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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>Module: TokyoCabinet [Tokyo Cabinet]</title>
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<table class="header-table">
<tr class="top-aligned-row">
<td><strong>Module</strong></td>
<td class="class-name-in-header">TokyoCabinet</td>
</tr>
<tr class="top-aligned-row">
<td><strong>In:</strong></td>
<td>
<a href="../files/tokyocabinet-doc_rb.html">
tokyocabinet-doc.rb
</a>
<br />
</td>
</tr>
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<div id="description">
<h1>Ruby Binding of Tokyo Cabinet</h1>
<p>
Tokyo Cabinet: a modern implementation of DBM
</p>
<h2>INTRODUCTION</h2>
<p>
Tokyo Cabinet is a library of routines for managing a database. The
database is a simple data file containing records, each is a pair of a key
and a value. Every key and value is serial bytes with variable length. Both
binary data and character string can be used as a key and a value. There is
neither concept of data tables nor data types. Records are organized in
hash table, B+ tree, or fixed-length array.
</p>
<p>
As for database of hash table, each key must be unique within a database,
so it is impossible to store two or more records with a key overlaps. The
following access methods are provided to the database: storing a record
with a key and a value, deleting a record by a key, retrieving a record by
a key. Moreover, traversal access to every key are provided, although the
order is arbitrary. These access methods are similar to ones of DBM (or its
followers: NDBM and GDBM) library defined in the UNIX standard. Tokyo
Cabinet is an alternative for DBM because of its higher performance.
</p>
<p>
As for database of B+ tree, records whose keys are duplicated can be
stored. Access methods of storing, deleting, and retrieving are provided as
with the database of hash table. Records are stored in order by a
comparison function assigned by a user. It is possible to access each
record with the cursor in ascending or descending order. According to this
mechanism, forward matching search for strings and range search for
integers are realized.
</p>
<p>
As for database of fixed-length array, records are stored with unique
natural numbers. It is impossible to store two or more records with a key
overlaps. Moreover, the length of each record is limited by the specified
length. Provided operations are the same as ones of hash database.
</p>
<p>
Table database is also provided as a variant of hash database. Each record
is identified by the primary key and has a set of named columns. Although
there is no concept of data schema, it is possible to search for records
with complex conditions efficiently by using indices of arbitrary columns.
</p>
<h3>Setting</h3>
<p>
Install the latest version of Tokyo Cabinet beforehand and get the package
of the Ruby binding of Tokyo Cabinet.
</p>
<p>
Enter the directory of the extracted package then perform installation.
</p>
<pre>
ruby extconf.rb
make
su
make install
</pre>
<p>
The package `tokyocabinet' should be loaded in each source file of
application programs.
</p>
<pre>
require 'tokyocabinet'
</pre>
<p>
All symbols of Tokyo Cabinet are defined in the module
`TokyoCabinet'. You can access them without any prefix by including
the module.
</p>
<pre>
include TokyoCabinet
</pre>
<h1>EXAMPLE</h1>
<p>
The following code is an example to use a hash database.
</p>
<pre>
require 'tokyocabinet'
include TokyoCabinet
# create the object
hdb = HDB::new
# open the database
if !hdb.open("casket.tch", HDB::OWRITER | HDB::OCREAT)
ecode = hdb.ecode
STDERR.printf("open error: %s\n", hdb.errmsg(ecode))
end
# store records
if !hdb.put("foo", "hop") ||
!hdb.put("bar", "step") ||
!hdb.put("baz", "jump")
ecode = hdb.ecode
STDERR.printf("put error: %s\n", hdb.errmsg(ecode))
end
# retrieve records
value = hdb.get("foo")
if value
printf("%s\n", value)
else
ecode = hdb.ecode
STDERR.printf("get error: %s\n", hdb.errmsg(ecode))
end
# traverse records
hdb.iterinit
while key = hdb.iternext
value = hdb.get(key)
if value
printf("%s:%s\n", key, value)
end
end
# hash-like usage
hdb["quux"] = "touchdown"
printf("%s\n", hdb["quux"])
hdb.each do |key, value|
printf("%s:%s\n", key, value)
end
# close the database
if !hdb.close
ecode = hdb.ecode
STDERR.printf("close error: %s\n", hdb.errmsg(ecode))
end
</pre>
<p>
The following code is an example to use a B+ tree database.
</p>
<pre>
require 'tokyocabinet'
include TokyoCabinet
# create the object
bdb = BDB::new
# open the database
if !bdb.open("casket.tcb", BDB::OWRITER | BDB::OCREAT)
ecode = bdb.ecode
STDERR.printf("open error: %s\n", bdb.errmsg(ecode))
end
# store records
if !bdb.put("foo", "hop") ||
!bdb.put("bar", "step") ||
!bdb.put("baz", "jump")
ecode = bdb.ecode
STDERR.printf("put error: %s\n", bdb.errmsg(ecode))
end
# retrieve records
value = bdb.get("foo")
if value
printf("%s\n", value)
else
ecode = bdb.ecode
STDERR.printf("get error: %s\n", bdb.errmsg(ecode))
end
# traverse records
cur = BDBCUR::new(bdb)
cur.first
while key = cur.key
value = cur.val
if value
printf("%s:%s\n", key, value)
end
cur.next
end
# hash-like usage
bdb["quux"] = "touchdown"
printf("%s\n", bdb["quux"])
bdb.each do |key, value|
printf("%s:%s\n", key, value)
end
# close the database
if !bdb.close
ecode = bdb.ecode
STDERR.printf("close error: %s\n", bdb.errmsg(ecode))
end
</pre>
<p>
The following code is an example to use a fixed-length database.
