Esempio n. 1
0
    def _set_trainier(self):
        """
        Initialize segment-wise trainer trainer
        """

        # initialize segment-wise trainer
        self.segment_wise_trainer = SegmentWiseTrainer(original_model=self.original_model,
                                                       pruned_model=self.pruned_model,
                                                       train_loader=self.train_loader,
                                                       val_loader=self.val_loader,
                                                       settings=self.settings,
                                                       logger=self.logger,
                                                       tensorboard_logger=self.tensorboard_logger)
        if self.aux_fc_state is not None:
            self.segment_wise_trainer.update_aux_fc(self.aux_fc_state)
Esempio n. 2
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class Experiment(object):
    """
    Run experiments with pre-defined pipeline
    """
    def __init__(self, options=None, conf_path=None):
        self.settings = options or Option(conf_path)
        self.checkpoint = None
        self.train_loader = None
        self.val_loader = None
        self.original_model = None
        self.pruned_model = None

        self.aux_fc_state = None
        self.aux_fc_opt_state = None
        self.seg_opt_state = None
        self.current_pivot_index = None

        self.epoch = 0

        os.environ['CUDA_VISIBLE_DEVICES'] = self.settings.gpu

        self.settings.set_save_path()
        write_settings(self.settings)
        self.logger = get_logger(self.settings.save_path, "dcp")
        self.tensorboard_logger = TensorboardLogger(self.settings.save_path)
        self.settings.copy_code(self.logger,
                                src=os.path.abspath('./'),
                                dst=os.path.join(self.settings.save_path,
                                                 'code'))
        self.logger.info("|===>Result will be saved at {}".format(
            self.settings.save_path))

        self.prepare()

    def prepare(self):
        """
        Preparing experiments
        """

        self._set_gpu()
        self._set_dataloader()
        self._set_model()
        self._cal_pivot()
        self._set_checkpoint()
        self._set_trainier()
        self._set_channel_selection()
        torch.set_num_threads(4)

    def _set_gpu(self):
        """
        Initialize the seed of random number generator
        """

        # set torch seed
        # init random seed
        torch.manual_seed(self.settings.seed)
        torch.cuda.manual_seed(self.settings.seed)
        torch.cuda.set_device(0)
        cudnn.benchmark = True

    def _set_dataloader(self):
        """
        Create train loader and validation loader for channel pruning
        """

        if 'cifar' in self.settings.dataset:
            self.train_loader, self.val_loader = get_cifar_dataloader(
                self.settings.dataset, self.settings.batch_size,
                self.settings.n_threads, self.settings.data_path, self.logger)
        elif self.settings.dataset in ['imagenet']:
            self.train_loader, self.val_loader = get_imagenet_dataloader(
                self.settings.dataset, self.settings.batch_size,
                self.settings.n_threads, self.settings.data_path, self.logger)
        elif self.settings.dataset in ['sub_imagenet']:
            num_samples_per_category = self.settings.max_samples // 1000
            self.train_loader, self.val_loader = get_sub_imagenet_dataloader(
                self.settings.dataset, self.settings.batch_size,
                num_samples_per_category, self.settings.n_threads,
                self.settings.data_path, self.logger)

    def _set_trainier(self):
        """
        Initialize segment-wise trainer trainer
        """

        # initialize segment-wise trainer
        self.segment_wise_trainer = SegmentWiseTrainer(
            original_model=self.original_model,
            pruned_model=self.pruned_model,
            train_loader=self.train_loader,
            val_loader=self.val_loader,
            settings=self.settings,
            logger=self.logger,
            tensorboard_logger=self.tensorboard_logger)
        if self.aux_fc_state is not None:
            self.segment_wise_trainer.update_aux_fc(self.aux_fc_state)

    def _set_channel_selection(self):
        self.layer_channel_selection = LayerChannelSelection(
            self.segment_wise_trainer, self.train_loader, self.val_loader,
            self.settings, self.checkpoint, self.logger,
            self.tensorboard_logger)

    def _set_model(self):
        """
        Available model
        cifar:
            preresnet
        imagenet:
            resnet
        """

        self.original_model, self.test_input = get_model(
            self.settings.dataset, self.settings.net_type, self.settings.depth,
            self.settings.n_classes)
        self.pruned_model, self.test_input = get_model(self.settings.dataset,
                                                       self.settings.net_type,
                                                       self.settings.depth,
                                                       self.settings.n_classes)

    def _set_checkpoint(self):
        """
        Load pre-trained model or resume checkpoint
        """

        assert self.original_model is not None and self.pruned_model is not None, "please create model first"

        self.checkpoint = DCPCheckPoint(self.settings.save_path, self.logger)
        self._load_pretrained()
        self._load_resume()

    def _load_pretrained(self):
        """
        Load pre-trained model
        """

        if self.settings.pretrained is not None:
            check_point_params = torch.load(self.settings.pretrained)
            model_state = check_point_params['model']
            self.aux_fc_state = check_point_params['aux_fc']
            self.original_model = self.checkpoint.load_state(
                self.original_model, model_state)
            self.pruned_model = self.checkpoint.load_state(
                self.pruned_model, model_state)
            self.logger.info("|===>load restrain file: {}".format(
                self.settings.pretrained))

    def _load_resume(self):
        """
        Load resume checkpoint
        """

        if self.settings.resume is not None:
            check_point_params = torch.load(self.settings.resume)
            original_model_state = check_point_params["original_model"]
            pruned_model_state = check_point_params["pruned_model"]
            self.aux_fc_state = check_point_params["aux_fc"]
            self.aux_fc_opt_state = check_point_params["aux_fc_opt"]
            self.seg_opt_state = check_point_params["seg_opt"]
            self.current_pivot_index = check_point_params["current_pivot"]
            self.segment_num = check_point_params["segment_num"]
            self.current_block_count = check_point_params["block_num"]

            if self.current_block_count > 0:
                self.replace_layer_mask_conv()
            self.original_model = self.checkpoint.load_state(
                self.original_model, original_model_state)
            self.pruned_model = self.checkpoint.load_state(
                self.pruned_model, pruned_model_state)
            self.logger.info("|===>load resume file: {}".format(
                self.settings.resume))

    def _cal_pivot(self):
        """
        Calculate the inserted layer for additional loss
        """

        self.num_segments, self.settings.pivot_set = cal_pivot(
            self.settings.n_losses, self.settings.net_type,
            self.settings.depth, self.logger)

    def replace_layer_mask_conv(self):
        """
        Replace the convolutional layer with mask convolutional layer
        """

        block_count = 0
        if self.settings.net_type in ["preresnet", "resnet"]:
            for module in self.pruned_model.modules():
                if isinstance(module, (PreBasicBlock, BasicBlock, Bottleneck)):
                    block_count += 1
                    layer = module.conv2
                    if block_count <= self.current_block_count and not isinstance(
                            layer, MaskConv2d):
                        temp_conv = MaskConv2d(in_channels=layer.in_channels,
                                               out_channels=layer.out_channels,
                                               kernel_size=layer.kernel_size,
                                               stride=layer.stride,
                                               padding=layer.padding,
                                               bias=(layer.bias is not None))
                        temp_conv.weight.data.copy_(layer.weight.data)

