From 82ce08b938d31412d2e84d63779070002f23e956 Mon Sep 17 00:00:00 2001
From: Patrick Jentsch <p.jentsch@uni-bielefeld.de>
Date: Wed, 6 Nov 2019 15:44:06 +0100
Subject: [PATCH] Add CQiClient

---
 app/corpora/CQiClient/CQi.py       | 406 +++++++++++++++++++
 app/corpora/CQiClient/CQiClient.py | 611 +++++++++++++++++++++++++++++
 app/corpora/events.py              |   5 +
 3 files changed, 1022 insertions(+)
 create mode 100644 app/corpora/CQiClient/CQi.py
 create mode 100644 app/corpora/CQiClient/CQiClient.py

diff --git a/app/corpora/CQiClient/CQi.py b/app/corpora/CQiClient/CQi.py
new file mode 100644
index 00000000..5d39395a
--- /dev/null
+++ b/app/corpora/CQiClient/CQi.py
@@ -0,0 +1,406 @@
+# ########################################################################### #
+# IMS CQi specification                                                       #
+#                                                                             #
+# Version:       0.1a ;o)                                                     #
+# Author:        Stefan Evert (evert@ims.uni-stuttgart.de)                    #
+# Modified by:   Patrick Jentsch <p.jentsch@uni-bielefeld.de                  #
+# Modified date: Thurs Oct 10 <Uhrzeit>                                       #
+# ########################################################################### #
+
+
+""" 1. padding """
+PAD = 0x00
+
+
+""" 2. CQi responses """
+""" 2.1 CQI_STATUS_* """
+STATUS = 0x01
+STATUS_OK = 0x0101
+STATUS_CONNECT_OK = 0x0102
+STATUS_BYE_OK = 0x0103
+STATUS_PING_OK = 0x0104
+
+""" 2.2 CQI_ERROR_*  """
+ERROR = 0x02
+ERROR_GENERAL_ERROR = 0x0201
+ERROR_CONNECT_REFUSED = 0x0202
+ERROR_USER_ABORT = 0x0203
+ERROR_SYNTAX_ERROR = 0x0204
+# includes corpus/attribute/subcorpus specifier syntax
+
+""" 2.3 CQI_DATA_* """
+DATA = 0x03
+DATA_BYTE = 0x0301
+DATA_BOOL = 0x0302
+DATA_INT = 0x0303
+DATA_STRING = 0x0304
+DATA_BYTE_LIST = 0x0305
+DATA_BOOL_LIST = 0x0306
+DATA_INT_LIST = 0x0307
+DATA_STRING_LIST = 0x0308
+DATA_INT_INT = 0x0309
+DATA_INT_INT_INT_INT = 0x030A
+DATA_INT_TABLE = 0x030B
+
+""" 2.4 CQI_CL_ERROR_* """
+"""
+" NOTE: some CL error codes are not represented in the CQi specs
+"       - usually because they're not used in the CL any more
+"       - CDA_ENOSTRING is not considered an error (returns -1)
+"       - CDA_EARGS: dynamic attribute calls not yet supported
+"""
+CL_ERROR = 0x04
+CL_ERROR_NO_SUCH_ATTRIBUTE = 0x0401
+# returned if CQi server couldn't open attribute
+CL_ERROR_WRONG_ATTRIBUTE_TYPE = 0x0402
+# CDA_EATTTYPE
+CL_ERROR_OUT_OF_RANGE = 0x0403
+# CDA_EIDORNG, CDA_EIDXORNG, CDA_EPOSORNG
+CL_ERROR_REGEX = 0x0404
+# CDA_EPATTERN (not used), CDA_EBADREGEX
+CL_ERROR_CORPUS_ACCESS = 0x0405
+# CDA_ENODATA
+CL_ERROR_OUT_OF_MEMORY = 0x0406
+# CDA_ENOMEM
+# this means the CQi server has run out of memory;
+# try discarding some other corpora and/or subcorpora
+CL_ERROR_INTERNAL = 0x0407
+# CDA_EOTHER, CDA_ENYI
+# this is the classical 'please contact technical support' error
+
+""" 2.5 CQI_CQP_ERROR_* """
+CQP_ERROR = 0x05
+# CQP error messages yet to be defined
+CQP_ERROR_GENERAL = 0x0501
+CQP_ERROR_NO_SUCH_CORPUS = 0x0502
+CQP_ERROR_INVALID_FIELD = 0x0503
+CQP_ERROR_OUT_OF_RANGE = 0x0504
+# various cases where a number is out of range
+
+
+""" 3. CQi commands """
+""" 3.1 CQI_CTRL_* """
+CTRL = 0x11
+CTRL_CONNECT = 0x1101
+# INPUT: (STRING username, STRING password)
+# OUTPUT: CQI_STATUS_CONNECT_OK, CQI_ERROR_CONNECT_REFUSED
+CTRL_BYE = 0x1102
+# INPUT: ()
+# OUTPUT: CQI_STATUS_BYE_OK
+CTRL_USER_ABORT = 0x1103
+# INPUT: ()
+# OUTPUT:
+CTRL_PING = 0x1104
+# INPUT: ()
+# OUTPUT: CQI_STATUS_PING_OK
+CTRL_LAST_GENERAL_ERROR = 0x1105
+# INPUT: ()
+# OUTPUT: CQI_DATA_STRING
+# full-text error message for the last general error reported by the CQi server
+
+""" 3.2 CQI_ASK_FEATURE_* """
+ASK_FEATURE = 0x12
+ASK_FEATURE_CQI_1_0 = 0x1201
+# INPUT: ()
+# OUTPUT: CQI_DATA_BOOL
+ASK_FEATURE_CL_2_3 = 0x1202
+# INPUT: ()
+# OUTPUT: CQI_DATA_BOOL
+ASK_FEATURE_CQP_2_3 = 0x1203
+# INPUT: ()
+# OUTPUT: CQI_DATA_BOOL
+
+""" 3.3 CQI_CORPUS_* """
+CORPUS = 0x13
+CORPUS_LIST_CORPORA = 0x1301
+# INPUT: ()
+# OUTPUT: CQI_DATA_STRING_LIST
+CORPUS_CHARSET = 0x1303
+# INPUT: (STRING corpus)
+# OUTPUT: CQI_DATA_STRING
+CORPUS_PROPERTIES = 0x1304
+# INPUT: (STRING corpus)
+# OUTPUT: CQI_DATA_STRING_LIST
+CORPUS_POSITIONAL_ATTRIBUTES = 0x1305
+# INPUT: (STRING corpus)
+# OUTPUT: CQI_DATA_STRING_LIST
+CORPUS_STRUCTURAL_ATTRIBUTES = 0x1306
+# INPUT: (STRING corpus)
+# OUTPUT: CQI_DATA_STRING_LIST
+CORPUS_STRUCTURAL_ATTRIBUTE_HAS_VALUES = 0x1307
+# INPUT: (STRING attribute)
+# OUTPUT: CQI_DATA_BOOL
