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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
|
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
<head>
<title>RTFL: Tips and tricks</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
</head>
<body>
<p>[<a href="rtfl.html">Back to RTFL documentation.</a>]</p>
<h1>Tips and tricks</h1>
<p>Here, I'll summarize some useful experiences during the work
on <a href="http://www.dillo.org/">dillo</a>, for which RTFL was
initially written.</p>
<h2>Preparing the tested program</h2>
<ul>
<li>Do not prepare your program for a specific purpose, but in a
way that the RTFL message tell what happens in the
program, <em>in an objective way</em>. Ideally, most
preparation work is done once and pays off for many different
debugging problems.</li>
<li>Use different aspects so that filtering (as
in <a href="rtfl.html#using_rtfl_objview"><tt>rtfl-objview</tt></a>)
helps to focus on your specific problem.
</li>
</ul>
<h2><a href="rtfl.html#using_rtfl_objview"><tt>rtfl-objview</tt></a></h2>
<h3>Work around bugs and flaws</h3>
<p>Currently, RTFL is not at the top of my priority list, but just
a mean to an end (with <a href="http://www.dillo.org/">dillo</a>
being the end). This means that I am not too motivated to fix
bugs which can be worked around:</p>
<ul>
<li><del>There are several redrawing problems. Calling
<tt>xrefresh</tt> or switching between virtual screens should
should redraw everything correctly.</del> <i>(Redrawing
problems seem fixed now.)</i></li>
<li><del>Sometimes, the focused command is not visible. Pressing
Ctrl+N and then Ctrl+P should get it back into the viewport
again.</del> <i>(Scrolling problems seem fixed now.)</i></li>
<li>Use scripts to filter the RTFL messages. Hacking a script in
Perl is often much faster as integrating the functionality
into <tt>rtfl-objview</tt>. Some <a href="rtfl.html#scripts">useful
scripts</a> are already part of RTFL.</li>
</ul>
<h3>General approach</h3>
<p>Run the tested program and pass the standard output via pipe
to <tt>rtfl-objview</tt>. The
<a href="rtfl.html#rtfl_objview_command_line_options">command
line options</a> <tt>-M</tt> and <tt>-O</tt> are useful to get
an overview, <tt>-a</tt> and <tt>-A</tt> will help you to filter
out irrelevant messages.</p>
<p>Then search for an entry point:</p>
<ul>
<li>First of all, get an overview what the objects displayed in
the diagram actually represent. In
<a href="http://www.dillo.org/">dillo</a>, many objects
represent elements of the rendered document, so if an element
is rendered wrong, it is important to find the respective
object.</li>
<li>Depending on the tested program, it may be useful to search
for strange patterns of function calls. Simple example:
endless recursions are easily recognized by a steadily
increasing indentation.</li>
<li>An often helpful approach is to examine the attributes:
search for the respective object and the respective attribute;
a value which looks strange is a good starting point.</li>
</ul>
<p>If you have troubles to find the respective object, try to
color it via
<a href="rtfl.html#protocol_obj_object_color">obj-object-color</a>,
using a filter like
this:<sup><a id="ref-pre-version-1" href="#note-pre-version-1">[1]</a></sup></p>
<pre>sed 's/^\(\[rtfl-obj-1\.[0-9]*\].*\):set:\([^:]*\):words\.0\.text\/widget\/breakSpace:"Abc"$/\0\n\1:object-color:\2:#ff80ff/g'</pre>
<p>which colors all objects to light purple which have the
attribute <tt>words.0.text/widget/breakSpace</tt> set to the
