Example #1
0
    def dump_ELMo_token_embeddings(self, x_train):
        if not self.use_ELMo:
            print(
                "Warning: ELMo embeddings dump requested but embeddings object wrongly initialised"
            )
            return

        description = self._get_description('elmo-en')
        if description is not None:
            print("Building ELMo token dump")

            self.lang = description["lang"]
            options_file = description["path-config"]
            weight_file = description["path_weights"]
            working_path = description["path-dump"]

            all_tokens = set(['<S>', '</S>'])
            for i in range(0, len(x_train)):
                # as it is training, it is already tokenized
                tokens = x_train[i]
                for token in tokens:
                    if token not in all_tokens:
                        all_tokens.add(token)

            vocab_file = os.path.join(working_path, 'vocab_small.txt')
            with open(vocab_file, 'w') as fout:
                fout.write('\n'.join(all_tokens))

            tf.reset_default_graph()
            token_embedding_file = os.path.join(working_path,
                                                'elmo_token_embeddings.hdf5')
            dump_token_embeddings(vocab_file, options_file, weight_file,
                                  token_embedding_file)
            tf.reset_default_graph()

            self.batcher_token_dump = TokenBatcher(vocab_file)

            self.bilm_token_dump = BidirectionalLanguageModel(
                options_file,
                weight_file,
                use_character_inputs=False,
                embedding_weight_file=token_embedding_file)

            self.token_ids = tf.placeholder('int32', shape=(None, None))
            self.embeddings_op_token_dump = self.bilm_token_dump(
                self.token_ids)
            """
            with tf.variable_scope('', reuse=tf.AUTO_REUSE):
                # the reuse=True scope reuses weights from the whole context 
                self.elmo_input_token_dump = weight_layers('input', self.embeddings_op_token_dump, l2_coef=0.0)
            """
            print("ELMo token dump completed")
Example #2
0
class Embeddings(object):
    def __init__(self,
                 name,
                 path='./embedding-registry.json',
                 lang='en',
                 extension='vec',
                 use_ELMo=False):
        self.name = name
        self.embed_size = 0
        self.static_embed_size = 0
        self.vocab_size = 0
        self.model = {}
        self.registry = self._load_embedding_registry(path)
        self.lang = lang
        self.extension = extension
        self.embedding_lmdb_path = None
        if self.registry is not None:
            self.embedding_lmdb_path = self.registry["embedding-lmdb-path"]
        self.env = None
        self.make_embeddings_simple(name)
        self.static_embed_size = self.embed_size
        self.bilm = None

        # below init for using ELMo embeddings
        self.use_ELMo = use_ELMo
        if use_ELMo:
            self.make_ELMo()
            self.embed_size = ELMo_embed_size + self.embed_size
            description = self._get_description('elmo-en')
            self.env_ELMo = None
            if description:
                self.embedding_ELMo_cache = os.path.join(
                    description["path-dump"], "cache")
                # clean possible remaining cache
                self.clean_ELMo_cache()
                # create and load a cache in write mode, it will be used only for training
                self.env_ELMo = lmdb.open(self.embedding_ELMo_cache,
                                          map_size=map_size)

    def __getattr__(self, name):
        return getattr(self.model, name)

    def _load_embedding_registry(self, path='./embedding-registry.json'):
        """
        Load the description of available embeddings. Each description provides a name, 
        a file path (used only if necessary) and a embeddings type (to take into account
        small variation of format)
        """
        registry_json = open(path).read()
        return json.loads(registry_json)

    def make_embeddings_simple_in_memory(self,
                                         name="fasttext-crawl",
                                         hasHeader=True):
        nbWords = 0
        print('loading embeddings...')
        begin = True
        description = self._get_description(name)
        if description is not None:
            embeddings_path = description["path"]
            embeddings_type = description["type"]
            self.lang = description["lang"]
            print("path:", embeddings_path)
            if self.extension == 'bin':
                self.model = fastText.load_model(embeddings_path)
                nbWords = len(self.model.get_words())
                self.embed_size = self.model.get_dimension()
            else:
                if embeddings_type == "glove":
                    hasHeader = False
                with open(embeddings_path) as f:
                    for line in f:
                        line = line.strip()
                        line = line.split(' ')
                        if begin:
                            if hasHeader:
                                # first line gives the nb of words and the embedding size
                                nbWords = int(line[0])
                                self.embed_size = int(line[1].replace(
                                    "\n", ""))
                                begin = False
                                continue
                            else:
                                begin = False
                        word = line[0]
                        #if embeddings_type == 'glove':
                        vector = np.array(
                            [float(val) for val in line[1:len(line)]],
                            dtype='float32')
                        #else:
                        #    vector = np.array([float(val) for val in line[1:len(line)-1]], dtype='float32')
                        if self.embed_size == 0:
                            self.embed_size = len(vector)
                        self.model[word] = vector
                if nbWords == 0:
                    nbWords = len(self.model)
            print('embeddings loaded for', nbWords, "words and",
                  self.embed_size, "dimensions")

