TODO
----

 General development directions

* More various databases support.
* More various transport protocols support.
* More various APIs. e.g write Java class with libudmsearch support.
* Support for huge databases with hundred or thousand millions documents.
* Make it more manageable, i.e. administration tools, etc.


  Below there are things that can be implemented somewhere in the future.
They are given in no particular order. If you want to change the order of
their development, please ask on general@mnogosearch.org.


Search quality and results presentation
---------------------------------------
* Click rank
* Administrator defined dynamic site priority:
	- approved sites which should be displayed in the top of results;
	- disapproved sites (e.g. for abuse) which should not be displayed.
* Take in account words context: <b>, <font size="xx">, <big> and so on.
* Optional automatic URL limit by SERVER_NAME variable.
* "Exclude" limits, for example "to search though everything except
  given site": ue=http://esite/
* Fuzzy search for accent letters, for example Cyrillic "io" and "ie".
* Regexp search
* Rank URLs with long pathnames lower than direct hits on let's say a domain 
name with no directory path.
* Query operators:
  +   (word required)
  -   (word excluded)
  NEAR

Administration and Search Analysis
----------------------------------
* Make administration completely done via web browser admin.
* Admin grants others access to all or limited set of features,front ends, etc.
* Search status: recent queries per second, per collection, etc.
* Search log report: a monthly, weekly or daily snapshot of search activity.
* For each time period, the report shows the top 100 queries, top no match
searches, traffic by day and hour, etc. 
* Crawl status - documents served, crawling rate and errors.
* Crawl reporting - provide interactive drill-down through directories to see
  the status of each page
* A list" which displays all the crawled URLs and status 

Indexing related stuff
----------------------
* Detect clones on site level. Currently it is implemented on page level
only. The idea is to detect that site being indexed is a mirror of another
site without having to index all pages but after indexing several pages only.
* SPAM clearance.
* Fix that indexer becomes slow when ServerTable is big. This is because
of full consecutive examination. Make in-memory cache for ServerTable part.
* FTP digest ls-lR.gz support. For example,ftp://ftp.chg.ru/ls-lR.gz
* Exclude auto-increment mode for 'url' table. We have to use CRC32 mode
  since it is much faster for indexing and probably would take less space.
* Adaptive re-crawling, based on change interval
* Form-based authentication
* NTLM 1 and NTLM 2 based authentication
* Real-time reporting of indexing progress
* Have a look into "Feed Protocol Developer Guide"
http://code.google.com/apis/searchappliance/documentation/46/feedsguide.html


Charset related stuff
---------------------
* Remove "ForceIISCharset1251 yes/no"command. Replace it with 
enhanced "CharsetByServer <charset> <regexp> [<regexp>...]" 
command.
* State-full character sets support: UTF-7, Asian ISO-2022-XX
and others. They will not be used as a LocalCharset because
of much space, however indexer should be able to index them,
as well as search front-end should be able to use them as
a BrowserCharset.


Misc
----
* Smart search results cache cleaning after re-indexing.
* Make it possible to set table names in indexer.conf and search.htm
* There was a discussion about word separators back in January; see 
http://www.mail-archive.com/udmsearch%40web.izhcom.ru/msg00200.html.
* Learn about Dublin core. A simple set of standard meta-data for web pages.
  http://www.searchtools.com/related/metadata.html#dc
* Add curl library support.
* Rewrite mirroring functions. Make it possible to optionally store whole 
document, not only MaxDocSize.


Portability and code quality
----------------------------
Remove warnings on various platforms. Currently it is built without
warnings on Linux and FreeBSD with these CFLAGS:

-Wall 
-Wconversion 
-Wshadow  
-Wpointer-arith 
-Wcast-qual 
-Wcast-align 
-Wwrite-strings  
-Waggregate-return  
-Wstrict-prototypes  
-Wmissing-prototypes 
-Wmissing-declarations 
-Wredundant-decls 
-Wnested-externs 
-Wlong-long 
-Winline

However some other platform compilers do produce warnings.
For example, mixed signed/unsigned chars on NetBSD Alpha compiler. 
Please report those warnings to general@mnogosearch.org!


Documentation
-------------
* Constantly improve it!
* PDF version.



