#!/usr/bin/env python 
#
# This script takes b2g process profiles and merged them into a single profile.
# The meta data is taken from the first profile. The startTime for each profile
# is used to syncronized the samples. Each thread is moved into the merged
# profile.
#
import json
import re
import sys

def MergeProfiles(files):
    threads = []
    fileData = []
    symTable = dict()
    meta = None
    libs = None
    videoUrl = None
    minStartTime = None

    for fname in files:
        if fname.startswith("--video="):
            videoUrl = fname[8:]
            continue

        match = re.match('profile_([0-9]+)_(.+)\.sym', fname)
        if match is None:
            raise Exception("Filename '" + fname + "' doesn't match expected pattern")
        pid = match.groups(0)[0]
        pname = match.groups(0)[1]

        fp = open(fname, "r")
        fileData = json.load(fp)
        fp.close()

        if meta is None:
            meta = fileData['profileJSON']['meta'].copy()
            libs = fileData['profileJSON']['libs']
            minStartTime = meta['startTime']
        else:
            minStartTime = min(minStartTime, fileData['profileJSON']['meta']['startTime'])
            meta['startTime'] = minStartTime

        for thread in fileData['profileJSON']['threads']:
            thread['name'] = thread['name'] + " (" + pname + ":" + pid + ")"
            threads.append(thread)

            # Note that pid + sym, pid + location could be ambigious
            # if we had pid=11 sym=1 && pid=1 sym=11.
            pidStr = pid + ":"

            thread['startTime'] = fileData['profileJSON']['meta']['startTime']
            if meta['version'] >= 3:
                stringTable = thread['stringTable']
                for i, str in enumerate(stringTable):
                    if str[:2] == '0x':
                        newLoc = pidStr + str
                        stringTable[i] = newLoc
                        symTable[newLoc] = str
            else:
                samples = thread['samples']
                for sample in thread['samples']:
                    for frame in sample['frames']:
                        if "location" in frame and frame['location'][0:2] == '0x':
                            oldLoc = frame['location']
                            newLoc = pidStr + oldLoc
                            frame['location'] = newLoc
                            # Default to the unprefixed symbol if no translation is
                            symTable[newLoc] = oldLoc

        filesyms = fileData['symbolicationTable']
        for sym in filesyms.keys():
            symTable[pidStr + sym] = filesyms[sym]

    # For each thread, make the time offsets line up based on the
    # earliest start
    for thread in threads:
        delta = thread['startTime'] - minStartTime
        if meta['version'] >= 3:
            idxTime = thread['samples']['schema']['time']
            for sample in thread['samples']['data']:
                sample[idxTime] += delta
            idxTime = thread['markers']['schema']['time']
            for marker in thread['markers']['data']:
                marker[idxTime] += delta
        else:
            for sample in thread['samples']:
                if "time" in sample:
                    sample['time'] += delta
            for marker in thread['markers']:
                marker['time'] += delta

    result = dict()
    result['profileJSON'] = dict()
    result['profileJSON']['meta'] = meta
    result['profileJSON']['libs'] = libs
    result['profileJSON']['threads'] = threads
    result['symbolicationTable'] = symTable
    result['format'] = "profileJSONWithSymbolicationTable,1"
    if videoUrl:
        result['profileJSON']['meta']['videoCapture'] = {"src": videoUrl}

    json.dump(result, sys.stdout)


if len(sys.argv) > 1:
    MergeProfiles(sys.argv[1:])
    sys.exit(0)

print "Usage: merge-profile.py profile_<pid1>_<pname1>.sym profile_<pid2>_<pname2>.sym > merged.sym"