    '''
    def make_embeddings_fasttext_bin(self, name="wiki.en.bin"):
        nbWords = 0
        print('loading embeddings...')
        description = self._get_description(name)
        if description is not None:
            embeddings_path = description["path"]
            print("path:", embeddings_path)

        self.model = load_fasttext_format(embeddings_path)
    '''

    def make_embeddings_lmdb(self, name="fasttext-crawl", hasHeader=True):
        nbWords = 0
        print(
            '\nCompiling embeddings... (this is done only one time per embeddings at first launch)'
        )
        begin = True
        description = self._get_description(name)
        if description is not None:
            embeddings_path = description["path"]
            embeddings_type = description["type"]
            self.lang = description["lang"]
            print("path:", embeddings_path)
            if embeddings_type == "glove":
                hasHeader = False
            txn = self.env.begin(write=True)
            batch_size = 1024
            i = 0
            nb_lines = 0
            with open(embeddings_path) as f:
                for line in f:
                    nb_lines += 1

            with open(embeddings_path) as f:
                #for line in f:
                for line in tqdm(f, total=nb_lines):
                    line = line.split(' ')
                    if begin:
                        if hasHeader:
                            # first line gives the nb of words and the embedding size
                            nbWords = int(line[0])
                            self.embed_size = int(line[1].replace("\n", ""))
                            begin = False
                            continue
                        else:
                            begin = False
                    word = line[0]
                    #if embeddings_type == 'glove':
                    vector = np.array(
                        [float(val) for val in line[1:len(line)]],
                        dtype='float32')
                    #else:
                    #    vector = np.array([float(val) for val in line[1:len(line)-1]], dtype='float32')
                    if self.embed_size == 0:
                        self.embed_size = len(vector)

                    if len(word.encode(
                            encoding='UTF-8')) < self.env.max_key_size():
                        txn.put(word.encode(encoding='UTF-8'),
                                _serialize_pickle(vector))
                        #txn.put(word.encode(encoding='UTF-8'), _serialize_byteio(vector))
                        i += 1

                    # commit batch
                    if i % batch_size == 0:
                        txn.commit()
                        txn = self.env.begin(write=True)

            #if i % batch_size != 0:
            txn.commit()
            if nbWords == 0:
                nbWords = i
            self.vocab_size = nbWords
            print('embeddings loaded for', nbWords, "words and",
                  self.embed_size, "dimensions")

    def make_embeddings_simple(self, name="fasttext-crawl", hasHeader=True):
        description = self._get_description(name)
        if description is not None:
            self.extension = description["format"]

        if self.extension == "bin":
            if fasttext_support == True:
                print(
                    "embeddings are of .bin format, so they will be loaded in memory..."
                )
                self.make_embeddings_simple_in_memory(name, hasHeader)
            else:
                if not (sys.platform == 'linux' or sys.platform == 'darwin'):
                    raise ValueError(
                        'FastText .bin format not supported for your platform')
                else:
                    raise ValueError(
                        'Go to the documentation to get more information on how to install FastText .bin support'
                    )

        elif self.embedding_lmdb_path is None or self.embedding_lmdb_path == "None":
            print(
                "embedding_lmdb_path is not specified in the embeddings registry, so the embeddings will be loaded in memory..."
            )
            self.make_embeddings_simple_in_memory(name, hasHeader)
        else:
            # check if the lmdb database exists
            envFilePath = os.path.join(self.embedding_lmdb_path, name)
            if os.path.isdir(envFilePath):
                description = self._get_description(name)
                if description is not None:
                    self.lang = description["lang"]

                # open the database in read mode
                self.env = lmdb.open(envFilePath,
                                     readonly=True,
                                     max_readers=2048,
                                     max_spare_txns=4)
                # we need to set self.embed_size and self.vocab_size
                with self.env.begin() as txn:
                    stats = txn.stat()
                    size = stats['entries']
                    self.vocab_size = size

                with self.env.begin() as txn:
                    cursor = txn.cursor()
                    for key, value in cursor:
                        vector = _deserialize_pickle(value)
                        self.embed_size = vector.shape[0]
                        break
                    cursor.close()