+CORPUS_ALIGNMENT_ATTRIBUTES = 0x1308
+# INPUT: (STRING corpus)
+# OUTPUT: CQI_DATA_STRING_LIST
+CORPUS_FULL_NAME = 0x1309
+# INPUT: (STRING corpus)
+# OUTPUT: CQI_DATA_STRING
+# the full name of <corpus> as specified in its registry entry
+CORPUS_INFO = 0x130A
+# INPUT: (STRING corpus)
+# OUTPUT: CQI_DATA_STRING_LIST
+# returns the contents of the .info file of <corpus> as a list of lines
+CORPUS_DROP_CORPUS = 0x130B
+# INPUT: (STRING corpus)
+# OUTPUT: CQI_STATUS_OK
+# try to unload a corpus and all its attributes from memory
+
+""" 3.4 CQI_CL_* """
+CL = 0x14
+# low-level corpus access (CL functions)
+CL_ATTRIBUTE_SIZE = 0x1401
+# INPUT: (STRING attribute)
+# OUTPUT: CQI_DATA_INT
+# returns the size of <attribute>:
+# - number of tokens (positional)
+# - number of regions (structural)
+# - number of alignments (alignment)
+CL_LEXICON_SIZE = 0x1402
+# INPUT: (STRING attribute)
+# OUTPUT: CQI_DATA_INT
+# returns the number of entries in the lexicon of a positional attribute;
+# valid lexicon IDs range from 0 .. (lexicon_size - 1)
+CL_DROP_ATTRIBUTE = 0x1403
+# INPUT: (STRING attribute)
+# OUTPUT: CQI_STATUS_OK
+# unload attribute from memory
+"""
+" NOTE: simple (scalar) mappings are applied to lists (the returned list has
+"       exactly the same length as the list passed as an argument)
+"""
+CL_STR2ID = 0x1404
+# INPUT: (STRING attribute, STRING_LIST strings)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns -1 for every string in <strings> that is not found in the lexicon
+CL_ID2STR = 0x1405
+# INPUT: (STRING attribute, INT_LIST id)
+# OUTPUT: CQI_DATA_STRING_LIST
+# returns "" for every ID in <id> that is out of range
+CL_ID2FREQ = 0x1406
+# INPUT: (STRING attribute, INT_LIST id)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns 0 for every ID in <id> that is out of range
+CL_CPOS2ID = 0x1407
+# INPUT: (STRING attribute, INT_LIST cpos)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns -1 for every corpus position in <cpos> that is out of range
+CL_CPOS2STR = 0x1408
+# INPUT: (STRING attribute, INT_LIST cpos)
+# OUTPUT: CQI_DATA_STRING_LIST
+# returns "" for every corpus position in <cpos> that is out of range
+CL_CPOS2STRUC = 0x1409
+# INPUT: (STRING attribute, INT_LIST cpos)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns -1 for every corpus position not inside a structure region
+"""
+" NOTE: temporary addition for the Euralex2000 tutorial, but should probably be
+"       included in CQi specs
+"""
+CL_CPOS2LBOUND = 0x1420
+# INPUT: (STRING attribute, INT_LIST cpos)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns left boundary of s-attribute region enclosing cpos, -1 if not in
+# region
+CL_CPOS2RBOUND = 0x1421
+# INPUT: (STRING attribute, INT_LIST cpos)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns right boundary of s-attribute region enclosing cpos, -1 if not in
+# region
+CL_CPOS2ALG = 0x140A
+# INPUT: (STRING attribute, INT_LIST cpos)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns -1 for every corpus position not inside an alignment
+CL_STRUC2STR = 0x140B
+# INPUT: (STRING attribute, INT_LIST strucs)
+# OUTPUT: CQI_DATA_STRING_LIST
+# returns annotated string values of structure regions in <strucs>; "" if out
+# of range
+# check CQI_CORPUS_STRUCTURAL_ATTRIBUTE_HAS_VALUES(<attribute>) first
+"""
+" NOTE: the following mappings take a single argument and return multiple
+"       values, including lists of arbitrary size
+"""
+CL_ID2CPOS = 0x140C
+# INPUT: (STRING attribute, INT id)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns all corpus positions where the given token occurs
+CL_IDLIST2CPOS = 0x140D
+# INPUT: (STRING attribute, INT_LIST id_list)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns all corpus positions where one of the tokens in <id_list>
+# occurs; the returned list is sorted as a whole, not per token id
+CL_REGEX2ID = 0x140E
+# INPUT: (STRING attribute, STRING regex)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns lexicon IDs of all tokens that match <regex>; the returned
+# list may be empty (size 0);
+CL_STRUC2CPOS = 0x140F
+# INPUT: (STRING attribute, INT struc)
+# OUTPUT: CQI_DATA_INT_INT
+# returns start and end corpus positions of structure region <struc>
+CL_ALG2CPOS = 0x1410
+# INPUT: (STRING attribute, INT alg)
+# OUTPUT: CQI_DATA_INT_INT_INT_INT
+# returns (src_start, src_end, target_start, target_end)
+
+""" 3.5 CQI_CQP_* """
+CQP = 0x15
+CQP_QUERY = 0x1501
+# INPUT: (STRING mother_corpus, STRING subcorpus_name, STRING query)
+# OUTPUT: CQI_STATUS_OK
+# <query> must include the ';' character terminating the query.