</p>
<pre>
require 'tokyocabinet'
include TokyoCabinet
# create the object
fdb = FDB::new
# open the database
if !fdb.open("casket.tcf", FDB::OWRITER | FDB::OCREAT)
ecode = fdb.ecode
STDERR.printf("open error: %s\n", fdb.errmsg(ecode))
end
# store records
if !fdb.put(1, "one") ||
!fdb.put(12, "twelve") ||
!fdb.put(144, "one forty four")
ecode = fdb.ecode
STDERR.printf("put error: %s\n", fdb.errmsg(ecode))
end
# retrieve records
value = fdb.get(1)
if value
printf("%s\n", value)
else
ecode = fdb.ecode
STDERR.printf("get error: %s\n", fdb.errmsg(ecode))
end
# traverse records
fdb.iterinit
while key = fdb.iternext
value = fdb.get(key)
if value
printf("%s:%s\n", key, value)
end
end
# hash-like usage
fdb[1728] = "seventeen twenty eight"
printf("%s\n", fdb[1728])
fdb.each do |key, value|
printf("%s:%s\n", key, value)
end
# close the database
if !fdb.close
ecode = fdb.ecode
STDERR.printf("close error: %s\n", fdb.errmsg(ecode))
end
</pre>
<p>
The following code is an example to use a table database.
</p>
<pre>
require 'tokyocabinet'
include TokyoCabinet
# create the object
tdb = TDB::new
# open the database
if !tdb.open("casket.tct", TDB::OWRITER | TDB::OCREAT)
ecode = tdb.ecode
STDERR.printf("open error: %s\n", tdb.errmsg(ecode))
end
# store a record
pkey = tdb.genuid
cols = { "name" => "mikio", "age" => "30", "lang" => "ja,en,c" }
if !tdb.put(pkey, cols)
ecode = tdb.ecode
STDERR.printf("get error: %s\n", tdb.errmsg(ecode))
end
# store another record
cols = { "name" => "falcon", "age" => "31", "lang" => "ja", "skill" => "cook,blog" }
if !tdb.put("x12345", cols)
ecode = tdb.ecode
STDERR.printf("get error: %s\n", tdb.errmsg(ecode))
end
# search for records
qry = TDBQRY::new(tdb)
qry.addcond("age", TDBQRY::QCNUMGE, "20")
qry.addcond("lang", TDBQRY::QCSTROR, "ja,en")
qry.setorder("name", TDBQRY::QOSTRASC)
qry.setlimit(10)
res = qry.search
res.each do |rkey|
rcols = tdb.get(rkey)
printf("name:%s\n", rcols["name"])
end
# hash-like usage
tdb["joker"] = { "name" => "ozma", "lang" => "en", "skill" => "song,dance" }
printf("%s\n", tdb["joker"]["name"])
tdb.each do |key, value|
printf("%s:%s\n", key, value["name"])
end
# close the database
if !tdb.close
ecode = tdb.ecode
STDERR.printf("close error: %s\n", tdb.errmsg(ecode))
end
</pre>
<p>
The following code is an example to use an abstract database.
</p>
<pre>
require 'tokyocabinet'
include TokyoCabinet
# create the object
adb = ADB::new
# open the database
if !adb.open("casket.tch")
STDERR.printf("open error\n")
end
# store records
if !adb.put("foo", "hop") ||
!adb.put("bar", "step") ||
!adb.put("baz", "jump")
STDERR.printf("put error\n")
end
# retrieve records
value = adb.get("foo")
if value
printf("%s\n", value)
else
STDERR.printf("get error\n")
end
# traverse records
adb.iterinit
while key = adb.iternext
value = adb.get(key)
if value
printf("%s:%s\n", key, value)
end
end
# hash-like usage
adb["quux"] = "touchdown"
printf("%s\n", adb["quux"])
adb.each do |key, value|
printf("%s:%s\n", key, value)
end
# close the database
if !adb.close
STDERR.printf("close error\n")
end
</pre>
<h2>LICENSE</h2>
<pre>
Copyright (C) 2006-2010 FAL Labs
All rights reserved.
</pre>
<p>
Tokyo Cabinet 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 2.1 of the License or any
later version. Tokyo Cabinet 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 Tokyo Cabinet; if not,
write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
Boston, MA 02111-1307 USA.
</p>
</div>
</div>
</div>
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<div id="section">
<div id="class-list">
<h3 class="section-bar">Classes and Modules</h3>
Class <a href="TokyoCabinet/ADB.html" class="link">TokyoCabinet::ADB</a><br />
Class <a href="TokyoCabinet/BDB.html" class="link">TokyoCabinet::BDB</a><br />
Class <a href="TokyoCabinet/BDBCUR.html" class="link">TokyoCabinet::BDBCUR</a><br />
Class <a href="TokyoCabinet/FDB.html" class="link">TokyoCabinet::FDB</a><br />
Class <a href="TokyoCabinet/HDB.html" class="link">TokyoCabinet::HDB</a><br />
Class <a href="TokyoCabinet/TDB.html" class="link">TokyoCabinet::TDB</a><br />
Class <a href="TokyoCabinet/TDBQRY.html" class="link">TokyoCabinet::TDBQRY</a><br />
</div>
<div id="constants-list">
<h3 class="section-bar">Constants</h3>
<div class="name-list">
<table summary="Constants">
<tr class="top-aligned-row context-row">
<td class="context-item-name">VERSION</td>
<td>=</td>
<td class="context-item-value">"x.y.z"</td>
<td> </td>
<td class="context-item-desc">
the version information
</td>
</tr>
</table>
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