estraier
Class Database

java.lang.Object
  estraier.Database

public class Database
extends java.lang.Object

Abstraction of database

Field Summary

static int	DBCHRCAT open mode: use character category analyzer
static int	DBCREAT open mode: a writer creating
static int	DBHUGE open mode: huge tuning
static int	DBHUGE2 open mode: huge tuning second
static int	DBHUGE3 open mode: huge tuning third
static int	DBLARGE open mode: large tuning
static int	DBLCKNB open mode: lock without blocking
static int	DBNOLCK open mode: open without locking
static int	DBPERFNG open mode: use perfect N-gram analyzer
static int	DBREADER open mode: open as a reader
static int	DBSCASIS open mode: refrain from adjustment of scores
static int	DBSCINT open mode: store scores as integer
static int	DBSCVOID open mode: store scores as void
static int	DBSMALL open mode: small tuning
static int	DBTRUNC open mode: a writer truncating
static int	DBWRITER open mode: open as a writer
static int	ERRACCES error code: access forbidden
static int	ERRDB error code: database problem
static int	ERRINVAL error code: invalid argument
static int	ERRIO error code: I/O problem
static int	ERRLOCK error code: lock failure
static int	ERRMISC error code: miscellaneous
static int	ERRNOERR error code: no error
static int	ERRNOITEM error code: no item
static int	GDNOATTR get_doc option: no attributes
static int	GDNOKWD get_doc option: no keywords
static int	GDNOTEXT get_doc option: no text
static int	IDXATTRNUM attribute index type: for narrowing with attributes as numbers
static int	IDXATTRSEQ attribute index type: for multipurpose sequencial access method
static int	IDXATTRSTR attribute index type: for narrowing with attributes as strings
static int	MGCLEAN merge option: clean up dispensable regions
static int	ODCLEAN out_doc option: clean up dispensable regions
static int	OPTNODBOPT optimize option: omit optimization of the database files
static int	OPTNOPURGE optimize option: omit purging dispensable region of deleted
static int	PDCLEAN put_doc option: clean up dispensable regions
static int	PDWEIGHT put_doc option: weight scores statically when indexing
static java.lang.String	VERSION version of Hyper Estraier

Constructor Summary

Database()
Create a database object.

Method Summary

boolean	add_attr_index(java.lang.String name, int type) Add an index for narrowing or sorting with document attributes.
boolean	add_pseudo_index(java.lang.String path) Add a pseudo index directory.
boolean	close() Close the database.
int	doc_num() Get the number of documents.
boolean	edit_doc(Document doc) Edit attributes of a document.
java.lang.String	err_msg(int ecode) Get the string of an error code.
int	error() Get the last happened error code.
boolean	fatal() Check whether the database has a fatal error.
protected void	finalize() Release resources.
boolean	flush(int max) Flush index words in the cache.
java.lang.String	get_doc_attr(int id, java.lang.String name) Retrieve the value of an attribute of a document.
Document	get_doc(int id, int options) Retrieve a document.
boolean	merge(java.lang.String name, int options) Merge another database.
java.lang.String	name() Get the name.
boolean	open(java.lang.String name, int omode) Open the database.
boolean	optimize(int options) Optimize the database.
boolean	out_doc(int id, int options) Remove a document.
boolean	put_doc(Document doc, int options) Add a document.
boolean	scan_doc(Document doc, Condition cond) Check whether a document object matches the phrase of a search condition object definitely.
static Result	search_meta(Database[] dbs, Condition cond) Search plural databases for documents corresponding a condition.
Result	search(Condition cond) Search for documents corresponding a condition.
void	set_cache_size(double size, int anum, int tnum, int rnum) Set the maximum size of the cache memory.
void	set_informer(DatabaseInformer informer) Set the callback function to inform of database events.
void	set_wildmax(int num) Set the maximum number of expansion of wild cards.
double	size() Get the size.
boolean	sync() Synchronize updating contents.
int	uri_to_id(java.lang.String uri) Get the ID of a document specified by URI.
int	word_num() Get the number of unique words.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DBCHRCAT