Things that will most likely be done in 3.3 (in no particular order)
--------------------------------------------------------------------

1. Better relevancy
   - DONE: separate word enumeration for each section
     and add number_of_words_in_this_section into coord, i.e. 
     "section + position_inside_section + number_of_words_in_this_section"
     instead of
     "section + position_inside_document"
     Note, number_of_words_in_this_section doesn't need to be exact,
     it can be approximate, to safe space.
   - DONE: Use number_of_words_in_this_section in relevancy formula,
     i.e. be close to the classic TF*IDF rank algorithm.
   - DONE: better "body" capacity (get rid of "64K words in body" limit)
     and more sections (reg rid of "256 sections" limit).
     It can be done using dynamic encoding, e.g.
     128 sections with 256*256*256 words plus
     128*256 sections with 256*256 words.
   - DONE: Change MinCordFactor and MaxCoordFactor to work per-section,
     not per document.
   - DONE: Move processing of DateFactor and RelevancyFactor to score.c
   - DONE: Move processing of UserScore/UserScoreFactor to score.c
   - NumSections auto-detection from wf
     and from secno specifiers, e.g. "body:a b c".
   - Find the best combination of the default values for all score commands.
     (romip?)
   - DONE: Link all score commands in the manual,
     add a new section "commands affecting score".

2. Cluster
   - Res2XML (built-in XML template)
   - DONE: XML2Res (to parse built-in XML template)
   - DONE: DBAddr http://hostname/path/to/searchxml.cgi
   - DONE: Make it possible to run search.cgi as a inetd/xinetd service
   - Make it possible to run search.cgi as a HTTP server
   - Site enumerating without having to talk to each cluster node
     (e.g. crc48 or crc56, with direct encoding for short names)
   - Clone detection at search time
   - Configurable distribution type: by site_id, by seed, etc.
   - Add "did you mean?" support into cluster.

3. Extend SQL drivers to use prepared statements in sql.c
   - DONE: Prepare/Bind/Exec for MySQL (using PS API in 4.1 and later)
   - DONE: Prepare/Bind/Exec for PgSQL
   - DONE: Prepare/Bind/Exec for Interbase
   - Prepare/Bind/Exec for SQLite3
   - Prepare/Bind/Exec for CTLib
   - Use pseudo-prepared statenents with substituting HEX/Escape
     notation for the databases which do not support prepared statements
   - Modify sql.c to use Prepare/Bind/Exec for all databases


4. DBType=myinnodb (and maybe for other handler types)
   - scripts MySQL with Engine=InnoDB
   - true transactional code in sql.c, instead of LOCK TABLE.
   - instead of separate DBType, it can perhaps use auto-detection
     of engines

5. More concurrent "indexer" safety
   - test with concurrent indexers with all databases
   - set isolation levels or lock tables when running
     "indexer -Eblob" to avoid concurrent indexers update
     tables (especially table "bdicti")
     which will give an inconsistent result in table "bdict".
     
     Oracle: 
             SELECT FOR UPDATE
             LOCK TABLE t1 IN {ROW SHARE|SHARE|EXCLUSIVE} MODE
             SET TRANSACTION
     
     DB2:    
             SELECT .. FOR {READ ONLY|FETCH ONLY|UPDATE [OF column [, column]*]}
             LOCK TABLE t1 IN {SHARE|EXCLUSIVE} MODE
             SET TRANSACTION
     
     PostgreSQL:
             SELECT FOR UPDATE
             LOCK [ TABLE ] name [, ...] [ IN lockmode MODE ] [ NOWAIT ]
               lockmode ::= ACCESS SHARE | ROW SHARE | ROW EXCLUSIVE |
                           | SHARE UPDATE EXCLUSIVE | SHARE
                           | SHARE ROW EXCLUSIVE | EXCLUSIVE | ACCESS EXCLUSIVE
             SET TRANSACTION ISOLATION LEVEL
     
     MSSQL:
             SET TRANSACTION ISOLATION LEVEL
             Hints in SELECT statement: UPDLOCK,  XLOCK, TABLOC
             SELECT...table_name (TABLOCK)  - share mode 
             SELECT...table_name (TABLOCK REPEATABLEREAD) - exclusive mode
             SELECT...table_name (TABLOCKX) - lock until the end of trans
             
             SELECT FOR UPDATE allowed only for DECLARE CURSOR.
             An exclusive lock can be placed on a SQL Server table with
             the SELECT..table_name (TABLOCKX) statement.
             This statement requests an exclusive lock on a table.
             It is used to prevent others from reading or updating
             the table and is held until the end of the command or transaction.
             It is similar in function to the Oracle
             LOCK TABLE..IN EXCLUSIVE MODE statement.
             
     Sybase:
             SELECT FOR UPDATE
             LOCK TABLE table-name IN { SHARE | EXCLUSIVE } MODE
             sa_locks - Displays all locks in the database.
             
             FOR UPDATE can not be used in a SELECT which is not part of the
             declaration of a cursor or which is not inside a stored procedure.
     
