File Coverage

blib/lib/CWB/CQI/IOClient.pm

Criterion	Covered	Total	%
statement	21	485	4.3
branch	0	102	0.0
condition	0	63	0.0
subroutine	7	78	8.9
pod	0	71	0.0
total	28	799	3.5

package CWB::CQI::IOClient;
# -*-cperl-*-

use strict;
use warnings;

use CWB::CQI;
use IO::Socket;
use FileHandle;
use Carp;

# export CQi client functions
use base qw(Exporter);
our @EXPORT = (
           qw,
           qw,
           qw,
           qw,
          );

=head1 NAME

CWB::CQI::IOClient - Alternative CQi client library (based on IO::Socket)


=head1 DESCRIPTION

This is an alternative version of the B library, which uses the object-oriented
B module instead of calling low-level socket functions.  It is a direct replacement and
presents exactly the same API, so one can simply change

    use CWB::CQI::Client;

to

    use CWB::CQI::IOClient;

in any CQi client script.  See the L manpage for more information and a description
of available CQi functions.

=cut


our $conn = new FileHandle;

#
#
#  Error Handling
#
#

our $LastCmd = "";            # keep track of last command in case we receive an error code

sub CqiError (@) {
  foreach (@_) {
    print STDERR "CQi ERROR: $_\n";
  }
  croak "CQI::Client -- connection aborted.";
  exit 1;                       # Perl/Tk seems to catch the croak ...
}

sub CqiErrorCode ($) {
  my $errcode = shift;
  my $group = $errcode >> 8;
  my $command = $errcode & 0xff;
  my $errhex = sprintf "%02X:%02X", $group, $command;
  my $name = $CWB::CQI::CommandName{$errcode};

  if ($name =~ /ERROR/) {
    CqiError "Received $name  [$errhex]  in response to", "$LastCmd";
  }
  else {
    CqiError "Unexpected response $name  [$errhex]  to", "$LastCmd";
  }
}

sub CqiCheckResponse ($@) {
  my $response = shift;
  my %expect = map { $_ => 1 } @_;

  CqiErrorCode $response
    unless defined $expect{$response};
}


#
#
#  Connect to CQi server / Disconnect
#
#

sub cqi_connect {
  my $user = shift;
  my $passwd = shift;
  my $host = shift;             # optional
  my $port = shift;             # optional

  $host = 'localhost'
    unless defined $host;
  $port = $CWB::CQI::PORT
    unless defined $port;

  croak "USAGE: cqi_connect(username, password, [, remotehost [, port]]);"
    unless defined $user and defined $passwd;
  $LastCmd = "CQI_CTRL_CONNECT($user, '$passwd', $host, $port)";

  my $ipaddr = inet_aton($host);
  my $sockaddr = sockaddr_in($port, $ipaddr);
  my $protocol = getprotobyname('tcp');

  $conn = new IO::Socket 'Domain' => AF_INET, 'Type' => SOCK_STREAM, 'Proto' => "tcp", 'PeerHost' => $host, 'PeerPort' => $port
    or do { croak "cqi_connect(): $!", exit 1};
  $conn->autoflush(0);

  cqi_send_word($CWB::CQI::CTRL_CONNECT);
  cqi_send_string($user);
  cqi_send_string($passwd);
  cqi_flush();

  my $response = cqi_read_word();
  CqiCheckResponse $response, $CWB::CQI::STATUS_CONNECT_OK;
}

sub cqi_bye {
  $LastCmd = "CQI_CTRL_BYE()";
  cqi_send_word($CWB::CQI::CTRL_BYE);
  cqi_flush();
  my $response = cqi_read_word();
  CqiCheckResponse $response, $CWB::CQI::STATUS_BYE_OK;
  $conn->close;
  $conn = undef;
}

sub cqi_ping {
  $LastCmd = "CQI_CTRL_PING()";
  cqi_send_word($CWB::CQI::CTRL_PING);
  cqi_flush();
  CqiCheckResponse cqi_read_word(), $CWB::CQI::STATUS_PING_OK;
}


