use strict;
  use warnings;

  use BerkeleyDB;
  use DB_File;
  use TokyoCabinet;
  use KyotoCabinet;

  unlink qw( /tmp/file.db /tmp/file.tch /tmp/file.kch );
  unlink qw(              /tmp/file.tct /tmp/file.kct );

# --

# my $ob = tie my %hash, 'BerkeleyDB::Hash',
#       -Filename => '/tmp/file.db', -Flags => DB_CREATE
#    or die "open error: $!";
#
# my $ob = tie my %hash, 'BerkeleyDB::Btree',
#       -Filename => '/tmp/file.db', -Flags => DB_CREATE
#    or die "open error: $!";
#

# my $ob = tie my %hash, 'DB_File',
#       '/tmp/file.db', O_RDWR|O_CREAT, 0644, $DB_HASH
#    or die "open error: $!";
#
# my $ob = tie my %hash, 'DB_File',
#       '/tmp/file.db', O_RDWR|O_CREAT, 0644, $DB_BTREE
#    or die "open error: $!";
#

# my $ob = tie my %hash, 'TokyoCabinet::HDB', '/tmp/file.tch',
#       TokyoCabinet::HDB::OWRITER | TokyoCabinet::HDB::OCREAT
#    or die "open error: $!";
#
# my $ob = tie my %hash, 'TokyoCabinet::BDB', '/tmp/file.tcb',
#       TokyoCabinet::BDB::OWRITER | TokyoCabinet::BDB::OCREAT
#    or die "open error: $!";
#

# my $ob = tie my %hash, 'KyotoCabinet::DB', '/tmp/file.kch',
#       KyotoCabinet::DB::OWRITER | KyotoCabinet::DB::OCREATE
#    or die "open error: $!";
#
  my $ob = tie my %hash, 'KyotoCabinet::DB', '/tmp/file.kct',
        KyotoCabinet::DB::OWRITER | KyotoCabinet::DB::OCREATE
     or die "open error: $!";

# --

# Tie interface : 23.875 seconds, 793 MiB  - BerkeleyDB::Btree
#                 19.812 seconds, 793 MiB  - DB_File $DB_BTREE
#                 19.208 seconds, 353 MiB  - TokyoCabinet *.tcb
#                 17.232 seconds, 306 MiB  - KyotoCabinet *.kct
#
# for ( 1 .. 10e6 ) {
#     $hash{$_} = "$_ some string...";
# }
#

# OO interface  : 82.573 seconds, 639 MiB  - BerkeleyDB::Hash
#                 73.383 seconds, 639 MiB  - DB_File $DB_HASH
#                 87.695 seconds, 458 MiB  - TokyoCabinet *.tch
#                 38.312 seconds, 464 MiB  - KyotoCabinet *.kch
#
#                 19.899 seconds, 793 MiB  - BerkeleyDB::Btree
#                 14.340 seconds, 793 MiB  - DB_File $DB_BTREE
#                 14.763 seconds, 353 MiB  - TokyoCabinet *.tcb
#                 10.970 seconds, 306 MiB  - KyotoCabinet *.kct
#
  for ( 1 .. 10e6 ) {
      $ob->STORE($_ => "$_ some string...");
  }


##</code><code>##

$ tar xf $HOME/Downloads/kyotocabinet-1.2.76.tar.gz
$ cd kyotocabinet-1.2.76

$ patch -p0 < $HOME/Downloads/patch-kccommon.h.diff
$ patch -p0 < $HOME/Downloads/patch-configure.diff
$ patch -p0 < $HOME/Downloads/patch-kcthread.cc

$ ./configure --disable-lzo --disable-lzma

$ make -j2
$ sudo make install


##</code><code>##

$ tar xf $HOME/Downloads/kyotocabinet-perl-1.20.tar.gz
$ cd kyotocabinet-perl-1.20

$ perl Makefile.PL
$ sudo make install

$ cd doc
$ open index.html


##</code><code>##

my $ob1 = tie my %h1, 'TokyoCabinet::ADB', '*';  # in-memory hash
my $ob2 = tie my %h2, 'TokyoCabinet::ADB', '+';  # in-memory tree

my $ob3 = tie my %h3, 'KyotoCabinet::DB',  '*';  # in-memory hash
my $ob4 = tie my %h4, 'KyotoCabinet::DB',  '%';  # in-memory tree


##</code><code>##

use strict;
use warnings;

use Time::HiRes 'time';
use TokyoCabinet;
use KyotoCabinet;

my %hash;
my $ob2 = tie my %h2, 'TokyoCabinet::ADB', '+';  # in-memory tree
my $ob4 = tie my %h4, 'KyotoCabinet::DB',  '%';  # in-memory tree
my $start = time;

# Plain hash                   1911 MiB, 10.182 seconds
# for ( 1 .. 10e6 ) {
#     $hash{$_} = "$_ some string...";
# }

# Tokyo Cabinet                 627 MiB, 10.165 seconds
# for ( 1 .. 10e6 ) {
#     $ob2->STORE($_ => "$_ some string...");
# }

# Kyoto Cabinet                 453 MiB, 10.062 seconds
  for ( 1 .. 10e6 ) {
      $ob4->STORE($_ => "$_ some string...");
  }

printf {*STDERR} "capture memory consumption in top: %0.03f\n",
    time - $start;

1 for ( 1 .. 2e8 );


##</code><code>##

use strict;
use warnings;

use List::Util 'shuffle';
use Time::HiRes 'time';
use TokyoCabinet;
use KyotoCabinet;

srand 0;

my %hash;
my $ob2  = tie my %h2, 'TokyoCabinet::ADB', '+';             # Tree
my $ob4  = tie my %h4, 'KyotoCabinet::DB',  '%#pccap=256m';  # Tree
my $size = 5e6;
my $start;

my @keys = shuffle 1 .. $size;

# plain hash                   4.342 seconds
# for ( 1 .. $size ) {
#     $hash{$_} = "$_ some string...";
# }
# $start = time;
# for ( @keys ) {
#     my $v = $hash{$_};
# }

# TokyoCabinet                11.572 seconds '+' tree
# TokyoCabinet                 8.936 seconds '*' hash
# for ( 1 .. $size ) {
#     $ob2->STORE($_ => "$_ some string...");
# }
# $start = time;
# for ( @keys ) {
#     my $v = $ob2->FETCH($_);
# }

# KyotoCabinet                11.991 seconds '%' tree
# KyotoCabinet                 6.087 seconds '*' hash
  for ( 1 .. $size ) {
      $ob4->STORE($_ => "$_ some string...");
  }
  $start = time;
  for ( @keys ) {
      my $v = $ob4->FETCH($_);
  }

printf "duration: %0.03f seconds\n", time - $start;


##</code><code>##

"/tmp/file.kch#bnum=5000000" # hash
"/tmp/file.kct#pccap=256m" # tree

"*#bnum=5000000#capsiz=1024m" # in-memory hash
"%#pccap=256m" # in-memory tree