tsan reported that rand() is not thread safe, so create
a thread safe wrapper, use rand_r() if available.
Consolidate the function, initialization and cleanup in
dict.c and make sure it is initialized in xmlInitParser()
For https://bugzilla.gnome.org/show_bug.cgi?id=654567
I use xmlTextReader to parse failed that might be incomplete. These files are
the beginning of a well-formed file, but the end is missing so the file as a
whole is not well-formed.
The problem is that xmlTextReader starts returning errors when it encounters
the early EOF, even though I haven't finished reading all of the valid data in
the file. It would be helpful if xmlTextReader kept working until the very
end.
For https://bugzilla.gnome.org/show_bug.cgi?id=622023
when compiled with LDFLAGS="${LDFLAGS} -Wl,-z,-defs -Wl,--no-undefined"
the python module would failed due to the undefined. This add an
explicit reference to python lib.
For https://bugzilla.gnome.org/show_bug.cgi?id=643148
Reported by Bill Clarke <llib@computer.org>, it used a global variable
as a counter for the input id and this was not thread safe. To avoid the
race without adding unneeded locking in the parser path, move the id to
the parser context instead.
The freeing function wasn't called due to a bogus #ifdef surrounding
value. Also switch the code to use the normal libxml2 allocation and
freeing routines.
On Fri, May 11, 2012 at 9:10 AM, Daniel Veillard <veillard@redhat.com> wrote:
> Hi Conrad,
>
> that's interesting ! I was initially afraid of a sudden explosion of
> memory allocations for building a tree since by default buffers tend to
> "waste" memory by using doubling allocations, but that's not the case.
> xmllint --noout doc/libxml2-api.xml
> when compiled with memory debug produce
>
> paphio:~/XML -> cat .memdump
> MEMORY ALLOCATED : 0, MAX was 12756699
>
> and without your patch 12755657, i.e. the increase is minimal.
Heh, I thought that too. Actually you're looking at the result with XML_ALLOC_EXACT! This
is because EXACT adds 10bytes "spare" on each alloc, and that interestingly wastes about the
same amount of space as XML_ALLOC_DOUBLEIT on this example (see below).
So it turns out that the default realloc() on my system actually handles this case really
well — and I guess that all the time in xmlRealloc() was actually in xmlStrlen, not the
underlying realloc() after all (sorry for misleading you). If you replace the realloc()
with a bad one (like valgrind's), then the performance degrades severely.
This patch implements a HYBRID allocator which has the behaviour you describe (it's
like EXACT to start with, though without the spare 10 bytes; and switches to DOUBLEIT
after 4kb) — that gets the memory back down to 12755657, with no noticeable impact on the
performance of the synthetic pathological example under valgrind.
In summary:
max_memory on ./xmllint --noout doc/libxml2-api.xml,
valgrind time on https://gist.github.com/2656940
max_memory valgrind time
before | 12755657 | 29:18.2
EXACT | 12756699 | 2:58.6 <-- this is the state after the first patch.
DOUBLEIT | 12756727 | 0:02.7
HYBRID | 12755754 | 0:02.7 <-- this is the state with both patches.
>
> There is also the cost of creating the buffers all the time.
> I need to read the code and check but I may be interested in an hybrid
> approach where we switch to buffer only when the text node starts to
> become too big (4k would remove nearly all usuall types of "document"
> usage, i.e. not blocks of data)
I tried to avoid too much buffer creation by introducing the xmlBufferDetach function,
which allows re-using one buffer to construct many strings. It's maybe a bit of a "hack"
in API terms though I thought the gains would be worth it.
Conrad
------8<------
To keep memory usage tight in normal conditions it's desirable to only
allocate as much space as is needed. Unfortunately this can lead to
problems when constructing a long string out of small chunks, because
every chunk you add will need to resize the buffer.
To fix this XML_ALLOC_HYBRID will switch (when the buffer is 4kb big)
from using exact allocations to doubling buffer size every time it is
full. This limits the number of buffer resizes to O(log n) (down from
O(n)), and thus greatly increases the performance of constructing very
large strings in this manner.
Hi Veillard and all,
Firstly, thanks for libxml: it's awesome!
I noticed recently that libxml was taking a surprisingly long time to perform some
operations (many minutes instead of milliseconds), and so I did some digging. It turns out
that the problem was caused by the realloc()ing done in xmlNodeAddContentLen() which can
be called many (many) times when assigning some content into a node.
For background, I'm dealing with XML that contains emails, these can have large
attachments (~6MB) which are base-64 encoded, line-wrapped at 78 chars, and each line ends
with . This means that xmlNodeAddContentLen() is being called about 200,000 times,
and so there are 200,000 reallocs of a 6MB string, which takes a while... (I put a synthetic
example of this at https://gist.github.com/2656940)
The attached patch works around that problem by using the existing buffer API to merge the
strings together before even creating the text node, this keeps the number of realloc()s
at a managable level.
I'd love feedback on the patch, and am happy to fix problems with it, or explore other
solutions if you think that this is barking up the wrong tree :).
Thanks,
Conrad
P.S. Should I create a bug for this too?