+CQP_LIST_SUBCORPORA = 0x1502
+# INPUT: (STRING corpus)
+# OUTPUT: CQI_DATA_STRING_LIST
+CQP_SUBCORPUS_SIZE = 0x1503
+# INPUT: (STRING subcorpus)
+# OUTPUT: CQI_DATA_INT
+CQP_SUBCORPUS_HAS_FIELD = 0x1504
+# INPUT: (STRING subcorpus, BYTE field)
+# OUTPUT: CQI_DATA_BOOL
+CQP_DUMP_SUBCORPUS = 0x1505
+# INPUT: (STRING subcorpus, BYTE field, INT first, INT last)
+# OUTPUT: CQI_DATA_INT_LIST
+# Dump the values of <field> for match ranges <first> .. <last> in <subcorpus>.
+# <field> is one of the CQI_CONST_FIELD_* constants.
+CQP_DROP_SUBCORPUS = 0x1509
+# INPUT: (STRING subcorpus)
+# OUTPUT: CQI_STATUS_OK
+# delete a subcorpus from memory
+"""
+" NOTE: The following two functions are temporarily included for the Euralex
+"       2000 tutorial demo
+"""
+""" NOTE: frequency distribution of single tokens """
+CQP_FDIST_1 = 0x1510
+# INPUT: (STRING subcorpus, INT cutoff, BYTE field, STRING attribute)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns <n> (id, frequency) pairs flattened into a list of size 2*<n>
+# field is one of CQI_CONST_FIELD_MATCH, CQI_CONST_FIELD_TARGET,
+# CQI_CONST_FIELD_KEYWORD
+# NB: pairs are sorted by frequency desc.
+""" NOTE: frequency distribution of pairs of tokens """
+CQP_FDIST_2 = 0x1511
+# INPUT: (STRING subcorpus, INT cutoff, BYTE field1, STRING attribute1,
+#         BYTE field2, STRING attribute2)
+# OUTPUT: CQI_DATA_INT_LIST
+# returns <n> (id1, id2, frequency) pairs flattened into a list of size 3*<n>
+# NB: triples are sorted by frequency desc.
+
+
+""" 4. Constant Definitions """
+CONST_FALSE = 0x00
+CONST_NO = 0x00
+CONST_TRUE = 0x01
+CONST_YES = 0x01
+"""
+" NOTE: The following constants specify which field will be returned by
+"       CQI_CQP_DUMP_SUBCORPUS and some other subcorpus commands.
+"""
+CONST_FIELD_MATCH = 0x10
+CONST_FIELD_MATCHEND = 0x11
+"""
+" NOTE: The constants specifiying target0 .. target9 are guaranteed to have the
+" numerical values 0 .. 9, so clients do not need to look up the constant
+" values if they're handling arbitrary targets.
+"""
+CONST_FIELD_TARGET_0 = 0x00
+CONST_FIELD_TARGET_1 = 0x01
+CONST_FIELD_TARGET_2 = 0x02
+CONST_FIELD_TARGET_3 = 0x03
+CONST_FIELD_TARGET_4 = 0x04
+CONST_FIELD_TARGET_5 = 0x05
+CONST_FIELD_TARGET_6 = 0x06
+CONST_FIELD_TARGET_7 = 0x07
+CONST_FIELD_TARGET_8 = 0x08
+CONST_FIELD_TARGET_9 = 0x09
+"""
+" NOTE: The following constants are provided for backward compatibility with
+"       traditional CQP field names & while the generalised target concept
+"       isn't yet implemented in the CQPserver.
+"""
+CONST_FIELD_TARGET = 0x00
+CONST_FIELD_KEYWORD = 0x09
+""" NOTE: CQi version is CQI_MAJOR_VERSION.CQI_MINOR_VERSION """
+MAJOR_VERSION = 0x00
+MINOR_VERSION = 0x01
+
+
+""" 5. CQi lookup dictionary. """
+lookup = {
+    257: 'CQI_STATUS_OK',
+    258: 'CQI_STATUS_CONNECT_OK',
+    259: 'CQI_STATUS_BYE_OK',
+    260: 'CQI_STATUS_PING_OK',
+    513: 'CQI_ERROR_GENERAL_ERROR',
+    514: 'CQI_ERROR_CONNECT_REFUSED',
+    515: 'CQI_ERROR_USER_ABORT',
+    516: 'CQI_ERROR_SYNTAX_ERROR',
+    769: 'CQI_DATA_BYTE',
+    770: 'CQI_DATA_BOOL',
+    771: 'CQI_DATA_INT',
+    772: 'CQI_DATA_STRING',
+    773: 'CQI_DATA_BYTE_LIST',
+    774: 'CQI_DATA_BOOL_LIST',
+    775: 'CQI_DATA_INT_LIST',
+    776: 'CQI_DATA_STRING_LIST',
+    777: 'CQI_DATA_INT_INT',
+    778: 'CQI_DATA_INT_INT_INT_INT',
+    779: 'CQI_DATA_INT_TABLE',
+    1025: 'CQI_CL_ERROR_NO_SUCH_ATTRIBUTE',
+    1026: 'CQI_CL_ERROR_WRONG_ATTRIBUTE_TYPE',
+    1027: 'CQI_CL_ERROR_OUT_OF_RANGE',
+    1028: 'CQI_CL_ERROR_REGEX',
+    1029: 'CQI_CL_ERROR_CORPUS_ACCESS',
+    1030: 'CQI_CL_ERROR_OUT_OF_MEMORY',
+    1031: 'CQI_CL_ERROR_INTERNAL',
+    1281: 'CQI_CQP_ERROR_GENERAL',
+    1282: 'CQI_CQP_ERROR_NO_SUCH_CORPUS',
+    1283: 'CQI_CQP_ERROR_INVALID_FIELD',
+    1284: 'CQI_CQP_ERROR_OUT_OF_RANGE',
+    4353: 'CQI_CTRL_CONNECT',
+    4354: 'CQI_CTRL_BYE',
+    4355: 'CQI_CTRL_USER_ABORT',
+    4356: 'CQI_CTRL_PING',
+    4357: 'CQI_CTRL_LAST_GENERAL_ERROR',
+    4609: 'CQI_ASK_FEATURE_CQI_1_0',
+    4610: 'CQI_ASK_FEATURE_CL_2_3',
+    4611: 'CQI_ASK_FEATURE_CQP_2_3',
+    4865: 'CQI_CORPUS_LIST_CORPORA',
+    4867: 'CQI_CORPUS_CHARSET',
+    4868: 'CQI_CORPUS_PROPERTIES',
+    4869: 'CQI_CORPUS_POSITIONAL_ATTRIBUTES',
+    4870: 'CQI_CORPUS_STRUCTURAL_ATTRIBUTES',
+    4871: 'CQI_CORPUS_STRUCTURAL_ATTRIBUTE_HAS_VALUES',
+    4872: 'CQI_CORPUS_ALIGNMENT_ATTRIBUTES',
+    4873: 'CQI_CORPUS_FULL_NAME',
+    4874: 'CQI_CORPUS_INFO',
+    4875: 'CQI_CORPUS_DROP_CORPUS',
+    5121: 'CQI_CL_ATTRIBUTE_SIZE',
+    5122: 'CQI_CL_LEXICON_SIZE',
+    5123: 'CQI_CL_DROP_ATTRIBUTE',
+    5124: 'CQI_CL_STR2ID',
+    5125: 'CQI_CL_ID2STR',
+    5126: 'CQI_CL_ID2FREQ',
+    5127: 'CQI_CL_CPOS2ID',
+    5128: 'CQI_CL_CPOS2STR',