#
#
#  CQi Commands
#
#

sub cqi_ask_feature {
  my $feature = lc shift;
  my %features = (
                  "cqi1.0" => $CWB::CQI::ASK_FEATURE_CQI_1_0,
                  "cl2.3"  => $CWB::CQI::ASK_FEATURE_CL_2_3,
                  "cqp2.3" => $CWB::CQI::ASK_FEATURE_CQP_2_3,
                  );
  croak "USAGE: \$supported = cqi_ask_feature('cqi1.0' | 'cl2.3' | 'cqp2.3');"
    unless defined $features{$feature};
  $LastCmd = $CWB::CQI::CommandName{$features{$feature}} . "()";
  cqi_send_word($features{$feature});
  cqi_flush();
  return cqi_expect_bool();
}

sub cqi_list_corpora {
  $LastCmd = "CQI_CORPUS_LIST_CORPORA()";
  croak "USAGE: \@corpora = cqi_list_corpora();"
    unless @_ == 0;
  cqi_send_word($CWB::CQI::CORPUS_LIST_CORPORA);
  cqi_flush();
  return cqi_expect_string_list();
}

sub cqi_charset {
  my $corpus = shift;
  $LastCmd = "CQI_CORPUS_CHARSET($corpus)";
  cqi_send_word($CWB::CQI::CORPUS_CHARSET);
  cqi_send_string($corpus);
  cqi_flush();
  return cqi_expect_string();
}

sub cqi_properties {
  my $corpus = shift;
  $LastCmd = "CQI_CORPUS_PROPERTIES($corpus)";
  cqi_send_word($CWB::CQI::CORPUS_PROPERTIES);
  cqi_send_string($corpus);
  cqi_flush();
  return cqi_expect_string_list();
}

sub cqi_attributes {
  my $corpus = shift;
  my $type = shift;
  my %types = (
               'p' => $CWB::CQI::CORPUS_POSITIONAL_ATTRIBUTES,
               's' => $CWB::CQI::CORPUS_STRUCTURAL_ATTRIBUTES,
               'a' => $CWB::CQI::CORPUS_ALIGNMENT_ATTRIBUTES,
              );
  croak "USAGE: \@attributes = cqi_attributes(\$corpus, ('p'|'s'|'a'));"
    unless defined $types{$type};
  $LastCmd = $CWB::CQI::CommandName{$types{$type}} . "($corpus)";
  cqi_send_word($types{$type});
  cqi_send_string($corpus);
  cqi_flush();
  return cqi_expect_string_list();
}

sub cqi_structural_attribute_has_values {
  my $attribute = shift;
  $LastCmd = "CQI_CORPUS_STRUCTURAL_ATTRIBUTE_HAS_VALUES($attribute)";
  cqi_send_word($CWB::CQI::CORPUS_STRUCTURAL_ATTRIBUTE_HAS_VALUES);
  cqi_send_string($attribute);
  cqi_flush();
  return cqi_expect_bool();
}

sub cqi_full_name {
  my $corpus = shift;
  $LastCmd = "CQI_CORPUS_FULL_NAME($corpus)";
  cqi_send_word($CWB::CQI::CORPUS_FULL_NAME);
  cqi_send_string($corpus);
  cqi_flush();
  return cqi_expect_string();
}

sub cqi_corpus_info {
  my $corpus = shift;
  $LastCmd = "CQI_CORPUS_INFO($corpus)";
  cqi_send_word($CWB::CQI::CORPUS_INFO);
  cqi_send_string($corpus);
  cqi_flush();
  return cqi_expect_string_list();
}

sub cqi_drop_corpus {
  my $corpus = shift;
  $LastCmd = "CQI_CORPUS_DROP_CORPUS($corpus)";
  cqi_send_word($CWB::CQI::CORPUS_DROP_CORPUS);
  cqi_send_string($corpus);
  cqi_flush();
  cqi_expect_status($CWB::CQI::STATUS_OK);
}

sub cqi_attribute_size {
  my $attribute = shift;
  $LastCmd = "CQI_CL_ATTRIBUTE_SIZE($attribute)";
  cqi_send_word($CWB::CQI::CL_ATTRIBUTE_SIZE);
  cqi_send_string($attribute);
  cqi_flush();
  return cqi_expect_int();
}

sub cqi_lexicon_size {
  my $attribute = shift;
  $LastCmd = "CQI_CL_LEXICON_SIZE($attribute)";
  cqi_send_word($CWB::CQI::CL_LEXICON_SIZE);
  cqi_send_string($attribute);
  cqi_flush();
  return cqi_expect_int();
}

sub cqi_drop_attribute {
  my $attribute = shift;
  $LastCmd = "CQI_CL_DROP_ATTRIBUTE($attribute)";
  cqi_send_word($CWB::CQI::CL_DROP_ATTRIBUTE);
  cqi_send_string($attribute);
  cqi_flush();
  cqi_expect_status($CWB::CQI::STATUS_OK);
}