                        if layer.bias is not None:
                            temp_conv.bias.data.copy_(layer.bias.data)
                        module.conv2 = temp_conv

                    if isinstance(module, Bottleneck):
                        layer = module.conv3
                        if block_count <= self.current_block_count and not isinstance(
                                layer, MaskConv2d):
                            temp_conv = MaskConv2d(
                                in_channels=layer.in_channels,
                                out_channels=layer.out_channels,
                                kernel_size=layer.kernel_size,
                                stride=layer.stride,
                                padding=layer.padding,
                                bias=(layer.bias is not None))
                            temp_conv.weight.data.copy_(layer.weight.data)

                            if layer.bias is not None:
                                temp_conv.bias.data.copy_(layer.bias.data)
                            module.conv3 = temp_conv

    def channel_selection_for_network(self):
        """
        Conduct channel selection
        """

        # get testing error
        self.segment_wise_trainer.val(0)
        time_start = time.time()

        restart_index = None

        # find restart segment index
        if self.current_pivot_index:
            if self.current_pivot_index in self.settings.pivot_set:
                restart_index = self.settings.pivot_set.index(
                    self.current_pivot_index)
            else:
                restart_index = len(self.settings.pivot_set)

        for index in range(self.num_segments):
            if restart_index is not None:
                if index < restart_index:
                    continue
                elif index == restart_index:
                    if self.current_block_count == self.current_pivot_index:
                        continue

            if index == self.num_segments - 1:
                self.current_pivot_index = self.segment_wise_trainer.final_block_count
            else:
                self.current_pivot_index = self.settings.pivot_set[index]

            # conduct channel selection
            # contains [0:index] segments
            original_segment_list = []
            pruned_segment_list = []
            for j in range(index + 1):
                original_segment_list += utils.model2list(
                    self.segment_wise_trainer.ori_segments[j])
                pruned_segment_list += utils.model2list(
                    self.segment_wise_trainer.pruned_segments[j])

            original_segment = nn.Sequential(*original_segment_list)
            pruned_segment = nn.Sequential(*pruned_segment_list)

            net_pruned = self.channel_selection_for_one_segment(
                original_segment, pruned_segment,
                self.segment_wise_trainer.aux_fc[index],
                self.current_pivot_index, index)

            self.logger.info(self.segment_wise_trainer.pruned_segments)
            self.logger.info(net_pruned)
            self.logger.info(self.original_model)
            self.logger.info(self.pruned_model)
            self.segment_wise_trainer.val(0)
            self.current_pivot_index = None

        self.checkpoint.save_dcp_model(
            self.original_model,
            self.pruned_model,
            self.segment_wise_trainer.aux_fc,
            self.segment_wise_trainer.final_block_count,
            index=self.num_segments)
        self.pruning()

        self.checkpoint.save_dcp_model(
            self.original_model,
            self.pruned_model,
            self.segment_wise_trainer.aux_fc,
            self.segment_wise_trainer.final_block_count,
            index=self.num_segments + 1)

        time_interval = time.time() - time_start
        log_str = "cost time: {}".format(
            str(datetime.timedelta(seconds=time_interval)))
        self.logger.info(log_str)

    def channel_selection_for_resnet_like_segment(self, original_segment,
                                                  pruned_segment, aux_fc,
                                                  pivot_index, index):
        """
        Conduct channel selection for one segment in resnet
        """

        block_count = 0
        for module in pruned_segment.modules():
            if isinstance(module, (PreBasicBlock, BasicBlock)):
                block_count += 1
                # We will not prune the pruned blocks again
                if not isinstance(module.conv2, MaskConv2d):
                    self.layer_channel_selection.channel_selection_for_one_layer(
                        original_segment, pruned_segment, aux_fc, module,
                        block_count, "conv2")
                    self.logger.info("|===>checking layer type: {}".format(
                        type(module.conv2)))

                    self.checkpoint.save_dcp_model(
                        self.original_model,
                        self.pruned_model,
                        self.segment_wise_trainer.aux_fc,
                        pivot_index,
                        index=index,
                        block_count=block_count)
                    self.checkpoint.save_dcp_checkpoint(
                        self.original_model,
                        self.pruned_model,
                        self.segment_wise_trainer.aux_fc,
                        self.segment_wise_trainer.fc_optimizer,
                        self.segment_wise_trainer.seg_optimizer,
                        pivot_index,
                        index=index,
                        block_count=block_count)

            elif isinstance(module, Bottleneck):
                block_count += 1
                if not isinstance(module.conv2, MaskConv2d):
                    self.layer_channel_selection.channel_selection_for_one_layer(
                        original_segment, pruned_segment, aux_fc, module,
                        block_count, "conv2")

                    self.checkpoint.save_dcp_model(
                        self.original_model,
                        self.pruned_model,
                        self.segment_wise_trainer.aux_fc,
                        pivot_index,
                        index=index,
                        block_count=block_count)
                    self.checkpoint.save_dcp_checkpoint(
                        self.original_model,
                        self.pruned_model,
                        self.segment_wise_trainer.aux_fc,
                        self.segment_wise_trainer.fc_optimizer,
                        self.segment_wise_trainer.seg_optimizer,
                        pivot_index,
                        index=index,
                        block_count=block_count)

                if not isinstance(module.conv3, MaskConv2d):
                    self.layer_channel_selection.channel_selection_for_one_layer(
                        original_segment, pruned_segment, aux_fc, module,
                        block_count, "conv3")

                    self.checkpoint.save_dcp_model(
                        self.original_model,
                        self.pruned_model,
                        self.segment_wise_trainer.aux_fc,
                        pivot_index,
                        index=index,
                        block_count=block_count)
                    self.checkpoint.save_dcp_checkpoint(
                        self.original_model,
                        self.pruned_model,
                        self.segment_wise_trainer.aux_fc,
                        self.segment_wise_trainer.fc_optimizer,
                        self.segment_wise_trainer.seg_optimizer,
                        pivot_index,
                        index=index,
                        block_count=block_count)

    def channel_selection_for_one_segment(self, original_segment,
                                          pruned_segment, aux_fc, pivot_index,
                                          index):
        """
        Conduct channel selection for one segment
        :param original_segment: original network segments
        :param pruned_segment: pruned network segments
        :param aux_fc: auxiliary fully-connected layer
        :param pivot_index: the layer index of the additional loss
        :param index: the index of segment
        """

        if self.settings.net_type in ["preresnet", "resnet"]:
            self.channel_selection_for_resnet_like_segment(
                original_segment, pruned_segment, aux_fc, pivot_index, index)
        return pruned_segment

    def pruning(self):
        """
        Prune channels
        """
        self.logger.info("Before pruning:")
        self.logger.info(self.pruned_model)
        self.segment_wise_trainer.val(0)
        model_analyse = ModelAnalyse(self.pruned_model, self.logger)
        params_num = model_analyse.params_count()
        zero_num = model_analyse.zero_count()
        zero_rate = zero_num * 1.0 / params_num
        self.logger.info("zero rate is: {}".format(zero_rate))
        model_analyse.madds_compute(self.test_input)