+    5129: 'CQI_CL_CPOS2STRUC',
+    5130: 'CQI_CL_CPOS2ALG',
+    5131: 'CQI_CL_STRUC2STR',
+    5132: 'CQI_CL_ID2CPOS',
+    5133: 'CQI_CL_IDLIST2CPOS',
+    5134: 'CQI_CL_REGEX2ID',
+    5135: 'CQI_CL_STRUC2CPOS',
+    5136: 'CQI_CL_ALG2CPOS',
+    5152: 'CQI_CL_CPOS2LBOUND',
+    5153: 'CQI_CL_CPOS2RBOUND',
+    5377: 'CQI_CQP_QUERY',
+    5378: 'CQI_CQP_LIST_SUBCORPORA',
+    5379: 'CQI_CQP_SUBCORPUS_SIZE',
+    5380: 'CQI_CQP_SUBCORPUS_HAS_FIELD',
+    5381: 'CQI_CQP_DUMP_SUBCORPUS',
+    5385: 'CQI_CQP_DROP_SUBCORPUS',
+    5392: 'CQI_CQP_FDIST_1',
+    5393: 'CQI_CQP_FDIST_2'
+}
diff --git a/app/corpora/CQiClient/CQiClient.py b/app/corpora/CQiClient/CQiClient.py
new file mode 100644
index 00000000..39a24c4c
--- /dev/null
+++ b/app/corpora/CQiClient/CQiClient.py
@@ -0,0 +1,611 @@
+from . import CQi
+import socket
+import struct
+
+
+class CQiClient:
+    def __init__(self, host='127.0.0.1', port=4877):
+        self.host = host
+        self.port = port
+        self.connection = socket.socket()
+        self.connection.connect((self.host, self.port))
+
+    def ctrl_connect(self, username, password):
+        # INPUT: (STRING username, STRING password)
+        # OUTPUT: CQI_STATUS_CONNECT_OK, CQI_ERROR_CONNECT_REFUSED
+        # print('CTRL_CONNECT')
+        self.__send_WORD(CQi.CTRL_CONNECT)
+        self.__send_STRING(username)
+        self.__send_STRING(password)
+        self.__recv_response()
+
+    def ctrl_bye(self):
+        # INPUT: ()
+        # OUTPUT: CQI_STATUS_BYE_OK
+        # print('CTRL_BYE')
+        self.__send_WORD(CQi.CTRL_BYE)
+        self.__recv_response()
+
+    def ctrl_user_abort(self):
+        # INPUT: ()
+        # OUTPUT:
+        # print('CTRL_USER_ABORT')
+        self.__send_WORD(CQi.CTRL_USER_ABORT)
+
+    def ctrl_ping(self):
+        # INPUT: ()
+        # OUTPUT: CQI_STATUS_PING_OK
+        # print('CTRL_PING')
+        self.__send_WORD(CQi.CTRL_PING)
+        self.__recv_response()
+
+    def ctrl_last_general_error(self):
+        # INPUT: ()
+        # OUTPUT: CQI_DATA_STRING
+        # full-text error message for the last general error reported by the
+        # CQi server
+        # print('CTRL_LAST_GENERAL_ERROR')
+        self.__send_WORD(CQi.CTRL_LAST_GENERAL_ERROR)
+        return self.__recv_response()
+
+    def ask_feature_cqi_1_0(self):
+        # INPUT: ()
+        # OUTPUT: CQI_DATA_BOOL
+        # print('ASK_FEATURE_CQI_1_0')
+        self.__send_WORD(CQi.ASK_FEATURE_CQI_1_0)
+        return self.__recv_response()
+
+    def ask_feature_cl_2_3(self):
+        # INPUT: ()
+        # OUTPUT: CQI_DATA_BOOL
+        # print('ASK_FEATURE_CL_2_3')
+        self.__send_WORD(CQi.ASK_FEATURE_CL_2_3)
+        return self.__recv_response()
+
+    def ask_feature_cqp_2_3(self):
+        # INPUT: ()
+        # OUTPUT: CQI_DATA_BOOL
+        # print('ASK_FEATURE_CL_2_3')
+        self.__send_WORD(CQi.ASK_FEATURE_CL_2_3)
+        return self.__recv_response()
+
+    def corpus_list_coprora(self):
+        # INPUT: ()
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # print('CORPUS_LIST_CORPORA')
+        self.__send_WORD(CQi.CORPUS_LIST_CORPORA)
+        return self.__recv_response()
+
+    def corpus_charset(self, corpus):
+        # INPUT: (STRING corpus)
+        # OUTPUT: CQI_DATA_STRING
+        # print('CORPUS_CHARSET')
+        self.__send_WORD(CQi.CORPUS_CHARSET)
+        self.__send_STRING(corpus)
+        return self.__recv_response()
+
+    def corpus_properties(self, corpus):
+        # INPUT: (STRING corpus)
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # print('CORPUS_PROPERTIES')
+        self.__send_WORD(CQi.CORPUS_PROPERTIES)
+        self.__send_STRING(corpus)
+        return self.__recv_response()
+
+    def corpus_positional_attributes(self, corpus):
+        # INPUT: (STRING corpus)
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # print('CORPUS_POSITIONAL_ATTRIBUTES')
+        self.__send_WORD(CQi.CORPUS_POSITIONAL_ATTRIBUTES)
+        self.__send_STRING(corpus)
+        return self.__recv_response()
+
+    def corpus_structural_attributes(self, corpus):
+        # INPUT: (STRING corpus)
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # print('CORPUS_STRUCTURAL_ATTRIBUTES')
+        self.__send_WORD(CQi.CORPUS_STRUCTURAL_ATTRIBUTES)
+        self.__send_STRING(corpus)
+        return self.__recv_response()
+
+    def corpus_structural_attribute_has_values(self, attribute):
+        # INPUT: (STRING attribute)
+        # OUTPUT: CQI_DATA_BOOL
+        # print('CORPUS_STRUCTURAL_ATTRIBUTE_HAS_VALUES')
+        self.__send_WORD(CQi.CORPUS_STRUCTURAL_ATTRIBUTE_HAS_VALUES)
+        self.__send_STRING(attribute)
+        return self.__recv_response()
+
+    def corpus_alignment_attributes(self, corpus):
