py : add GPT4All conversion script

For now: copy-paste
Too much time for me to deduplicate the python code

1 files changed, 107 insertions, 0 deletions

diff --git a/convert-gpt4all-to-ggml.py b/convert-gpt4all-to-ggml.py
new file mode 100644
index 0000000..f1d9d7a
--- /dev/null
+++ b/convert-gpt4all-to-ggml.py
@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+
+#
+# TODO: deduplicate GPT4All with convert-unversioned-ggml-to-ggml.py
+#
+
+# Original by https://github.com/eiz
+# https://github.com/ggerganov/llama.cpp/issues/324#issuecomment-1476227818
+import argparse
+import glob
+import os
+import struct
+import sys
+from sentencepiece import SentencePieceProcessor
+
+HPARAMS = keys = ["vocab_size", "dim", "multiple_of", "n_heads", "n_layers"]
+
+def parse_args():
+    parser = argparse.ArgumentParser(description='Upgrade a GPT4All model to the current format')
+    parser.add_argument('gpt4all_model', help='path to gpt4all-lora-quantized.bin')
+    parser.add_argument('tokenizer_model', help='path to LLaMA tokenizer.model file')
+    return parser.parse_args()
+
+def read_header(f_in):
+    struct_fmt = "i" * (3 + len(HPARAMS))
+    struct_size = struct.calcsize(struct_fmt)
+    buf = f_in.read(struct_size)
+    return struct.unpack(struct_fmt, buf)
+
+def write_header(f_out, header):
+    (magic, vocab_size, dim, multiple_of, n_heads, n_layers, rot, ftype) = header
+
+    if magic != 0x67676d6c:
+        raise Exception('Invalid file magic. Must be an old style ggml file.')
+
+    values = [
+        0x67676d66, # magic: ggml in hex
+        1,          # file version
+        vocab_size,
+        dim,
+        multiple_of,
+        n_heads,
+        n_layers,
+        rot,
+        ftype
+    ]
+    f_out.write(struct.pack("i" * len(values), *values))
+
+def write_tokens(fout, tokenizer):
+    for i in range(tokenizer.vocab_size()):
+        if tokenizer.is_unknown(i):
+            text = " \u2047 ".encode("utf-8")
+        elif tokenizer.is_control(i):
+            text = b""
+        elif tokenizer.is_byte(i):
+            piece = tokenizer.id_to_piece(i)
+            if len(piece) != 6:
+                print(f"Invalid token: {piece}")
+                sys.exit(1)
+            byte_value = int(piece[3:-1], 16)
+            text = struct.pack("B", byte_value)
+        else:
+            text = tokenizer.id_to_piece(i).replace("\u2581", " ").encode("utf-8")
+        fout.write(struct.pack("i", len(text)))
+        fout.write(text)
+        fout.write(struct.pack("f", tokenizer.get_score(i)))
+
+    # TODO: GPT4All - add extra <pad> token
+    text = "<pad>".encode("utf-8")
+    fout.write(struct.pack("i", len(text)))
+    fout.write(text)
+    fout.write(struct.pack("f", 0.0))
+
+def read_tokens(f_in, tokenizer):
+    for i in range(tokenizer.vocab_size()):
+        len_b = f_in.read(4)
+        (length,) = struct.unpack("i", len_b)
+        f_in.read(length)
+
+def copy_all_data(f_out, f_in):
+    while True:
+        buf = f_in.read(1024 * 1024)
+        if not buf:
+            break
+        f_out.write(buf)
+
+def convert_one_file(path_in, tokenizer):
+    path_tmp = f"{path_in}.tmp"
+    path_orig= f"{path_in}.orig"
+    print(f"converting {path_in}")
+    with open(path_in, "rb") as f_in, open(path_tmp, "wb") as f_out:
+        write_header(f_out, read_header(f_in))
+        read_tokens(f_in, tokenizer)
+        write_tokens(f_out, tokenizer)
+        copy_all_data(f_out, f_in)
+    os.rename(path_in, path_orig)
+    os.rename(path_tmp, path_in)
+
+def main():
+    args = parse_args()
+
+    tokenizer = SentencePieceProcessor(args.tokenizer_model)
+
+    convert_one_file(args.gpt4all_model, tokenizer)
+
+if __name__ == "__main__":
+    main()