Version 1.3.52

[metaproxy-moved-to-github.git] / NEWS

--- 1.3.52 2012/11/30

zoom: fix http://-check. SRU search broken in 1.3.51.

--- 1.3.51 2012/11/15

zoom: only append http:// for SRU if not already given . Makes it
possible to use https-URLs.

Use yazpp 1.4 or later due to new ABI.

frontend_net: allow max package size to be specified. Controlled by
attribute 'max_recv_bytes' of element 'port'.

--- 1.3.50 2012/10/29

For most generated diagnostics by filters, typically temporary
system error, augment addinfo message with filter name.

Add support for CentOS 6 packages.

sru_z3950: interpret Z39.50 diagnostics part of Init Response.

Add man page for metaproxy-config.

--- 1.3.49 2012/10/18

zoom: new config element passthru. This defines an element set that is
passed verbatim to the backend in pz2 mode.

auth_simple: allow both idPass and open auth. Also fix SEGV that could
occur for open auth.

--- 1.3.48 2012/10/08

z3950_client: fix string handling for init diagnostics in the case where
addinfo was absent.

query_rewrite: no charset conversion for error queries. Avoid performing
charset conversion for query conversion errors. The resulting Type-1
query is invalid in this case.

--- 1.3.47 2012/10/04

For graceful stop (SIGUSR1), metaproxy will kill children processes.

Log when metaproxy is invoked in test mode (-t).

Log PID for each log message.

multi: combine both NSDs and multiple NSDs into one (diagnostics).

z3950_client: fixup multiple NSD's too. Like surrogate diagnostics,
a (backend=target) is appended for each diagnostic so that can be
determined the origin of error.

multi: hideerrors also in use for present response.

Solr example in zoom man page.

Fix typo in query_rewrite config example.

Log at least first non surrogate diagnostic. Instead of
"Z_Records_multipleNSD"

multi: Fix check for opt Records in present response. A SEGV could occur
if a target did not return records and no diagnostics.

--- 1.3.46 2012/09/24

Yet another fix for graceful stop.

--- 1.3.45 2012/09/12

sru_z3950: relay surrogate diagnostics.

--- 1.3.44 2012/09/10

zoom: Honor extraArgs, strip # in zurl.

multi: fix SEGV for scan. Reported by Rustam T. Usmanov.

zoom: url_recipe allow %{var[reg]} substitutions.
It's like ${var[reg]} but does URI component encoding as well.

--- 1.3.43 2012/08/22

RPM/Deb: require yazpp 1.3.2, because it fixes a missing close of
non-keepalive HTTP sessions.

http_file: allow zero size files (bug fix)

Fix zoom schema: auth_url is optional

--- 1.3.42 2012/08/20

zoom: fix un-init memory (could result in SEGV at session close)

frontend_net: handle X-Forwarded-For. This is stored in package.origin()
and may be used in filters as usual.

zoom: authentication via Torus lookup
Enabled by new configuration setting: auth_url . If this is defined,
the zoom module will contact Torus for auth/IP lookup and that will
define realm to be used in session.

--- 1.3.41 2012/08/10

virt_db: Fix database name - first character we removed by mistake.
Bug introduced in 1.3.40.

--- 1.3.40 2012/08/06

virt_db: Don't use "unix path" as database for Unix sockets.

--- 1.3.39 2012/08/02

z3950_client: Don't tamper with / in zurl - fixes problems
using Unix sockets for backends.

session_shared: fix integer overflow problem with hit count.

session_shared: avoid long usage of cached queries.

zoom: New database argument , torus_url to set URL of Torus
record to be fetched.

--- 1.3.38 2012/07/04

Fixes for 'metaproxy reload' for RPM/Debian packages. 

zoom: Allow rpn2cql conversion to be augmented with a properties file.
Element rpn2cql can be specified per-target for the zoom filter.

log: New category "line" which is a single-line log message with
most important parts of a HTTP/Z39.50 request/response.

--- 1.3.37 2012/06/01

frontend_net: add facility to report live statistics about response
times and current thread usage. The report is an XML document
and is triggered for a specific URL path. This is set by <stat-req>
in the configuration of frontend_net. By default this report is
disabled (same as empty value for <stat-req>).

Fix reload problem in init.d script for RPM/Debian. 
The '/etc/init.d/metaproxy reload' in some cases would stop but not
start metaproxy - effectively stopping the service.

