# https://fallabs.com/kyotocabinet/api/

use Inline C => config => inc  => '-I/usr/local/include';
use Inline C => config => libs => '-L/usr/local/lib -lkyotocabinet';
use Inline C => <<'EOC';

#include <string.h>
#include <kclangc.h>

KCDB  *db;
KCCUR *cur;

// open the database
int open_db(char* file) {
    db = kcdbnew();
    if (!kcdbopen(db, file, KCOREADER | KCONOLOCK)) return 0;
    cur = kcdbcursor(db);
    return 1;
}

// close the database
int close_db() {
    if (cur) kccurdel(cur);
    if (!kcdbclose(db)) return 0;
    return 1;
}

// search records containing substring
SV * search_db(char* substr) {
    AV *ret = newAV();

    char *kbuf, *vbuf;
    size_t ksiz, vsiz;
    const char *cvbuf;

    kccurjump(cur);
    while ((kbuf = kccurget(cur, &ksiz, &cvbuf, &vsiz, 1)) != NULL) {
        if (strstr(cvbuf, substr) != NULL) {
            av_push(ret, newSVpvn(kbuf, ksiz));
        }
        kcfree(kbuf);
    }

    return newRV_noinc((SV *) ret);
}

EOC


##</code><code>##

# https://fallabs.com/kyotocabinet/api/

use Inline CPP => config => inc  => '-I/usr/local/include';
use Inline CPP => config => libs => '-L/usr/local/lib -lkyotocabinet';
use Inline CPP => <<'EOCPP';

#undef do_open
#undef do_close

#include <string.h>
#include <kcpolydb.h>

using namespace std;
using namespace kyotocabinet;

PolyDB db;
DB::Cursor *cur;

// open the database
int open_db(char* file) {
    if (!db.open(file, PolyDB::OREADER | PolyDB::ONOLOCK)) return 0;
    cur = db.cursor();
    return 1;
}

// close the database
int close_db() {
    if (cur) delete cur;
    if (!db.close()) return 0;
    return 1;
}

// search records containing substring
SV * search_db(char* substr) {
    AV *ret = newAV();
    string ckey, cvalue;

    cur->jump();
    while (cur->get(&ckey, &cvalue, true)) {
        if (strstr(cvalue.c_str(), substr) != NULL) {
            av_push(ret, newSVpvn(ckey.c_str(), ckey.length()));
        }
    }

    return newRV_noinc((SV *) ret);
}

EOCPP


##</code><code>##

# https://www.perlmonks.org/?node_id=11110379
# usage: perl search_db_inline_c.pl > Outfile.txt

use strict;
use warnings;

# insert the Inline::C or Inline::CPP code here

open_db('db.kch#msiz=128m') or die "db.kch: open error\n";
open my $fh, '<', 'peptides.txt' or die "open error: $!\n";

while ( my $pep = <$fh> ) {
    chomp $pep; my $ids = search_db($pep);
    print "$pep\t", join(',', @$ids), "\n" if @$ids;
}

close $fh;
close_db();


##</code><code>##

# https://www.perlmonks.org/?node_id=11110379
# usage: perl search_db_inline_c_mce.pl > Outfile.txt

use strict;
use warnings;

# insert the Inline::C or Inline::CPP code here

use MCE;

my $mce = MCE->new(
    max_workers => MCE::Util::get_ncpu(),
    chunk_size  => 1,
    init_relay  => 1,

    user_begin => sub {
        open_db('db.kch#msiz=128m') or die "db.kch: open error\n";
    },

    user_end => sub {
        close_db();
    },

    user_func => sub {
        my $pep = $_; chomp $pep;
        my $ids = search_db($pep);

        # output serially, one worker at a time
        MCE::relay {
            print "$pep\t", join(',', @$ids), "\n" if @$ids;
        };
    }
);

$mce->process('peptides.txt');
$mce->shutdown;


##</code><code>##

GAAGGACTGGGACCA	>NR_000001,>NR_006611
AGGCTGCGGCAGGAC	>NR_062102
GTGAGCCGGGCAGAG	>NR_089584
AGGGGGGGTTGCTGA	>NR_036454,>NR_068535,>NR_097889
CTGACATGCGGCGCA	>NR_087289
GTGCATCGATGGCCG	>NR_005535
GGGGTCAAGCGAACC	>NR_076289,>NR_087856
TGAGACGGCGAACCT	>NR_064242
AGCGACAAAGGAAAC	>NR_045865
AGGTGCAACCATGGA	>NR_046602,>NR_056869
GAGTAAACCGCGCGA	>NR_093455
AACGACTGAACAGCG	>NR_070693
ACGCGTAATTCGATA	>NR_080086
GATGAGCGGAGCACT	>NR_070118
CGTAGCGAAACCGAG	>NR_092384,>NR_098291
GGGGGGGAGGTCCGA	>NR_021671,>NR_036907,>NR_080961
AGGGAGGGGGGTTGT	>NR_026207
ATGGGGCAGACGCGA	>NR_072314

##</code><code>##

62.883 seconds - op's code

33.594 seconds - search_db.pl
 6.367 seconds - search_db_mce.pl
 4.991 seconds - search_db_chunk.pl
 8.093 seconds - search_db_inline_c.pl
 1.530 seconds - search_db_inline_c_mce.pl

##</code><code>##

36.684 seconds - search_db.pl
 7.403 seconds - search_db_mce.pl
 5.986 seconds - search_db_chunk.pl
11.009 seconds - search_db_inline_c.pl
 2.188 seconds - search_db_inline_c_mce.pl

##</code><code>##

28.857 seconds - search_db.pl
 6.130 seconds - search_db_mce.pl
 5.219 seconds - search_db_chunk.pl
27.322 seconds - search_db_inline_c.pl
 5.808 seconds - search_db_inline_c_mce.pl