File size: 4,380 Bytes
4968ea3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
"""Memory LoRA_u module: create, load, save per-user LoRA adapters."""

import os
import re

from peft import LoraConfig, get_peft_model, PeftModel

from src.utils import load_yaml, setup_logger

logger = setup_logger(__name__)


def create_memory_lora(model, config_path: str = "configs/model/memory_lora.yaml"):
    """Create a new Memory LoRA adapter on the base model.

    Targets early-to-mid layers (0-23 out of 36) for knowledge memory.

    Args:
        model: Base model (Qwen3ForCausalLM).
        config_path: Path to memory LoRA config.

    Returns:
        PEFT model with LoRA adapter.
    """
    config = load_yaml(config_path)

    # Build layers_to_transform list (early-to-mid layers)
    num_target_layers = config.get("num_target_layers", 24)
    layers_to_transform = list(range(num_target_layers))

    lora_config = LoraConfig(
        r=config["lora_rank"],
        lora_alpha=config["lora_alpha"],
        lora_dropout=config["lora_dropout"],
        target_modules=config["target_modules"],
        layers_to_transform=layers_to_transform,
        bias="none",
        task_type="CAUSAL_LM",
    )

    peft_model = get_peft_model(model, lora_config)

    trainable_params = sum(p.numel() for p in peft_model.parameters() if p.requires_grad)
    total_params = sum(p.numel() for p in peft_model.parameters())
    logger.info(
        f"Memory LoRA created: {trainable_params:,} trainable / {total_params:,} total "
        f"({100 * trainable_params / total_params:.2f}%)"
    )
    logger.info(f"Target layers: 0-{num_target_layers - 1}, modules: {config['target_modules']}")

    return peft_model


def resolve_lora_path(user_dir: str, step: str = "latest") -> str:
    """Resolve the actual adapter path for a user.

    Args:
        user_dir: User's LoRA directory (e.g., checkpoints/memory_lora_longmem/user_001/).
        step: Which checkpoint to load:
            - "latest" or "final": root directory (final save after training)
            - "max": highest step_N checkpoint
            - integer string (e.g., "66"): specific step_66/ checkpoint

    Returns:
        Resolved path containing adapter_config.json.

    Raises:
        FileNotFoundError: if no valid adapter found.
    """
    # Try root directory first for "latest"/"final"
    root_adapter = os.path.join(user_dir, "adapter_config.json")
    if step in ("latest", "final"):
        if os.path.exists(root_adapter):
            return user_dir
        # Fallback: find max step checkpoint
        step = "max"

    # Find all step_N checkpoints
    step_dirs = []
    if os.path.isdir(user_dir):
        for name in os.listdir(user_dir):
            m = re.match(r"step_(\d+)$", name)
            if m:
                ckpt_path = os.path.join(user_dir, name)
                if os.path.exists(os.path.join(ckpt_path, "adapter_config.json")):
                    step_dirs.append((int(m.group(1)), ckpt_path))

    if not step_dirs:
        if os.path.exists(root_adapter):
            return user_dir
        raise FileNotFoundError(f"No adapter found in {user_dir}")

    step_dirs.sort(key=lambda x: x[0])

    if step == "max":
        return step_dirs[-1][1]

    # Specific step number
    target_step = int(step)
    for s, path in step_dirs:
        if s == target_step:
            return path

    raise FileNotFoundError(
        f"step_{target_step} not found in {user_dir}. "
        f"Available: {[s for s, _ in step_dirs]}"
    )


def load_memory_lora(base_model, adapter_path: str, step: str = "latest"):
    """Load a pre-trained Memory LoRA adapter.

    Args:
        base_model: Base model without adapter.
        adapter_path: User's LoRA directory (e.g., checkpoints/memory_lora_longmem/user_001/).
        step: Which checkpoint to load ("latest", "max", or specific step number).

    Returns:
        Model with loaded adapter.
    """
    resolved_path = resolve_lora_path(adapter_path, step=step)
    logger.info(f"Loading Memory LoRA from {resolved_path}")
    model = PeftModel.from_pretrained(base_model, resolved_path)
    return model


def save_memory_lora(peft_model, save_path: str):
    """Save only the LoRA adapter weights.

    Args:
        peft_model: PEFT model with adapter.
        save_path: Directory to save adapter.
    """
    logger.info(f"Saving Memory LoRA to {save_path}")
    peft_model.save_pretrained(save_path)