Don't display start log message when config testing (-t).

zoom: avoid CCL message limit of 1K in ZOOM filter.

--- 1.3.36 2012/05/10

metaproxy init script reacts to reload which does graceful stop +
start and is used by logrorate script.

--- 1.3.35 2012/05/09

Fixes for Windows compilation.

Metaproxy daemon reacts to SIGUSR1 in which case it will leave
existing sessions running but terminate the monitor process that is
used in keepalive mode.

Change start log message to 'metaproxy start'. Was 'Metaproxy start'
before. Consistent with 'metaproxy stop' message.

zoom: document zoom's proxy_timeout

z3950_client: fixup addinfo for init response

virt_db: return other diagnostic if init is rejected. Diagnostic 236:
"Access to specified database denied" is returned, but only if init
response from backend does not carry diagnostics already.

multi: relays user info for first rejected target. The other-information
field for init response for first rejected target is in common init
response. This ensures that some backend init diagnostics are returned to
the frontend.

--- 1.3.34 2012/04/25

frontend_log: extend logging (when message is given in config).

--- 1.3.33 2012/04/25

zoom: Fix check for proxy. Use diagnostic 1074 for proxy failures.

--- 1.3.32 2012/04/24

sru_z3950 filter passes through incoming Z39.50 requests again. Was
not handled by mistake in Metaproxy versions 1.3.29, 1.3.30 and 1.3.31.

--- 1.3.31 2012/04/24

zoom: fixes for retry/proxy failover logic. More logging.

--- 1.3.30 2012/04/23

zoom: return addinfo="proxy failure" for proxy failures. This also
changes the scheme for dealing with proxies a bit.  zoom now always
do proxy check, even if there's no failover. Fortunately, that's not
very expensive.

zoom: Init rejected wo diagnostics maps to Bib-1:1014.
Bib-1 1014, "Init/AC: Authentication System error", seems pretty
generic. We don't know why the init would fail; IP, user, block IP, etc.
sru_z3950 filter maps this to SRU diagnostic 3: "Authentication error".

zoom: guess if invalid SRU response was an auth failure

session_shared: disable session retry by default . Can be enabled by
restart="true" in resultset section.

--- 1.3.29 2012/04/18

zoom: may read cf-proxy's config settings.
This reduces manual configuration of the content proxy server host.
The ZOOM module will use the old style session.proxyhost if "server"
is given (deprecated) and use the new style proxyhost/session if
"config_file" is in use.

frontend_net: remove incoming requests that can not be handled
Requests in queue for filter frontend_net are removed if client
closes connection for the session and request is not yet handled.

sru_z3950: serialize requests. This is to ensure that pipelined
HTTP requests are handled properly.

--- 1.3.28 2012/04/04

New class, wrbuf, that wraps YAZ' WRBUF.

--- 1.3.27 2012/03/30

Metaproxy daemon is now running as user "metaproxy". This user is
managed by package maintainer scripts. The user information is stored
in /etc/metaproxy/metaproxy.user . 

--- 1.3.26 2012/03/20

New filter, sort, that allows sorting of XML records via Z39.50
retrieval.

Filter record_transform: USEMarcon support. For example:
  <retrieval syntax="usmarc">
     <backend syntax="unimarc" name="F">
       <usemarcon stage1="/etc/usemarcon/uni2us/uni2us.ini"/>
     </backend>
  </retrieval>

Filter multi: empty route pattern uses route as default.
  That is
   <target route="z3950.indexdata.com">z3950.indexdata.com</route>
  may use the shorter notation
   <target route="z3950.indexdata.com"/>

Filter query_rewrite: use config path to locate XSLT.

Filter frontend_net:  log statistics.
If a custom message element in frontend_net configuration it makes
the frontend_net filter produce a log entry whenever an operation
is completed. The log is always written using yaz_log with the
custom message given, the package ID (session ID) , the time
the operation has been active (end-to-end) , the threads currently
active/total and the size of the request input/output queues.

query_rewrite: charset conversion of query terms.
This is an optional feature. Enabled by element <charset> in
configuration with attribute 'from' and 'to' that specifies
from/to encodings. The default 'from' encoding is UTF-8.

Filter record_transform: honor piggyback searches.