public static final int DBCHRCAT

open mode: use character category analyzer

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Constant Field Values

DBCREAT

public static final int DBCREAT

open mode: a writer creating

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DBHUGE

public static final int DBHUGE

open mode: huge tuning

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DBHUGE2

public static final int DBHUGE2

open mode: huge tuning second

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DBHUGE3

public static final int DBHUGE3

open mode: huge tuning third

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DBLARGE

public static final int DBLARGE

open mode: large tuning

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DBLCKNB

public static final int DBLCKNB

open mode: lock without blocking

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DBNOLCK

public static final int DBNOLCK

open mode: open without locking

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DBPERFNG

public static final int DBPERFNG

open mode: use perfect N-gram analyzer

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DBREADER

public static final int DBREADER

open mode: open as a reader

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DBSCASIS

public static final int DBSCASIS

open mode: refrain from adjustment of scores

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DBSCINT

public static final int DBSCINT

open mode: store scores as integer

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DBSCVOID

public static final int DBSCVOID

open mode: store scores as void

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DBSMALL

public static final int DBSMALL

open mode: small tuning

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DBTRUNC

public static final int DBTRUNC

open mode: a writer truncating

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DBWRITER

public static final int DBWRITER

open mode: open as a writer

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ERRACCES

public static final int ERRACCES

error code: access forbidden

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ERRDB

public static final int ERRDB

error code: database problem

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ERRINVAL

public static final int ERRINVAL

error code: invalid argument

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ERRIO

public static final int ERRIO

error code: I/O problem

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ERRLOCK

public static final int ERRLOCK

error code: lock failure

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ERRMISC

public static final int ERRMISC

error code: miscellaneous

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ERRNOERR

public static final int ERRNOERR

error code: no error

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ERRNOITEM

public static final int ERRNOITEM

error code: no item

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GDNOATTR

public static final int GDNOATTR

get_doc option: no attributes

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GDNOKWD

public static final int GDNOKWD

get_doc option: no keywords

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GDNOTEXT

public static final int GDNOTEXT

get_doc option: no text

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Constant Field Values

IDXATTRNUM

public static final int IDXATTRNUM

attribute index type: for narrowing with attributes as numbers

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Constant Field Values

IDXATTRSEQ

public static final int IDXATTRSEQ

attribute index type: for multipurpose sequencial access method

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IDXATTRSTR

public static final int IDXATTRSTR

attribute index type: for narrowing with attributes as strings

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MGCLEAN

public static final int MGCLEAN

merge option: clean up dispensable regions

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ODCLEAN

public static final int ODCLEAN

out_doc option: clean up dispensable regions

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OPTNODBOPT

public static final int OPTNODBOPT

optimize option: omit optimization of the database files

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OPTNOPURGE

public static final int OPTNOPURGE

optimize option: omit purging dispensable region of deleted

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PDCLEAN

public static final int PDCLEAN

put_doc option: clean up dispensable regions

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PDWEIGHT

public static final int PDWEIGHT

put_doc option: weight scores statically when indexing

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Constant Field Values

VERSION

public static final java.lang.String VERSION

version of Hyper Estraier

Constructor Detail

Database

public Database()

Create a database object.

Method Detail

add_attr_index

public boolean add_attr_index(java.lang.String name,
                              int type)

Add an index for narrowing or sorting with document attributes.

Parameters:

name - the name of an attribute.

type - the data type of attribute index; `Database.IDXATTRSEQ' for multipurpose sequencial access method, `Database.IDXATTRSTR' for narrowing with attributes as strings, `Database.IDXATTRNUM' for narrowing with attributes as numbers.

Returns:

true if success, else it is false.

add_pseudo_index

public boolean add_pseudo_index(java.lang.String path)

Add a pseudo index directory.

Parameters:

path - the path of a pseudo index directory.

Returns:

true if success, else it is false.

close

public boolean close()

Close the database.

Returns:

true if success, else it is false.

doc_num

public int doc_num()

Get the number of documents.

Returns:

the number of documents in the database.

edit_doc

public boolean edit_doc(Document doc)

Edit attributes of a document.

Parameters:

doc - a document object.

Returns:

true if success, else it is false.

err_msg

public java.lang.String err_msg(int ecode)

Get the string of an error code.

Parameters:

ecode - an error code.

Returns:

the string of the error code.

error

public int error()

Get the last happened error code.

Returns:

the last happened error code.

fatal

public boolean fatal()

Check whether the database has a fatal error.

Returns:

true if the database has fatal erroor, else it is false.

finalize

protected void finalize()

Release resources.

Overrides:

finalize in class java.lang.Object

flush

public boolean flush(int max)

Flush index words in the cache.

Parameters:

max - the maximum number of words to be flushed. If it not more than zero, all words are flushed.

Returns:

true if success, else it is false.

get_doc_attr

public java.lang.String get_doc_attr(int id,
                                     java.lang.String name)

Retrieve the value of an attribute of a document.

Parameters:

id - the ID number of a registered document.

name - the name of an attribute.

Returns:

the value of the attribute or `null' if it does not exist.

get_doc

public Document get_doc(int id,
                        int options)

Retrieve a document.

Parameters:

id - the ID number of a registered document.

options - options: `Database.GDNOATTR' to ignore attributes, `Database.GDNOTEXT' to ignore the body text, `Database.GDNOKWD' to ignore keywords. The three can be specified at # the same time by bitwise or.

