ESTRAIER(3)                     Hyper Estraier                     ESTRAIER(3)



NAME
       estraier.h - the core API of Hyper Estraier


SYNOPSIS
       #include <estraier.h>
       #include <cabin.h>
       #include <stdlib.h>


API FOR DOCUMENT
       The API for documents aims to handle documents which were registered
       into the index.

       The type of the structure `ESTDOC' is for abstraction of a document.  A
       document is composed of some attributes and some text sentences.  No
       entity of `ESTDOC' is accessed directly, but it is accessed by the
       pointer.  The term of document object means the pointer and its
       referent.  A document object is created by the function `est_doc_new'
       and destroyed by `est_doc_delete'.  Every created document object
       should be destroyed.

       Target documents of search are to be registered in the database
       beforehand.  The ID is assigned to each registered document.  When
       search, they can be retrieved from the database by their ID.  The
       encoding of attributes and text sentences should be UTF-8.

       The function `est_doc_new' is used in order to create a document
       object.

       ESTDOC *est_doc_new(void);
              The return value is an object of a document.

       The function `est_doc_new_from_draft' is used in order to create a
       document object made from draft data.

       ESTDOC *est_doc_new_from_draft(const char *draft);
              `draft' specifies a string of draft data.  The return value is
              an object of a document.

       The function `est_doc_delete' is used in order to destroy a document
       object.

       void est_doc_delete(ESTDOC *doc);
              `doc' specifies a document object.

       The function `est_doc_add_attr' is used in order to add an attribute to
       a document object.

       void est_doc_add_attr(ESTDOC *doc, const char *name, const char
       *value);
              `doc' specifies a document object.  `name' specifies the name of
              an attribute.  `value' specifies the value of the attribute.  If
              it is `NULL', the attribute is removed.

       The function `est_doc_add_text' is used in order to add a sentence of
       text to a document object.

       void est_doc_add_text(ESTDOC *doc, const char *text);
              `doc' specifies a document object.  `text' specifies a sentence
              of text.

       The function `est_doc_add_hidden_text' is used in order to add a hidden
       sentence to a document object.

       void est_doc_add_hidden_text(ESTDOC *doc, const char *text);
              `doc' specifies a document object.  `text' specifies a hidden
              sentence.

       The function `est_doc_set_keywords' is used in order to attach keywords
       to a document object.

       void est_doc_set_keywords(ESTDOC *doc, CBMAP *kwords);
              `doc' specifies a document object.  `kwords' specifies a map
              object of keywords.  Keys of the map should be keywords of the
              document and values should be their scores in decimal string.
              The map object is copied internally.

       The function `est_doc_set_score' is used in order to set the substitute
       score of a document object.

       void est_doc_set_score(ESTDOC *doc, int score);
              `doc' specifies a document object.  `score' specifies the
              substitute score.  It it is negative, the substitute score
              setting is nullified.

       The function `est_doc_id' is used in order to get the ID number of a
       document object.

       int est_doc_id(ESTDOC *doc);
              `doc' specifies a document object.  The return value is the ID
              number of the document object.  If the object has not been
              registered, -1 is returned.

       The function `est_doc_attr_names' is used in order to get a list of
       attribute names of a document object.

       CBLIST *est_doc_attr_names(ESTDOC *doc);
              `doc' specifies a document object.  The return value is a new
              list object of attribute names of the document object.  Because
              the object of the return value is opened with the function
              `cblistopen', it should be closed with the function
              `cblistclose' if it is no longer in use.

       The function `est_doc_attr' is used in order to get the value of an
       attribute of a document object.

       const char *est_doc_attr(ESTDOC *doc, const char *name);
              `doc' specifies a document object.  `name' specifies the name of
              an attribute.  The return value is the value of the attribute or
              `NULL' if it does not exist.  The life duration of the returned
              string is synchronous with the one of the document object.

       The function `est_doc_texts' is used in order to get a list of
       sentences of the text of a document object.

       const CBLIST *est_doc_texts(ESTDOC *doc);
              `doc' specifies a document object.  The return value is a list
              object of sentences of the text of the document object.  The
              life duration of the returned object is synchronous with the one
              of the document object.

