include custom safetensor and gguf format checking based on implement…

…ation in instructlab.utils

In our case, .safetensor file validation is not needed since we don't read it to load a tokenizer

Signed-off-by: Khaled Sulayman <[email protected]>

src/instructlab/sdg/utils/model_formats.py

@@ -0,0 +1,83 @@
+# Standard
+import json
+import logging
+import pathlib
+import struct
+
+# Third Party
+from gguf.constants import GGUF_MAGIC
+
+logger = logging.getLogger(__name__)
+
+
+def is_model_safetensors(model_path: pathlib.Path) -> bool:
+    """Check if model_path is a valid safe tensors directory
+
+    Directory must contain a specific set of files to qualify as a safetensors model directory
+    Args:
+        model_path (Path): The path to the model directory
+    Returns:
+        bool: True if the model is a safetensors model, False otherwise.
+    """
+    try:
+        files = list(model_path.iterdir())
+    except (FileNotFoundError, NotADirectoryError, PermissionError) as e:
+        logger.debug("Failed to read directory: %s", e)
+        return False
+
+    # directory should contain either .safetensors or .bin files to be considered valid
+    filetypes = [file.suffix for file in files]
+    if not ".safetensors" in filetypes and not ".bin" in filetypes:
+        logger.debug("'%s' has no .safetensors or .bin files", model_path)
+        return False
+
+    basenames = {file.name for file in files}
+    requires_files = {
+        "config.json",
+        "tokenizer.json",
+        "tokenizer_config.json",
+    }
+    diff = requires_files.difference(basenames)
+    if diff:
+        logger.debug("'%s' is missing %s", model_path, diff)
+        return False
+
+    for file in model_path.glob("*.json"):
+        try:
+            with file.open(encoding="utf-8") as f:
+                json.load(f)
+        except (PermissionError, json.JSONDecodeError) as e:
+            logger.debug("'%s' is not a valid JSON file: e", file, e)
+            return False
+
+    return True
+
+
+def is_model_gguf(model_path: pathlib.Path) -> bool:
+    """
+    Check if the file is a GGUF file.
+    Args:
+        model_path (Path): The path to the file.
+    Returns:
+        bool: True if the file is a GGUF file, False otherwise.
+    """
+    try:
+        with model_path.open("rb") as f:
+            first_four_bytes = f.read(4)
+
+        # Convert the first four bytes to an integer
+        first_four_bytes_int = int(struct.unpack("<I", first_four_bytes)[0])
+
+        return first_four_bytes_int == GGUF_MAGIC
+    except struct.error as e:
+        logger.debug(
+            f"Failed to unpack the first four bytes of {model_path}. "
+            f"The file might not be a valid GGUF file or is corrupted: {e}"
+        )
+        return False
+    except IsADirectoryError as e:
+        logger.debug(f"GGUF Path {model_path} is a directory, returning {e}")
+        return False
+    except OSError as e:
+        logger.debug(f"An unexpected error occurred while processing {model_path}: {e}")
+        return False