------8<------
Before this change xmlStringGetNodeList would perform a realloc() of the
entire new content for every XML entity in the assigned text in order to
merge together adjacent text nodes. This had the effect of making
xmlSetNodeContent O(n^2), which led to unexpectedly bad performance on
inputs that contained a large number of XML entities.
After this change the memory management is done by the buffer API,
avoiding the need to continually re-measure and realloc() the string.
For my test data (6MB of 80 character lines, each ending with )
this takes the time to xmlSetNodeContent from about 500 seconds to
around 50ms. I have not profiled smaller cases, though I tried to
minimize the performance impact of my change by avoiding unnecessary
string copying.
Signed-off-by: Conrad Irwin <conrad.irwin@gmail.com>
For https://bugzilla.gnome.org/show_bug.cgi?id=615785
When the <noscript> is found, <head> is closed and a <body> element is created.
The real <body id="xxx"> gets skipped over, so I can't see any of the
body's attributes.
Just don't close <head> when encountering a <noscript>
Add a regression test too
For https://bugzilla.gnome.org/show_bug.cgi?id=609796
Libxml2 fails to validate an instance document against a schema if an element
whose type is a complex extension of some base type with an optional child
element and that child element is not specified in the instance document. For
example, suppose I have some complex type BaseType that is defined to have one
child element in a sequence group that has minOccurs set to 0
For https://bugzilla.gnome.org/show_bug.cgi?id=630682
The python tests were reporting errors, some of it was due to
a small change in case encoding, but the main one was about
htmlSetMetaEncoding(doc, NULL) being broken by not removing
the associated meta tag anymore
For https://bugzilla.gnome.org/show_bug.cgi?id=642916
I just noticed that the HTML_PARSE_NOIMPLIED flag that you can pass to the
HTML-Parser methods doesn't do anything. Its intended purpose is to stop the
HTML-parser from forcibly adding a pair of html/body tags if the stream does
not contain any.
This is highly useful when you don't need this level of strictness.
Unfortunately, specifying it doesn't work, because the option is not
copied into the parsing context.
For https://bugzilla.gnome.org/show_bug.cgi?id=643949
In case of error on an IO creation input the given context
is terminated with the given close function, except if the
error happened in xmlParserInputBufferCreateIO. This can
lead to a resource leak which is fixed by this patch.
For https://bugzilla.gnome.org/show_bug.cgi?id=655218http://www.w3.org/TR/2011/WD-html5-20110525/semantics.html#the-meta-element
"""
The charset attribute specifies the character encoding used by the document.
This is a character encoding declaration. If the attribute is present in an XML
document, its value must be an ASCII case-insensitive match for the string
"UTF-8" (and the document is therefore forced to use UTF-8 as its
encoding).
"""
However, while <meta http-equiv="Content-Type" content="text/html;
charset=utf8"> works, <meta charset="utf8"> does not.
While libxml2 HTML parser is not tuned for HTML5, this is a simple
addition
Also added a testcase
For https://bugzilla.gnome.org/show_bug.cgi?id=665526
When building on Win32 configure the suport to use native Windows
threads since there is support for it unless pthreads are found
and asked for explicitely
For https://bugzilla.gnome.org/show_bug.cgi?id=666491
This patch adds project files to compile and debug libxml2 using Visual
Studio 2010. Only few minor changes have been made to the actual source
code.
This patch also requires for the iconv package to be compiled with visual
studio 2010 which has been submitted to the iconv project (see:
https://savannah.gnu.org/bugs/?35088)
When a node is dumped with a new encoding, we may encounter characters
that are not supported in the new encoding. libxml2 handles this by
replacing the character with character references, but in some encodings
this can result in an infinite loop when the character references
themselves contain unsupported characters.
This fixes the infinite loop by undoing a character reference substitution
when it cannot be inserted, and returning an encoder error.
This bug was noticed when looking into an infinite loop bug report for
the Ruby Nokogiri project. The original bug report, "nokogiri process
hangs on call to inner_html" is here:
https://github.com/tenderlove/nokogiri/issues/400
When you call xmlParseNodeInContext on a fragment node with an
empty document, the parser associates the first new node twice --
once with the document, and once with the fragment node.
This fixes the issue by only associating the new node with the
fragment node.
The data in node_seq in xmlParserCtxt was not updated properly
when parsing HTML. This patch fixes the accounting for both
pull and push mode of HTML parsing.
When playing with xpath in the xmllint shell, it's really handy to be
able to ask where the returned nodes live in the tree, in the same
way "pwd" asks where the current node lives.
The feature is actually quite easy to implement by combining the
functionality of the existing dir/ls and pwd commands (see proposed patch).
Example usage:
/ > whereis //last_name
/clinical_study/overall_official/last_name
/clinical_study/location/contact/last_name
/clinical_study/location/investigator/last_name
For https://bugzilla.gnome.org/show_bug.cgi?id=310222
adds namespace support to ls, du and the element named in
the command shell prompt. It also fixes du to actually dump
the requested path, if the user gives one, rather than always
dumping the whole file.
configure.ac (AM_C_PROTOTYPES): Remove call to this macro.
The support for automatic de-ANSI-fication has been deprecated in
automake 1.11.2, and will be removed altogether in automake 1.12.0
