cr2/thermal.py

#!/usr/bin/python
"""Process the output of the power allocator trace in the current directory's trace.dat"""

import os
import re
from StringIO import StringIO
import pandas as pd
from matplotlib import pyplot as plt

class Thermal(object):
    def __init__(self):
        if not os.path.isfile("trace.txt"):
            self.__run_trace_cmd_report()
        self.data_csv = ""
        self.data_frame = False


    def __run_trace_cmd_report(self):
        """Run "trace-cmd report > trace.txt".  Overwrites the contents of trace.txt if it exists."""
        from subprocess import check_output

        if not os.path.isfile("trace.dat"):
            raise IOError("No such file or directory: trace.dat")

        with open(os.devnull) as devnull:
            out = check_output(["trace-cmd", "report"], stderr=devnull)

        with open("trace.txt", "w") as f:
            f.write(out)

    def __parse_into_csv(self):
        """Create a csv representation of the thermal data and store it in self.data_csv"""
        pat_timestamp = re.compile(r"([0-9]+\.[0-9]+):")
        pat_data = re.compile(r"[A-Za-z0-9_]+=([0-9]+) ")
        header = ""

        with open("trace.txt") as fin:
            for line in fin:
                if not re.search("Ptot_out", line):
                    continue

                line = line[:-1]

                m = re.search(pat_timestamp, line)
                timestamp = m.group(1)

                semi_idx = line.index(" : ")
                data_str = line[semi_idx + 3:]

                if not header:
                    header = re.sub(r"([A-Za-z0-9_]+)=[0-9]+ ", r"\1,", data_str)
                    header = header[:-1]
                    header = "time," + header + "\n"
                    self.data_csv = header

                parsed_data = re.sub(pat_data, r"\1,", data_str)
                # Drop the last comma
                parsed_data = parsed_data[:-1]

                parsed_data = timestamp + "," + parsed_data + "\n"
                self.data_csv += parsed_data

    def write_thermal_csv(self):
        """Write the csv info in thermal.csv"""
        if not self.data_csv:
            self.__parse_into_csv()

        with open("thermal.csv", "w") as fout:
            fout.write(self.data_csv)

    def get_data_frame(self):
        """Return a pandas data frame for the run"""
        if self.data_frame:
            return self.data_frame

        if not self.data_csv:
            self.__parse_into_csv()

        self.data_frame = pd.read_csv(StringIO(self.data_csv)).set_index("time")
        return self.data_frame

    def __default_plot_settings(self, title=""):
        plt.xlabel("Time")
        if title:
            plt.title(title)

    def plot_temperature(self):
        """Plot the temperature"""
        df = self.get_data_frame()
        (df["currT"] / 1000).plot()
        self.__default_plot_settings(title="Temperature")