#!/usr/bin/perl -w
#
## Copyright (C) 1996-2021 The Squid Software Foundation and contributors
##
## Squid software is distributed under GPLv2+ license and includes
## contributions from numerous individuals and organizations.
## Please see the COPYING and CONTRIBUTORS files for details.
##

# Reads cache.log and displays lines that correspond to the master transaction
# that has a given async job. Master transaction is all activities tied to a
# a single received HTTP request (client side, ACL, ICAP, server side, etc.).
#
# See trace-job.pl for tracing a single job instead of all jobs related to
# a master transaction.
#
# Currently, many master transaction activities are not tracked because they
# do not use AsyncJob API. Eventually, most activities should be identifiable.
#
# Currently, the script reads and remembers all master transactions because it
# does not know which one should be tracked in advance. Eventually, we may
# have a more efficient way of tying master transaction to a job.
#


use strict;
use warnings;

my @InterestingJobs = @ARGV or die("usage: $0 <job id> ...\n");

my %Jobs = ();

my $inside = 0;
my $entering;

while (<STDIN>) {
    $entering = $_ if !$inside && /[|:] entering\b/;
    undef $entering if /[|:] leaving\b/;

    if (!$inside && /\bstatus in\b.*\b(?:async|job|icapx)(\d+)\b/o) {
        $inside = $1;
        &enterJob($inside);
        &updateJob($inside, $entering) if defined $entering;
        undef $entering;
    }
    elsif (!$inside && /\b(?:async|job|icapx)(\d+)\b/o) {
        updateJob($1, "$_\n"); # isolated line
    }

    next unless $inside;

    &updateJob($inside, $_);

    if (/AsyncJob constructed.*\[\S+?(\d+)\]/) {
        &linkJobs($inside, $1, $_);
    }

    if (/[|:] leaving\b/) {
        $inside = 0;
    }
}

foreach my $id (@InterestingJobs) {
    # Squid uses asyncNNN, jobNNN, icapxNNN for the same job/transaction
    $id =~ s/^(?:async|job|icapx)(\d+)$/$1/;
    reportJob($id, 1);
}

exit(0);


sub enterJob {
    my ($id) = @_;
    my $job = &getJob($id);
}

sub updateJob {
    my ($id, $line) = @_;

    my $job = &getJob($id);
    $job->{history} .= $line;

    if ($line =~ /\bFD (\d+)/) {
        $job->{fds}->{$1} = 1;
    }
}

sub linkJobs {
    my ($parentId, $kidId, $line) = @_;

    my $parent = $Jobs{$parentId} or die("missing linked job $parentId");
    push @{$parent->{kids}}, $kidId;

    my $kid = &getJob($kidId);
    die("two parents for $kidId: ". $kid->{parent}. " and $parentId") if $kid->{parent};
    $kid->{parent} = $parentId;

    $kid->{history} .= $line; # birth
}

sub getJob {
    my $id = shift;

    my $job = $Jobs{$id};
    return $job if $job;

    $job = {
        id => $id,
        kids => [],
        fds => {},
        parent => undef(),
        start => undef(),
        history => '',
        reported => 0,
        };

    $Jobs{$id} = $job;
    return $job;
}


sub reportJob {
    my ($id, $recursive) = @_;

    my $job = $Jobs{$id} or die("Did not see job$id\n");

    # several kids may try to report their common parent
    return if $job->{reported};
    $job->{reported} = 1;

    &reportJob($job->{parent}, 0) if $job->{parent};

    &reportJobParam($id, 'parent');
    &reportJobParam($id, 'kids', join(', ', @{$job->{kids}}));
    &reportJobParam($id, 'FDs', join(', ', keys %{$job->{fds}}));
    &reportJobHistory($id);

    return unless $recursive;

    foreach my $kidId (@{$job->{kids}}) {
        &reportJob($kidId, $recursive);
    }
}

sub reportJobParam {
    my ($id, $name, $value) = @_;
    my $job = $Jobs{$id} or die;

    $value = $job->{$name} if @_ < 3;
    $value = '?' unless defined $value;
    $value = "\n$value" if $value =~ /\n/m;
    printf("job%d %s: %s\n", $id, $name, $value);
}

sub reportJobHistory {
    my ($id) = @_;
    my $job = $Jobs{$id} or die;

    my $history = $job->{history};
    my @lines = split(/\n/, $history);
    &reportJobParam($id, 'history', (scalar @lines) . " entries");

    foreach my $line (@lines) {
        print "$line\n";
        print "\n" if $line =~ /[|:] leaving\b/;
    }
}
