This parser adds support for any XML based format other than already
supported XML vocabularies such XHTML, RSS/Atom feeds... It will
eventually be used as a fallback if one of these specific parsers fail,
before falling back to the existing genericParser which extracts not
that much useful information except URL tokens.
Also add when possible a warning level log message on input stream
closing error instead of failing silently. This could help understanding
some IO exceptions such as "too many files open".
Revealed by commit c77e43a : the exception was then thrown when indexing
pages containing mailto: scheme URL links with the Solr Webgraph core
enabled.
Fixed the error case and restored filtering on mailto links in
Document.resortLinks() as these URLs still should not appear in
Document.hyperlinks.
On MediaWiki dump imports, the SurrogateReader was trying to unread too
many bytes, then failing with the following exception :
"java.io.IOException: Push back buffer is full".
When using a public HTTP URL in /IndexImportMediawiki_p.html, the remote
file now is directly streamed and processed, allowing import of several
GB dumps even with a low memory remote peer, and without need to
manually download the dump file first.
warc = Web ARChive File Format.
Warc files with extension .warc or compressed warc.gz can be placed in the
DATA/surrogate/in and contained responses are imported to the index.
The used library is stream based so we can easily extend it later to use
and load warc's from the net.
by using icu.ULocale for languages not already covered (ICU normalizes
to ISO639-1 2 char codes).
Add test class
Use DublinCore vocabulary declarations in DCEntry and SurrogateReader
for easier usage debugging,
Init SurrogateReader.inputSource on first use.
recognized as tag like 1<a
reported in https://github.com/yacy/yacy_search_server/issues/109
Script content is ignored by default, but the text is filtered for html
tags. Modified scraper to skip tag filtering while within a <script>
section (until a closing tag is detected </script>.
Possible side effect, missing </script> end-tag will truncate trailing
content text.
add "datetime" property of <time> tag to scrapers startdate list.
Datetime is parsed as iso8601 (xml) date, html5 allows partial as well
as duration (not handled by this)
NullPointerException occurred when using and Identificator instance
which encountered and error in its constructor.
This error could be caused by a missing "langdetect" folder in the
current folder of the main process, or by simultaneous first calls to
the constructor, initializing concurrently the DetectorFactory.langlist.
Fixes the mantis 714 (http://mantis.tokeek.de/view.php?id=714)
Could occur when a search request was performed just after peer startup,
and the Switchboard Thread "LibraryProvider.initialize" had completed,
thus requesting a ProbabilisticClassifier not completely initialized
(and having a null contexts property).
Applied strategy : when there is no restriction on domains or
sub-path(s), stack anchor links once discovered by the content scraper
instead of waiting the complete parsing of the file.
This makes it possible to handle a crawling start file with thousands of
links in a reasonable amount of time.
Performance limitation : even if the crawl start faster with a large
file, the content of the parsed file still is fully loaded in memory.
to make sure current dates are recognized (was fixed to 2014 - 2016)
+ adjust holiday date parser from pattern.match to pattern.find to deal with leading and trailing text
+ moved relative date recognition (morgen, tomorrow) to parseline (used by query parser only), as not working and problematic for indexing
+ add test case for parseline (used by query parser)
including a small change, word posintext counting.
We remember/store 1st posintext. Previously following words got a handle (posintext)
excluding found. Now it just counts and assigns true posintext as handle (posintext)
to also support handling of urls w/o corresponding file-extension.
For this refactor use of document.getParserObject() to alway return a Parser (for clean logic)
and define/move the scraperObject as local var of AbstractParser.
Adjust related calls to getParserObject (where actually a scraperObject is wanted).
Addionally skip appending url token to parsed text for dht metadata entries
(by default returned as result by rwi index).
- Above brought up that parser start url parameter, declared as AnchorURL uses only methodes of parent object DigestURL (changed parameter declaration accordingly).
Language identification may show poor performance on documents with short or no
title but clear lang indication in text content. Using content text too
improves lang detection.
+ remove double caching of text in Identificator
in worker thread.
Writer of importer keeps needs a poison to close the file. On exception (e.g. OOM)
add a poison marker in outer most try/catch to assure output queue will terminate
in this condition too (and closes+renames the surrogate/in/xxx.prt file)
JVM registers each file in a list regardless of already deleted and never
cleans up the list during runtime.
This accumulates to a considerable amount of mem during large crawls and/or
long uptime.
To tackle this, all temp files are now created in a subdir of java.io.tmpdir
and the jvm tmpdir property is set to this subdir, which is deleted by
code on shutdown.
Additionally let pdfParser use this tmp subdir too.
