b0d59743ff05ca4f7ec7f429a3cc81be (patch) | |
| tree | f1c10a5446805fcff2f1f59f20624d00f68da785 | |
| parent | a19ff2508e37fce5e4909e0b717c3a4d2f0be679 (diff) | |
| download | trappy-3fdf6872b0d59743ff05ca4f7ec7f429a3cc81be.tar.gz | |
ftrace: Store and retrieve window params in trace cache
Store a JSON file with the parameters used to parse a trace in the cache. If, on
retrieval, we find a mismatch then simply invalidate the cache.
A richer implementation might detect whether we can still use the cache (e.g. if
the requested window is a subset of the cached one), but for now I don't think
that's worth the effort/complexity.
Reviewed-by: KP Singh <kpsingh@google.com>
| -rw-r--r-- | trappy/ftrace.py | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/trappy/ftrace.py b/trappy/ftrace.py index 2176d30..dae1e43 100644 --- a/trappy/ftrace.py +++ b/trappy/ftrace.py @@ -18,6 +18,7 @@ # pylint: disable=no-member import itertools +import json import os import re import pandas as pd @@ -74,27 +75,32 @@ subclassed by FTrace (for parsing FTrace coming from trace-cmd) and SysTrace.""" cache_path = os.path.join(tracefile_dir, cache_dir) return cache_path - def _check_trace_cache(self): + def _check_trace_cache(self, params): cache_path = self._trace_cache_path() md5file = os.path.join(cache_path, 'md5sum') + params_path = os.path.join(cache_path, 'params.json') - if not os.path.exists(cache_path) or not os.path.exists(md5file): - return False + for path in [cache_path, md5file, params_path]: + if not os.path.exists(path): + return False with open(md5file) as f: cache_md5sum = f.read() with open(self.trace_path, 'rb') as f: trace_md5sum = hashlib.md5(f.read()).hexdigest() + with open(params_path) as f: + cache_params = json.load(f) # check if cache is valid - if cache_md5sum != trace_md5sum: + if cache_md5sum != trace_md5sum or cache_params != params: shutil.rmtree(cache_path) return False return True - def _create_trace_cache(self): + def _create_trace_cache(self, params): cache_path = self._trace_cache_path() md5file = os.path.join(cache_path, 'md5sum') + params_path = os.path.join(cache_path, 'params.json') if os.path.exists(cache_path): shutil.rmtree(cache_path) @@ -104,6 +110,9 @@ subclassed by FTrace (for parsing FTrace coming from trace-cmd) and SysTrace.""" with open(md5file, 'w') as f: f.write(md5sum) + with open(params_path, 'w') as f: + json.dump(params, f) + def _get_csv_path(self, trace_class): path = self._trace_cache_path() return os.path.join(path, trace_class.__class__.__name__ + '.csv') @@ -173,7 +182,8 @@ subclassed by FTrace (for parsing FTrace coming from trace-cmd) and SysTrace.""" del scope_classes[name] def _do_parse(self): - if not self.__class__.disable_cache and self._check_trace_cache(): + params = {'window': self.window, 'abs_window': self.abs_window} + if not self.__class__.disable_cache and self._check_trace_cache(params): # Read csv into frames for trace_class in self.trace_classes: try: @@ -190,7 +200,7 @@ subclassed by FTrace (for parsing FTrace coming from trace-cmd) and SysTrace.""" try: # Recreate basic cache directories only if nothing cached if not all([c.cached for c in self.trace_classes]): - self._create_trace_cache() + self._create_trace_cache(params) # Write out only events that weren't cached before for trace_class in self.trace_classes: |