Filter zoom: re-connect when database is reused.
Re-connect is necessary if a connection is lost or a timeout occurs.
If not, we'll be seeing zero hits, when we shouldn't.

--- 1.3.25 2012/02/29

zoom: Change scheme for dealing with content proxy URLs. The module
now has its own common XSL transform that is enabled by record_xsl
attribute in the configuration. This XSL gets parameter cproxyhost
that holds the host for the content proxy session . The genearted-url
is created only if urlRecipe is enabled. In previous version default
value of urlRecipe was ${md-electronic-url}; it is now empty and
disabled by default. Also generated-url no longer includes the content
proxy host. Content proxying URLs is supposed to the handle in the record_xsl
stylesheet.

zoom: new setting timeout that specifies timeout for outgoing Z39.50/SRU
connections. Default value is 40 (seconds).

zoom: tune CCL to Z39.50 diagnostics mapping. Throw Bib-1: 108
"Malformed query" for syntax errors and related ones; throw
Bib-1: 3 "Unsupported search" for everything else. Details from
the CCL parser is provided as additional-info.

multi: new setting hideerrors that makes multi only relay diagnostics
to a client if all backends fail.

--- 1.3.24 2012/02/23

zoom: empty ccl_map field-mappings disables CCL map.

zoom: fix Explain search that could return error if session was
re-used.

--- 1.3.23 2012/02/10

zoom: returns Explain records for database IR-Explain---1. The
target profile records are converted to Explain records via XSLT.

session_shared: make error recovery configurable. Whether a search
is restarted on errors or not, is configurable by attribute "restart"
in element "resultset" in configuration.

session_shared: only relay init for first request. session_shared, for
each backend class, now only relays first init request (rather than all).
The module only needs to save init response info once. This avoids the
need to check for session max.

--- 1.3.22 2012/02/02

zoom: fix memory leaks.

session_shared: maximum number of sessons is configurable. Default
value is 100. Result-sets for backends without named result sets are
only re-used if databases is identical for a search. This is under the
assumption that performance may suffer for those backends when
changing the database for each search.

multi: combines diagnostics from all backends. All diagnostics from
backends are combined into multiple non-surrogate diagnostics; rather
than just one diagnostic from first backend.

--- 1.3.21 2011/12/27

zoom: relay realm to cproxy parameter file.

Configuration: Allow filter collection element inside route. This
makes it possible to include multiple filters at once.

zoom: nocproxy also disables urlRecipe.

--- 1.3.20 2011/12/21

zoom: return diagnostic if CQL sortby conv fails.  Diagnostic Bib-1 214
"Illegal sort relation" is returned. Gets translated to SRU diagnostic
90: "Unsupported direction value".

zoom: honor database argument nocproxy. This disables creating a content
connector session (for non-CF targets, usually) and also relays nocproxy
as database argument to a CF target.

--- 1.3.19 2011/12/16

zoom: Multiple proxy hosts may be given for proxy rich database 
parameter. List is comma separated.

http_file: decodes URI paths properly. Does not return 404: not found
if no prefix are matches. Instead packages are passed on.

--- 1.3.18 2011/12/08

zoom: content-{user,password,proxy} are passed on to content proxy
system and takes precedence over user,password,proxy .

sru_z3950: SRU extra argument x-log-enable=1 enables a search response
with a log element including log material from children filters. At
this point, only the zoom filter uses this log facility. It will
eventually be used by other filters as well. In particular it might be
useful for this feature to track all filters in used during a search.

zoom: for x-log-enable=1, APDUs sent by ZOOM C, records as received
and queries as they are manipulated are logged.

zoom:  extend addinfo with native diagnostics. Diagnostics as received
by ZOOM C are put into addinfo - including ZOOM, HTTP, SRU and Bib-1
diagnostics. This indicates both a backend diagnostic and the original
form.

zoom: default urlRecipe value is ${md-electronic-url}

zoom: target profile setting sruVersion is recognized.

--- 1.3.17 2011/11/17

zoom: log target profile record fetched (AKA Torus).

--- 1.3.16 2011/11/17

Change target profile parameter CfSubDb to CfSubDB.

--- 1.3.15 2011/11/12

zoom: bug fix: realm was relayed to CF targets by mistake (realm only
makes sense to the zoom module itself).

--- 1.3.14 2011/11/11

zoom: realm may be given as part of database.