       The function `est_doc_cat_texts' is used in order to concatenate
       sentences of the text of a document object.

       char *est_doc_cat_texts(ESTDOC *doc);
              `doc' specifies a document object.  The return value is
              concatenated sentences of the document object.  Because the
              region of the return value is allocated with the `malloc' call,
              it should be released with the `free' call if it is no longer in
              use.

       The function `est_doc_keywords' is used in order to get attached
       keywords of a document object.

       CBMAP *est_doc_keywords(ESTDOC *doc);
              `doc' specifies a document object.  The return value is a map
              object of keywords and their scores in decimal string.  If no
              keyword is attached, `NULL' is returned.  The life duration of
              the returned object is synchronous with the one of the document
              object.

       The function `est_doc_dump_draft' is used in order to dump draft data
       of a document object.

       char *est_doc_dump_draft(ESTDOC *doc);
              `doc' specifies a document object.  The return value is draft
              data of the document object.  Because the region of the return
              value is allocated with the `malloc' call, it should be released
              with the `free' call if it is no longer in use.

       The function `est_doc_make_snippet' is used in order to make a snippet
       of the body text of a document object.

       char *est_doc_make_snippet(ESTDOC *doc, const CBLIST *words, int
       wwidth, int hwidth, int awidth);
              `doc' specifies a document object.  `word' specifies a list
              object of words to be highlight.  `wwidth' specifies whole width
              of the result.  `hwidth' specifies width of strings picked up
              from the beginning of the text.  `awidth' specifies width of
              strings picked up around each highlighted word.  The return
              value is a snippet string of the body text of the document
              object.  There are tab separated values.  Each line is a string
              to be shown.  Though most lines have only one field, some lines
              have two fields.  If the second field exists, the first field is
              to be shown with highlighted, and the second field means its
              normalized form.  Because the region of the return value is
              allocated with the `malloc' call, it should be released with the
              `free' call if it is no longer in use.


API FOR SEARCH CONDITIONS
       The API for search conditions aims to specify search conditions given
       to the index.

       The type of the structure `ESTCOND' is for abstraction of search
       conditions.  A unit of search conditions is composed of one search
       phrase, some attribute expressions, and one order expression.  No
       entity of `ESTCOND' is accessed directly, but it is accessed by the
       pointer.  The term of condition object means the pointer and its
       referent.  A condition object is created by the function `est_cond_new'
       and destroyed by `est_cond_delete'.  Every created condition object
       should be destroyed.

       Condition objects are used as a parameter to search for documents
       registered in the database so that a list of IDs of corresponding
       documents are returned.  See the manual for the formats of expressions.
       The encoding of conditional expressions should be UTF-8.

       The function `est_cond_new' is used in order to create a condition
       object.

       ESTCOND *est_cond_new(void);
              The return value is an object of search conditions.

       The function `est_cond_delete' is used in order to destroy a condition
       object.

       void est_cond_delete(ESTCOND *cond);
              `cond' specifies a condition object.

       The function `est_cond_set_phrase' is used in order to set the search
       phrase to a condition object.

       void est_cond_set_phrase(ESTCOND *cond, const char *phrase);
              `cond' specifies a condition object.  `phrase' specifies a
              search phrase.

       The function `est_cond_add_attr' is used in order to add an expression
       for an attribute to a condition object.

       void est_cond_add_attr(ESTCOND *cond, const char *expr);
              `cond' specifies a condition object.  `expr' specifies an
              expression for an attribute.

       The function `est_cond_set_order' is used in order to set the order of
       a condition object.

       void est_cond_set_order(ESTCOND *cond, const char *expr);
              `cond' specifies a condition object.  `expr' specifies an
              expression for the order.  By default, the order is by score
              descending.

       The function `est_cond_set_max' is used in order to set the maximum
       number of retrieval of a condition object.

       void est_cond_set_max(ESTCOND *cond, int max);
              `cond' specifies a condition object.  `max' specifies the
              maximum number of retrieval.  By default, the number of
              retrieval is not limited.

