initial commit

models/backbones/base_model.py

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+"""
+ Copyright (c) 2022, salesforce.com, inc.
+ All rights reserved.
+ SPDX-License-Identifier: BSD-3-Clause
+ For full license text, see the LICENSE_Lavis file in the repo root or https://opensource.org/licenses/BSD-3-Clause
+"""
+
+import logging
+import os
+
+import numpy as np
+import torch
+import torch.nn as nn
+from models.common.dist_utils import download_cached_file, is_dist_avail_and_initialized
+from models.common.utils import get_abs_path, is_url
+from omegaconf import OmegaConf
+
+
+class BaseModel(nn.Module):
+    """Base class for models."""
+
+    def __init__(self):
+        super().__init__()
+
+    @property
+    def device(self):
+        return list(self.parameters())[0].device
+
+    def load_checkpoint(self, url_or_filename):
+        """
+        Load from a finetuned checkpoint.
+
+        This should expect no mismatch in the model keys and the checkpoint keys.
+        """
+
+        if is_url(url_or_filename):
+            cached_file = download_cached_file(
+                url_or_filename, check_hash=False, progress=True
+            )
+            checkpoint = torch.load(cached_file, map_location="cpu")
+        elif os.path.isfile(url_or_filename):
+            checkpoint = torch.load(url_or_filename, map_location="cpu")
+        else:
+            raise RuntimeError("checkpoint url or path is invalid")
+
+        if "model" in checkpoint.keys():
+            state_dict = checkpoint["model"]
+        else:
+            state_dict = checkpoint
+
+        msg = self.load_state_dict(state_dict, strict=False)
+
+        logging.info("Missing keys {}".format(msg.missing_keys))
+        logging.info("load checkpoint from %s" % url_or_filename)
+
+        return msg
+
+    @classmethod
+    def from_pretrained(cls, model_type):
+        """
+        Build a pretrained model from default configuration file, specified by model_type.
+
+        Args:
+            - model_type (str): model type, specifying architecture and checkpoints.
+
+        Returns:
+            - model (nn.Module): pretrained or finetuned model, depending on the configuration.
+        """
+        model_cfg = OmegaConf.load(cls.default_config_path(model_type)).model
+        model = cls.from_config(model_cfg)
+
+        return model
+
+    @classmethod
+    def default_config_path(cls, model_type):
+        assert (
+            model_type in cls.PRETRAINED_MODEL_CONFIG_DICT
+        ), "Unknown model type {}".format(model_type)
+        return get_abs_path(cls.PRETRAINED_MODEL_CONFIG_DICT[model_type])
+
+    def load_checkpoint_from_config(self, cfg, **kwargs):
+        """
+        Load checkpoint as specified in the config file.
+
+        If load_finetuned is True, load the finetuned model; otherwise, load the pretrained model.
+        When loading the pretrained model, each task-specific architecture may define their
+        own load_from_pretrained() method.
+        """
+        load_finetuned = cfg.get("load_finetuned", True)
+        if load_finetuned:
+            finetune_path = cfg.get("finetuned", None)
+            assert (
+                finetune_path is not None
+            ), "Found load_finetuned is True, but finetune_path is None."
+            self.load_checkpoint(url_or_filename=finetune_path)
+        else:
+            # load pre-trained weights
+            pretrain_path = cfg.get("pretrained", None)
+            assert "Found load_finetuned is False, but pretrain_path is None."
+            self.load_from_pretrained(url_or_filename=pretrain_path, **kwargs)
+
+    def before_evaluation(self, **kwargs):
+        pass
+
+    def show_n_params(self, return_str=True):
+        tot = 0
+        for p in self.parameters():
+            w = 1
+            for x in p.shape:
+                w *= x
+            tot += w
+        if return_str:
+            if tot >= 1e6:
+                return "{:.1f}M".format(tot / 1e6)
+            else:
+                return "{:.1f}K".format(tot / 1e3)
+        else:
+            return tot
+
+
+class BaseEncoder(nn.Module):
+    """
+    Base class for primitive encoders, such as ViT, TimeSformer, etc.