# 'scalar' functions which map to lists in the CQi are wrapped
# in a scalar-safe client interface, so we CAN use them with simple
# scalars in CQI::Client.
sub cqi_str2id {
  my $attribute = shift;
  $LastCmd = "CQI_CL_STR2ID($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_STR2ID);
  cqi_send_string($attribute);
  cqi_send_string_list(@_);
  cqi_flush();
  my @list = cqi_expect_int_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_id2str {
  my $attribute = shift;
  $LastCmd = "CQI_CL_ID2STR($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_ID2STR);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  my @list = cqi_expect_string_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_id2freq {
  my $attribute = shift;
  $LastCmd = "CQI_CL_ID2FREQ($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_ID2FREQ);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  my @list = cqi_expect_int_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_cpos2id {
  my $attribute = shift;
  $LastCmd = "CQI_CL_CPOS2ID($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_CPOS2ID);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  my @list = cqi_expect_int_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_cpos2str {
  my $attribute = shift;
  $LastCmd = "CQI_CL_CPOS2STR($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_CPOS2STR);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  my @list = cqi_expect_string_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_cpos2struc {
  my $attribute = shift;
  $LastCmd = "CQI_CL_CPOS2STRUC($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_CPOS2STRUC);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  my @list = cqi_expect_int_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_cpos2lbound {
  my $attribute = shift;
  $LastCmd = "CQI_CL_CPOS2LBOUND($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_CPOS2LBOUND);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  my @list = cqi_expect_int_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_cpos2rbound {
  my $attribute = shift;
  $LastCmd = "CQI_CL_CPOS2RBOUND($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_CPOS2RBOUND);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  my @list = cqi_expect_int_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_cpos2alg {
  my $attribute = shift;
  $LastCmd = "CQI_CL_CPOS2ALG($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_CPOS2ALG);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  my @list = cqi_expect_int_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_struc2str {
  my $attribute = shift;
  $LastCmd = "CQI_CL_STRUC2STR($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_STRUC2STR);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  my @list = cqi_expect_string_list();
  if (wantarray) {
    return @list;
  }
  else {
    croak "Called in scalar context with list argument." unless @list == 1;
    return $list[0];
  }
}

sub cqi_id2cpos {
  croak "USAGE: \@cposlist = cqi_id2cpos(\$attribute, \$id);"
    unless @_ == 2 and wantarray;
  my $attribute = shift;
  my $id = shift;

  $LastCmd = "CQI_CL_ID2CPOS($attribute, $id)";
  cqi_send_word($CWB::CQI::CL_ID2CPOS);
  cqi_send_string($attribute);
  cqi_send_int($id);
  cqi_flush();
  return cqi_expect_int_list();
}

sub cqi_idlist2cpos {
  my $attribute = shift;
  $LastCmd = "CQI_CL_IDLIST2CPOS($attribute, [@_])";
  cqi_send_word($CWB::CQI::CL_IDLIST2CPOS);
  cqi_send_string($attribute);
  cqi_send_int_list(@_);
  cqi_flush();
  return cqi_expect_int_list();
}

sub cqi_regex2id {
  croak "USAGE: \@idlist = cqi_regex2id(\$attribute, \$regex);"
    unless @_ == 2 and wantarray;
  my $attribute = shift;
  my $regex = shift;

  $LastCmd = "CQI_CL_REGEX2ID($attribute, $regex)";
  cqi_send_word($CWB::CQI::CL_REGEX2ID);
  cqi_send_string($attribute);
  cqi_send_string($regex);
  cqi_flush();
  return cqi_expect_int_list();
}

sub cqi_struc2cpos {
  croak "USAGE: (\$start, \$end) = cqi_struc2cpos(\$attribute, \$struc);"
    unless @_ == 2 and wantarray;
  my $attribute = shift;
  my $struc = shift;

