add a read_log.py flie

add a read.py flie
used to extract the data form load.ycsb.log
BUG=

[Liangzijie1437, 2017-09-25 19:29:30]

add a read_log.py file, used to extract overall running time and throughput data
from experiment logs.
note that: FOLDER is "the path to load.ycsb.log", I just test it on my machine,
if you want to test, change the path.


import os

FOLDER = "/Users/liangzijie/Desktop/testdemo/lx3/out/"
FLAG = "OVERALL"


def read_file(filename, pattern):
    with open(filename) as f:
        lines = f.readlines()
        for line in lines:
            if pattern in line:
                print(line.strip())


for each_file in os.listdir(FOLDER):
    if each_file.startswith("2017"):
        filename = os.path.join(FOLDER + each_file, "load.ycsb.log")
        if os.path.exists(filename):
            read_file(filename, FLAG)

[01tonythomas, 2017-09-25 19:55:09]

01tonythomas@gmail.com changed reviewers:
+ 01tonythomas@gmail.com

[01tonythomas, 2017-09-25 19:55:09]

Nice to see this. Also, You can now extend this to extract the exact number
value from the line so that we get meaningful output.

https://codereview.chromium.org/3018633002/diff/20001/read_log.py
File read_log.py (right):

https://codereview.chromium.org/3018633002/diff/20001/read_log.py#newcode3
read_log.py:3: FOLDER = "/Users/liangzijie/Desktop/testdemo/lx3/out/"
We cannot have this going into the program, but I dont think we will have to
iterate through folders. Can you check if running a workload creates a different
directory or create one extra log file in the same directory ? If its the same,
we dont need this functionality to scan through folders

https://codereview.chromium.org/3018633002/diff/20001/read_log.py#newcode7
read_log.py:7: def read_file(filename, pattern):
minor, but for next time - the function name should reflect what it is doing -
like here - its not just reading a file. I would better name it
`get_lines_for_pattern_in_file(filename, pattern)` or something like that. but
this is okey though.

[david.tomic11, 2017-09-25 20:25:58]

david.tomic11@gmail.com changed reviewers:
+ david.tomic11@gmail.com

[david.tomic11, 2017-09-25 20:25:58]

I like this, its a good starting point for our plotting tasks. I would suggest
to make another patch where you comment what exactly the code is doing, so that
it is easier to read when you need info about it fast. 

Overall nice work!