--- 1.3.13 2011/10/26

Fix Origin class assigment method; was removd by mistake in 1.3.12.

--- 1.3.12 2011/10/26

zoom: database args x-name=value are passed through to backend database.

SRU filter: user may specify session ID that is passed to log entries
that follows. It is specified by using x-session-id in the SRU arguments.

zoom: fix null pointer reference which would occur for bad url parameter
inside "torus" or if url was not given.

--- 1.3.11 2011/09/09
Fix bug in filter session_shared where sessions would not expire
properly (session ttl). This in turn could make the target close the
connection before expected and session_shared would return diagnostic
2: system temporarily available.

--- 1.3.10 2011/09/09

zoom: new target profile setting: sortmap_field. If sortmap_field is given
the field is mapped to the value for the sortmap. Values not matching
sortmap_field are passed verbatim.
  
zoom: new target profile setting: sortStrategy. One of: "z3950", "type7",
"cql", "sru11" or "embed". The "embed" chooses type-7 or CQL sortby
depending on whether RPN or CQL is actually sent to the target.

--- 1.3.9 2011/08/25

zoom: urlRecipe result is stored in <pz:metadata type="generated-url">.

zoom: For content proxy authentication is stored in param name
"auth", instead of "authentication".

--- 1.3.8 2011/08/22

zoom: relay schema in SRU mode. Previously recordSchema was not affected
by elementSet.

--- 1.3.6 2011/08/22

zoom: new target profile element literalTransform that holds XSLT
(encoded as string) for target. Only if present and non-zero length it is
considered present. This takes precedence over transform.

Don't rely on trang anymore for Git checkout builds. Configuration in etc
will only be properly validated if trang is available. From now on only
relax NC files are bundled with the source dist.

Updates to check for Boost unit test (autoconf stuff). On MacOSX this
component was not detected when it should be.

--- 1.3.5 2011/08/12

z3950_client: mark non-surrogate diagnostics from backend.

zoom: a proxy may be specified for HTTP fetch of target profiles.

--- 1.3.4 2011/08/01

Honor piggyback. Makes some SRU targets behave that insist on
maximumRecords > 0, but also increases performance.

--- 1.3.3 2011/08/01

Fix dlpath in installed metaproxy.xml for RPM/Deb package. The
file was not update for libdir/metaproxy4 in version 1.3.2.

--- 1.3.2 2011/08/01

Change location of Metaproxy modules from libdir/metaproxy to
libdir/metaproxy4. Directory libdir/metaproxy is also owned by 
libmetaproxy3 and, thus, should not be used by libmetaproxy4.

New facility to dump APDUs from zoom filter. Enabled by 
<log apdu="true"/> in the zoom filter configuation.

zoom filter bug fix: SRU diagnostics received from backend was
not properly converted to Bib-1 diagnostics.

Package metaproxy depends on libmetaproxy4, same version.

--- 1.3.1 2011/07/28

zoom: fix a bug WRT passing authentication parameters to backends.

--- 1.3.0 2011/07/27

Fixes for windows Makefile.

--- 1.2.10 2011/07/25 

Change major version of metaproxy library from 3 to 4. This in turn
makes new package names for Debian and RPM.

--- 1.2.9 2011/06/27

zoom: enable marc-8 encoding by default for usmarc and opac (in pz2
transforn mode).

zoom: configurable element sets for record transforms.
    
zoom: the target profile based transform is specified by element_transform
in element torus of of the ZOOM filter configuration ; default value
is "pz2". Target profile based retrieval is specified by element_raw
in configuration. It will perform same steps, but omit the XSL transform.
Default value is "raw".

zoom: element set is omitted if not set in profile. But only if pz2
transform is in effect. Previously the default element set was to "F".

zoom: For non-CF targets database arguments are parsed. User may supply
db,user=myuser&password=mypass for non-CF targets. These values override
what's given the authentication from the target profile.

session_shared: fix reference to freed memory. Would occur if a search
response had non-surrogate diagnostics.

--- 1.2.8 2011/06/22

Route may be given for each port in frontend_net.

--- 1.2.7 2011/06/22

Documentation for zoom filter. Local target profiles may be specified.

Fixes for zoom filter.

--- 1.2.6 2011/06/15

First version with zoom filter.