  $LastCmd = "CQI_CL_STRUC2CPOS($attribute, $struc)";
  cqi_send_word($CWB::CQI::CL_STRUC2CPOS);
  cqi_send_string($attribute);
  cqi_send_int($struc);
  cqi_flush();
  return cqi_expect_int_int();
}

sub cqi_alg2cpos {
  croak "USAGE: (\$s1, \$s2, \$t1, \$t2) = cqi_alg2cpos(\$attribute, \$alg);"
    unless @_ == 2 and wantarray;
  my $attribute = shift;
  my $alg = shift;

  $LastCmd = "CQI_CL_ALG2CPOS($attribute, $alg)";
  cqi_send_word($CWB::CQI::CL_ALG2CPOS);
  cqi_send_string($attribute);
  cqi_send_int($alg);
  cqi_flush();
  return cqi_expect_int_int_int_int();
}

# cqi_query() returns a CQi response code (CQI_STATUS_OK or error).
# An error code usually indicates a mistake in the query syntax.
# It aborts the program unless one of the following responses is received:
#   CQI_STATUS_OK
#   CQI_ERROR_*
#   CQI_CQP_ERROR_*
sub cqi_query {
  my ($mother, $child, $query) = @_;
  croak "USAGE: \$ok = cqi_query(\$mother_corpus, \$subcorpus_name, \$query);"
    unless @_ == 3 and $mother =~ /^[A-Z0-9_-]+(:[A-Z_][A-Za-z0-9_-]*)?$/
      and $child =~ /^[A-Z_][A-Za-z0-9_-]*$/;
  $query .= ";"
    unless $query =~ /;\s*$/;

  $LastCmd = "CQI_CQP_QUERY($mother, $child, '$query')";
  cqi_send_word($CWB::CQI::CQP_QUERY);
  cqi_send_string($mother);
  cqi_send_string($child);
  cqi_send_string($query);
  cqi_flush();
  my $response = cqi_read_word();
  my $group = $response >> 8;
  CqiError $response
    unless $response == $CWB::CQI::STATUS_OK or $group == $CWB::CQI::ERROR or $group == $CWB::CQI::CQP_ERROR;
  return $response;
}

sub cqi_list_subcorpora {
  my $corpus = shift;
  $LastCmd = "CQI_CQP_LIST_SUBCORPORA($corpus)";
  cqi_send_word($CWB::CQI::CQP_LIST_SUBCORPORA);
  cqi_send_string($corpus);
  cqi_flush();
  return cqi_expect_string_list();
}

sub cqi_subcorpus_size {
  my $subcorpus = shift;
  $LastCmd = "CQI_CQP_SUBCORPUS_SIZE($subcorpus)";
  cqi_send_word($CWB::CQI::CQP_SUBCORPUS_SIZE);
  cqi_send_string($subcorpus);
  cqi_flush();
  return cqi_expect_int();
}

# used internally
sub cqi_get_field_key {
  my $field = uc shift;
  if ($field =~ /^(MATCH(END)?|TARGET|KEYWORD)$/) {
    return eval "\$CWB::CQI::CONST_FIELD_$field";
  }
  else {
    return undef;
  }
}

sub cqi_subcorpus_has_field {
  my ($subcorpus, $field) = @_;
  croak "USAGE: \$ok = cqi_subcorpus_has_field(\$subcorpus, 'match'|'matchend'|'target'|'keyword');"
    unless @_ == 2 and defined (my $field_key = cqi_get_field_key($field));
  $LastCmd = "CQI_CQP_SUBCORPUS_HAS_FIELD($subcorpus, CQI_CONST_FIELD_".(uc $field).")";
  cqi_send_word($CWB::CQI::CQP_SUBCORPUS_HAS_FIELD);
  cqi_send_string($subcorpus);
  cqi_send_byte($field_key);
  cqi_flush();
  return cqi_expect_bool();
}