+        # INPUT: (STRING corpus)
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # print('CORPUS_ALIGNMENT_ATTRIBUTES')
+        self.__send_WORD(CQi.CORPUS_ALIGNMENT_ATTRIBUTES)
+        self.__send_STRING(corpus)
+        return self.__recv_response()
+
+    def corpus_full_name(self, corpus):
+        # INPUT: (STRING corpus)
+        # OUTPUT: CQI_DATA_STRING
+        # the full name of <corpus> as specified in its registry entry
+        # print('CORPUS_FULL_NAME')
+        self.__send_WORD(CQi.CORPUS_FULL_NAME)
+        self.__send_STRING(corpus)
+        return self.__recv_response()
+
+    def corpus_info(self, corpus):
+        # INPUT: (STRING corpus)
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # returns the contents of the .info file of <corpus> as a list of lines
+        # print('CORPUS_INFO')
+        self.__send_WORD(CQi.CORPUS_INFO)
+        self.__send_STRING(corpus)
+        return self.__recv_response()
+
+    def corpus_drop_corpus(self, corpus):
+        '''
+        ' Broken
+        ' TODO: Check what type of return value is provided by the server.
+        '''
+        # INPUT: (STRING corpus)
+        # OUTPUT: CQI_STATUS_OK
+        # try to unload a corpus and all its attributes from memory
+        # print('CORPUS_DROP_CORPUS')
+        self.__send_WORD(CQi.CORPUS_DROP_CORPUS)
+        self.__send_STRING(corpus)
+        self.__recv_response()
+
+    def cl_attribute_size(self, attribute):
+        # INPUT: (STRING attribute)
+        # OUTPUT: CQI_DATA_INT
+        # returns the size of <attribute>:
+        #     number of tokens        (positional)
+        #     number of regions       (structural)
+        #     number of alignments    (alignment)
+        # print('CL_ATTRIBUTE_SIZE')
+        self.__send_WORD(CQi.CL_ATTRIBUTE_SIZE)
+        self.__send_STRING(attribute)
+        return self.__recv_response()
+
+    def cl_lexicon_size(self, attribute):
+        # INPUT: (STRING attribute)
+        # OUTPUT: CQI_DATA_INT
+        # returns the number of entries in the lexicon of a positional
+        # attribute;
+        # valid lexicon IDs range from 0 .. (lexicon_size - 1)
+        # print('CL_LEXICON_SIZE')
+        self.__send_WORD(CQi.CL_LEXICON_SIZE)
+        self.__send_STRING(attribute)
+        return self.__recv_response()
+
+    def cl_drop_attribute(self, attribute):
+        # INPUT: (STRING attribute)
+        # OUTPUT: CQI_STATUS_OK
+        # unload attribute from memory
+        # print('CL_DROP_ATTRIBUTE')
+        self.__send_WORD(CQi.CL_LEXICON_SIZE)
+        self.__send_STRING(attribute)
+        self.__recv_response()
+
+    """
+    " NOTE: simple (scalar) mappings are applied to lists (the returned list
+    "       has exactly the same length as the list passed as an argument)
+    """
+
+    def cl_str2id(self, attribute, strings):
+        # INPUT: (STRING attribute, STRING_LIST strings)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns -1 for every string in <strings> that is not found in the
+        # lexicon
+        # print('CL_STR2ID')
+        self.__send_WORD(CQi.CL_LEXICON_SIZE)
+        self.__send_STRING(attribute)
+        self.__send_STRING_LIST(strings)
+        return self.__recv_response()
+
+    def cl_id2str(self, attribute, id):
+        # INPUT: (STRING attribute, INT_LIST id)
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # returns "" for every ID in <id> that is out of range
+        # print('CL_ID2STR')
+        self.__send_WORD(CQi.CL_ID2STR)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(id)
+        return self.__recv_response()
+
+    def cl_id2freq(self, attribute, id):
+        # INPUT: (STRING attribute, INT_LIST id)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns 0 for every ID in <id> that is out of range
+        # print('CL_ID2FREQ')
+        self.__send_WORD(CQi.CL_ID2FREQ)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(id)
+        return self.__recv_response()
+
+    def cl_cpos2id(self, attribute, cpos):
+        # INPUT: (STRING attribute, INT_LIST cpos)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns -1 for every corpus position in <cpos> that is out of range
+        # print('CL_CPOS2ID')
+        self.__send_WORD(CQi.CL_ID2FREQ)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(cpos)
+        return self.__recv_response()
+
+    def cl_cpos2str(self, attribute, cpos):
+        # INPUT: (STRING attribute, INT_LIST cpos)
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # returns "" for every corpus position in <cpos> that is out of range
+        # print('CL_CPOS2STR')
+        self.__send_WORD(CQi.CL_CPOS2STR)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(cpos)
+        return self.__recv_response()
+
