server : (refactoring) do not rely on JSON internally (#10643)

* server : (refactoring) reduce usage of json internally

* move all response types to struct

* wip [no ci]

* many fixes

* add virtual function

* fix index

* minor style fix

* add std::move

* refactor handle_completions_generic

* add virtual functions

* remove server.hpp

* clarify server_sent_event RFC specs

* apply review comments

* fix model_alias and completion_probabilities

* small clean up

* remove virtual for to_json_oai_compat()

* naming oai_compat --> oaicompat

* fix unwanted recursive call

* update docs

examples/server/tests/README.md

@@ -44,4 +44,10 @@ To run with stdout/stderr display in real time (verbose output, but useful for d
 DEBUG=1 ./tests.sh -s -v -x
 ```
 
+Hint: You can compile and run test in single command, useful for local developement:
+
+```shell
+cmake --build build -j --target llama-server && ./examples/server/tests/tests.sh
+```
+
 To see all available arguments, please refer to [pytest documentation](https://docs.pytest.org/en/stable/how-to/usage.html)

examples/server/tests/tests.sh

@@ -1,5 +1,9 @@
 #!/bin/bash
 
+# make sure we are in the right directory
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+cd $SCRIPT_DIR
+
 set -eu
 
 if [ $# -lt 1 ]

examples/server/tests/unit/test_chat_completion.py

@@ -12,13 +12,13 @@ def create_server():
 
 
 @pytest.mark.parametrize(
-    "model,system_prompt,user_prompt,max_tokens,re_content,n_prompt,n_predicted,truncated",
+    "model,system_prompt,user_prompt,max_tokens,re_content,n_prompt,n_predicted,finish_reason",
     [
-        ("llama-2", "Book", "What is the best book", 8, "(Suddenly)+", 77, 8, False),
-        ("codellama70b", "You are a coding assistant.", "Write the fibonacci function in c++.", 128, "(Aside|she|felter|alonger)+", 104, 64, False),
+        (None, "Book", "What is the best book", 8, "(Suddenly)+", 77, 8, "length"),
+        ("codellama70b", "You are a coding assistant.", "Write the fibonacci function in c++.", 128, "(Aside|she|felter|alonger)+", 104, 64, "length"),
     ]
 )
-def test_chat_completion(model, system_prompt, user_prompt, max_tokens, re_content, n_prompt, n_predicted, truncated):
+def test_chat_completion(model, system_prompt, user_prompt, max_tokens, re_content, n_prompt, n_predicted, finish_reason):
     global server
     server.start()
     res = server.make_request("POST", "/chat/completions", data={
@@ -30,29 +30,27 @@ def test_chat_completion(model, system_prompt, user_prompt, max_tokens, re_conte
         ],
     })
     assert res.status_code == 200
+    assert res.body["model"] == model if model is not None else server.model_alias
     assert res.body["usage"]["prompt_tokens"] == n_prompt
     assert res.body["usage"]["completion_tokens"] == n_predicted
     choice = res.body["choices"][0]
     assert "assistant" == choice["message"]["role"]
     assert match_regex(re_content, choice["message"]["content"])
-    if truncated:
-        assert choice["finish_reason"] == "length"
-    else:
-        assert choice["finish_reason"] == "stop"
+    assert choice["finish_reason"] == finish_reason
 
 
 @pytest.mark.parametrize(
-    "model,system_prompt,user_prompt,max_tokens,re_content,n_prompt,n_predicted,truncated",
+    "system_prompt,user_prompt,max_tokens,re_content,n_prompt,n_predicted,finish_reason",
     [
-        ("llama-2", "Book", "What is the best book", 8, "(Suddenly)+", 77, 8, False),
-        ("codellama70b", "You are a coding assistant.", "Write the fibonacci function in c++.", 128, "(Aside|she|felter|alonger)+", 104, 64, False),
+        ("Book", "What is the best book", 8, "(Suddenly)+", 77, 8, "length"),
+        ("You are a coding assistant.", "Write the fibonacci function in c++.", 128, "(Aside|she|felter|alonger)+", 104, 64, "length"),