--- 1.2.5 2011/05/06

Filter z3950_client may be configured to always send a close APDU
to backend target when connection/session is closed. This will only
happen if close APDU is not already sent. Enabled by configuration
for z3950_client (force_close).

Filter virt_db and multi: relay close APDU.

Filter virt_db and multi: relay init size parameters 
preferredMessageSize and maximumRecordSize.

Filter sru_z3950: increase init sz parameters from 1MB to 10 MB.

--- 1.2.4 2011/01/27

RPM package for Metaproxy works for both SLES11 and Centos 5.5.

metaproxy-config: exec_prefix, libdir, includedir. Use these variables
as determined by configure.

RPM: Release includes 'indexdata' name. Use indexdata in release name so
this package can be distinguished from other vendors.

--- 1.2.3 2010/10/04

Fix filter multi: relay idAuthentication parameters.

--- 1.2.2 2010/09/15

Add metaproxy-config for returning compiler flags, libraries.

--- 1.2.1 2010/08/18

Fix --with-boost=PREFIX .

--- 1.2.0 2010/07/09

session_shared: fix use of maintenance thread.

Introduce 'start' method for filters and routers. It gets called after
configure and after fork, but before processing. This changes API -
from libmetaproxy2 to libmetaproxy3.

--- 1.1.7 2010/06/30

session_shared: ensure backend session is closed if init rejected
is received.

z3950_client: fix NULL ptr reference that could occur if two clients
connected concurrently and if max-sockets was in effect.

--- 1.1.6 2010/06/21

Fix bug 3497 - Metaproxy unstable while stopping.

Fix bug 3495 - SEGV in SRU filter.

--- 1.1.5 2010/06/15

Filter multi throws diagnostic 'Present Out of Range' when
appropriate - rather than returning 0 records.

Filter virt_db: fix bad result reuse. Could happen if a result
was overriden and a backend did not supported named result sets.

--- 1.1.4 2010/05/11

Filter log: category access logs diagnostics even if searchStatus
or presentStatus is 'success'.

--- 1.1.3 2010/04/21

The SRU to Z39.50 filter does repeated Z39.50 present requests
to fetch all records. Needed when a Z39.50 server returns partial
results (due to message size limits).

--- 1.1.2 2010/03/18

Metaproxy now kills all child processes that are spawned by
modules (in case of fork, exec).

--- 1.1.1 2010/01/28

Debian package now installs /etc/metaproxy/metaproxy.xml which
includes all XML files /etc/metaproxy/filters-enabled .
The include facility uses YAZ' yaz_xml_include_simple (YAZ 4.0.1).

--- 1.1.0 2010/01/20

Package based on YAZ version 4 and YAZ++ 1.2.0. It now includes a
development package to facilitate 3rd party Metaproxy modules.

--- 1.0.23 2010/01/04

Filter virt_db: Close backend filter session when Init rejected is received
from it (in which case it's not really closed yet). This will ensure we don't
run out of resources such as FDs in this case.

sru_z3950 filter: Accept any database (including those not listed).

--- 1.0.22 2009/12/03

Prepare for 64-bit YAZ. yazproxy will still work with YAZ++ 1.1.4 or
later which means YAZ 3.0.47 or later.

--- 1.0.20 2009/11/19

For filter virt_db, the database is a glob pattern and the virtual
database sections are consulted in the order given.

--- 1.0.19 2009/07/08

For filter multi, the target (for routing) may be given as a glob-pattern.

More documentation for filters virt_db and multi.

Update schema to allow for no database in sru_z3950 filter.

--- 1.0.18 2009/06/30

Added limit filter to put sleep (penalty) for heavy use.

Filter frontend_net may be configured to limit the number of new connections
from same IP to some value (connect-max).

Fixed the load_balance filter.

--- 1.0.17 2009/06/16

Fix path for metaproxy executable for Debian init.d script.

--- 1.0.16 2009/06/10

SRU to Z39.50 filter honors x-username and x-password. If only
x-username is given that translates to open authentication (Z39.50v2). If
both x-username and x-password is present that translates to idPass
authentication (Z39.50v3).

New facility to change current working directory (-w).

Update to upstream skeleton of init.d script. Should fix bug #2619.

Filter session_shared now caches records (used to only cache connections
and result sets).

Filter session_shared now invalidates a Z39.50 session if a server
returns -1 hits. This facility was also part of yazproxy and gets around
a bug in Voyager-based Z39.50 servers.