+    def cl_cpos2struc(self, attribute, cpos):
+        # INPUT: (STRING attribute, INT_LIST cpos)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns -1 for every corpus position not inside a structure region
+        # print('CL_CPOS2STRUC')
+        self.__send_WORD(CQi.CL_CPOS2STRUC)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(cpos)
+        return self.__recv_response()
+
+    """
+    " NOTE: temporary addition for the Euralex2000 tutorial, but should
+    "       probably be included in CQi specs
+    """
+
+    def cl_cpos2lbound(self, attribute, cpos):
+        # INPUT: (STRING attribute, INT_LIST cpos)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns left boundary of s-attribute region enclosing cpos, -1 if not
+        # in region
+        # print('CL_CPOS2LBOUND')
+        self.__send_WORD(CQi.CL_CPOS2LBOUND)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(cpos)
+        return self.__recv_response()
+
+    def cl_cpos2rbound(self, attribute, cpos):
+        # INPUT: (STRING attribute, INT_LIST cpos)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns right boundary of s-attribute region enclosing cpos, -1 if
+        # not in region
+        # print('CL_CPOS2RBOUND')
+        self.__send_WORD(CQi.CL_CPOS2RBOUND)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(cpos)
+        return self.__recv_response()
+
+    def cl_cpos2alg(self, attribute, cpos):
+        # INPUT: (STRING attribute, INT_LIST cpos)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns -1 for every corpus position not inside an alignment
+        # print('CL_CPOS2ALG')
+        self.__send_WORD(CQi.CL_CPOS2ALG)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(cpos)
+        return self.__recv_response()
+
+    def cl_struc2str(self, attribute, strucs):
+        # INPUT: (STRING attribute, INT_LIST strucs)
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # returns annotated string values of structure regions in <strucs>; ""
+        # if out of range
+        # check CQI_CORPUS_STRUCTURAL_ATTRIBUTE_HAS_VALUES(<attribute>) first
+        # print('CL_STRUC2STR')
+        self.__send_WORD(CQi.CL_STRUC2STR)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(strucs)
+        return self.__recv_response()
+
+    """
+    " NOTE: the following mappings take a single argument and return multiple
+    "       values, including lists of arbitrary size
+    """
+
+    def cl_id2cpos(self, attribute, id):
+        # INPUT: (STRING attribute, INT id)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns all corpus positions where the given token occurs
+        # print('CL_ID2CPOS')
+        self.__send_WORD(CQi.CL_ID2CPOS)
+        self.__send_STRING(attribute)
+        self.__send_INT(id)
+        return self.__recv_response()
+
+    def cl_idlist2cpos(self, attribute, id_list):
+        # INPUT: (STRING attribute, INT_LIST id_list)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns all corpus positions where one of the tokens in <id_list>
+        # occurs; the returned list is sorted as a whole, not per token id
+        # print('CL_IDLIST2CPOS')
+        self.__send_WORD(CQi.CL_IDLIST2CPOS)
+        self.__send_STRING(attribute)
+        self.__send_INT_LIST(id_list)
+        return self.__recv_response()
+
+    def cl_regex2id(self, attribute, regex):
+        # INPUT: (STRING attribute, STRING regex)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns lexicon IDs of all tokens that match <regex>; the returned
+        # list may be empty (size 0);
+        # print('CL_REGEX2ID')
+        self.__send_WORD(CQi.CL_REGEX2ID)
+        self.__send_STRING(attribute)
+        self.__send_STRING(regex)
+        return self.__recv_response()
+
+    def cl_struc2cpos(self, attribute, struc):
+        # INPUT: (STRING attribute, INT struc)
+        # OUTPUT: CQI_DATA_INT_INT
+        # returns start and end corpus positions of structure region <struc>
+        # print('CL_STRUC2CPOS')
+        self.__send_WORD(CQi.CL_STRUC2CPOS)
+        self.__send_STRING(attribute)
+        self.__send_INT(struc)
+        return self.__recv_response()
+
+    def cl_alg2cpos(self, attribute, alg):
+        # INPUT: (STRING attribute, INT alg)
+        # OUTPUT: CQI_DATA_INT_INT_INT_INT
+        # returns (src_start, src_end, target_start, target_end)
+        # print('CL_ALG2CPOS')
+        self.__send_WORD(CQi.CL_ALG2CPOS)
+        self.__send_STRING(attribute)
+        self.__send_INT(alg)
+        return self.__recv_response()
+
+    def cqp_query(self, mother_corpus, subcorpus_name, query):
+        # INPUT: (STRING mother_corpus, STRING subcorpus_name, STRING query)
+        # OUTPUT: CQI_STATUS_OK
+        # <query> must include the ';' character terminating the query.