     ]
 )
-def test_chat_completion_stream(model, system_prompt, user_prompt, max_tokens, re_content, n_prompt, n_predicted, truncated):
+def test_chat_completion_stream(system_prompt, user_prompt, max_tokens, re_content, n_prompt, n_predicted, finish_reason):
     global server
+    server.model_alias = None # try using DEFAULT_OAICOMPAT_MODEL
     server.start()
     res = server.make_stream_request("POST", "/chat/completions", data={
-        "model": model,
         "max_tokens": max_tokens,
         "messages": [
             {"role": "system", "content": system_prompt},
@@ -63,16 +61,13 @@ def test_chat_completion_stream(model, system_prompt, user_prompt, max_tokens, r
     content = ""
     for data in res:
         choice = data["choices"][0]
+        assert "gpt-3.5" in data["model"] # DEFAULT_OAICOMPAT_MODEL, maybe changed in the future
         if choice["finish_reason"] in ["stop", "length"]:
             assert data["usage"]["prompt_tokens"] == n_prompt
             assert data["usage"]["completion_tokens"] == n_predicted
             assert "content" not in choice["delta"]
             assert match_regex(re_content, content)
-            # FIXME: not sure why this is incorrect in stream mode
-            # if truncated:
-            #   assert choice["finish_reason"] == "length"
-            # else:
-            #   assert choice["finish_reason"] == "stop"
+            assert choice["finish_reason"] == finish_reason
         else:
             assert choice["finish_reason"] is None
             content += choice["delta"]["content"]
@@ -93,7 +88,7 @@ def test_chat_completion_with_openai_library():
         temperature=0.8,
     )
     print(res)
-    assert res.choices[0].finish_reason == "stop"
+    assert res.choices[0].finish_reason == "length"
     assert res.choices[0].message.content is not None
     assert match_regex("(Suddenly)+", res.choices[0].message.content)
 

examples/server/tests/unit/test_completion.py

@@ -51,6 +51,24 @@ def test_completion_stream(prompt: str, n_predict: int, re_content: str, n_promp
             content += data["content"]
 
 
+def test_completion_stream_vs_non_stream():
+    global server
+    server.start()
+    res_stream = server.make_stream_request("POST", "/completion", data={
+        "n_predict": 8,
+        "prompt": "I believe the meaning of life is",
+        "stream": True,
+    })
+    res_non_stream = server.make_request("POST", "/completion", data={
+        "n_predict": 8,
+        "prompt": "I believe the meaning of life is",
+    })
+    content_stream = ""
+    for data in res_stream:
+        content_stream += data["content"]
+    assert content_stream == res_non_stream.body["content"]
+
+
 @pytest.mark.parametrize("n_slots", [1, 2])
 def test_consistent_result_same_seed(n_slots: int):
     global server
@@ -221,3 +239,24 @@ def test_completion_parallel_slots(n_slots: int, n_requests: int):
         assert len(res.body["content"]) > 10
         # FIXME: the result is not deterministic when using other slot than slot 0
         # assert match_regex(re_content, res.body["content"])
+
+
+def test_n_probs():
+    global server
+    server.start()
+    res = server.make_request("POST", "/completion", data={
+        "prompt": "I believe the meaning of life is",
+        "n_probs": 10,
+        "temperature": 0.0,
+        "n_predict": 5,
+    })
+    assert res.status_code == 200
+    assert "completion_probabilities" in res.body
+    assert len(res.body["completion_probabilities"]) == 5
+    for tok in res.body["completion_probabilities"]:
+        assert "probs" in tok
+        assert len(tok["probs"]) == 10
+        for prob in tok["probs"]:
+            assert "prob" in prob
+            assert "tok_str" in prob
+            assert 0.0 <= prob["prob"] <= 1.0