       The function `est_cond_set_skip' is used in order to set the number of
       skipped documents of a condition object.

       void est_cond_set_skip(ESTCOND *cond, int skip);
              `cond' specifies a condition object.  `skip' specifies the
              number of documents to be skipped in the search result.

       The function `est_cond_set_options' is used in order to set options of
       retrieval of a condition object.

       void est_cond_set_options(ESTCOND *cond, int options);
              `cond' specifies a condition object.  `options' specifies
              options: `ESTCONDSURE' specifies that it checks every N-gram
              key, `ESTCONDUSUAL', which is the default, specifies that it
              checks N-gram keys with skipping one key, `ESTCONDFAST' skips
              two keys, `ESTCONDAGITO' skips three keys, `ESTCONDNOIDF'
              specifies not to perform TF-IDF tuning, `ESTCONDSIMPLE'
              specifies to use simplified phrase, `ESTCONDROUGH' specifies to
              use rustic phrase, `ESTCONDUNION' specifies to use union phrase,
              `ESTCONDISECT' specifies to use intersection phrase,
              `ESTCONDSCFB' specifies to feed back scores (only for
              debugging).  Each option can be specified at the same time by
              bitwise or.  If keys are skipped, though search speed is
              improved, the relevance ratio grows less.

       The function `est_cond_set_auxiliary' is used in order to set
       permission to adopt result of the auxiliary index.

       void est_cond_set_auxiliary(ESTCOND *cond, int min);
              `cond' specifies a condition object.  `min' specifies the
              minimum hits to adopt result of the auxiliary index.  If it is
              not more than 0, the auxiliary index is not used.  By default,
              it is 32.

       The function `est_cond_set_eclipse' is used in order to set the lower
       limit of similarity eclipse.

       void est_cond_set_eclipse(ESTCOND *cond, double limit);
              `cond' specifies a condition object.  `limit' specifies the
              lower limit of similarity for documents to be eclipsed.
              Similarity is between 0.0 and 1.0.  If the limit is added by
              `ESTECLSIMURL', similarity is weighted by URL.  If the limit is
              `ESTECLSERV', similarity is ignored and documents in the same
              server are eclipsed.  If the limit is `ESTECLDIR', similarity is
              ignored and documents in the same directory are eclipsed.  If
              the limit is `ESTECLFILE', similarity is ignored and documents
              of the same file are eclipsed.

       The function `est_cond_set_distinct' is used in order to set the
       attribute distinction filter.

       void est_cond_set_distinct(ESTCOND *cond, const char *name);
              `cond' specifies a condition object.  `name' specifies the name
              of an attribute to be distinct.  If this filter is set,
              candidates which have same value of the attribute is omitted.

       The function `est_set_cond_mask' is used in order to set the mask of
       targets of meta search.

       void est_cond_set_mask(ESTCOND *cond, int mask);
              `cond' specifies a condition object.  `mask' specifies a masking
              number.  1 means the first target, 2 means the second target, 4
              means the third target, and power values of 2 and their
              summation compose the mask.


API FOR DATABASE
       The API for database aims to handle the database of the index.

       The type of the structure `ESTDB' is for abstraction of access methods
       to database.  A database has inverted index, document data, and meta
       data.  One of writer or reader is selected when the connection is
       established.  No entity of `ESTDB' is accessed directly, but it is
       accessed by the pointer.  The term of database object means the pointer
       and its referent.  A database object is created by the function
       `est_db_open' and destroyed by `est_db_close'.  Every created database
       object should be destroyed.

       Errors with some operations are informed to by the function
       `est_db_error'.  The meaning of each error code can be gotten as a
       string by the function `est_err_msg'.

       The following constant are defined for error codes.

       The function `est_err_msg' is used in order to get the string of an
       error code.

       const char *est_err_msg(int ecode);
              `ecode' specifies an error code.  The return value is the string
              of the error code.

       The function `est_db_open' is used in order to open a database.