+    """
+
+    def __init__(self):
+        super().__init__()
+
+    def forward_features(self, samples, **kwargs):
+        raise NotImplementedError
+
+    @property
+    def device(self):
+        return list(self.parameters())[0].device
+
+
+class SharedQueueMixin:
+    @torch.no_grad()
+    def _dequeue_and_enqueue(self, image_feat, text_feat, idxs=None):
+        # gather keys before updating queue
+        image_feats = concat_all_gather(image_feat)
+        text_feats = concat_all_gather(text_feat)
+
+        batch_size = image_feats.shape[0]
+
+        ptr = int(self.queue_ptr)
+        assert self.queue_size % batch_size == 0  # for simplicity
+
+        # replace the keys at ptr (dequeue and enqueue)
+        self.image_queue[:, ptr : ptr + batch_size] = image_feats.T
+        self.text_queue[:, ptr : ptr + batch_size] = text_feats.T
+
+        if idxs is not None:
+            idxs = concat_all_gather(idxs)
+            self.idx_queue[:, ptr : ptr + batch_size] = idxs.T
+
+        ptr = (ptr + batch_size) % self.queue_size  # move pointer
+        self.queue_ptr[0] = ptr
+
+
+class MomentumDistilationMixin:
+    @torch.no_grad()
+    def copy_params(self):
+        for model_pair in self.model_pairs:
+            for param, param_m in zip(
+                model_pair[0].parameters(), model_pair[1].parameters()
+            ):
+                param_m.data.copy_(param.data)  # initialize
+                param_m.requires_grad = False  # not update by gradient
+
+    @torch.no_grad()
+    def _momentum_update(self):
+        for model_pair in self.model_pairs:
+            for param, param_m in zip(
+                model_pair[0].parameters(), model_pair[1].parameters()
+            ):
+                param_m.data = param_m.data * self.momentum + param.data * (
+                    1.0 - self.momentum
+                )
+
+
+class GatherLayer(torch.autograd.Function):
+    """
+    Gather tensors from all workers with support for backward propagation:
+    This implementation does not cut the gradients as torch.distributed.all_gather does.
+    """
+
+    @staticmethod
+    def forward(ctx, x):
+        output = [
+            torch.zeros_like(x) for _ in range(torch.distributed.get_world_size())
+        ]
+        torch.distributed.all_gather(output, x)
+        return tuple(output)
+
+    @staticmethod
+    def backward(ctx, *grads):
+        all_gradients = torch.stack(grads)
+        torch.distributed.all_reduce(all_gradients)
+        return all_gradients[torch.distributed.get_rank()]
+
+
+def all_gather_with_grad(tensors):
+    """
+    Performs all_gather operation on the provided tensors.
+    Graph remains connected for backward grad computation.
+    """
+    # Queue the gathered tensors
+    world_size = torch.distributed.get_world_size()
+    # There is no need for reduction in the single-proc case
+    if world_size == 1:
+        return tensors
+
+    # tensor_all = GatherLayer.apply(tensors)
+    tensor_all = GatherLayer.apply(tensors)
+
+    return torch.cat(tensor_all, dim=0)
+
+
+@torch.no_grad()
+def concat_all_gather(tensor):
+    """
+    Performs all_gather operation on the provided tensors.
+    *** Warning ***: torch.distributed.all_gather has no gradient.
+    """
+    # if use distributed training
+    if not is_dist_avail_and_initialized():
+        return tensor
+
+    tensors_gather = [
+        torch.ones_like(tensor) for _ in range(torch.distributed.get_world_size())
+    ]
+    torch.distributed.all_gather(tensors_gather, tensor, async_op=False)
+
+    output = torch.cat(tensors_gather, dim=0)
+    return output
+
+
+def tile(x, dim, n_tile):
+    init_dim = x.size(dim)
+    repeat_idx = [1] * x.dim()
+    repeat_idx[dim] = n_tile
+    x = x.repeat(*(repeat_idx))
+    order_index = torch.LongTensor(
+        np.concatenate([init_dim * np.arange(n_tile) + i for i in range(init_dim)])
+    )
+    return torch.index_select(x, dim, order_index.to(x.device))