feature(whl): add rlhf pipeline.

ding/bonus/config.py

@@ -167,6 +167,13 @@
             cfg.batch_size = 320
             cfg.epoch_per_collect = 10
             cfg.learning_rate = 3e-4
+        elif env_id == 'chat':
+            cfg.epoch_per_collect = 1
+            cfg.batch_size = 1
+            cfg.learning_rate = 5e-7
+            cfg.answers_per_question = 3
+            cfg.kl_penalty_weight = 0.1
+            cfg.ppo_param_init = False
         else:
             raise KeyError("not supported env type: {}".format(env_id))
     else:
@@ -315,6 +322,16 @@
         )
         cfg = EasyDict(cfg)
         return DriveEnvWrapper(MetaDrivePPOOriginEnv(cfg))
+    elif env_id == 'chat':
+        from dizoo.chat.env import ChatEnv
+        return ChatEnv(
+            batch_size=1,
+            reward_model_path="/mnt/nfs/whl/rlhf/MOSS-RLHF/models/moss-rlhf-reward-model-7B-en/recover",
+            tokenizer_path="/mnt/nfs/whl/rlhf/MOSS-RLHF/models/moss-rlhf-reward-model-7B-en",
+            data_path="/mnt/nfs/whl/rlhf/MOSS-RLHF/data/ppo_data",
+            maxlen_prompt=128,
+            maxlen_res=128,
+        )
     else:
         raise KeyError("not supported env type: {}".format(env_id))
 

ding/bonus/ppof.py

@@ -1,3 +1,4 @@
+import copy
 from typing import Optional, Union, List
 from ditk import logging
 from easydict import EasyDict
@@ -9,7 +10,7 @@
 import torch
 from ding.framework import task, OnlineRLContext
 from ding.framework.middleware import interaction_evaluator_ttorch, PPOFStepCollector, multistep_trainer, CkptSaver, \
-    wandb_online_logger, offline_data_saver, termination_checker, ppof_adv_estimator
+    wandb_online_logger, offline_data_saver, termination_checker, ppof_adv_estimator, ChatCollector
 from ding.envs import BaseEnv, BaseEnvManagerV2, SubprocessEnvManagerV2
 from ding.policy import PPOFPolicy, single_env_forward_wrapper_ttorch
 from ding.utils import set_pkg_seed
@@ -62,6 +63,8 @@
         'Hopper-v3',
         'HalfCheetah-v3',
         'Walker2d-v3',
+        # rlhf
+        'chat'
     ]
     """
     Overview:
@@ -170,6 +173,8 @@
             action_shape = int(action_space.n)
         elif isinstance(action_space, (gym.spaces.Tuple, gymnasium.spaces.Tuple)):
             action_shape = get_hybrid_shape(action_space)
+        elif action_space is None:
+            pass
         else:
             action_shape = action_space.shape
 
@@ -191,7 +196,11 @@
                     popart_head=True,
                     **self.cfg.model
                 )
-        self.policy = PPOFPolicy(self.cfg, model=model)
+        if self.cfg.chat_data:
+            orig_model = copy.deepcopy(model)
+        else:
+            orig_model = None
+        self.policy = PPOFPolicy(self.cfg, model=model, orig_model=orig_model)
         if policy_state_dict is not None:
             self.policy.load_state_dict(policy_state_dict)
         self.checkpoint_save_dir = os.path.join(self.exp_name, "ckpt")
@@ -246,10 +255,14 @@
             pass
 
         with task.start(ctx=OnlineRLContext()):
-            task.use(interaction_evaluator_ttorch(self.seed, self.policy, evaluator_env))
-            task.use(CkptSaver(self.policy, save_dir=self.checkpoint_save_dir, train_freq=n_iter_save_ckpt))
-            task.use(PPOFStepCollector(self.seed, self.policy, collector_env, self.cfg.n_sample))
-            task.use(ppof_adv_estimator(self.policy))
+            if self.policy._cfg.chat_data:
+                # task.use(interaction_evaluator_ttorch(self.seed, self.policy, evaluator_env))
+                # task.use(CkptSaver(self.policy, save_dir=self.checkpoint_save_dir, train_freq=n_iter_save_ckpt))
+                task.use(ChatCollector(self.seed, self.policy, collector_env, self.cfg.n_sample))
+            else:
+                task.use(interaction_evaluator_ttorch(self.seed, self.policy, evaluator_env))
+                task.use(CkptSaver(self.policy, save_dir=self.checkpoint_save_dir, train_freq=n_iter_save_ckpt))
+                task.use(PPOFStepCollector(self.seed, self.policy, collector_env, self.cfg.n_sample))
             task.use(multistep_trainer(self.policy, log_freq=n_iter_log_show))
             task.use(
                 wandb_online_logger(

ding/framework/middleware/__init__.py

@@ -1,5 +1,5 @@
 from .functional import *
-from .collector import StepCollector, EpisodeCollector, PPOFStepCollector
+from .collector import StepCollector, EpisodeCollector, PPOFStepCollector, ChatCollector
 from .learner import OffPolicyLearner, HERLearner
 from .ckpt_handler import CkptSaver
 from .distributer import ContextExchanger, ModelExchanger, PeriodicalModelExchanger

ding/framework/middleware/collector.py

@@ -1,3 +1,4 @@
+import copy
 from typing import TYPE_CHECKING
 from easydict import EasyDict
 import treetensor.torch as ttorch
@@ -190,4 +191,64 @@
                 break
 