       ESTDB *est_db_open(const char *name, int omode, int *ecp);
              `name' specifies the name of a database directory.  `omode'
              specifies open modes: `ESTDBWRITER' as a writer, `ESTDBREADER'
              as a reader.  If the mode is `ESTDBWRITER', the following may be
              added by bitwise or: `ESTDBCREAT', which means it creates a new
              database if not exist, `ESTDBTRUNC', which means it creates a
              new database regardless if one exists.  Both of `ESTDBREADER'
              and  `ESTDBWRITER' can be added to by bitwise or: `ESTDBNOLCK',
              which means it opens a database file without file locking, or
              `ESTDBLCKNB', which means locking is performed without blocking.
              If `ESTDBNOLCK' is used, the application is responsible for
              exclusion control.  `ESTDBCREAT' can be added to by bitwise or:
              `ESTDBPERFNG', which means N-gram analysis is performed against
              European text also, `ESTDBCHRCAT', which means character
              category analysis is performed instead of N-gram analysis,
              `ESTDBSMALL', which means the index is tuned to register less
              than 50000 documents, `ESTDBLARGE', which means the index is
              tuned to register more than 300000 documents, `ESTDBHUGE', which
              means the index is tuned to register more than 1000000
              documents, `ESTDBHUGE2', which means the index is tuned to
              register more than 5000000 documents, `ESTDBHUGE3', which means
              the index is tuned to register more than 10000000 documents,
              `ESTDBSCVOID', which means scores are stored as void,
              `ESTDBSCINT', which means scores are stored as 32-bit integer,
              `ESTDBSCASIS', which means scores are stored as-is and marked
              not to be tuned when search.  `ecp' specifies the pointer to a
              variable to which the error code is assigned.  The return value
              is a database object of the database or `NULL' if failure.

       The function `est_db_close' is used in order to close a database.

       int est_db_close(ESTDB *db, int *ecp);
              `db' specifies a database object.  `ecp' specifies the pointer
              to a variable to which the error code is assigned.  The return
              value is true if success, else it is false.

       The function `est_db_error' is used in order to get the last happened
       error code of a database.

       int est_db_error(ESTDB *db);
              `db' specifies a database object.  The return value is the last
              happened error code of the database.

       The function `est_db_fatal' is used in order to check whether a
       database has a fatal error.

       int est_db_fatal(ESTDB *db);
              `db' specifies a database object.  The return value is true if
              the database has fatal error, else it is false.

       The function `est_db_add_attr_index' is used in order to add an index
       for narrowing or sorting with document attributes.

       int est_db_add_attr_index(ESTDB *db, const char *name, int type);
              `db' specifies a database object connected as a writer.  `name'
              specifies the name of an attribute.  `type' specifies the data
              type of attribute index; `ESTIDXATTRSEQ' for multipurpose
              sequencial access method, `ESTIDXATTRSTR' for narrowing with
              attributes as strings, `ESTIDXATTRNUM' for narrowing with
              attributes as numbers.  The return value is true if success,
              else it is false.  Note that this function should be called
              before the first document is registered.

       The function `est_db_flush' is used in order to flush index words in
       the cache of a database.

       int est_db_flush(ESTDB *db, int max);
              `db' specifies a database object connected as a writer.  `max'
              specifies the maximum number of words to be flushed.  If it not
              more than zero, all words are flushed.  The return value is true
              if success, else it is false.

       The function `est_db_sync' is used in order to synchronize updating
       contents of a database.

       int est_db_sync(ESTDB *db);
              `db' specifies a database object connected as a writer.  The
              return value is true if success, else it is false.

       The function `est_db_optimize' is used in order to optimize a database.

       int est_db_optimize(ESTDB *db, int options);
              `db' specifies a database object connected as a writer.
              `options' specifies options: `ESTOPTNOPURGE' to omit purging
              dispensable region of deleted documents, `ESTOPTNODBOPT' to omit
              optimization of the database files.  The three can be specified
              at the same time by bitwise or.  The return value is true if
              success, else it is false.

       The function `est_db_merge' is used in order to merge another database.

       int est_db_merge(ESTDB *db, const char *name, int options);
              `db' specifies a database object connected as a writer.  `name'
              specifies the name of another database directory.  `options'
              specifies options: `ESTMGCLEAN' to clean up dispensable regions
              of the deleted document.  The return value is true if success,
              else it is false.  Creation options of the two databases should
              be same entirely.  ID numbers of imported documents are changed
              within the sequence of the desitination database.  If URIs of
              imported documents conflict ones of exsisting documents,
              existing documents are removed.