                # no idea why, but we need to close and reopen the environment to avoid
                # mdb_txn_begin: MDB_BAD_RSLOT: Invalid reuse of reader locktable slot
                # when opening new transaction !
                self.env.close()
                self.env = lmdb.open(envFilePath,
                                     readonly=True,
                                     max_readers=2048,
                                     max_spare_txns=2)
            else:
                # create and load the database in write mode
                self.env = lmdb.open(envFilePath, map_size=map_size)
                self.make_embeddings_lmdb(name, hasHeader)

    def make_ELMo(self):
        # Location of pretrained BiLM for the specified language
        # TBD check if ELMo language resources are present
        description = self._get_description('elmo-en')
        if description is not None:
            self.lang = description["lang"]
            vocab_file = description["path-vocab"]
            options_file = description["path-config"]
            weight_file = description["path_weights"]

            print('init ELMo')

            # Create a Batcher to map text to character ids
            self.batcher = Batcher(vocab_file, 50)

            # Build the biLM graph.
            self.bilm = BidirectionalLanguageModel(options_file, weight_file)

            # Input placeholders to the biLM.
            self.character_ids = tf.placeholder('int32',
                                                shape=(None, None, 50))
            self.embeddings_op = self.bilm(self.character_ids)

            with tf.variable_scope('', reuse=tf.AUTO_REUSE):
                # the reuse=True scope reuses weights from the whole context
                self.elmo_input = weight_layers('input',
                                                self.embeddings_op,
                                                l2_coef=0.0)

    def dump_ELMo_token_embeddings(self, x_train):
        if not self.use_ELMo:
            print(
                "Warning: ELMo embeddings dump requested but embeddings object wrongly initialised"
            )
            return

        description = self._get_description('elmo-en')
        if description is not None:
            print("Building ELMo token dump")

            self.lang = description["lang"]
            options_file = description["path-config"]
            weight_file = description["path_weights"]
            working_path = description["path-dump"]

            all_tokens = set(['<S>', '</S>'])
            for i in range(0, len(x_train)):
                # as it is training, it is already tokenized
                tokens = x_train[i]
                for token in tokens:
                    if token not in all_tokens:
                        all_tokens.add(token)

            vocab_file = os.path.join(working_path, 'vocab_small.txt')
            with open(vocab_file, 'w') as fout:
                fout.write('\n'.join(all_tokens))

            tf.reset_default_graph()
            token_embedding_file = os.path.join(working_path,
                                                'elmo_token_embeddings.hdf5')
            dump_token_embeddings(vocab_file, options_file, weight_file,
                                  token_embedding_file)
            tf.reset_default_graph()

            self.batcher_token_dump = TokenBatcher(vocab_file)

            self.bilm_token_dump = BidirectionalLanguageModel(
                options_file,
                weight_file,
                use_character_inputs=False,
                embedding_weight_file=token_embedding_file)

            self.token_ids = tf.placeholder('int32', shape=(None, None))
            self.embeddings_op_token_dump = self.bilm_token_dump(
                self.token_ids)
            """
            with tf.variable_scope('', reuse=tf.AUTO_REUSE):
                # the reuse=True scope reuses weights from the whole context 
                self.elmo_input_token_dump = weight_layers('input', self.embeddings_op_token_dump, l2_coef=0.0)
            """
            print("ELMo token dump completed")

    def get_sentence_vector_only_ELMo(self, token_list):
        """
            Return the ELMo embeddings only for a full sentence
        """

        if not self.use_ELMo:
            print(
                "Warning: ELMo embeddings requested but embeddings object wrongly initialised"
            )
            return

        # Create batches of data
        local_token_ids = self.batcher.batch_sentences(token_list)
        max_size_sentence = local_token_ids[0].shape[0]
        # check lmdb cache
        elmo_result = self.get_ELMo_lmdb_vector(token_list, max_size_sentence)
        if elmo_result is not None:
            return elmo_result

        with tf.Session() as sess:
            # weird, for this cpu is faster than gpu (1080Ti !)
            with tf.device("/cpu:0"):
                # It is necessary to initialize variables once before running inference
                sess.run(tf.global_variables_initializer())