+        # print('CQP_QUERY')
+        self.__send_WORD(CQi.CQP_QUERY)
+        self.__send_STRING(mother_corpus)
+        self.__send_STRING(subcorpus_name)
+        self.__send_STRING(query)
+        self.__recv_WORD()
+
+    def cqp_list_subcorpora(self, corpus):
+        # INPUT: (STRING corpus)
+        # OUTPUT: CQI_DATA_STRING_LIST
+        # print('CQP_LIST_SUBCORPORA')
+        self.__send_WORD(CQi.CQP_LIST_SUBCORPORA)
+        self.__send_STRING(corpus)
+        return self.__recv_response()
+
+    def cqp_subcorpus_size(self, subcorpus):
+        # INPUT: (STRING subcorpus)
+        # OUTPUT: CQI_DATA_INT
+        # print('CQP_SUBCORPUS_SIZE')
+        self.__send_WORD(CQi.CQP_SUBCORPUS_SIZE)
+        self.__send_STRING(subcorpus)
+        return self.__recv_response()
+
+    def cqp_subcorpus_has_field(self, subcorpus, field):
+        # INPUT: (STRING subcorpus, BYTE field)
+        # OUTPUT: CQI_DATA_BOOL
+        # print('CQP_SUBCORPUS_HAS_FIELD')
+        self.__send_WORD(CQi.CQP_SUBCORPUS_HAS_FIELD)
+        self.__send_STRING(subcorpus)
+        self.__send_BYTE(field)
+        return self.__recv_response()
+
+    def cqp_dump_subcorpus(self, subcorpus, field, first, last):
+        # INPUT: (STRING subcorpus, BYTE field, INT first, INT last)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # Dump the values of <field> for match ranges <first> .. <last>
+        # in <subcorpus>. <field> is one of the CQI_CONST_FIELD_* constants.
+        # print('CQP_DUMP_SUBCORPUS')
+        self.__send_WORD(CQi.CQP_DUMP_SUBCORPUS)
+        self.__send_STRING(subcorpus)
+        self.__send_BYTE(field)
+        self.__send_INT(first)
+        self.__send_INT(last)
+        return self.__recv_response()
+
+    def cqp_drop_subcorpus(self, subcorpus):
+        # INPUT: (STRING subcorpus)
+        # OUTPUT: CQI_STATUS_OK
+        # delete a subcorpus from memory
+        # print('CQP_DROP_SUBCORPUS')
+        self.__send_WORD(CQi.CQP_DROP_SUBCORPUS)
+        self.__send_STRING(subcorpus)
+        self.__recv_response()
+
+    """
+    " NOTE: The following two functions are temporarily included for the
+    "       Euralex 2000 tutorial demo
+    """
+
+    def cqp_fdist_1(self, subcorpus, cutoff, field, attribute):
+        """ NOTE: frequency distribution of single tokens """
+        # INPUT: (STRING subcorpus, INT cutoff, BYTE field, STRING attribute)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns <n> (id, frequency) pairs flattened into a list of size 2*<n>
+        # field is one of CQI_CONST_FIELD_MATCH, CQI_CONST_FIELD_TARGET,
+        #                 CQI_CONST_FIELD_KEYWORD
+        # NB: pairs are sorted by frequency desc.
+        # print('CQP_FDIST_1')
+        self.__send_WORD(CQi.CQP_FDIST_1)
+        self.__send_STRING(subcorpus)
+        self.__send_INT(cutoff)
+        self.__send_BYTE(field)
+        self.__send_STRING(attribute)
+        return self.__recv_response()
+
+    def cqp_fdist_2(self, subcorpus, cutoff, field1, attribute1, field2,
+                    attribute2):
+        """ NOTE: frequency distribution of pairs of tokens """
+        # INPUT: (STRING subcorpus, INT cutoff, BYTE field1, STRING attribute1,
+        #         BYTE field2, STRING attribute2)
+        # OUTPUT: CQI_DATA_INT_LIST
+        # returns <n> (id1, id2, frequency) pairs flattened into a list of size
+        # 3*<n>
+        # NB: triples are sorted by frequency desc.
