File size: 6,327 Bytes
d98c605
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
"""Standalone inference for Process-FM checkpoints (fm-v6 and scaling/sc*).

Dependency: torch + numpy only. The models use global activity/resource ids:
activities 4..776 (UNK=1), resources 2..2739 (UNK=1), log ids from vocab["log_ids"].
"""
import json
from datetime import datetime
from pathlib import Path

import numpy as np
import torch
import torch.nn as nn

N_NUM = 6
ACT_OFFSET = 4
RES_OFFSET = 2
UNK_ACT = 1
UNK_RES = 1


class EventTransformer(nn.Module):
    def __init__(self, n_act: int, n_res: int, n_logs: int, n_classes: int,
                 d_model: int = 256, n_layers: int = 6, n_heads: int = 8,
                 dropout: float = 0.1, max_len: int = 256,
                 act_dim: int = 64, res_dim: int = 32, log_dim: int = 16):
        super().__init__()
        self.act_emb = nn.Embedding(n_act, act_dim, padding_idx=0)
        self.res_emb = nn.Embedding(n_res, res_dim, padding_idx=0)
        self.log_emb = nn.Embedding(n_logs, log_dim)
        self.proj = nn.Linear(act_dim + res_dim + log_dim + N_NUM, d_model)
        self.pos = nn.Embedding(max_len, d_model)
        layer = nn.TransformerEncoderLayer(
            d_model=d_model, nhead=n_heads, dim_feedforward=4 * d_model,
            dropout=dropout, batch_first=True, norm_first=True, activation="gelu",
        )
        self.encoder = nn.TransformerEncoder(layer, num_layers=n_layers)
        self.norm = nn.LayerNorm(d_model)
        self.act_out = nn.Linear(d_model, n_classes)
        self.res_out = nn.Linear(d_model, n_res)
        self.max_len = max_len

    def forward(self, gact: torch.Tensor, gres: torch.Tensor, num: torch.Tensor,
                log_id: torch.Tensor, causal: bool = True,
                return_hidden: bool = False):
        b, t = gact.shape
        x = torch.cat([
            self.act_emb(gact),
            self.res_emb(gres),
            self.log_emb(log_id).unsqueeze(1).expand(b, t, -1),
            num,
        ], dim=-1)
        x = self.proj(x)
        idx = torch.arange(t, device=gact.device).unsqueeze(0).expand(b, t)
        x = x + self.pos(idx)
        if causal:
            x = self.encoder(x, mask=torch.triu(
                torch.ones(t, t, device=gact.device, dtype=torch.bool), diagonal=1))
        else:
            x = self.encoder(x)
        h = self.norm(x)
        if return_hidden:
            return h
        return self.act_out(h), self.res_out(h)


def build_model(config: dict) -> EventTransformer:
    return EventTransformer(
        n_act=config["n_act"], n_res=config["n_res"], n_logs=config["n_logs"],
        n_classes=config["n_classes"], d_model=config["d_model"],
        n_layers=config["n_layers"], n_heads=config["n_heads"],
        dropout=config["dropout"], max_len=config["max_len"],
        act_dim=config["act_dim"], res_dim=config["res_dim"], log_dim=config["log_dim"],
    )


def _to_ns(ts) -> int:
    if isinstance(ts, datetime):
        return int(ts.timestamp() * 1e9)
    return int(np.datetime64(ts, "ns").astype("int64"))


def featurize(events: list[dict], vocab: dict, amount: float = 0.0,
              log: str | None = None):
    max_len = min(int(vocab.get("max_prefix_len", 256)), 256)
    events = events[-max_len:]
    n = len(events)
    ts = np.array([_to_ns(e["timestamp"]) for e in events], dtype=np.int64)
    dt_prev = np.zeros(n, dtype=np.float64)
    dt_prev[1:] = (ts[1:] - ts[:-1]) / 1e9
    dt_start = (ts - ts[0]) / 1e9
    hours = ((ts // 3_600_000_000_000) % 24).astype(np.float64)
    weekday = ((ts // 86_400_000_000_000) + 3) % 7
    amount_feat = np.log1p(max(amount, 0.0)) / 14.0
    num = np.stack([
        np.log1p(dt_prev) / 20.0,
        np.log1p(dt_start) / 20.0,
        np.sin(2 * np.pi * hours / 24.0),
        np.cos(2 * np.pi * hours / 24.0),
        weekday / 6.0,
        np.full(n, amount_feat),
    ], axis=1).astype(np.float32)

    act_ids = {str(a): ACT_OFFSET + i for i, a in enumerate(vocab["activities"])}
    res_ids = {str(r): RES_OFFSET + i for i, r in enumerate(vocab["resources"])}
    gact = np.array([act_ids.get(str(e.get("activity", "")), UNK_ACT) for e in events],
                    dtype=np.int64)
    gres = np.array([res_ids.get(str(e.get("resource", "")), UNK_RES) for e in events],
                    dtype=np.int64)
    log_name = log or vocab.get("default_log")
    log_id = int(vocab["log_ids"].get(log_name, vocab.get("log_unk_id", vocab["n_logs"] - 1)))
    return (
        torch.from_numpy(gact)[None],
        torch.from_numpy(gres)[None],
        torch.from_numpy(num)[None],
        torch.tensor([log_id], dtype=torch.long),
    )


def load_model(release_dir: str | Path = "."):
    release_dir = Path(release_dir)
    config = json.loads((release_dir / "config.json").read_text())
    vocab = json.loads((release_dir / "vocab.json").read_text())
    model = build_model(config)
    state = torch.load(release_dir / "model.pt", map_location="cpu", weights_only=True)
    model.load_state_dict(state)
    model.eval()
    return model, vocab


@torch.no_grad()
def predict(model: EventTransformer, vocab: dict, events: list[dict],
            amount: float = 0.0, top_k: int = 5, log: str | None = None) -> list[tuple[str, float]]:
    gact, gres, num, log_id = featurize(events, vocab, amount=amount, log=log)
    h = model(gact, gres, num, log_id, causal=True, return_hidden=True)
    logits = model.act_out(h[0, gact.shape[1] - 1].float())
    probs = torch.softmax(logits, dim=-1)
    k = min(top_k, probs.numel() - 1)
    values, indices = torch.topk(probs, k)
    id_to_act = {ACT_OFFSET + i: str(a) for i, a in enumerate(vocab["activities"])}
    return [(id_to_act.get(int(i), "UNK"), float(v)) for v, i in zip(values, indices)]


if __name__ == "__main__":
    here = Path(__file__).resolve().parent
    model, vocab = load_model(here / "fm-v6")
    activities = [str(a) for a in vocab["activities"][:3]]
    resources = [str(r) for r in vocab["resources"][:2]]
    events = [
        {"activity": activities[0], "resource": resources[0], "timestamp": "2024-01-01 10:00:00"},
        {"activity": activities[1], "resource": resources[1], "timestamp": "2024-01-01 11:00:00"},
        {"activity": activities[2], "resource": resources[0], "timestamp": "2024-01-01 12:00:00"},
    ]
    print(predict(model, vocab, events, top_k=3, log=vocab.get("default_log")))