sub cqi_dump_subcorpus {
  my ($subcorpus, $field, $first, $last) = @_;
  croak "USAGE: \@column = cqi_dump_subcorpus(\$subcorpus, 'match'|'matchend'|'target'|'keyword', \$from, \$to);"
    unless @_ == 4 and defined (my $field_key = cqi_get_field_key($field));
  $LastCmd = "CQI_CQP_DUMP_SUBCORPUS($subcorpus, CQI_CONST_FIELD_".(uc $field).", $first, $last)";
  cqi_send_word($CWB::CQI::CQP_DUMP_SUBCORPUS);
  cqi_send_string($subcorpus);
  cqi_send_byte($field_key);
  cqi_send_int($first);
  cqi_send_int($last);
  cqi_flush();
  return cqi_expect_int_list();
}

sub cqi_drop_subcorpus {
  my $subcorpus = shift;
  $LastCmd = "CQI_CQP_DROP_SUBCORPUS($subcorpus)";
  cqi_send_word($CWB::CQI::CQP_DROP_SUBCORPUS);
  cqi_send_string($subcorpus);
  cqi_flush();
  cqi_expect_status($CWB::CQI::STATUS_OK);
}

## cqi_fdist() subsumes both cqi_fdist_1() and cqi_fdist_2()
## returns list of (id, f) or (id1, id2, f) tuples as hashref's
sub cqi_fdist {
  my $subcorpus = shift;
  my $cutoff = shift;
  my $key1 = shift;
  my $key2 = shift;
  my ($field1, $field2, $att1, $att2, $tmp);
  ($tmp, $att1) = split /\./, $key1;
  $field1 = cqi_get_field_key($tmp);
  if (defined $key2) {
    ($tmp, $att2) = split /\./, $key2;
    $field2 = cqi_get_field_key($tmp);
  }
  else {
    $field2 = "";
    $att2 = "x";
  }
  croak "USAGE: \@table = cqi_fdist(\$subcorpus, \$cutoff, \$key1 [, \$key2]);"
    unless @_ == 0 and defined $field1 and defined $field2 and defined $att1 and defined $att2
      and $att1 =~ /^[a-z]+$/ and $att2 =~ /^[a-z]+$/ and $cutoff >= 0;
  if ($field2 ne "") {
    $LastCmd = "CQI_CQP_FDIST_2($subcorpus, $cutoff, $key1, $key2)";
    cqi_send_word($CWB::CQI::CQP_FDIST_2);
    cqi_send_string($subcorpus);
    cqi_send_int($cutoff);
    cqi_send_byte($field1);
    cqi_send_string($att1);
    cqi_send_byte($field2);
    cqi_send_string($att2);
    cqi_flush();
    return cqi_expect_int_table();
  }
  else {
    $LastCmd = "CQI_CQP_FDIST_1($subcorpus, $cutoff, $key1)";
    cqi_send_word($CWB::CQI::CQP_FDIST_1);
    cqi_send_string($subcorpus);
    cqi_send_int($cutoff);
    cqi_send_byte($field1);
    cqi_send_string($att1);
    cqi_flush();
    return cqi_expect_int_table();
  }
}


#
#
#  CQi expect response / data
#
#
sub cqi_expect_byte {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_BYTE;
  return cqi_read_byte();
}

sub cqi_expect_bool {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_BOOL;
  return cqi_read_byte();
}

sub cqi_expect_int {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_INT;
  return cqi_read_int();
}

sub cqi_expect_string {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_STRING;
  return cqi_read_string();
}

sub cqi_expect_byte_list {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_BYTE_LIST;
  return cqi_read_byte_list();
}

sub cqi_expect_bool_list {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_BOOL_LIST;
  return cqi_read_byte_list();
}

sub cqi_expect_int_list {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_INT_LIST;
  return cqi_read_int_list();
}

sub cqi_expect_string_list {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_STRING_LIST;
  return cqi_read_string_list();
}

sub cqi_expect_int_int {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_INT_INT;
  return cqi_read_int(), cqi_read_int();
}

sub cqi_expect_int_int_int_int {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_INT_INT_INT_INT;
  return cqi_read_int(), cqi_read_int(), cqi_read_int(), cqi_read_int();
}

sub cqi_expect_int_table {
  my $r = cqi_read_word();
  CqiCheckResponse $r, $CWB::CQI::DATA_INT_TABLE;
  return cqi_read_int_table();
}

sub cqi_expect_status {
  my @expected = @_;            # arguments are list of acceptable responses
  my $r = cqi_read_word();
  CqiCheckResponse $r, @expected;
  return $r;
}