        if self.settings.net_type in ["preresnet", "resnet"]:
            model_prune = ResModelPrune(model=self.pruned_model,
                                        net_type=self.settings.net_type,
                                        depth=self.settings.depth)
        else:
            assert False, "unsupport net_type: {}".format(
                self.settings.net_type)

        model_prune.run()

        aux_fc_state = []
        for i in range(len(self.segment_wise_trainer.aux_fc)):
            if isinstance(self.segment_wise_trainer.aux_fc[i],
                          nn.DataParallel):
                temp_state = self.segment_wise_trainer.aux_fc[
                    i].module.state_dict()
            else:
                temp_state = self.segment_wise_trainer.aux_fc[i].state_dict()
            aux_fc_state.append(temp_state)
        self.segment_wise_trainer.update_model(self.original_model,
                                               self.pruned_model)

        self.logger.info("After pruning:")
        self.logger.info(self.pruned_model)
        self.segment_wise_trainer.val(0)
        model_analyse = ModelAnalyse(self.pruned_model, self.logger)
        params_num = model_analyse.params_count()
        zero_num = model_analyse.zero_count()
        zero_rate = zero_num * 1.0 / params_num
        self.logger.info("zero rate is: {}".format(zero_rate))
        model_analyse.madds_compute(self.test_input)
Esempio n. 3
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class Experiment(object):
    """
    Run experiments with pre-defined pipeline
    """

    def __init__(self, options=None, conf_path=None):
        self.settings = options or Option(conf_path)
        self.checkpoint = None
        self.train_loader = None
        self.val_loader = None
        self.original_model = None
        self.epoch = 0

        os.environ['CUDA_VISIBLE_DEVICES'] = self.settings.gpu

        self.settings.set_save_path()
        write_settings(self.settings)
        self.logger = get_logger(self.settings.save_path, "dcp")
        self.tensorboard_logger = TensorboardLogger(self.settings.save_path)
        self.settings.copy_code(self.logger, src=os.path.abspath('./'),
                                dst=os.path.join(self.settings.save_path, 'code'))
        self.logger.info("|===>Result will be saved at {}".format(self.settings.save_path))

        self.prepare()


        # put your job-ralated varible below

    def prepare(self):
        """
        Preparing experiments
        """

        self._set_gpu()
        self._set_dataloader()
        self._set_model()
        self._set_checkpoint()
        self._set_trainier()
        torch.set_num_threads(4)

    def _set_gpu(self):
        """
        Initialize the seed of random number generator
        """

        # set torch seed
        # init random seed
        torch.manual_seed(self.settings.seed)
        torch.cuda.manual_seed(self.settings.seed)
        torch.cuda.set_device(0)
        cudnn.benchmark = True

    def _set_dataloader(self):
        """
        Create train loader and validation loader for channel pruning
        """

        if 'cifar' in self.settings.dataset:
            self.train_loader, self.val_loader = get_cifar_dataloader(self.settings.dataset,
                                                                      self.settings.batch_size,
                                                                      self.settings.n_threads,
                                                                      self.settings.data_path,
                                                                      self.logger)
        elif self.settings.dataset in ['imagenet']:
            self.train_loader, self.val_loader = get_imagenet_dataloader(self.settings.dataset,
                                                                         self.settings.batch_size,
                                                                         self.settings.n_threads,
                                                                         self.settings.data_path,
                                                                         self.logger)
        elif self.settings.dataset in ['sub_imagenet']:
            num_samples_per_category = self.settings.max_samples // 1000
            self.train_loader, self.val_loader = get_sub_imagenet_dataloader(self.settings.dataset,
                                                                             self.settings.batch_size,
                                                                             num_samples_per_category,
                                                                             self.settings.n_threads,
                                                                             self.settings.data_path,
                                                                             self.logger)

    def _set_trainier(self):
        """
        Initialize segment-wise trainer trainer
        """

        # initialize segment-wise trainer
        self.segment_wise_trainer = SegmentWiseTrainer(original_model=self.original_model,
                                                       pruned_model=self.pruned_model,
                                                       train_loader=self.train_loader,
                                                       val_loader=self.val_loader,
                                                       settings=self.settings,
                                                       logger=self.logger,
                                                       tensorboard_logger=self.tensorboard_logger)
        if self.aux_fc_state is not None:
            self.segment_wise_trainer.update_aux_fc(self.aux_fc_state)


    def _set_model(self):
        """
        Available model
        cifar:
            preresnet
        imagenet:
            resnet
        """

        self.original_model, self.test_input = get_model(self.settings.dataset,
                                                         self.settings.net_type,
                                                         self.settings.depth,
                                                         self.settings.n_classes)

    def _set_checkpoint(self):
        """
        Load pre-trained model or resume checkpoint
        """

        assert self.original_model is not None and self.pruned_model is not None, "please create model first"

        self.checkpoint = CheckPoint(self.settings.save_path, self.logger)
        self._load_pretrained()
        self._load_resume()

    def _load_pretrained(self):
        """
        Load pre-trained model
        """

        if self.settings.pretrained is not None:
            check_point_params = torch.load(self.settings.pretrained)
            model_state = check_point_params['model']
            self.original_model = self.checkpoint.load_state(self.original_model, model_state)
            self.logger.info("|===>load restrain file: {}".format(self.settings.pretrained))

    def _load_resume(self):
        """
        Load resume checkpoint
        """

        if self.settings.resume is not None:
            check_point_params = torch.load(self.settings.resume)
            original_model_state = check_point_params["original_model"]
            
            self.original_model = self.checkpoint.load_state(self.original_model, original_model_state)
            
            self.logger.info("|===>load resume file: {}".format(self.settings.resume))
class Experiment(object):
    """
    run experiments with pre-defined pipeline
    """
    def __init__(self, options=None, conf_path=None):
        self.settings = options or Option(conf_path)
        self.checkpoint = None
        self.train_loader = None
        self.val_loader = None
        self.ori_model = None
        self.pruned_model = None
        self.segment_wise_trainer = None

        self.aux_fc_state = None
        self.aux_fc_opt_state = None
        self.seg_opt_state = None
        self.current_pivot_index = None
        self.is_segment_wise_finetune = False
        self.is_channel_selection = False

        self.epoch = 0

        self.feature_cache_origin = {}
        self.feature_cache_pruned = {}

        os.environ['CUDA_VISIBLE_DEVICES'] = self.settings.gpu

        self.settings.set_save_path()
        self.write_settings()
        self.logger = self.set_logger()
        self.tensorboard_logger = TensorboardLogger(self.settings.save_path)

        self.prepare()

    def write_settings(self):
        """
        save experimental settings to a file
        """

        with open(os.path.join(self.settings.save_path, "settings.log"),
                  "w") as f:
            for k, v in self.settings.__dict__.items():
                f.write(str(k) + ": " + str(v) + "\n")

    def set_logger(self):
        """
        initialize logger
        """
        logger = logging.getLogger('channel_selection')
        file_formatter = logging.Formatter(
            '%(asctime)s %(levelname)s: %(message)s')
        console_formatter = logging.Formatter('%(message)s')
        # file log
        file_handler = logging.FileHandler(
            os.path.join(self.settings.save_path, "train_test.log"))
        file_handler.setFormatter(file_formatter)