--- 1.0.15 2008/11/18

Fixed reference counting bug in Z39.50 client module (could cause SEGV).

--- 1.0.14 2008/06/09

Fixed the value of SRU record schema in searchRetrieve response. It was set
to a fixed value of "dc" before.

Serialize identical SRU requests. This is useful if HTTP client software
fires identical requests against metaproxy.

Allow Z39.50 target to be specified for SRU requests by using SRU extra
parameter x-target. Allows SRU to contact arbitrary Z39.50 targets and
avoid static configuration. This facility is handled by the sru_z3950 module
and the z3950_client module.

Allow maximum number of sockets to be used for a Z39.50 client by the
use of SRU extra parameter x-max-sockets. This facility is handled by the
sru_z3950 module and the z3950_client module.

--- 1.0.13.1 2008/02/29

Simplified check for Boost libraries.

--- 1.0.13 2008/02/29

First Debian package.

The sru_z9350 filter now recognizes SRU parameter z-target as being
a ZURL of the form host/database . 

Mergetype may be specified for filter 'multi'.

--- 1.0.12 2007/09/19

Fixed problem in Makefile WRT library specifictions. This could produce
linker errors (when they should not happen).

Fixed bug #1341: MetaProxy returning different results. Problem was that
fix-up of record database did not normalize the database name.

Documentation updates for Windows compilation.

--- 1.0.11 2007/06/14

Fixed problem with logfile being truncated.

--- 1.0.10 2007/05/23

Fixed bug #1136: Access rights not enforced.

Extension for log module. The log category 'access' logs more details.
New category 'user-access' added which is simlar to 'access' but adds
the Z39.50 user as for all entries in a session.

Switched to GPL v2.

Added support for configurable default/force target/vhost for module Z39.50
client module.

--- 1.0.8 2007/01/25

Implemented filter, session_shared, which optimizes usage of Z39.50
sessions and result sets.

New filter, record_transform, which converts MARC/XML records.

New filter, sru_z3950, which converts SRU to Z39.50 packages.

New filter, load_balance, in development.

New filter, zeerex_xplain.

XML framework for config files started.

Master RelaxNG Compact schema's are found in xml/schema/*.rnc,
RelaxNG XML schemas and XML Schema's are generated from RNC syntax.
XML config files are checked against RNG and XML Schema's.

XSLT transformation framework added in xml/xslt/*.xsl, consisting mainly of 
LOC Marc21 stylesheets found at http://www.loc.gov/marcxml/xslt.
Added stylesheet explain2cqlpqftxt.xsl which transforms a standard SRU ZeeReX 
explain record to YAZ CQL-to-PQF text config file. 

--- 1.0.7 2006/11/07

Added 'timeout' setting for filter frontend_net which specifies the number
of seconds a session is idle before it is closed. Default timeout is
300 (5 minutes).

--- 1.0.6 2006/07/07

Database name in records returned set for virt_db/multi filters.

Filter session_shared now functional.

Log filter can be configured to write to a given file using 'filename'
element. Also information category can be specified with 'category'. If
filename is omitted, the log filter writes to stdout. See etc/config5.xml
for example.

--- 1.0.5 2006/05/16

Fixed compilation on Windows.

--- 1.0.4 2006/05/16

Added documentation for the hidenavailable option for the multi filter.

--- 1.0.3 2006/05/16

Fixed bug #573: Hide errors for individual servers. If the element
'hideunavailable' is given in the configuration, individual servers
being unavailable are hidden (unless all are unavailable). 

Fixed bug #574: Database names are recognised case-sensitively.

Fixed bug #567: Fix up database name in Name-Plus-Record.

Fixed bug #568: Update win/makefile for VS 2005.

Fixed bug #569: Some options throws unknown exception.

--- 1.0.2 2006/04/28

More information about virtual hosts. The 'etc' directory is part of the
distribution tar.

--- 1.0.1 2006/04/27

Build instructions for Windows. NMake makefile part of distribution tar.

--- 1.0.0 2006/04/24

More documentation.

Filters functional: auth_simple, backend_test, frontend_net, http_file,
 log, multi, query_rewrite, template, virt_db, z3950_client.

Filters in development: session_shared.

Pseudo-filters: template, dl

--- 0.9 2006/03/27