     Mimer:
             SELECT FOR UPDATE - is not allowed for a read-only cursor
             
             SET TRANSACTION ISOLATION LEVEL

6. More multi-thread safety
   - more tests with multiple threads
   - DONE: better robot.txt locking
     Currently all threads are waiting for a single thread
     to fetch robots.txt file, independently of host name.
     It can be done by implementing of a shared array
     of "robots.txt currently being fetched".

7. DBMode=blob improvements
   - RENAME TABLE for more databases
     MSSQL, Sybase:
       [EXEC] sp_rename t1,t2
       SELECT * INTO t1 FROM t2 WHERE 1=0; - copy structure (without indexes)
     Oracle:
       CREATE TABLE t2 AS SELECT field FROM t1 WHERE 1=0; -- does not copy idx
       ALTER TABLE t1 RENAME TO t2;
       RENAME t1 TO t2
     PostgreSQL:
       CREATE TABLE t2 (LIKE t1);  -- does not copy indexes

       /* Statring with 8.3: */
       CREATE TABLE t2 (LIKE t1 INCLUDING INDEXES); -- copy indexes

       ATLER TABLE t1 RENAME TO t2;
     DB2:
       CREATE TABLE t1 LIKE t2; -- does not copy indexes
       RENAME TABLE t1 TO t2
     SQLite:
       CREATE TABLE t2 (LIKE t1);  -- does not copy indexes
       
     Mimer, Interbase: do not seem to have table rename.
   - Check a possibility to use VIEWs for those databases
     not supporting RENAME. Or use fast index creation date
     to choose which table to use for search.
   - Partial incremental "indexer -Eblob"
   - Configurable choice to run partial or full
     "indexer -Eblob", depending on amount
     of new data collected.
   - Optionally put information from "url" into "bdict" table ???
   - Optionally put information from "urlinfo" ???
   - DONE: Add HIGH_PRIORITY into this query:
       SELECT rec_id, site_id, pop_rank, last_mod_time
       FROM url WHERE rec_id IN (...)
       ORDER BY rec_id
   - Check Oracle's "DROP TABLE t1 PURGE"
   - DONE: DBMode=blob for sqlite3?
   - DONE: DBMode=blob for Interbase 
   - DONE: DBMode=rawblob and a mixed blob+rawblob mode (live updates).

8. Database consistency check (and maybe repair) tools,
   - e.g. report (and/or remove) all bdicti/urlinfo records
   which don't have corresponding url records.
   - don't put lost URL records during "indexer -Eblob" run,
   generate warnings if found lost records.

9. Source code and packaging improvements
   (see some more info added by Svoj in TODO.ru)
   - more separate files (e.g. break utils.c)
   - dynamically loadable database modules
   - build statically linked (platform independent) and
     dynamically linked (distribution-specific) RPMs,
     FreeBSD packages and so on.
     Gentoo: http://www.mnogosearch.org/board/message.php?id=17992
     Solaris SPARC: http://www.mnogosearch.org/board/message.php?id=17955

10. mnoGoSearch benchmark suite
   - tiny (~1000 documents)
   - medium (~10000 documents
   - huge (~1000000 documents)
   - with 1,2,3,5,10,20 simultaneous users
   - cluster with huge databases on several machines

11. Windows version
   - Check if it's possible to use CHM decompiler as a parser on Windows:
     http://www.keyworks.net/keytools.htm
   - Unix compatible indexer.conf
       - UdmEnvWrite()  (can be done by a Unix developer)
       - GUI for all missing important commands
       - GUI for "extra" (i.e. not so important) commands 
   - package prepared plugins, for example for Ispell or external parsers,
     to reduce manual actions required from user.
   - build MySQL fulltext parser plug-in

12. API improvements (PHP, ASP, Perl) ???
   - DONE: Stabilize and document C API.
   - DONE: Put module code into the main tree,
     add --with-php, --with-perl, and so on, options to configure.
   - Add tests with Perl and PHP modules - find a way to cover 
     Perl and PHP modules by "msearch-test" tests.
   - Add "PHP via COM" front-end example (Windows)
   - From Yannick LE NY
     http://pecl.php.net/package/mnogosearch, there is an update.
     This update correct:
     - Initial PECL release
     - fix compiler warnings and errors on 64bit platform
     - #34705 (php bugs), disable udm_clear_search_limits when used with mnogosearch 3.2+
       *this is a required backward compatibility break*


13. Better internationalization (from Yannick LE NY)
     http://www.mnogosearch.org/board/message.php?id=17948
   - add i18n templates 
   - use gettext to i18n the indexer binary help and messages.
   - Korean frequency dictionaries ???
     See this thread:
     http://www.mnogosearch.org/board/message.php?id=17984
     http://www.mnogosearch.org/board/message.php?id=18219
   - Character set for FTP requests, replies, file listings.
     http://www.mnogosearch.org/board/message.php?id=17992