+        # print('CQP_FDIST_2')
+        self.__send_WORD(CQi.CQP_FDIST_2)
+        self.__send_STRING(subcorpus)
+        self.__send_INT(cutoff)
+        self.__send_BYTE(field1)
+        self.__send_STRING(attribute1)
+        self.__send_BYTE(field2)
+        self.__send_STRING(attribute2)
+        return self.__recv_response()
+
+    def __recv_response(self):
+        byte_data = self.__recv_WORD()
+        response_type = byte_data >> 8
+        if response_type == CQi.STATUS:
+            response = byte_data
+        elif response_type == CQi.ERROR:
+            raise Exception(CQi.lookup[byte_data])
+        elif response_type == CQi.DATA:
+            response = self.__recv_DATA(byte_data)
+        elif response_type == CQi.CL_ERROR:
+            raise Exception(CQi.lookup[byte_data])
+        elif response_type == CQi.CQP_ERROR:
+            raise Exception(CQi.lookup[byte_data])
+        else:
+            raise Exception(
+                'Unknown response type: {}'.format(hex(response_type))
+            )
+        return response
+
+    def __recv_DATA(self, data_type):
+        if data_type == CQi.DATA_BYTE:
+            data = self.__recv_DATA_BYTE()
+        elif data_type == CQi.DATA_BOOL:
+            data = self.__recv_DATA_BOOL()
+        elif data_type == CQi.DATA_INT:
+            data = self.__recv_DATA_INT()
+        elif data_type == CQi.DATA_STRING:
+            data = self.__recv_DATA_STRING()
+        elif data_type == CQi.DATA_BYTE_LIST:
+            data = self.__recv_DATA_BYTE_LIST()
+        elif data_type == CQi.DATA_BOOL_LIST:
+            data = self.__recv_DATA_BOOL_LIST()
+        elif data_type == CQi.DATA_INT_LIST:
+            data = self.__recv_DATA_INT_LIST()
+        elif data_type == CQi.DATA_STRING_LIST:
+            data = self.__recv_DATA_STRING_LIST()
+        elif data_type == CQi.DATA_INT_INT:
+            data = self.__recv_DATA_INT_INT()
+        elif data_type == CQi.DATA_INT_INT_INT_INT:
+            data = self.__recv_DATA_INT_INT_INT_INT()
+        elif data_type == CQi.DATA_INT_TABLE:
+            data = self.__recv_DATA_INT_TABLE()
+        else:
+            raise Exception('Unknown data type: {}'.format(hex(data_type)))
+        return data
+
+    def __recv_DATA_BYTE(self):
+        byte_data = self.connection.recv(1)
+        return struct.unpack('!B', byte_data)[0]
+
+    def __recv_DATA_BOOL(self):
+        byte_data = self.connection.recv(1)
+        return struct.unpack('!?', byte_data)[0]
+
+    def __recv_DATA_INT(self):
+        byte_data = self.connection.recv(4)
+        return struct.unpack('!i', byte_data)[0]
+
+    def __recv_DATA_STRING(self):
+        n = self.__recv_WORD()
+        byte_data = self.connection.recv(n)
+        return struct.unpack('!{}s'.format(n), byte_data)[0].decode()
+
+    def __recv_DATA_BYTE_LIST(self):
+        data = []
+        n = self.__recv_DATA_INT()
+        while n > 0:
+            data.append(self.__recv_DATA_BYTE())
+            n -= 1
+        return data
+
+    def __recv_DATA_BOOL_LIST(self):
+        data = []
+        n = self.__recv_DATA_INT()
+        while n > 0:
+            data.append(self.__recv_DATA_BOOL())
+            n -= 1
+        return data
+
+    def __recv_DATA_INT_LIST(self):
+        data = []
+        n = self.__recv_DATA_INT()
+        while n > 0:
+            data.append(self.__recv_DATA_INT())
+            n -= 1
+        return data
+
+    def __recv_DATA_STRING_LIST(self):
+        data = []
+        n = self.__recv_DATA_INT()
+        while n > 0:
+            data.append(self.__recv_DATA_STRING())
+            n -= 1
+        return data
+
+    def __recv_DATA_INT_INT(self):
+        return (self.__recv_INT(), self.__recv_INT())
+
+    def __recv_DATA_INT_INT_INT_INT(self):
+        return (self.__recv_INT(),
+                self.__recv_INT(),
+                self.__recv_INT(),
+                self.__recv_INT())
+
+    def __recv_DATA_INT_TABLE(self):
+        rows = self.__recv_DATA_INT()
+        columns = self.__recv_DATA_INT()
+        data = []
+        for i in range(0, rows):
+            row = []
+            for j in range(0, columns):
+                row.append(self.__recv_DATA_INT())
+            data.append(row)
+        return data
+
+    def __recv_WORD(self):
+        byte_data = self.connection.recv(2)
+        return struct.unpack('!H', byte_data)[0]
+
+    def __send_BYTE(self, byte_data):
+        data = struct.pack('!B', byte_data)
+        self.connection.sendall(data)
+
+    def __send_BOOL(self, bool_data):
+        data = struct.pack('!?', bool_data)
+        self.connection.sendall(data)
+
+    def __send_INT(self, int_data):
+        data = struct.pack('!i', int_data)
+        self.connection.sendall(data)
+
+    def __send_STRING(self, string_data):
+        encoded_string_data = string_data.encode('utf-8')
+        n = len(encoded_string_data)
+        data = struct.pack('!H{}s'.format(n), n, encoded_string_data)
+        self.connection.sendall(data)
+
+    def __send_INT_LIST(self, int_list_data):
+        n = len(int_list_data)
+        self.__send_INT(n)
+        for int_data in int_list_data:
+            self.__send_INT(int_data)
+
+    def __send_STRING_LIST(self, string_list_data):
+        n = len(string_list_data)
+        self.__send_INT(n)
+        for string_data in string_list_data:
+            self.__send_STRING(string_data)
+
+    def __send_WORD(self, word_data):
+        data = struct.pack('!H', word_data)
+        self.connection.sendall(data)
diff --git a/app/corpora/events.py b/app/corpora/events.py
index 51b240ac..f513052e 100644
--- a/app/corpora/events.py
+++ b/app/corpora/events.py
@@ -3,12 +3,15 @@ from app.events import connected_sessions
 from app.models import Corpus
 from flask import current_app, request
 from flask_login import login_required
+from .CQiClient.CQiClient import CQiClient
 import logging
 
 
 @socketio.on('init_corpus_analysis')
 @login_required
 def init_corpus_analysis(corpus_id):
+    logger = logging.getLogger(__name__)
+    logger.warning('init_corpus_analysis')
     ''' TODO: Check if current_user is allowed to subscribe to this '''
     socketio.start_background_task(observe_corpus_analysis_connection,
                                    current_app._get_current_object(),
@@ -25,7 +28,9 @@ def recv_query(message):
 def observe_corpus_analysis_connection(app, corpus_id, session_id):
     logger = logging.getLogger(__name__)
     with app.app_context():
+        cqi_client = CQiClient(host='172.25.0.2')
         while session_id in connected_sessions:
+            logger.warning(cqi_client.ctrl_ping())
             logger.warning('Run container, run!')
             socketio.sleep(3)
         corpus = Corpus.query.filter_by(id=corpus_id).first()
-- 
GitLab