#!/usr/bin/python

import re
import math
import cairo

class ReadFile:
    def __init__(self, filename):
        self.filename = filename

    def __enter__(self):
        self.f = open(self.filename, 'r') 
        self.lineno = 0
        self.getnext();
        return self

    def __exit__(self, type, value, traceback):
        self.f.close()

    def __nonzero__(self):
        return self.line != ""

    def getnext(self):
        self.lineno += 1
        self.line = self.f.readline()

def read_times(rf):
    times = []

    while True:
        match = re.match('[0-9]+ ', rf.line)
        if not match:
            break
        times += [int(x) for x in re.split(' ', rf.line.rstrip())]
        rf.getnext()

    return times[::-1]

class Thread:
    thread_number = 0

    def __init__(self, thread_name):
        # no one cares about the thread address
        match = re.match('(.*) \(0x.*?\) (.*)', thread_name)
        if match:
            thread_name = match.group(1) + " " + match.group(2)

        self.thread_name = thread_name
        self.thread_number = Thread.thread_number
        self.events = []
        Thread.thread_number += 1

class Event:
    def __init__(self, thread, gate_location, gate_name, start, stop):
        self.thread = thread
        self.gate_location = gate_location
        self.gate_name = gate_name
        self.start = start
        self.stop = stop

        self.work = False
        self.wait = False
        if re.match('.*work.*', gate_name):
            self.work = True
        if re.match('.*wait.*', gate_name):
            self.wait = True

        thread.events.append(self)

input_filename = 'vips-profile.txt'

thread_id = 0
threads = []
n_events = 0
print 'reading from', input_filename
with ReadFile(input_filename) as rf:
    while rf:
        if rf.line.rstrip() == "":
            rf.getnext()
            continue
        if rf.line[0] == "#":
            rf.getnext()
            continue

        match = re.match('thread: (.*)', rf.line)
        if not match:
            print 'parse error line %d, expected "thread"' % rf.lineno
        thread_name = match.group(1) + " " + str(thread_id)
        thread_id += 1
        thread = Thread(thread_name)
        threads.append(thread)
        rf.getnext()

        while True:
            match = re.match('gate: (.*?): (.*)', rf.line)
            if not match:
                break
            gate_location = match.group(1)
            gate_name = match.group(2)
            rf.getnext()

            match = re.match('start:', rf.line)
            if not match:
                continue
            rf.getnext()

            start = read_times(rf)

            match = re.match('stop:', rf.line)
            if not match:
                continue
            rf.getnext()

            stop = read_times(rf)

            if len(start) != len(stop):
                print 'start and stop length mismatch'

            for a, b in zip(start, stop):
                Event(thread, gate_location, gate_name, a, b)
                n_events += 1

for thread in threads:
    thread.events.sort(lambda x, y: cmp(x.start, y.start))

print 'loaded %d events' % n_events

# normalise time axis to secs of computation
ticks_per_sec = 1000000.0
start_time = threads[0].events[0].start
last_time = 0
for thread in threads:
    for event in thread.events:
        event.start = (event.start - start_time) / ticks_per_sec
        event.stop = (event.stop - start_time) / ticks_per_sec

        if event.stop > last_time:
            last_time = event.stop

print 'last time =', last_time

# calculate some simple stats
for thread in threads:
    thread.start = last_time
    thread.stop = 0
    thread.wait = 0
    thread.work = 0
    for event in thread.events:
        if event.start < thread.start:
            thread.start = event.start
        if event.stop > thread.stop:
            thread.stop = event.stop
        if event.wait:
            thread.wait += event.stop - event.start
        if event.work:
            thread.work += event.stop - event.start

    thread.alive = thread.stop - thread.start

    # hide very short-lived threads 
    thread.hide = thread.alive < 0.01

print 'name\t\talive\twait%\twork%\tunknown%'
for thread in threads:
    if thread.hide:
        continue

    wait_percent = 100 * thread.wait / thread.alive
    work_percent = 100 * thread.work / thread.alive
    unkn_percent = 100 - 100 * (thread.work + thread.wait) / thread.alive

    print '%13s\t%6.2g\t' % (thread.thread_name, thread.alive),
    print '%.3g\t%.3g\t%.3g' % (wait_percent, work_percent, unkn_percent)

# do two gates overlap?
def is_overlap(events, gate_name1, gate_name2):
    for event1 in events:
        if event1.gate_name != gate_name1:
            continue

        for event2 in events:
            if event2.gate_name != gate_name2:
                continue