                # Compute ELMo representations (2 times as a heavy warm-up)
                elmo_result = sess.run(
                    self.elmo_input['weighted_op'],
                    feed_dict={self.character_ids: local_token_ids})
                elmo_result = sess.run(
                    self.elmo_input['weighted_op'],
                    feed_dict={self.character_ids: local_token_ids})
                #cache computation
                self.cache_ELMo_lmdb_vector(token_list, elmo_result)
        return elmo_result

    def get_sentence_vector_with_ELMo(self, token_list):
        """
            Return a concatenation of standard embeddings (e.g. Glove) and ELMo embeddings 
            for a full sentence
        """
        if not self.use_ELMo:
            print(
                "Warning: ELMo embeddings requested but embeddings object wrongly initialised"
            )
            return
        """
        # trick to extend the context for short sentences
        token_list_extended = token_list.copy()
        #print("token_list_extended before: ", token_list_extended)
        for i in range(0, len(token_list_extended)):
            local_list = token_list_extended[i]
            j = i
            while len(local_list) <= 5:
                #print(j, local_list)
                if j < len(token_list_extended)-1:
                    local_list = local_list + token_list_extended[j+1]
                else:
                    break
                j = j + 1
            token_list_extended[i] = local_list
        #print("token_list_extended after: ", token_list_extended)
        
        max_size_sentence = 0
        for i in range(0, len(token_list)):
            local_length = len(token_list[i])
            if local_length > max_size_sentence:
                max_size_sentence = local_length
        """

        # Create batches of data
        local_token_ids = self.batcher.batch_sentences(token_list)
        max_size_sentence = local_token_ids[0].shape[0]
        # check lmdb cache
        elmo_result = self.get_ELMo_lmdb_vector(token_list, max_size_sentence)
        if elmo_result is None:
            with tf.Session() as sess:
                # weird, for this cpu is faster than gpu (1080Ti !)
                with tf.device("/cpu:0"):
                    # It is necessary to initialize variables once before running inference
                    sess.run(tf.global_variables_initializer())

                    # Compute ELMo representations (2 times as a heavy warm-up)
                    elmo_result = sess.run(
                        self.elmo_input['weighted_op'],
                        feed_dict={self.character_ids: local_token_ids})
                    elmo_result = sess.run(
                        self.elmo_input['weighted_op'],
                        feed_dict={self.character_ids: local_token_ids})
                    #cache computation
                    self.cache_ELMo_lmdb_vector(token_list, elmo_result)
        concatenated_result = np.zeros(
            (elmo_result.shape[0], max_size_sentence - 2, self.embed_size),
            dtype=np.float32)
        for i in range(0, elmo_result.shape[0]):
            for j in range(0, len(token_list[i])):
                #if is_int(token_list[i][j]) or is_float(token_list[i][j]):
                #    dummy_result = np.zeros((elmo_result.shape[2]), dtype=np.float32)
                #    concatenated_result[i][j] = np.concatenate((dummy_result, self.get_word_vector(token_list[i][j])), )
                #else:
                concatenated_result[i][j] = np.concatenate(
                    (elmo_result[i][j], self.get_word_vector(
                        token_list[i][j])), )
        return concatenated_result

    def get_sentence_vector_ELMo_with_token_dump(self, token_list):
        if not self.use_ELMo:
            print(
                "Warning: ELMo embeddings requested but embeddings object wrongly initialised"
            )
            return

        with tf.variable_scope('', reuse=tf.AUTO_REUSE):
            # the reuse=True scope reuses weights from the whole context
            self.elmo_input_token_dump = weight_layers(
                'input', self.embeddings_op_token_dump, l2_coef=0.0)

        # Create batches of data
        local_token_ids = self.batcher_token_dump.batch_sentences(token_list)

        with tf.Session() as sess:
            # weird, for this cpu is faster than gpu (1080Ti !)
            with tf.device("/cpu:0"):
                # It is necessary to initialize variables once before running inference
                sess.run(tf.global_variables_initializer())

                # Compute ELMo representations
                elmo_result = sess.run(
                    self.elmo_input_token_dump['weighted_op'],
                    feed_dict={self.token_ids: local_token_ids})
        return elmo_result

    def _get_description(self, name):
        for emb in self.registry["embeddings"]:
            if emb["name"] == name:
                return emb
        for emb in self.registry["embeddings-contextualized"]:
            if emb["name"] == name:
                return emb
        return None