        # console log
        console_handler = logging.StreamHandler(sys.stdout)
        console_handler.setFormatter(console_formatter)

        logger.addHandler(file_handler)
        logger.addHandler(console_handler)

        logger.setLevel(logging.INFO)
        return logger

    def prepare(self):
        """
        preparing experiments
        """

        self._set_gpu()
        self._set_dataloader()
        self._set_model()
        self._cal_pivot()
        self._set_checkpoint()
        self._set_trainier()

    def _set_gpu(self):
        """
        initialize the seed of random number generator
        """

        # set torch seed
        # init random seed
        torch.manual_seed(self.settings.seed)
        torch.cuda.manual_seed(self.settings.seed)
        torch.cuda.set_device(0)
        cudnn.benchmark = True

    def _set_dataloader(self):
        """
        create train loader and validation loader for channel pruning
        """

        if self.settings.dataset == 'cifar10':
            data_root = os.path.join(self.settings.data_path, "cifar")

            norm_mean = [0.49139968, 0.48215827, 0.44653124]
            norm_std = [0.24703233, 0.24348505, 0.26158768]
            train_transform = transforms.Compose([
                transforms.RandomCrop(32, padding=4),
                transforms.RandomHorizontalFlip(),
                transforms.ToTensor(),
                transforms.Normalize(norm_mean, norm_std)
            ])
            val_transform = transforms.Compose([
                transforms.ToTensor(),
                transforms.Normalize(norm_mean, norm_std)
            ])

            train_dataset = datasets.CIFAR10(root=data_root,
                                             train=True,
                                             transform=train_transform,
                                             download=True)
            val_dataset = datasets.CIFAR10(root=data_root,
                                           train=False,
                                           transform=val_transform)

            self.train_loader = torch.utils.data.DataLoader(
                dataset=train_dataset,
                batch_size=self.settings.batch_size,
                shuffle=True,
                pin_memory=True,
                num_workers=self.settings.n_threads)
            self.val_loader = torch.utils.data.DataLoader(
                dataset=val_dataset,
                batch_size=self.settings.batch_size,
                shuffle=False,
                pin_memory=True,
                num_workers=self.settings.n_threads)
        elif self.settings.dataset == 'imagenet':
            dataset_path = os.path.join(self.settings.data_path, "imagenet")
            traindir = os.path.join(dataset_path, "train")
            valdir = os.path.join(dataset_path, 'val')
            normalize = transforms.Normalize(mean=[0.485, 0.456, 0.406],
                                             std=[0.229, 0.224, 0.225])

            self.train_loader = torch.utils.data.DataLoader(
                datasets.ImageFolder(
                    traindir,
                    transforms.Compose([
                        transforms.RandomResizedCrop(224),
                        transforms.RandomHorizontalFlip(),
                        transforms.ToTensor(),
                        normalize,
                    ])),
                batch_size=self.settings.batch_size,
                shuffle=True,
                num_workers=self.settings.n_threads,
                pin_memory=True)

            self.val_loader = torch.utils.data.DataLoader(
                datasets.ImageFolder(
                    valdir,
                    transforms.Compose([
                        transforms.Resize(256),
                        transforms.CenterCrop(224),
                        transforms.ToTensor(),
                        normalize,
                    ])),
                batch_size=self.settings.batch_size,
                shuffle=False,
                num_workers=self.settings.n_threads,
                pin_memory=True)

    def _set_trainier(self):
        """
        initialize segment-wise trainer trainer
        """

        # initialize segment-wise trainer
        self.segment_wise_trainer = SegmentWiseTrainer(
            ori_model=self.ori_model,
            pruned_model=self.pruned_model,
            train_loader=self.train_loader,
            val_loader=self.val_loader,
            settings=self.settings,
            logger=self.logger,
            tensorboard_logger=self.tensorboard_logger)
        if self.aux_fc_state is not None:
            self.segment_wise_trainer.update_aux_fc(self.aux_fc_state,
                                                    self.aux_fc_opt_state,
                                                    self.seg_opt_state)

    def _set_model(self):
        """
        get model
        """

        if self.settings.dataset in ["cifar10", "cifar100"]:
            if self.settings.net_type == "preresnet":
                self.ori_model = md.PreResNet(
                    depth=self.settings.depth,
                    num_classes=self.settings.n_classes)
                self.pruned_model = md.PreResNet(
                    depth=self.settings.depth,
                    num_classes=self.settings.n_classes)
            else:
                assert False, "use {} data while network is {}".format(
                    self.settings.dataset, self.settings.net_type)

        elif self.settings.dataset in ["imagenet"]:
            if self.settings.net_type == "resnet":
                self.ori_model = md.ResNet(depth=self.settings.depth,
                                           num_classes=self.settings.n_classes)
                self.pruned_model = md.ResNet(
                    depth=self.settings.depth,
                    num_classes=self.settings.n_classes)
            else:
                assert False, "use {} data while network is {}".format(
                    self.settings.dataset, self.settings.net_type)

        else:
            assert False, "unsupported data set: {}".format(
                self.settings.dataset)

    def _set_checkpoint(self):
        """
        load pre-trained model or resume checkpoint
        """

        assert self.ori_model is not None and self.pruned_model is not None, "please create model first"

        self.checkpoint = CheckPoint(self.settings.save_path, self.logger)
        self._load_retrain()
        self._load_resume()

    def _load_retrain(self):
        """
        load pre-trained model
        """

        if self.settings.retrain is not None:
            check_point_params = torch.load(self.settings.retrain)
            if "ori_model" not in check_point_params:
                model_state = check_point_params
                self.ori_model = self.checkpoint.load_state(
                    self.ori_model, model_state)
                self.pruned_model = self.checkpoint.load_state(
                    self.pruned_model, model_state)
                self.logger.info("|===>load restrain file: {}".format(
                    self.settings.retrain))
            else:
                ori_model_state = check_point_params["ori_model"]
                pruned_model_state = check_point_params["pruned_model"]
                # self.current_block_count = check_point_params["current_pivot"]
                self.aux_fc_state = check_point_params["aux_fc"]
                # self.replace_layer()
                self.ori_model = self.checkpoint.load_state(
                    self.ori_model, ori_model_state)
                self.pruned_model = self.checkpoint.load_state(
                    self.pruned_model, pruned_model_state)
                self.logger.info("|===>load pre-trained model: {}".format(
                    self.settings.retrain))

    def _load_resume(self):
        """
        load resume checkpoint
        """

        if self.settings.resume is not None:
            check_point_params = torch.load(self.settings.resume)
            ori_model_state = check_point_params["ori_model"]
            pruned_model_state = check_point_params["pruned_model"]
            self.aux_fc_state = check_point_params["aux_fc"]
            self.aux_fc_opt_state = check_point_params["aux_fc_opt"]
            self.seg_opt_state = check_point_params["seg_opt"]
            self.current_pivot_index = check_point_params["current_pivot"]
            self.is_segment_wise_finetune = check_point_params[
                "segment_wise_finetune"]
            self.is_channel_selection = check_point_params["channel_selection"]
            self.epoch = check_point_params["epoch"]
            self.epoch = self.settings.segment_wise_n_epochs
            self.current_block_count = check_point_params[
                "current_block_count"]