value <tt>"Abc"</tt>. This example is again taken
from <a href="http://www.dillo.org/">dillo</a>, like the
following one, which colors objects in the color in which they
are rendered (represented by the attribute
<tt>style.background-color</tt>):<sup><a id="ref-pre-version-2" href="#note-pre-version-2">[2]</a></sup></p>
<pre>sed 's/^\(\[rtfl-obj-1\.[0-9]*\].*\):set:\([^:]*\):style.background-color:\(#[0-9a-f]*\)$/\0\n\1:object-color:\2:\3/g'</pre>
<p>As soon as you have selected a specific command, try to
determine the commands before:</p>
<ul>
<li>Navigate through the
<a href="rtfl.html#rtfl_objview_navigation">previous
commands</a>.</li>
<li>Or use the <a href="rtfl.html#rtfl_objview_stack_traces">stack
traces</a> function to get an overview.</li>
<li>One more tip: Use <i>Switch between related</i> for skipping
the messages within one method call if you think that the
problem is found outside of this method.</li>
</ul>
<h3>Advanced problems</h3>
<h4>CPU hogging</h4>
<p>In this case, the number of messages (infinite) will be too
large for <tt>rtfl-objview</tt>. Simply use <tt>head(1)</tt> to
reduce them; for the number of lines, some trial and error is
necessary.</p>
<h4>Too many messages</h4>
<p>In some cases, it is useful to concentrate on what happens at
the end, especially if the program aborts. In this cases, the
script <a href="rtfl.html#scripts"><tt>rtfl-objtail</tt></a>
helps to filter messages, but preserve relevant object
creations, associations etc. at the beginning. Again, some tests
are needed for the number of lines.</p>
<h4 id="transformation_of_attributes">Transformation of attributes</h4>
<p>While <a href="rtfl.html#protocol_obj_set"><tt>obj-set</tt></a>
is used to set actual attributes, it is sometimes useful to
accumulate values. Instead of adding code to the tested program,
filters can do this and add respective pseudo attributes. The
following snippet counts for each object (and each process) the
number of calls of the method
<tt>draw</tt>:<sup><a id="ref-pre-version-3" href="#note-pre-version-3">[3]</a></sup></p>
<pre><a href="rtfl.html#using_rtfl_tee">rtfl-tee</a> -b sh -c \
"grep '^\[rtfl\].*:obj-enter:[^:]*:[^:]*:[^:]*:draw:' | \
sed 's/^.*:\([^:]*\):obj-enter:\([^:]*\):.*$/\1:\2/g' | \
sort | uniq -c | \
sed 's/^ *\([^ ]*\) *\([^:]*\):\(.*\)$/[rtfl]:0:\2:obj-set:\3:<b>called <i>draw<\/i><\/b>:\1/g'"</pre>
<h3>More tips</h3>
<ul>
<li>Use the script
<a href="rtfl.html#scripts"><tt>rtfl-filter-out-classes</tt></a>
to reduce again messages. (I plan to integrate this
into <tt>rtfl-objview</tt>.)</li>
<li>The serial numbers preceding commands are often useful to
determine which command follows the other. E. g., by
comparing the numbers of attributes, it can be determined
which attribute possibly depends on another.</li>
</ul>
<h2>Attic</h2>
<p>Some ideas proved to be less practical that they looked at
first. Here, you will find several smaller projects which I have
abandoned, but you might find them useful as an inspiration.</p>
<h3><a href="http://www.dillo.org/">Dillo</a>: HTML
attribute <tt>rtfl-id</tt></h3>
<p>To make finding the exact relation between HTML elements of a
tested page and the <a href="http://www.dillo.org/">dillo</a>
widgets simpler, one could define a new HTML
element, <tt>rtfl-id</tt>, which is recognized by the HTML
parser of dillo and eventually passed to the respective
widget. (Printing a
<a href="rtfl.html#protocol_obj_set"><tt>obj-set</tt></a>
message is sufficient, storage in the widget is not necessary.)