 
+class ChatCollector:
+    """
+    Overview:
+        The class of the collector running by steps, including model inference and transition \
+        process. Use the `__call__` method to execute the whole collection process.
+    """
+
+    def __new__(cls, *args, **kwargs):
+        if task.router.is_active and not task.has_role(task.role.COLLECTOR):
+            return task.void()
+        return super(ChatCollector, cls).__new__(cls)
+
+    def __init__(self, seed: int, policy, env: BaseEnvManager, n_sample: int, unroll_len: int = 1) -> None:
+        """
+        Arguments:
+            - seed (:obj:`int`): Random seed.
+            - policy (:obj:`Policy`): The policy to be collected.
+            - env (:obj:`BaseEnvManager`): The env for the collection, the BaseEnvManager object or \
+                its derivatives are supported.
+        """
+        self.env = env
+        self.env.seed(seed)
+        self.env.launch()
+        self.env = self.env._envs[0]
+        self.policy = policy
+        self.n_sample = n_sample
+        self.unroll_len = unroll_len
+
+    def __call__(self, ctx: "OnlineRLContext") -> None:
+        """
+        Overview:
+            An encapsulation of inference and rollout middleware. Stop when completing \
+                the target number of steps.
+        Input of ctx:
+            - env_step (:obj:`int`): The env steps which will increase during collection.
+        """
+        device = self.policy._device
+
+        obs = ttorch.as_tensor(self.env.last_batch['text_vec'])
+        batch_size = obs.shape[0]
+        obs = obs.to(device)
+
+        total_action = [[] for _ in range(batch_size)]  # [B, answers_per_question, T]
+        for _ in range(self.policy._cfg.answers_per_question):
+            _, inference_output = self.policy._model.actor.generate(obs, **ctx.collect_kwargs)
+            for i in range(batch_size):
+                total_action[i].append(copy.deepcopy(inference_output[i]))
+
+        mask, resp, rew = self.env.step(total_action)
+        ctx.env_step += 1
+        ctx.env_episode += 1
+
+        train_data = {}
+        train_data['obs'] = resp  # [B x answer-per-question, T]
+        train_data['reward'] = rew  # [B x answer-per-question, ]
+        train_data['mask'] = mask  # [B x answer-per-question, T]
+
+        ctx.train_data = ttorch.as_tensor(train_data)
+
+
 # TODO battle collector

ding/model/common/__init__.py

@@ -2,4 +2,4 @@
     QuantileHead, FQFHead, RegressionHead, ReparameterizationHead, MultiHead, BranchingHead, head_cls_map, \
     independent_normal_dist, AttentionPolicyHead, PopArtVHead, EnsembleHead
 from .encoder import ConvEncoder, FCEncoder, IMPALAConvEncoder
-from .utils import create_model
+from .utils import create_model, top_p_logits

ding/model/common/tests/test_utils.py

@@ -0,0 +1,15 @@
+import pytest
+import torch
+from ding.model.common.utils import top_p_logits
+
+
+@pytest.mark.unittest
+class TestUtils:
+
+    def test_top_p_logits(self):
+        test_logit = torch.Tensor([[0., 0.91, 0.05, 0.04], [0.04, 0.46, 0.46, 0.04]])
+
+        gt_logit = torch.Tensor([[0., 1., 0., 0.], [0., 0.5, 0.5, 0.]])
+
+        pred_logit = top_p_logits(test_logit)
+        assert torch.sum((gt_logit - pred_logit) ** 2).item() < 1e-8

ding/model/common/utils.py

@@ -29,3 +29,29 @@ def create_model(cfg: EasyDict) -> torch.nn.Module:
     import_module(cfg.pop('import_names', []))
     # here we must use the pop opeartion to ensure compatibility
     return MODEL_REGISTRY.build(cfg.pop("type"), **cfg)
+
+
+def top_p_logits(logits: torch.Tensor, topp: float = 0.9, filter_value: float = 0, min_topk: int = 1):
+    """
+    Overview:
+        Filter a distribution of logits using nucleus (top-p) filtering. The output is also logit tensors but some \
+        values are masked.
+    Arguments:
+        - logits (:obj:`torch.Tensor`): The input logits for top-p sampling.
+        - topp (:obj:`float`): The top-p value, such as 0.9.
+        - filter_value (:obj:`float`): The value for masked logits in output, default as 0.
+        - min_topk (:obj:`int`): The min number of sampled logit, default as 1 (which means that at least one sample \
+            will not be masked.)
+    Returns:
+        - cum_logits (:obj:`torch.Tensor`): The output logits after masking.
+    """
+    cum_logits = logits.clone()
+    if topp > 0:
+        logits_sorted, inds = torch.sort(logits, dim=-1, descending=True)
+        mask = (logits_sorted.cumsum(dim=-1) - logits_sorted) >= topp
+        mask[..., :min_topk] = False
+        # Remove tokens with cumulative top_p above the threshold
+        mask = torch.zeros_like(mask).to(torch.bool).scatter_(dim=-1, index=inds, src=mask)
+        cum_logits[mask] = filter_value
+        cum_logits.div_(cum_logits.sum(dim=-1, keepdim=True))
+    return cum_logits

ding/model/template/__init__.py

@@ -5,6 +5,7 @@
 from .vac import VAC, DREAMERVAC
 from .bc import DiscreteBC, ContinuousBC
 from .language_transformer import LanguageTransformer
+from .lm_vac import LlamaVAC
 # algorithm-specific
 from .pg import PG
 from .ppg import PPG