#
#
#  Internal subroutines (read / write)
#
#
sub cqi_send_byte ($) {
  $conn->print((pack "C", shift))
    or croak "cqi_send_byte(): $!";
}

sub cqi_send_word ($) {
  $conn->print((pack "n", shift))
    or croak "cqi_send_word(): $!";
}

sub cqi_send_int ($) {
  my $number = shift;           # safely convert native int to 32bit value
  $number = unpack "L", (pack "l", $number); # pack 32bit signed, unpack unsigned -> uses type which can hold unsigned 32bit value
  $conn->print(pack("N", $number)) # 'N' packs unsigned 32bit integer
    or croak "cqi_send_int(): $!";
}

sub cqi_send_string ($) {
  my $str = shift;
  $conn->print((pack "n", length $str), $str)
    or croak "cqi_send_str(): $!";
}

sub cqi_send_byte_list (@) {
  cqi_send_int(scalar @_);
  map {cqi_send_byte($_)} @_;
}

sub cqi_send_word_list (@) {
  cqi_send_int(scalar @_);
  map {cqi_send_word($_)} @_;
}

sub cqi_send_int_list (@) {
  cqi_send_int(scalar @_);
  map {cqi_send_int($_)} @_;
}

sub cqi_send_string_list (@) {
  cqi_send_int(scalar @_);
  map {cqi_send_string($_)} @_;
}

sub cqi_flush () {
  $conn->flush
    or croak "cqi_flush(): $!";
}

sub cqi_read_byte () {
  my $msg = $conn->getc();
  croak "cqi_read_byte(): $!"
    unless defined $msg;
  return unpack "C", $msg;
}

sub cqi_read_word () {
  my $msg;
  my $bytes_read = $conn->read($msg, 2);
  croak "cqi_read_word(): $!"
    unless defined $bytes_read and $bytes_read == 2;
  return unpack "N", "\x00\x00$msg"; # this should safely unpack an unsigned short
}

sub cqi_read_int () {
  my $msg;
  my $number;

  my $bytes_read = $conn->read($msg, 4);
  croak "cqi_read_word(): $!"
    unless defined $bytes_read and $bytes_read == 4;
  $number = unpack "N", $msg;   # unpack seems to default to unsigned
  $number = unpack "l", (pack "L", $number); # convert unsigned 32bit to internal signed int *phew*
  return $number;
}

sub cqi_read_string () {
  my ($msg, $len, $bytes_read);
  $len = cqi_read_word();
  $bytes_read = $conn->read($msg, $len);
  croak "cqi_read_string(): $!"
    unless defined $bytes_read and $bytes_read == $len;
  return $msg;
}

sub cqi_read_byte_list() {
  my ($i, $len, @list);
  $len = cqi_read_int();
  for ($i = $len; $i > 0; $i--) {
    push @list, cqi_read_byte;
  }
  return @list;
}

sub cqi_read_word_list() {
  my ($i, $len, @list);
  $len = cqi_read_int();
  for ($i = $len; $i > 0; $i--) {
    push @list, cqi_read_word();
  }
  return @list;
}

sub cqi_read_int_list() {
  my ($i, $len, @list);
  $len = cqi_read_int();
  for ($i = $len; $i > 0; $i--) {
    push @list, cqi_read_int();
  }
  return @list;
}

sub cqi_read_string_list() {
  my ($i, $len, @list);
  $len = cqi_read_int();
  for ($i = $len; $i > 0; $i--) {
    push @list, cqi_read_string();
  }
  return @list;
}

sub cqi_read_int_table() {
  my $rows = cqi_read_int();
  my $columns = cqi_read_int();
  my @table = ();
  for (my $i = 0; $i < $rows; $i++) {
    my @line = ();
    for (my $j = 0; $j < $columns; $j++) {
      push @line, cqi_read_int();
    }
    push @table, [@line];
  }
  return @table;
}


1;

__END__