support using xgrammar to get json output (#12870)

python/llm/src/ipex_llm/transformers/xgrammar.py

@@ -0,0 +1,47 @@
+#
+# Copyright 2016 The BigDL Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+
+from transformers import PreTrainedTokenizer, LogitsProcessor
+from ipex_llm.utils.modules import insert_fake_module
+
+insert_fake_module("xgrammar.kernels.apply_token_bitmask_inplace_cuda")
+insert_fake_module("xgrammar.kernels.apply_token_bitmask_inplace_triton")
+insert_fake_module(
+    "xgrammar.kernels.apply_token_bitmask_inplace_cuda.apply_token_bitmask_inplace_cuda"
+)
+insert_fake_module(
+    "xgrammar.kernels.apply_token_bitmask_inplace_triton.apply_token_bitmask_inplace_triton"
+)
+
+import xgrammar as xgr
+
+
+def create_json_logits_processor(tokenizer: PreTrainedTokenizer, vocab_size: int, schema=None):
+    tokenizer_info = xgr.TokenizerInfo.from_huggingface(tokenizer, vocab_size=vocab_size)
+    grammar_compiler = xgr.GrammarCompiler(tokenizer_info)
+    if schema is None:
+        compiled_grammar = grammar_compiler.compile_builtin_json_grammar()
+    else:
+        compiled_grammar = grammar_compiler.compile_json_schema(schema)
+    processor = xgr.contrib.hf.LogitsProcessor(compiled_grammar)
+    return processor
+
+
+def reset_json_logits_processor(processor: LogitsProcessor) -> LogitsProcessor:
+    compiled_grammar = processor.compiled_grammar
+    new_processor = xgr.contrib.hf.LogitsProcessor(compiled_grammar)
+    return new_processor