    def get_word_vector(self, word):
        """
            Get static embeddings (e.g. glove) for a given token
        """
        if (self.name == 'wiki.fr') or (self.name == 'wiki.fr.bin'):
            # the pre-trained embeddings are not cased
            word = word.lower()
        if self.env is None or self.extension == 'bin':
            # db not available or embeddings in bin format, the embeddings should be available in memory (normally!)
            return self.get_word_vector_in_memory(word)
        try:
            with self.env.begin() as txn:
                txn = self.env.begin()
                vector = txn.get(word.encode(encoding='UTF-8'))
                if vector:
                    word_vector = _deserialize_pickle(vector)
                    vector = None
                else:
                    word_vector = np.zeros((self.static_embed_size, ),
                                           dtype=np.float32)
                    # alternatively, initialize with random negative values
                    #word_vector = np.random.uniform(low=-0.5, high=0.0, size=(self.embed_size,))
                    # alternatively use fasttext OOV ngram possibilities (if ngram available)
        except lmdb.Error:
            # no idea why, but we need to close and reopen the environment to avoid
            # mdb_txn_begin: MDB_BAD_RSLOT: Invalid reuse of reader locktable slot
            # when opening new transaction !
            self.env.close()
            envFilePath = os.path.join(self.embedding_lmdb_path, self.name)
            self.env = lmdb.open(envFilePath,
                                 readonly=True,
                                 max_readers=2048,
                                 max_spare_txns=2,
                                 lock=False)
            return self.get_word_vector(word)
        return word_vector

    def get_ELMo_lmdb_vector(self, token_list, max_size_sentence):
        """
            Try to get the ELMo embeddings for a sequence cached in LMDB
        """
        if self.env_ELMo is None:
            # db cache not available, we don't cache ELMo stuff
            return None
        try:
            ELMo_vector = np.zeros(
                (len(token_list), max_size_sentence - 2, ELMo_embed_size),
                dtype='float32')
            with self.env_ELMo.begin() as txn:
                for i in range(0, len(token_list)):
                    txn = self.env_ELMo.begin()
                    # get a hash for the token_list
                    the_hash = list_digest(token_list[i])
                    vector = txn.get(the_hash.encode(encoding='UTF-8'))
                    if vector:
                        # adapt expected shape/padding
                        local_embeddings = _deserialize_pickle(vector)
                        if local_embeddings.shape[0] > max_size_sentence - 2:
                            # squeeze the extra padding space
                            ELMo_vector[
                                i] = local_embeddings[:max_size_sentence - 2, ]
                        elif local_embeddings.shape[
                                0] == max_size_sentence - 2:
                            # bingo~!
                            ELMo_vector[i] = local_embeddings
                        else:
                            # fill the missing space with padding
                            filler = np.zeros((max_size_sentence -
                                               (local_embeddings.shape[0] + 2),
                                               ELMo_embed_size),
                                              dtype='float32')
                            ELMo_vector[i] = np.concatenate(
                                (local_embeddings, filler))
                        vector = None
                    else:
                        return None
        except lmdb.Error:
            # no idea why, but we need to close and reopen the environment to avoid
            # mdb_txn_begin: MDB_BAD_RSLOT: Invalid reuse of reader locktable slot
            # when opening new transaction !
            self.env_ELMo.close()
            self.env_ELMo = lmdb.open(embedding_ELMo_cache,
                                      readonly=True,
                                      max_readers=2048,
                                      max_spare_txns=2,
                                      lock=False)
            return self.get_ELMo_lmdb_vector(token_list)
        return ELMo_vector

    def cache_ELMo_lmdb_vector(self, token_list, ELMo_vector):
        """
            Cache in LMDB the ELMo embeddings for a given sequence 
        """
        if self.env_ELMo is None:
            # db cache not available, we don't cache ELMo stuff
            return None
        txn = self.env_ELMo.begin(write=True)
        for i in range(0, len(token_list)):
            # get a hash for the token_list
            the_hash = list_digest(token_list[i])
            txn.put(the_hash.encode(encoding='UTF-8'),
                    _serialize_pickle(ELMo_vector[i]))
        txn.commit()

    def clean_ELMo_cache(self):
        """
            Delete ELMo embeddings cache, this takes place normally after the completion of a training
        """
        if self.env_ELMo is None:
            # db cache not available, nothing to clean
            return
        else:
            for file in os.listdir(self.embedding_ELMo_cache):
                file_path = os.path.join(self.embedding_ELMo_cache, file)
                if os.path.isfile(file_path):
                    os.remove(file_path)
            os.rmdir(self.embedding_ELMo_cache)

    def get_word_vector_in_memory(self, word):
        if (self.name == 'wiki.fr') or (self.name == 'wiki.fr.bin'):
            # the pre-trained embeddings are not cased
            word = word.lower()
        if self.extension == 'bin':
            return self.model.get_word_vector(word)
        if word in self.model:
            return self.model[word]
        else:
            # for unknown word, we use a vector filled with 0.0
            return np.zeros((self.static_embed_size, ), dtype=np.float32)