Returns:

a document object. On error, `null' is returned.

merge

public boolean merge(java.lang.String name,
                     int options)

Merge another database.

Parameters:

name - the name of another database directory.

options - options: `Database.MGCLEAN' to clean up dispensable regions of the deleted document.

Returns:

true if success, else it is false.

name

public java.lang.String name()

Get the name.

Returns:

the name of the database.

open

public boolean open(java.lang.String name,
                    int omode)

Open the database.

Parameters:

name - the name of a database directory.

omode - open modes: `Database.DBWRITER' as a writer, `Database.DBREADER' as a reader. If the mode is `Database.DBWRITER', the following may be added by bitwise or: `Database.DBCREAT', which means it creates a new database if not exist, `Database.DBTRUNC', which means it creates a new database regardless if one exists. Both of `Database.DBREADER' and `Database.DBWRITER' can be added to by bitwise or: `Database.DBNOLCK', which means it opens a database file without file locking, or `Database.DBLCKNB', which means locking is performed without blocking. If `Database.DBNOLCK' is used, the application is responsible for exclusion control. `Database.DBCREAT' can be added to by bitwise or: `Database.DBPERFNG', which means N-gram analysis is performed against European text also, `Database.DBCHACAT', which means character category analysis is performed instead of N-gram analysis, `Database.DBSMALL', which means the index is tuned to register less than 50000 documents, `Database.DBLARGE', which means the index is tuned to register more than 300000 documents, `Database.DBHUGE', which means the index is tuned to register more than 1000000 documents, `Database.DBHUGE2', which means the index is tuned to register more than 5000000 documents, `Database.DBHUGE3', which means the index is tuned to register more than 10000000 documents, `Database.DBSCVOID', which means scores are stored as void, `Database.DBSCINT', which means scores are stored as 32-bit integer, `Database.DBSCASIS', which means scores are stored as-is and marked not to be tuned when search.

Returns:

true if success, else it is false.

optimize

public boolean optimize(int options)

Optimize the database.

Parameters:

options - options: `Database.OPTNOPURGE' to omit purging dispensable region of deleted documents, `Database.OPTNODBOPT' to omit optimization of the database files. The two can be specified at the same time by bitwise or.

Returns:

true if success, else it is false.

out_doc

public boolean out_doc(int id,
                       int options)

Remove a document.

Parameters:

id - the ID number of a registered document.

options - options: `Database.ODCLEAN' to clean up dispensable regions of the deleted document.

Returns:

true if success, else it is false.

put_doc

public boolean put_doc(Document doc,
                       int options)

Add a document.

Parameters:

doc - a document object. The document object should have the URI attribute.

options - options: `Database.PDCLEAN' to clean up dispensable regions of the overwritten document.

Returns:

true if success, else it is false.

scan_doc

public boolean scan_doc(Document doc,
                        Condition cond)

Check whether a document object matches the phrase of a search condition object definitely.

Parameters:

doc - a document object.

cond - a search condition object.

Returns:

true if the document matches the phrase of the condition object definitely, else it is false.

search_meta

public static Result search_meta(Database[] dbs,
                                 Condition cond)

Search plural databases for documents corresponding a condition.

Parameters:

dbs - an array whose elements are database objects.

cond - a condition object.

Returns:

a result object. On error, `null' is returned.

search

public Result search(Condition cond)

Search for documents corresponding a condition.

Parameters:

cond - a condition object.

Returns:

a result object. On error, `null' is returned.

set_cache_size

public void set_cache_size(double size,
                           int anum,
                           int tnum,
                           int rnum)

Set the maximum size of the cache memory.

Parameters:

size - the maximum size of the index cache. By default, it is 64MB. If it is not more than 0, the current size is not changed.

anum - the maximum number of cached records for document attributes. By default, it is 8192. If it is not more than 0, the current size is not changed.

tnum - the maximum number of cached records for document texts. By default, it is 1024. If it is not more than 0, the current size is not changed.

rnum - the maximum number of cached records for occurrence results. By default, it is 256. If it is not more than 0, the current size is not changed.

set_informer

public void set_informer(DatabaseInformer informer)

Set the callback function to inform of database events.

Parameters:

informer - an arbitrary object with a method named as `inform'.

set_wildmax

public void set_wildmax(int num)

Set the maximum number of expansion of wild cards.

Parameters:

num - the maximum number of expansion of wild cards.

size

public double size()

Get the size.

Returns:

the size of the database.

sync

public boolean sync()

Synchronize updating contents.

Returns:

true if success, else it is false.

uri_to_id

public int uri_to_id(java.lang.String uri)

Get the ID of a document specified by URI.

Parameters:

uri - the URI of a registered document.

Returns:

the ID of the document. On error, -1 is returned.

word_num

public int word_num()

Get the number of unique words.

Returns:

the number of unique words in the database.