Provided by: libestraier-dev_1.4.13-14ubuntu2_amd64 
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 sequential 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.