This is demonstrated by the patch
<a href="#appendix_dillo_rtfl_id_diff"><tt>dillo-rtfl-id.diff</tt></a>
below.</p>
<p>Furthermore, a simple Perl
script, <a href="#appendix_add_rtfl_id_pl"><tt>add-rtfl-id.pl</tt></a>,
adds unique <tt>rtfl-id</tt>'s to a given HTML page (standard
input to standard output).</p>
<p>(<em>Warning:</em> both are incomplete.)</p>
<h3 id="attic_rtfl_findrepeat"><tt>rtfl-findrepeat</tt></h3>
<p><tt>Rtfl-findrepeat</tt> is a program which searches in a
stream for identical sequences. See comment at the beginning
of <tt>common/rtfl_findrepeat.cc</tt> for more details on
usage. Suitable arguments should be achieved by trial and
error.</p>
<p>The idea behind this: if a program hogs the CPU, it is most
likely that it does similar things again and again, by
error. With a bit of luck, this will result in identical RTFL
messages, which <tt>rtfl-findrepeat</tt> helps to
find. With <a href="http://www.dillo.org/">dillo</a>, however,
this rendered not as really usable, so I have moved
<tt>rtfl-findrepeat</tt> to here.</p>
<h2>Appendix</h2>
<h3 id="appendix_dillo_rtfl_id_diff"><tt>dillo-rtfl-id.diff</tt></h3>
<pre>diff -r 45a8d0d4b0d6 dw/widget.hh
--- a/dw/widget.hh Mon Sep 08 23:20:10 2014 +0200
+++ b/dw/widget.hh Tue Sep 09 13:09:08 2014 +0200
@@ -502,6 +502,11 @@
*/
virtual Iterator *iterator (Content::Type mask, bool atEnd) = 0;
virtual void removeChild (Widget *child);
+
+ void setRtflId (const char *rtflId) {
+ if (rtflId) DBG_OBJ_SET_STR ("rtfl-id", rtflId);
+ else DBG_OBJ_SET_SYM ("rtfl-id", "none");
+ }
};
void splitHeightPreserveAscent (int height, int *ascent, int *descent);
diff -r 45a8d0d4b0d6 src/doctree.hh
--- a/src/doctree.hh Mon Sep 08 23:20:10 2014 +0200
+++ b/src/doctree.hh Tue Sep 09 13:09:08 2014 +0200
@@ -13,6 +13,7 @@
lout::misc::SimpleVector<char*> *klass;
const char *pseudo;
const char *id;
+ const char *rtflId;
DoctreeNode () {
parent = NULL;
@@ -21,11 +22,13 @@
klass = NULL;
pseudo = NULL;
id = NULL;
+ rtflId = NULL;
element = 0;
};
~DoctreeNode () {
dFree ((void*) id);
+ dFree ((void*) rtflId);
while (lastChild) {
DoctreeNode *n = lastChild;
lastChild = lastChild->sibling;
diff -r 45a8d0d4b0d6 src/form.cc
--- a/src/form.cc Mon Sep 08 23:20:10 2014 +0200
+++ b/src/form.cc Tue Sep 09 13:09:08 2014 +0200
@@ -938,6 +938,7 @@
* but it caused 100% CPU usage.
*/
page = new Textblock (false);
+ page->setRtflId (html->rtflId ());
page->setStyle (html->backgroundStyle ());
ResourceFactory *factory = HT2LT(html)->getResourceFactory();
diff -r 45a8d0d4b0d6 src/html.cc
--- a/src/html.cc Mon Sep 08 23:20:10 2014 +0200
+++ b/src/html.cc Tue Sep 09 13:09:08 2014 +0200
@@ -362,6 +362,7 @@
static void Html_add_textblock(DilloHtml *html, bool addBreaks, int breakSpace)
{
Textblock *textblock = new Textblock (prefs.limit_text_width);
+ textblock->setRtflId (html->rtflId ());
if (addBreaks)
HT2TB(html)->addParbreak (breakSpace, html->wordStyle ());
@@ -2186,6 +2187,7 @@
}
dw::Image *dw = new dw::Image(alt_ptr);
+ dw->setRtflId (html->rtflId ());
image =
a_Image_new(html->dw->getLayout(), (void*)(dw::core::ImgRenderer*)dw, 0);
@@ -3038,6 +3040,7 @@
HT2TB(html)->addParbreak (5, html->wordStyle ());
hruler = new Ruler();
+ hruler->setRtflId (html->rtflId ());
hruler->setStyle (html->style ());
HT2TB(html)->addWidget (hruler, html->style ());
HT2TB(html)->addParbreak (5, html->wordStyle ());
@@ -3783,6 +3786,10 @@
const char *attrbuf;
char lang[3];
+ if (tagsize >= 13 && /* length of "<t rtfl-id=i>" */
+ (attrbuf = a_Html_get_attr(html, tag, tagsize, "rtfl-id")))