            if self.is_channel_selection or \
                    (self.is_segment_wise_finetune and self.current_pivot_index > self.settings.pivot_set[0]):
                self.replace_layer()
            self.ori_model = self.checkpoint.load_state(
                self.ori_model, ori_model_state)
            self.pruned_model = self.checkpoint.load_state(
                self.pruned_model, pruned_model_state)
            self.logger.info("|===>load resume file: {}".format(
                self.settings.resume))

    def _cal_pivot(self):
        """
        calculate the inserted layer for additional loss
        """

        self.num_segments = self.settings.n_losses + 1
        num_block_per_segment = (
            block_num[self.settings.net_type + str(self.settings.depth)] //
            self.num_segments) + 1
        pivot_set = []
        for i in range(self.num_segments - 1):
            pivot_set.append(num_block_per_segment * (i + 1))
        self.settings.pivot_set = pivot_set
        self.logger.info("pivot set: {}".format(pivot_set))

    def segment_wise_fine_tune(self, index):
        """
        conduct segment-wise fine-tuning
        :param index: segment index
        """

        best_top1 = 100
        best_top5 = 100

        start_epoch = 0
        if self.is_segment_wise_finetune and self.epoch != 0:
            start_epoch = self.epoch + 1
            self.epoch = 0
        for epoch in range(start_epoch, self.settings.segment_wise_n_epochs):
            train_error, train_loss, train5_error = self.segment_wise_trainer.train(
                epoch, index)
            val_error, val_loss, val5_error = self.segment_wise_trainer.val(
                epoch)

            # write and print result
            if isinstance(train_error, list):
                best_flag = False
                if best_top1 >= val_error[-1]:
                    best_top1 = val_error[-1]
                    best_top5 = val5_error[-1]
                    best_flag = True

            else:
                best_flag = False
                if best_top1 >= val_error:
                    best_top1 = val_error
                    best_top5 = val5_error
                    best_flag = True

            if best_flag:
                self.checkpoint.save_model(
                    ori_model=self.ori_model,
                    pruned_model=self.pruned_model,
                    aux_fc=self.segment_wise_trainer.aux_fc,
                    current_pivot=self.current_pivot_index,
                    segment_wise_finetune=True,
                    index=index)

            self.logger.info(
                "|===>Best Result is: Top1 Error: {:f}, Top5 Error: {:f}\n".
                format(best_top1, best_top5))
            self.logger.info(
                "|===>Best Result is: Top1 Accuracy: {:f}, Top5 Accuracy: {:f}\n"
                .format(100 - best_top1, 100 - best_top5))

            if self.settings.dataset in ["imagenet"]:
                self.checkpoint.save_checkpoint(
                    ori_model=self.ori_model,
                    pruned_model=self.pruned_model,
                    aux_fc=self.segment_wise_trainer.aux_fc,
                    aux_fc_opt=self.segment_wise_trainer.fc_optimizer,
                    seg_opt=self.segment_wise_trainer.seg_optimizer,
                    current_pivot=self.current_pivot_index,
                    segment_wise_finetune=True,
                    index=index,
                    epoch=epoch)
            else:
                self.checkpoint.save_checkpoint(
                    ori_model=self.ori_model,
                    pruned_model=self.pruned_model,
                    aux_fc=self.segment_wise_trainer.aux_fc,
                    aux_fc_opt=self.segment_wise_trainer.fc_optimizer,
                    seg_opt=self.segment_wise_trainer.seg_optimizer,
                    current_pivot=self.current_pivot_index,
                    segment_wise_finetune=True,
                    index=index)

    def replace_layer(self):
        """
        Replace the convolutional layer to mask convolutional layer
        """

        block_count = 0
        if self.settings.net_type in ["preresnet", "resnet"]:
            for module in self.pruned_model.modules():
                if isinstance(module, (PreBasicBlock, BasicBlock, Bottleneck)):
                    block_count += 1
                    layer = module.conv2
                    if block_count <= self.current_block_count and not isinstance(
                            layer, MaskConv2d):
                        temp_conv = MaskConv2d(in_channels=layer.in_channels,
                                               out_channels=layer.out_channels,
                                               kernel_size=layer.kernel_size,
                                               stride=layer.stride,
                                               padding=layer.padding,
                                               bias=(layer.bias is not None))
                        temp_conv.weight.data.copy_(layer.weight.data)

                        if layer.bias is not None:
                            temp_conv.bias.data.copy_(layer.bias.data)
                        module.conv2 = temp_conv

                    if isinstance(module, Bottleneck):
                        layer = module.conv3
                        if block_count <= self.current_block_count and not isinstance(
                                layer, MaskConv2d):
                            temp_conv = MaskConv2d(
                                in_channels=layer.in_channels,
                                out_channels=layer.out_channels,
                                kernel_size=layer.kernel_size,
                                stride=layer.stride,
                                padding=layer.padding,
                                bias=(layer.bias is not None))
                            temp_conv.weight.data.copy_(layer.weight.data)

                            if layer.bias is not None:
                                temp_conv.bias.data.copy_(layer.bias.data)
                            module.conv3 = temp_conv

    def channel_selection(self):
        """
        conduct channel selection
        """

        # get testing error
        self.segment_wise_trainer.val(0)
        time_start = time.time()

        restart_index = None
        # find restart segment index
        if self.current_pivot_index:
            if self.current_pivot_index in self.settings.pivot_set:
                restart_index = self.settings.pivot_set.index(
                    self.current_pivot_index)
            else:
                restart_index = len(self.settings.pivot_set)

        for index in range(self.num_segments):
            if restart_index is not None:
                if index < restart_index:
                    continue
                elif index == restart_index:
                    if self.is_channel_selection and self.current_block_count == self.current_pivot_index:
                        self.is_channel_selection = False
                        continue

            if index == self.num_segments - 1:
                self.current_pivot_index = self.segment_wise_trainer.final_block_count
            else:
                self.current_pivot_index = self.settings.pivot_set[index]

            # fine tune the network with additional loss and final loss
            if (not self.is_segment_wise_finetune and not self.is_channel_selection) or \
                    (self.is_segment_wise_finetune and self.epoch != self.settings.segment_wise_n_epochs - 1):
                self.segment_wise_fine_tune(index)
            else:
                self.is_segment_wise_finetune = False

            # load best model
            best_model_path = os.path.join(
                self.checkpoint.save_path,
                'model_{:0>3d}_swft.pth'.format(index))
            check_point_params = torch.load(best_model_path)
            ori_model_state = check_point_params["ori_model"]
            pruned_model_state = check_point_params["pruned_model"]
            aux_fc_state = check_point_params["aux_fc"]
            self.ori_model = self.checkpoint.load_state(
                self.ori_model, ori_model_state)
            self.pruned_model = self.checkpoint.load_state(
                self.pruned_model, pruned_model_state)
            self.segment_wise_trainer.update_model(self.ori_model,
                                                   self.pruned_model,
                                                   aux_fc_state)