            # if either endpoint of 1 is within 2
            if event1.start > event2.start and event1.stop < event2.stop:
                return True
            if event1.stop > event2.start and event1.stop < event2.stop:
                return True

    return False

# allocate a y position for each gate
total_y = 0
for thread in threads:
    if thread.hide:
        continue

    thread.total_y = total_y

    # first pass .. move work and wait events to y == 0
    gate_positions = {}
    for event in thread.events:
        if not event.work and not event.wait:
            continue

        # no works and waits must overlap
        if not event.gate_name in gate_positions:
            for gate_name in gate_positions:
                if is_overlap(thread.events, event.gate_name, gate_name):
                    print 'gate overlap on thread', thread.thread_name
                    print '\t', event.gate_location 
                    print '\t', event.gate_name
                    print '\t', gate_name 
                    break

            gate_positions[event.gate_name] = 0

        event.y = gate_positions[event.gate_name] 
        event.total_y = total_y + event.y

    # second pass: move all other events to non-overlapping ys
    y = 1
    for event in thread.events:
        if event.work or event.wait:
            continue

        if not event.gate_name in gate_positions:
            # look at all the ys we've allocated previously and see if we can 
            # add this gate to one of them
            for gate_y in range(1, y):
                found_overlap = False
                for gate_name in gate_positions:
                    if gate_positions[gate_name] != gate_y:
                        continue

                    if is_overlap(thread.events, event.gate_name, gate_name):
                        found_overlap = True
                        break

                if not found_overlap:
                    gate_positions[event.gate_name] = gate_y
                    break

            # failure? add a new y
            if not event.gate_name in gate_positions:
                gate_positions[event.gate_name] = y
                y += 1

        event.y = gate_positions[event.gate_name]

    # third pass: flip the order of the ys to get the lowest-level ones at the
    # top, next to the wait/work line
    for event in thread.events:
        if event.work or event.wait:
            continue

        event.y = y - event.y
        event.total_y = total_y + event.y

    total_y += y

PIXELS_PER_SECOND = 1000
PIXELS_PER_GATE = 20
LEFT_BORDER = 130
BAR_HEIGHT = 5
WIDTH = int(LEFT_BORDER + last_time * PIXELS_PER_SECOND) + 20
HEIGHT = int((total_y + 1) * PIXELS_PER_GATE)

output_filename = "vips-profile.svg"
print 'writing to', output_filename

surface = cairo.SVGSurface(output_filename, WIDTH, HEIGHT)

ctx = cairo.Context(surface)
ctx.select_font_face('Sans')
ctx.set_font_size(15)

ctx.rectangle(0, 0, WIDTH, HEIGHT)
ctx.set_source_rgba(0.0, 0.0, 0.3, 1.0)
ctx.fill()

def draw_event(ctx, event):
    left = event.start * PIXELS_PER_SECOND + LEFT_BORDER
    top = event.total_y * PIXELS_PER_GATE + BAR_HEIGHT / 2 
    width = (event.stop - event.start) * PIXELS_PER_SECOND 
    height = BAR_HEIGHT

    ctx.rectangle(left, top, width, height)

    if event.wait:
        ctx.set_source_rgb(0.9, 0.1, 0.1)
    elif event.work:
        ctx.set_source_rgb(0.1, 0.9, 0.1)
    else:
        ctx.set_source_rgb(0.1, 0.1, 0.9)

    ctx.fill()

    if not event.wait and not event.work:
        xbearing, ybearing, twidth, theight, xadvance, yadvance = \
                ctx.text_extents(event.gate_name)

        ctx.move_to(left + width / 2 - twidth / 2, top + 3 * BAR_HEIGHT)
        ctx.set_source_rgb(1.00, 0.83, 0.00)
        ctx.show_text(event.gate_name)

for thread in threads:
    if thread.hide:
        continue

    ctx.rectangle(0, thread.total_y * PIXELS_PER_GATE, WIDTH, 1)
    ctx.set_source_rgb(1.00, 1.00, 1.00)
    ctx.fill()

    xbearing, ybearing, twidth, theight, xadvance, yadvance = \
            ctx.text_extents(thread.thread_name)
    ctx.move_to(0, theight + thread.total_y * PIXELS_PER_GATE + BAR_HEIGHT / 2)
    ctx.set_source_rgb(1.00, 1.00, 1.00)
    ctx.show_text(thread.thread_name)

    for event in thread.events:
        draw_event(ctx, event)

surface.finish()