- adjust check of data available according to doc
- return null on no recognized content (to not exit TextParser next parser try)
- use commons.compress directly
skip reading bz2 file magicbyte to identify bz2 format as inputstream reset would be required. Common compress reads and checks the magicbytes internally and throws ioexception if wrong, making preread obsolete.
see freshly deprecated https://developers.google.com/webmasters/ajax-crawling/
Implementation improves parsing of the homepage (ajax page) which uses metatag "fragment" in header and parses supplied html snapshot instead of mostly empty ajax/scripted page.
Implementation supports also hash-bang urls (url with anchor starting with ! like ...path#!hashfragment) but our crawler filters it
(use of hash-bang is controversly discussed and proposal is deprecated, makes no sense to adjust the crawler, but as long as it is used by some sites the minor change/improvement in htmlparser is good for some time).
Quick - how does it work
- if metatag fragment with content "!" is found
- htmlparser tries to get content of htmls snapshot (using a different url)
- htmlparser returns 2 documents (original url and snapshot content - but using same original url)
- after parsing result documents are joined (and stored to index containing content also from snapshot page... as the original ajax page contains typically no parseable html content)
Reads document level included title and description and skips the graphic content to save bandwidth.
svg metadata element is not interpreted
- remove rdfParser from init (current function identical with genericParser)
to prevent blank thumbnail display in image search because of not handled source which don't load on click.
Now the cross icon indicates the problem (inlcuding not supported format)
bayesian filters. This can be used to classify documents during
indexing-time using a pre-definied bayesian filter.
New wordings:
- a context is a class where different categories are possible. The
context name is equal to a facet name.
- a category is a facet type within a facet navigation. Each context
must have several categories, at least one custom name (things you want
to discover) and one with the exact name "negative".
To use this, you must do:
- for each context, you must create a directory within
DATA/CLASSIFICATION with the name of the context (the facet name)
- within each context directory, you must create text files with one
document each per line for every categroy. One of these categories MUST
have the name 'negative.txt'.
Then, each new document is classified to match within one of the given
categories for each context.
during surrogate reading: those attributes from the dump are removed
during the import process and replaced by new detected attributes
according to the setting of the YaCy peer.
This may cause that all such attributes are removed if the importing
peer has no synonyms and/or no vocabularies defined.
reason: experimental implementatin of RDFa parser not executed (limited to special urls) but may cause error on normal html parsing due to a inputstream.reset
keeping surrogates after processing is essential for some users. If the
space they are taking is too high, please set up an automatic deletion
process (like a cronjob).
to support the new time parser and search functions in YaCy a high
precision detection of date and time on the day is necessary. That
requires that the time zone of the document content and the time zone of
the user, doing a search, is detected. The time zone of the search
request is done automatically using the browsers time zone offset which
is delivered to the search request automatically and invisible to the
user. The time zone for the content of web pages cannot be detected
automatically and must be an attribute of crawl starts. The advanced
crawl start now provides an input field to set the time zone in minutes
as an offset number. All parsers must get a time zone offset passed, so
this required the change of the parser java api. A lot of other changes
had been made which corrects the wrong handling of dates in YaCy which
was to add a correction based on the time zone of the server. Now no
correction is added and all dates in YaCy are UTC/GMT time zone, a
normalized time zone for all peers.
- date navigation
The date is taken from the CONTENT of the documents / web pages, NOT
from a date submitted in the context of metadata (i.e. http header or
html head form). This makes it possible to search for documents in the
future, i.e. when documents contain event descriptions for future
events.
The date is written to an index field which is now enabled by default.
All documents are scanned for contained date mentions.
To visualize the dates for a specific search results, a histogram
showing the number of documents for each day is displayed. To render
these histograms the morris.js library is used. Morris.js requires also
raphael.js which is now also integrated in YaCy.
The histogram is now also displayed in the index browser by default.
To select a specific range from a search result, the following modifiers
had been introduced:
from:<date>
to:<date>
These modifiers can be used separately (i.e. only 'from' or only 'to')
to describe an open interval or combined to have a closed interval. Both
dates are inclusive. To select a specific single date only, use the
'to:' - modifier.
The histogram shows blue and green lines; the green lines denot weekend
days (saturday and sunday).
Clicking on bars in the histogram has the following reaction:
1st click: add a from:<date> modifier for the date of the bar
2nd click: add a to:<date> modifier for the date of the bar
3rd click: remove from and date modifier and set a on:<date> for the bar
When the on:<date> modifier is used, the histogram shows an unlimited
time period. This makes it possible to click again (4th click) which is
then interpreted as a 1st click again (sets a from modifier).
The display feature is NOT switched on by default; to switch it on use
the /ConfigSearchPage_p.html servlet.
luccioman