            # replace the baseline model
            if index == 0:
                if self.settings.net_type in ['preresnet']:
                    self.ori_model.conv = copy.deepcopy(self.pruned_model.conv)
                    for ori_module, pruned_module in zip(
                            self.ori_model.modules(),
                            self.pruned_model.modules()):
                        if isinstance(ori_module, PreBasicBlock):
                            ori_module.bn1 = copy.deepcopy(pruned_module.bn1)
                            ori_module.bn2 = copy.deepcopy(pruned_module.bn2)
                            ori_module.conv1 = copy.deepcopy(
                                pruned_module.conv1)
                            ori_module.conv2 = copy.deepcopy(
                                pruned_module.conv2)
                            if ori_module.downsample is not None:
                                ori_module.downsample = copy.deepcopy(
                                    pruned_module.downsample)
                    self.ori_model.bn = copy.deepcopy(self.pruned_model.bn)
                    self.ori_model.fc = copy.deepcopy(self.pruned_model.fc)
                elif self.settings.net_type in ['resnet']:
                    self.ori_model.conv1 = copy.deepcopy(
                        self.pruned_model.conv)
                    self.ori_model.bn1 = copy.deepcopy(self.pruned_model.bn1)
                    for ori_module, pruned_module in zip(
                            self.ori_model.modules(),
                            self.pruned_model.modules()):
                        if isinstance(ori_module, BasicBlock):
                            ori_module.conv1 = copy.deepcopy(
                                pruned_module.conv1)
                            ori_module.conv2 = copy.deepcopy(
                                pruned_module.conv2)
                            ori_module.bn1 = copy.deepcopy(pruned_module.bn1)
                            ori_module.bn2 = copy.deepcopy(pruned_module.bn2)
                            if ori_module.downsample is not None:
                                ori_module.downsample = copy.deepcopy(
                                    pruned_module.downsample)
                        if isinstance(ori_module, Bottleneck):
                            ori_module.conv1 = copy.deepcopy(
                                pruned_module.conv1)
                            ori_module.conv2 = copy.deepcopy(
                                pruned_module.conv2)
                            ori_module.conv3 = copy.deepcopy(
                                pruned_module.conv3)
                            ori_module.bn1 = copy.deepcopy(pruned_module.bn1)
                            ori_module.bn2 = copy.deepcopy(pruned_module.bn2)
                            ori_module.bn3 = copy.deepcopy(pruned_module.bn3)
                            if ori_module.downsample is not None:
                                ori_module.downsample = copy.deepcopy(
                                    pruned_module.downsample)
                    self.ori_model.fc = copy.deepcopy(self.pruned_model.fc)

                aux_fc_state = []
                for i in range(len(self.segment_wise_trainer.aux_fc)):
                    if isinstance(self.segment_wise_trainer.aux_fc[i],
                                  nn.DataParallel):
                        temp_state = self.segment_wise_trainer.aux_fc[
                            i].module.state_dict()
                    else:
                        temp_state = self.segment_wise_trainer.aux_fc[
                            i].state_dict()
                    aux_fc_state.append(temp_state)
                self.segment_wise_trainer.update_model(self.ori_model,
                                                       self.pruned_model,
                                                       aux_fc_state)
            self.segment_wise_trainer.val(0)

            # conduct channel selection
            # contains [0:index] segments
            net_origin_list = []
            net_pruned_list = []
            for j in range(index + 1):
                net_origin_list += utils.model2list(
                    self.segment_wise_trainer.ori_segments[j])
                net_pruned_list += utils.model2list(
                    self.segment_wise_trainer.pruned_segments[j])

            net_origin = nn.Sequential(*net_origin_list)
            net_pruned = nn.Sequential(*net_pruned_list)

            self._seg_channel_selection(
                net_origin=net_origin,
                net_pruned=net_pruned,
                aux_fc=self.segment_wise_trainer.aux_fc[index],
                pivot_index=self.current_pivot_index,
                index=index)

            # update optimizer
            aux_fc_state = []
            for i in range(len(self.segment_wise_trainer.aux_fc)):
                if isinstance(self.segment_wise_trainer.aux_fc[i],
                              nn.DataParallel):
                    temp_state = self.segment_wise_trainer.aux_fc[
                        i].module.state_dict()
                else:
                    temp_state = self.segment_wise_trainer.aux_fc[
                        i].state_dict()
                aux_fc_state.append(temp_state)

            self.segment_wise_trainer.update_model(self.ori_model,
                                                   self.pruned_model,
                                                   aux_fc_state)

            self.checkpoint.save_checkpoint(
                self.ori_model,
                self.pruned_model,
                self.segment_wise_trainer.aux_fc,
                self.segment_wise_trainer.fc_optimizer,
                self.segment_wise_trainer.seg_optimizer,
                self.current_pivot_index,
                channel_selection=True,
                index=index,
                block_count=self.current_pivot_index)

            self.logger.info(self.ori_model)
            self.logger.info(self.pruned_model)
            self.segment_wise_trainer.val(0)
            self.current_pivot_index = None

        self.checkpoint.save_model(self.ori_model,
                                   self.pruned_model,
                                   self.segment_wise_trainer.aux_fc,
                                   self.segment_wise_trainer.final_block_count,
                                   index=self.num_segments)
        time_interval = time.time() - time_start
        log_str = "cost time: {}".format(
            str(datetime.timedelta(seconds=time_interval)))
        self.logger.info(log_str)

    def _hook_origin_feature(self, module, input, output):
        gpu_id = str(output.get_device())
        self.feature_cache_origin[gpu_id] = output

    def _hook_pruned_feature(self, module, input, output):
        gpu_id = str(output.get_device())
        self.feature_cache_pruned[gpu_id] = output

    @staticmethod
    def _concat_gpu_data(data):
        data_cat = data["0"]
        for i in range(1, len(data)):
            data_cat = torch.cat((data_cat, data[str(i)].cuda(0)))
        return data_cat

    def _layer_channel_selection(self,
                                 net_origin,
                                 net_pruned,
                                 aux_fc,
                                 module,
                                 block_count,
                                 layer_name="conv2"):
        """
        conduct channel selection for module
        :param net_origin: original network segments
        :param net_pruned: pruned network segments
        :param aux_fc: auxiliary fully-connected layer
        :param module: the module need to be pruned
        :param block_count: current block no.
        :param layer_name: the name of layer need to be pruned
        """

        self.logger.info(
            "|===>layer-wise channel selection: block-{}-{}".format(
                block_count, layer_name))
        # layer-wise channel selection
        if layer_name == "conv2":
            layer = module.conv2
        elif layer_name == "conv3":
            layer = module.conv3
        else:
            assert False, "unsupport layer: {}".format(layer_name)

        if not isinstance(layer, MaskConv2d):
            temp_conv = MaskConv2d(in_channels=layer.in_channels,
                                   out_channels=layer.out_channels,
                                   kernel_size=layer.kernel_size,
                                   stride=layer.stride,
                                   padding=layer.padding,
                                   bias=(layer.bias is not None))
            temp_conv.weight.data.copy_(layer.weight.data)

            if layer.bias is not None:
                temp_conv.bias.data.copy_(layer.bias.data)
            temp_conv.pruned_weight.data.fill_(0)
            temp_conv.d.fill_(0)

            if layer_name == "conv2":
                module.conv2 = temp_conv
            elif layer_name == "conv3":
                module.conv3 = temp_conv
            layer = temp_conv

