feat: reduce memory usage and add memory efficient option for model saving

library/utils.py

@@ -1,9 +1,12 @@
 import logging
 import sys
 import threading
+from typing import *
+import json
+import struct
+
 import torch
 from torchvision import transforms
-from typing import *
 from diffusers import EulerAncestralDiscreteScheduler
 import diffusers.schedulers.scheduling_euler_ancestral_discrete
 from diffusers.schedulers.scheduling_euler_ancestral_discrete import EulerAncestralDiscreteSchedulerOutput
@@ -79,6 +82,76 @@ def setup_logging(args=None, log_level=None, reset=False):
         logger.info(msg_init)
 
 
+def mem_eff_save_file(tensors: Dict[str, torch.Tensor], filename: str, metadata: Dict[str, Any] = None):
+    """
+    memory efficient save file
+    """
+
+    _TYPES = {
+        torch.float64: "F64",
+        torch.float32: "F32",
+        torch.float16: "F16",
+        torch.bfloat16: "BF16",
+        torch.int64: "I64",
+        torch.int32: "I32",
+        torch.int16: "I16",
+        torch.int8: "I8",
+        torch.uint8: "U8",
+        torch.bool: "BOOL",
+        getattr(torch, "float8_e5m2", None): "F8_E5M2",
+        getattr(torch, "float8_e4m3fn", None): "F8_E4M3",
+    }
+    _ALIGN = 256
+
+    def validate_metadata(metadata: Dict[str, Any]) -> Dict[str, str]:
+        validated = {}
+        for key, value in metadata.items():
+            if not isinstance(key, str):
+                raise ValueError(f"Metadata key must be a string, got {type(key)}")
+            if not isinstance(value, str):
+                print(f"Warning: Metadata value for key '{key}' is not a string. Converting to string.")
+                validated[key] = str(value)
+            else:
+                validated[key] = value
+        return validated
+
+    print(f"Using memory efficient save file: {filename}")
+
+    header = {}
+    offset = 0
+    if metadata:
+        header["__metadata__"] = validate_metadata(metadata)
+    for k, v in tensors.items():
+        if v.numel() == 0:  # empty tensor
+            header[k] = {"dtype": _TYPES[v.dtype], "shape": list(v.shape), "data_offsets": [offset, offset]}
+        else:
+            size = v.numel() * v.element_size()
+            header[k] = {"dtype": _TYPES[v.dtype], "shape": list(v.shape), "data_offsets": [offset, offset + size]}
+            offset += size
+
+    hjson = json.dumps(header).encode("utf-8")
+    hjson += b" " * (-(len(hjson) + 8) % _ALIGN)
+
+    with open(filename, "wb") as f:
+        f.write(struct.pack("<Q", len(hjson)))
+        f.write(hjson)
+
+        for k, v in tensors.items():
+            if v.numel() == 0:
+                continue
+            if v.is_cuda:
+                # Direct GPU to disk save
+                with torch.cuda.device(v.device):
+                    if v.dim() == 0:  # if scalar, need to add a dimension to work with view
+                        v = v.unsqueeze(0)
+                    tensor_bytes = v.contiguous().view(torch.uint8)
+                    tensor_bytes.cpu().numpy().tofile(f)
+            else:
+                # CPU tensor save
+                if v.dim() == 0:  # if scalar, need to add a dimension to work with view
+                    v = v.unsqueeze(0)
+                v.contiguous().view(torch.uint8).numpy().tofile(f)
+
 
 # TODO make inf_utils.py