       The function `est_db_put_doc' is used in order to add a document to a
       database.

       int est_db_put_doc(ESTDB *db, ESTDOC *doc, int options);
              `db' specifies a database object connected as a writer.  `doc'
              specifies a document object.  The document object should have
              the URI attribute.  `options' specifies options: `ESTPDCLEAN' to
              clean up dispensable regions of the overwritten document,
              `ESTPDWEIGHT' to weight scores statically with score weighting
              attribute.  The return value is true if success, else it is
              false.  If the URI attribute is same with an existing document
              in the database, the existing one is deleted.

       The function `est_db_out_doc' is used in order to remove a document
       from a database.

       int est_db_out_doc(ESTDB *db, int id, int options);
              `db' specifies a database object connected as a writer.  `id'
              specifies the ID number of a registered document.  `options'
              specifies options: `ESTODCLEAN' to clean up dispensable regions
              of the deleted document.  The return value is true if success,
              else it is false.

       The function `est_db_edit_doc' is used in order to edit attributes of a
       document in a database.

       int est_db_edit_doc(ESTDB *db, ESTDOC *doc);
              `db' specifies a database object connected as a writer.  `doc'
              specifies a document object.  The return value is true if
              success, else it is false.  The ID can not be changed.  If the
              URI is changed and it overlaps the URI of another registered
              document, this function fails.

       The function `est_db_get_doc' is used in order to retrieve a document
       in a database.

       ESTDOC *est_db_get_doc(ESTDB *db, int id, int options);
              `db' specifies a database object.  `id' specifies the ID number
              of a registered document.  `options' specifies options:
              `ESTGDNOATTR' to ignore attributes, `ESTGDNOTEXT' to ignore the
              body text, `ESTGDNOKWD' to ignore keywords.  The two can be
              specified at the same time by bitwise or.  The return value is a
              document object.  It should be deleted with `est_doc_delete' if
              it is no longer in use.  On error, `NULL' is returned.

       The function `est_db_get_doc_attr' is used in order to retrieve the
       value of an attribute of a document in a database.

       char *est_db_get_doc_attr(ESTDB *db, int id, const char *name);
              `db' specifies a database object.  `id' specifies the ID number
              of a registered document.  `name' specifies the name of an
              attribute.  The return value is the value of the attribute or
              `NULL' if it does not exist.  Because the region of the return
              value is allocated with the `malloc' call, it should be released
              with the `free' call if it is no longer in use.

       The function `est_db_uri_to_id' is used in order to get the ID of a
       document specified by URI.

       int est_db_uri_to_id(ESTDB *db, const char *uri);
              `db' specifies a database object.  `uri' specifies the URI of a
              registered document.  The return value is the ID of the
              document.  On error, -1 is returned.

       The function `est_db_name' is used in order to get the name of a
       database.

       const char *est_db_name(ESTDB *db);
              `db' specifies a database object.  The return value is the name
              of the database.  The life duration of the returned string is
              synchronous with the one of the database object.

       The function `est_db_doc_num' is used in order to get the number of
       documents in a database.

       int est_db_doc_num(ESTDB *db);
              `db' specifies a database object.  The return value is the
              number of documents in the database.

       The function `est_db_word_num' is used in order to get the number of
       unique words in a database.

       int est_db_word_num(ESTDB *db);
              `db' specifies a database object.  The return value is the
              number of unique words in the database.

       The function `est_db_size' is used in order to get the size of a
       database.

       double est_db_size(ESTDB *db);
              `db' specifies a database object.  The return value is the size
              of the database.

       The function `est_db_search' is used in order to search a database for
       documents corresponding a condition.

       int *est_db_search(ESTDB *db, ESTCOND *cond, int *nump, CBMAP *hints);
              `db' specifies a database object.  `cond' specifies a condition
              object.  `nump' specifies the pointer to a variable to which the
              number of elements in the result is assigned.  `hints' specifies
              a map object into which the number of documents corresponding to
              each word is stored.  If a word is in a negative condition, the
              number is negative.  The element whose key is an empty string
              specifies the number of whole result.  If it is `NULL', it is
              not used.  The return value is an array whose elements are ID
              numbers of corresponding documents.  This function does never
              fail.  Even if no document corresponds or an error occurs, an
              empty array is returned.  Because the region of the return value
              is allocated with the `malloc' call, it should be released with
              the `free' call if it is no longer in use.