        # define criterion
        criterion_mse = nn.MSELoss().cuda()
        criterion_softmax = nn.CrossEntropyLoss().cuda()

        # register hook
        if layer_name == "conv2":
            hook_origin = net_origin[block_count].conv2.register_forward_hook(
                self._hook_origin_feature)
            hook_pruned = module.conv2.register_forward_hook(
                self._hook_pruned_feature)
        elif layer_name == "conv3":
            hook_origin = net_origin[block_count].conv3.register_forward_hook(
                self._hook_origin_feature)
            hook_pruned = module.conv3.register_forward_hook(
                self._hook_pruned_feature)

        net_origin_parallel = utils.data_parallel(net_origin,
                                                  self.settings.n_gpus)
        net_pruned_parallel = utils.data_parallel(net_pruned,
                                                  self.settings.n_gpus)

        # avoid computing the gradient
        for params in net_origin_parallel.parameters():
            params.requires_grad = False
        for params in net_pruned_parallel.parameters():
            params.requires_grad = False

        net_origin_parallel.eval()
        net_pruned_parallel.eval()

        layer.pruned_weight.requires_grad = True
        aux_fc.cuda()
        logger_counter = 0
        record_time = utils.AverageMeter()

        for channel in range(layer.in_channels):
            if layer.d.eq(0).sum() <= math.floor(
                    layer.in_channels * self.settings.pruning_rate):
                break

            time_start = time.time()
            cum_grad = None
            record_selection_mse_loss = utils.AverageMeter()
            record_selection_softmax_loss = utils.AverageMeter()
            record_selection_loss = utils.AverageMeter()
            img_count = 0
            for i, (images, labels) in enumerate(self.train_loader):
                images = images.cuda()
                labels = labels.cuda()
                net_origin_parallel(images)
                output = net_pruned_parallel(images)
                softmax_loss = criterion_softmax(aux_fc(output), labels)

                origin_feature = self._concat_gpu_data(
                    self.feature_cache_origin)
                self.feature_cache_origin = {}
                pruned_feature = self._concat_gpu_data(
                    self.feature_cache_pruned)
                self.feature_cache_pruned = {}
                mse_loss = criterion_mse(pruned_feature, origin_feature)

                loss = mse_loss * self.settings.mse_weight + softmax_loss * self.settings.softmax_weight
                loss.backward()
                record_selection_loss.update(loss.item(), images.size(0))
                record_selection_mse_loss.update(mse_loss.item(),
                                                 images.size(0))
                record_selection_softmax_loss.update(softmax_loss.item(),
                                                     images.size(0))

                if cum_grad is None:
                    cum_grad = layer.pruned_weight.grad.data.clone()
                else:
                    cum_grad.add_(layer.pruned_weight.grad.data)
                    layer.pruned_weight.grad = None

                img_count += images.size(0)
                if self.settings.max_samples != -1 and img_count >= self.settings.max_samples:
                    break

            # write tensorboard log
            self.tensorboard_logger.scalar_summary(
                tag="S-block-{}_{}_LossAll".format(block_count, layer_name),
                value=record_selection_loss.avg,
                step=logger_counter)
            self.tensorboard_logger.scalar_summary(
                tag="S-block-{}_{}_MSELoss".format(block_count, layer_name),
                value=record_selection_mse_loss.avg,
                step=logger_counter)
            self.tensorboard_logger.scalar_summary(
                tag="S-block-{}_{}_SoftmaxLoss".format(block_count,
                                                       layer_name),
                value=record_selection_softmax_loss.avg,
                step=logger_counter)
            cum_grad.abs_()
            # calculate gradient F norm
            grad_fnorm = cum_grad.mul(cum_grad).sum((2, 3)).sqrt().sum(0)

            # find grad_fnorm with maximum absolute gradient
            while True:
                _, max_index = torch.topk(grad_fnorm, 1)
                if layer.d[max_index[0]] == 0:
                    layer.d[max_index[0]] = 1
                    layer.pruned_weight.data[:, max_index[
                        0], :, :] = layer.weight[:,
                                                 max_index[0], :, :].data.clone(
                                                 )
                    break
                else:
                    grad_fnorm[max_index[0]] = -1

            # fine-tune average meter
            record_finetune_softmax_loss = utils.AverageMeter()
            record_finetune_mse_loss = utils.AverageMeter()
            record_finetune_loss = utils.AverageMeter()

            record_finetune_top1_error = utils.AverageMeter()
            record_finetune_top5_error = utils.AverageMeter()

            # define optimizer
            params_list = []
            params_list.append({
                "params": layer.pruned_weight,
                "lr": self.settings.layer_wise_lr
            })
            if layer.bias is not None:
                layer.bias.requires_grad = True
                params_list.append({"params": layer.bias, "lr": 0.001})
            optimizer = torch.optim.SGD(
                params=params_list,
                weight_decay=self.settings.weight_decay,
                momentum=self.settings.momentum,
                nesterov=True)
            img_count = 0
            for epoch in range(1):
                for i, (images, labels) in enumerate(self.train_loader):
                    images = images.cuda()
                    labels = labels.cuda()
                    features = net_pruned_parallel(images)
                    net_origin_parallel(images)
                    output = aux_fc(features)
                    softmax_loss = criterion_softmax(output, labels)

                    origin_feature = self._concat_gpu_data(
                        self.feature_cache_origin)
                    self.feature_cache_origin = {}
                    pruned_feature = self._concat_gpu_data(
                        self.feature_cache_pruned)
                    self.feature_cache_pruned = {}
                    mse_loss = criterion_mse(pruned_feature, origin_feature)

                    top1_error, _, top5_error = utils.compute_singlecrop(
                        outputs=output,
                        labels=labels,
                        loss=softmax_loss,
                        top5_flag=True,
                        mean_flag=True)

