From edc95a0e7dc4c8e13a20fbf2c8e2b99a8c3e4549 Mon Sep 17 00:00:00 2001
From: zhangsibo1129 <134488188+zhangsibo1129@users.noreply.github.com>
Date: Tue, 26 Sep 2023 20:57:53 +0800
Subject: [PATCH] support local model config file (#1058)

# What does this PR do?

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Support local config file to avoid unexpected `discard_names`, which
causes #1057.

In the case of launching local mode without `model.safetensors` file,
the original code will result `discard_names = []` when
`hf_hub_download` throws an connection error.
```python
# server/text_generation_server/cli.py
    try:
        import transformers
        import json


        config_filename = hf_hub_download(model_id, revision=revision, filename="config.json")
        with open(config_filename, "r") as f:
            config = json.load(f)
        architecture = config["architectures"][0]

        class_ = getattr(transformers, architecture)

        # Name for this varible depends on transformers version.
        discard_names = getattr(class_, "_tied_weights_keys", [])
        discard_names.extend(getattr(class_, "_keys_to_ignore_on_load_missing", []))

    except Exception as e:
        discard_names = []
```

The expected `_tied_weights_keys` of OPT-1.3b is `["lm_head.weight"]`,
and its tied weight `"model.decoder.embed_tokens.weight"` will be kept
in the safetensors conversion. But the above empty `discard_names` will
lead to `"lm_head.weight"` being kept and
`"model.decoder.embed_tokens.weight"` being discard in the subsequent
method `_remove_duplicate_names`, which causes error #1057.

So add a local mode branch to get the expected `discard_names` like
follows. This modification also applies to other models

```python
# server/text_generation_server/cli.py
        if is_local_model:
            config_filename = os.path.join(model_id, "config.json")
        else:
            config_filename = hf_hub_download(model_id, revision=revision, filename="config.json")
```


In addition, when `_tied_weights_keys` or
`_keys_to_ignore_on_load_missing` is `None`, the above code will also
throw an error unexpectedly. This is fixed in PR #1052


## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the
other checks if that's the case).
- [x] Did you read the [contributor
guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?
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[forum](https://discuss.huggingface.co/)? Please add a link
      to it if that's the case.
- [ ] Did you make sure to update the documentation with your changes?
Here are the
[documentation
guidelines](https://github.com/huggingface/transformers/tree/main/docs),
and
[here are tips on formatting
docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
N/A
- [ ] Did you write any new necessary tests?  N/A


## Who can review?

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@Narsil
---
 server/text_generation_server/cli.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/server/text_generation_server/cli.py b/server/text_generation_server/cli.py
index e0b8c0fec5b..330481394c3 100644
--- a/server/text_generation_server/cli.py
+++ b/server/text_generation_server/cli.py
@@ -179,7 +179,10 @@ def download_weights(
             import json
 
 
-            config_filename = hf_hub_download(model_id, revision=revision, filename="config.json")
+            if is_local_model:
+                config_filename = os.path.join(model_id, "config.json")
+            else:
+                config_filename = hf_hub_download(model_id, revision=revision, filename="config.json")
             with open(config_filename, "r") as f:
                 config = json.load(f)
             architecture = config["architectures"][0]