summaryrefslogtreecommitdiffstats
path: root/HACKING
blob: bce40a9acca7b2ad6d15ec8e76b887b0acb4cbc0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
This file contains some tips for hacking on this code.

General OCaml advice:

(1) The *.mli file describes the interface of the module.  It's a good
    idea to look at this file first, then at *.ml (the implementation).

(2) Emacs users: use tuareg-mode for editing OCaml.

(3) http://www.ocaml-tutorial.org/

(4) http://camltastic.blogspot.com/2008/08/3-things-that-will-confuse-you-when.html

The code is structured into these files:

  virt_top_utils.mli / virt_top_utils.ml

    String functions and other small utility functions.  This is
    included directly into virt_top.ml.

  virt_top_version.ml

    The version number (automatically generated by configure).

  virt_top.mli / virt_top.ml

    This is the virt-top program.

    The two interesting functions are called 'collect' and 'redraw'.

    'collect' collects all the information about domains, etc.

    'redraw' updates the display on each frame.

    Another interesting function is 'start_up' which handles all
    start-up stuff, eg. command line arguments, connecting to the
    hypervisor, enabling curses.

    The function 'main_loop' runs the main loop and has sub-functions
    to deal with keypresses, help screens and so on.

  virt_top_xml.ml

    Any code which needs the optional xml-light library goes
    in here.  Mainly for parsing domain XML descriptions to get
    the list of block devices and network interfaces.

    The reason for having it in a separate file is so that we
    don't depend on xml-light.

  virt_top_csv.ml

    Any code which needs the optional ocaml-csv library goes
    in here.  This implements the --csv command line option.

  virt_top_calendar1.ml
  virt_top_calendar2.ml

    Any code which needs the optional ocaml-calendar library
    goes in here.  This implements the --end-time command line
    option.  Note there are two incompatible versions of the
    ocaml-calendar library, which is why we have two
    implementations.  The Makefile works out which one to use.

  virt_top_gettext.ml

    Gettext interaction (this is generated by ./configure).

  virt_top_main.ml

    This is just a small bit of code to glue the modules above
    together.

The man-page is generated from the single file:

  virt-top.pod

which generates (using perldoc) the following:

  virt-top.1
  virt-top.txt