                    # update parameters
                    optimizer.zero_grad()
                    loss = mse_loss * self.settings.mse_weight + softmax_loss * self.settings.softmax_weight
                    loss.backward()
                    torch.nn.utils.clip_grad_norm_(layer.parameters(),
                                                   max_norm=10.0)
                    layer.pruned_weight.grad.data.mul_(
                        layer.d.unsqueeze(0).unsqueeze(2).unsqueeze(
                            3).expand_as(layer.pruned_weight))
                    optimizer.step()
                    # update record info
                    record_finetune_softmax_loss.update(
                        softmax_loss.item(), images.size(0))
                    record_finetune_mse_loss.update(mse_loss.item(),
                                                    images.size(0))
                    record_finetune_loss.update(loss.item(), images.size(0))
                    record_finetune_top1_error.update(top1_error,
                                                      images.size(0))
                    record_finetune_top5_error.update(top5_error,
                                                      images.size(0))

                    img_count += images.size(0)
                    if self.settings.max_samples != -1 and img_count >= self.settings.max_samples:
                        break

            layer.pruned_weight.grad = None
            if layer.bias is not None:
                layer.bias.requires_grad = False

            self.tensorboard_logger.scalar_summary(
                tag="F-block-{}_{}_SoftmaxLoss".format(block_count,
                                                       layer_name),
                value=record_finetune_softmax_loss.avg,
                step=logger_counter)
            self.tensorboard_logger.scalar_summary(
                tag="F-block-{}_{}_Loss".format(block_count, layer_name),
                value=record_finetune_loss.avg,
                step=logger_counter)
            self.tensorboard_logger.scalar_summary(
                tag="F-block-{}_{}_MSELoss".format(block_count, layer_name),
                value=record_finetune_mse_loss.avg,
                step=logger_counter)
            self.tensorboard_logger.scalar_summary(
                tag="F-block-{}_{}_Top1Error".format(block_count, layer_name),
                value=record_finetune_top1_error.avg,
                step=logger_counter)
            self.tensorboard_logger.scalar_summary(
                tag="F-block-{}_{}_Top5Error".format(block_count, layer_name),
                value=record_finetune_top5_error.avg,
                step=logger_counter)

            # write log information to file
            self._write_log(
                dir_name=os.path.join(self.settings.save_path, "log"),
                file_name="log_block-{:0>2d}_{}.txt".format(
                    block_count, layer_name),
                log_str=
                "{:d}\t{:f}\t{:f}\t{:f}\t{:f}\t{:f}\t{:f}\t{:f}\t{:f}\t\n".
                format(int(layer.d.sum()), record_selection_loss.avg,
                       record_selection_mse_loss.avg,
                       record_selection_softmax_loss.avg,
                       record_finetune_loss.avg, record_finetune_mse_loss.avg,
                       record_finetune_softmax_loss.avg,
                       record_finetune_top1_error.avg,
                       record_finetune_top5_error.avg))
            log_str = "Block-{:0>2d}-{}\t#channels: [{:0>4d}|{:0>4d}]\t".format(
                block_count, layer_name, int(layer.d.sum()), layer.d.size(0))
            log_str += "[selection]loss: {:4f}\tmseloss: {:4f}\tsoftmaxloss: {:4f}\t".format(
                record_selection_loss.avg, record_selection_mse_loss.avg,
                record_selection_softmax_loss.avg)
            log_str += "[fine-tuning]loss: {:4f}\tmseloss: {:4f}\tsoftmaxloss: {:4f}\t".format(
                record_finetune_loss.avg, record_finetune_mse_loss.avg,
                record_finetune_softmax_loss.avg)
            log_str += "top1error: {:4f}\ttop5error: {:4f}".format(
                record_finetune_top1_error.avg, record_finetune_top5_error.avg)
            self.logger.info(log_str)

            logger_counter += 1
            time_interval = time.time() - time_start
            record_time.update(time_interval)

        for params in net_origin_parallel.parameters():
            params.requires_grad = True
        for params in net_pruned_parallel.parameters():
            params.requires_grad = True

        # remove hook
        hook_origin.remove()
        hook_pruned.remove()
        log_str = "|===>Select channel from block-{:d}_{}: time_total:{} time_avg: {}".format(
            block_count, layer_name,
            str(datetime.timedelta(seconds=record_time.sum)),
            str(datetime.timedelta(seconds=record_time.avg)))
        self.logger.info(log_str)
        log_str = "|===>fine-tuning result: loss: {:f}, mse_loss: {:f}, softmax_loss: {:f}, top1error: {:f} top5error: {:f}".format(
            record_finetune_loss.avg, record_finetune_mse_loss.avg,
            record_finetune_softmax_loss.avg, record_finetune_top1_error.avg,
            record_finetune_top5_error.avg)
        self.logger.info(log_str)

        self.logger.info("|===>remove hook")

    @staticmethod
    def _write_log(dir_name, file_name, log_str):
        """
        Write log to file
        :param dir_name:  the path of directory
        :param file_name: the name of the saved file
        :param log_str: the string that need to be saved
        """

        if not os.path.isdir(dir_name):
            os.mkdir(dir_name)
        with open(os.path.join(dir_name, file_name), "a+") as f:
            f.write(log_str)

    def _seg_channel_selection(self, net_origin, net_pruned, aux_fc,
                               pivot_index, index):
        """
        conduct segment channel selection
        :param net_origin: original network segments
        :param net_pruned: pruned network segments
        :param aux_fc: auxiliary fully-connected layer
        :param pivot_index: the layer index of the additional loss
        :param index: the index of segment
        :return:
        """
        block_count = 0
        if self.settings.net_type in ["preresnet", "resnet"]:
            for module in net_pruned.modules():
                if isinstance(module, (PreBasicBlock, BasicBlock)):
                    block_count += 1
                    # We will not prune the pruned blocks again
                    if not isinstance(module.conv2, MaskConv2d):
                        self._layer_channel_selection(net_origin=net_origin,
                                                      net_pruned=net_pruned,
                                                      aux_fc=aux_fc,
                                                      module=module,
                                                      block_count=block_count,
                                                      layer_name="conv2")
                        self.logger.info("|===>checking layer type: {}".format(
                            type(module.conv2)))

                        self.checkpoint.save_model(
                            self.ori_model,
                            self.pruned_model,
                            self.segment_wise_trainer.aux_fc,
                            pivot_index,
                            channel_selection=True,
                            index=index,
                            block_count=block_count)
                        self.checkpoint.save_checkpoint(
                            self.ori_model,
                            self.pruned_model,
                            self.segment_wise_trainer.aux_fc,
                            self.segment_wise_trainer.fc_optimizer,
                            self.segment_wise_trainer.seg_optimizer,
                            pivot_index,
                            channel_selection=True,
                            index=index,
                            block_count=block_count)

                elif isinstance(module, Bottleneck):
                    block_count += 1
                    if not isinstance(module.conv2, MaskConv2d):
                        self._layer_channel_selection(net_origin=net_origin,
                                                      net_pruned=net_pruned,
                                                      aux_fc=aux_fc,
                                                      module=module,
                                                      block_count=block_count,
                                                      layer_name="conv2")

                    if not isinstance(module.conv3, MaskConv2d):
                        self._layer_channel_selection(net_origin=net_origin,
                                                      net_pruned=net_pruned,
                                                      aux_fc=aux_fc,
                                                      module=module,
                                                      block_count=block_count,
                                                      layer_name="conv3")

                        self.checkpoint.save_model(
                            self.ori_model,
                            self.pruned_model,
                            self.segment_wise_trainer.aux_fc,
                            pivot_index,
                            channel_selection=True,
                            index=index,
                            block_count=block_count)
                        self.checkpoint.save_checkpoint(
                            self.ori_model,
                            self.pruned_model,
                            self.segment_wise_trainer.aux_fc,
                            self.segment_wise_trainer.fc_optimizer,
                            self.segment_wise_trainer.seg_optimizer,
                            pivot_index,
                            channel_selection=True,
                            index=index,
                            block_count=block_count)