14. Documentation
   - Full step-by-step instructions how to install and configure mnoGoSearch

15. Support for Internationalized domain name:
    http://en.wikipedia.org/wiki/Internationalized_domain_name
    Maybe using GNU IDN Library: Libidn http://www.gnu.org/software/libidn/

16. Misc:
   - Single char problem: <font>W</font>ord
     http://www.mnogosearch.org/board/message.php?id=17998
   - Add "indexer -Esql -e"SELECT xxx FROM"
   - List all DB software tested with, including versions.
   - Get rid of disk based search result cache,
   - search result cache for all SQL databases,
   - document new search result cache
   - Write/read cached copies in chunks, for faster excerpts
   - Learn about MySQL's "LOAD INDEX INTO CACHE"
   - Add FOREACH loop

For the near 3.3.x releases:
---------------------------

- More documentation on "QCache yes" and "search in found"
  This page is not up to date:
  http://www.mnogosearch.org/doc33/msearch-srcache.html

- Use prepared statements at search time as much as possible
  to avoid problems with quote and reverse solidus signs
  treated incorrectly (whic is possible when running with Asian 
  character sets).

- Document "Enabling SQL indexes" -
  "Repair with keycache" vs "Repair with sort".
  Or better fix not to use "disable keys"!
  Document DisableKeys=yes ?

- max_allowed_packet problem. Make indexer work with a smaller
  max_allowed_packet.

- Add new indexer.conf command "Suggest yes",
  to automatically create word statistics when "indexer -Eblob" is run.

- Add new manual sectons: using indexer as a spider
  to collect data to the database.

- Add new HTML manual files into the distribution.

- Use UdmStopTimer()

- Check feature requests

- When parsing a non-supported DBAddr,
  print "XXX support is not compiled"
  instead of "Wrong HTDBAddr" or "Wrong DBAddr".

- Document the new style of clones.
  Remove $(CL) variable, add new style code into search.htm.
  Document $(nclones) variable.

- Document -D (work with the D'th database only).

- Document indexer and search.cgi command line options

- Document RelevancyFactor.

- Document this feature: Make it possible for external parsers to return
converted content together with headers like Content-Type, Title and so on.

- Document ServerTable faq:
  http://www.mnogosearch.org/board/message.php?id=16226

- Put section names and secno into "bdict", to avoid
  writing section names into search.htm
  
- Update Pecl module at
  http://pecl.php.net/package/mnogosearch
  
- Add PHP module documentation into mnoGoSearch manual

- Fix CachedCopy in PHP module

- $(ndocs) doesn't work with cluster
  http://www.mnogosearch.org/bugs/index.php?id=1646
  
- Make sure "tmplt" variable removed from the  manual, or make it work.

- Document PostgreSQL + unixODBC

- Highlight color #FFFFCA

- Document "indexing performance tips": MySQL log and binary log,
  syslog, HoldBadHrefs, etc.

- FIX this problem:
==26951== Thread 79:
==26951== Invalid write of size 1
==26951==    at 0x4006181: strncat (mc_replace_strmem.c:218)
==26951==    by 0x405D766: UdmHTMLParseTag (parsehtml.c:870)
==26951==    by 0x405E407: UdmHTMLParse (parsehtml.c:1119)
==26951==    by 0x4019E1D: UdmDocParseContent (indexer.c:1412)
==26951==    by 0x401CE11: UdmIndexNextURL (indexer.c:2107)
==26951==    by 0x804C18C: thread_main (main.c:887)
==26951==    by 0x7153DA: start_thread (in /lib/libpthread-2.5.so)
==26951==    by 0x66F06D: clone (in /lib/libc-2.5.so)
==26951==  Address 0x73A4A88 is 0 bytes after a block of size 128 alloc'd
==26951==    at 0x4005400: malloc (vg_replace_malloc.c:149)
==26951==    by 0x405CDA4: UdmHTMLParseTag (parsehtml.c:761)
==26951==    by 0x405E407: UdmHTMLParse (parsehtml.c:1119)
==26951==    by 0x4019E1D: UdmDocParseContent (indexer.c:1412)
==26951==    by 0x401CE11: UdmIndexNextURL (indexer.c:2107)
==26951==    by 0x804C18C: thread_main (main.c:887)
==26951==    by 0x7153DA: start_thread (in /lib/libpthread-2.5.so)
==26951==    by 0x66F06D: clone (in /lib/libc-2.5.so)

- Add re-entrant gethostbyname() functions for non-Linux
  platforms. See HOWTO-RESOLVE.

- HEX literal in Firebird
  http://www.firebirdsql.org/rlsnotesh/rlsnotes25.html#rnfb25-dml-hex