+ html->styleEngine->setRtflId(attrbuf);
+
if (tagsize >= 8 && /* length of "<t id=i>" */
(attrbuf = a_Html_get_attr(html, tag, tagsize, "id"))) {
/* According to the SGML declaration of HTML 4, all NAME values
@@ -3882,6 +3889,7 @@
HT2TB(html)->addParbreak (0, wordStyle);
list_item = new ListItem ((ListItem*)*ref_list_item,prefs.limit_text_width);
+ list_item->setRtflId (html->rtflId ());
HT2TB(html)->addWidget (list_item, style);
HT2TB(html)->addParbreak (0, wordStyle);
*ref_list_item = list_item;
diff -r 45a8d0d4b0d6 src/html_common.hh
--- a/src/html_common.hh Mon Sep 08 23:20:10 2014 +0200
+++ b/src/html_common.hh Tue Sep 09 13:09:08 2014 +0200
@@ -234,6 +234,7 @@
inline void restyle () { styleEngine->restyle (bw); }
+ inline const char *rtflId () { return styleEngine->rtflId (); }
};
/*
diff -r 45a8d0d4b0d6 src/styleengine.cc
--- a/src/styleengine.cc Mon Sep 08 23:20:10 2014 +0200
+++ b/src/styleengine.cc Tue Sep 09 13:09:08 2014 +0200
@@ -160,6 +160,12 @@
dn->id = dStrdup (id);
}
+void StyleEngine::setRtflId (const char *rtflId) {
+ DoctreeNode *dn = doctree->top ();
+ assert (dn->rtflId == NULL);
+ dn->rtflId = dStrdup (rtflId);
+}
+
/**
* \brief split a string at sep chars and return a SimpleVector of strings
*/
diff -r 45a8d0d4b0d6 src/styleengine.hh
--- a/src/styleengine.hh Mon Sep 08 23:20:10 2014 +0200
+++ b/src/styleengine.hh Tue Sep 09 13:09:08 2014 +0200
@@ -77,6 +77,7 @@
void startElement (int tag, BrowserWindow *bw);
void startElement (const char *tagname, BrowserWindow *bw);
void setId (const char *id);
+ void setRtflId (const char *rtflId);
const char * getId () { return doctree->top ()->id; };
void setClass (const char *klass);
void setStyle (const char *style);
@@ -122,6 +123,10 @@
else
return wordStyle0 (bw);
};
+
+ inline const char *rtflId () {
+ return stack->getRef(stack->size()-1)->doctreeNode->rtflId;
+ };
};
#endif
diff -r 45a8d0d4b0d6 src/table.cc
--- a/src/table.cc Mon Sep 08 23:20:10 2014 +0200
+++ b/src/table.cc Tue Sep 09 13:09:08 2014 +0200
@@ -158,6 +158,7 @@
HT2TB(html)->addParbreak (0, html->wordStyle ());
table = new dw::Table(prefs.limit_text_width);
+ table->setRtflId (html->rtflId ());
HT2TB(html)->addWidget (table, html->style ());
HT2TB(html)->addParbreak (0, html->wordStyle ());
@@ -451,6 +452,7 @@
prefs.limit_text_width);
else
col_tb = new SimpleTableCell (prefs.limit_text_width);
+ col_tb->setRtflId (html->rtflId ());
if (html->style()->borderCollapse == BORDER_MODEL_COLLAPSE){
Html_set_collapsing_border_model(html, col_tb);</pre>
<h3 id="appendix_add_rtfl_id_pl"><tt>add-rtfl-id.pl</tt></h3>
<pre>#!/usr/bin/perl
$id = 0;
while(<STDIN>) {
chomp;
$first = 1;
foreach $part (split /w</) {
if ($first) {
print $part;
} else {
if ($part =~ /^\//) {
print "<$part";
} else {
$part =~ s/([^ >]*)/\1 rtfl-id="$id"/;
$id++;
print "<$part";
}
}
$first = 0;
}
print "\n";
}</pre>
<hr/>
<p><sup><a id="note-pre-version-1" href="#ref-pre-version-1">[1]</a></sup>
Use this for the pre-version protocol:</p>
<pre>sed 's/^\(\[rtfl\].*\):obj-set:\([^:]*\):words\.0\.text\/widget\/breakSpace:"Abc"$/\0\n\1:obj-object-color:\2:#ff80ff/g'</pre>
<p><sup><a id="note-pre-version-2" href="#ref-pre-version-2">[2]</a></sup>
Again, for the pre-version protocol:</p>
<pre>sed 's/^\(\[rtfl\].*\):obj-set:\([^:]*\):style.background-color:\(#[0-9a-f]*\)$/\0\n\1:obj-object-color:\2:\3/g'</pre>
<p><sup><a id="note-pre-version-3" href="#ref-pre-version-3">[3]</a></sup>
This works only with the pre-version protocol. Should be
adjusted eventually.</p>
</body>
</html>
|