       Search plural databases for documents corresponding a condition.

       int *est_db_search_meta(ESTDB **dbs, int dbnum, ESTCOND *cond, int
       *nump, CBMAP *hints);
              `dbs' specifies an array whose elements are database objects.
              `dbnum' specifies the number of elements of the array.  `cond'
              specifies a condition object.  `nump' specifies the pointer to a
              variable to which the number of elements in the result is
              assigned.  `hints' specifies a map object into which the number
              of documents corresponding to each word is stored.  If a word is
              in a negative condition, the number is negative.  The element
              whose key is an empty string specifies the number of whole
              result.  If it is `NULL', it is not used.  The return value is
              an array whose elements are indexes of container databases and
              ID numbers of in each database alternately.  This function does
              never fail.  Even if no document corresponds or an error occurs,
              an empty array is returned.  Because the region of the return
              value is allocated with the `malloc' call, it should be released
              with the `free' call if it is no longer in use.

       The function `est_db_scan_doc' is used in order to check whether a
       document object matches the phrase of a search condition object
       definitely.

       int est_db_scan_doc(ESTDB *db, ESTDOC *doc, ESTCOND *cond);
              `db' specifies a database object.  `doc' specifies a document
              object.  `cond' specifies a search condition object.  The return
              value is true if the document matches the phrase of the
              condition object definitely, else it is false.

       The function `est_db_set_cache_size' is used in order to set the
       maximum size of the cache memory of a database.

       void est_db_set_cache_size(ESTDB *db, size_t size, int anum, int tnum,
       int rnum);
              `db' specifies a database object.  `size' specifies the maximum
              size of the index cache.  By default, it is 64MB.  If it is
              negative, the current size is not changed.  `anum' specifies the
              maximum number of cached records for document attributes.  By
              default, it is 8192.  If it is negative, the current size is not
              changed.  `tnum' specifies the maximum number of cached records
              for document texts.  By default, it is 1024.  If it is negative,
              the current size is not changed.  `rnum' specifies the maximum
              number of cached records for occurrence results.  By default, it
              is 256.  If it is negative, the current size is not changed.


PARALLELING
       Databases of Hyper Estraier are protected by file locking.  While a
       writer is connected to a database, neither readers nor writers can be
       connected.  While a reader is connected to a database, other readers
       can be connect, but writers can not.

       If you use multi thread, it is suggested to use the MT-safe API of
       Hyper Estraier.  It is a wrapper to make the core API thread-safe.  As
       the MT-safe API provides the same functions as with the core API, the
       following is different.


AUTHOR
       Hyper Estraier is written by Mikio Hirabayashi.  You can contact the
       author by e-mail to <mikio@users.sourceforge.net>.  Any suggestion or
       bug report is welcome to the author.


ACKNOWLEDGEMENTS
       Hyper Estraier was developed under management by Fumitoshi Ukai and
       supports by Exploratory Software Project of Information-technology
       Promotion Agency, Japan (IPA).


COPYRIGHT
       Copyright (C) 2004-2007 Mikio Hirabayashi

       Hyper Estraier is free software; you can redistribute it and/or modify
       it under the terms of the GNU Lesser General Public License as
       published by the Free Software Foundation; either version 2 of the
       License, or any later version.

       Hyper Estraier is distributed in the hope that it will be useful, but
       WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
       Lesser General Public License for more details.

       You should have received a copy of the GNU Lesser General Public
       License along with Hyper Estraier; if not, write to the Free Software
       Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
       USA.


SEE ALSO
       estconfig(1), estcmd(1), estmaster(1), estcall(1), estwaver(1),
       cabin(3), estnode(3)

       Please see http://hyperestraier.sourceforge.net/pguide-en.html for
       detail.



Man Page                          2007-03-06                       ESTRAIER(3)
