Add Python wrapper for C library

CMakeLists.txt

@@ -247,9 +247,17 @@ add_library(rwkv
 target_include_directories(llama PUBLIC .)
 target_compile_features(llama PUBLIC cxx_std_11) # don't bump
 target_link_libraries(llama PRIVATE ggml ${LLAMA_EXTRA_LIBS})
+
+target_include_directories(rwkv PUBLIC .)
+target_compile_features(rwkv PUBLIC cxx_std_11) # don't bump
+target_link_libraries(rwkv PRIVATE ggml ${LLAMA_EXTRA_LIBS})
+
 if (BUILD_SHARED_LIBS)
     set_target_properties(llama PROPERTIES POSITION_INDEPENDENT_CODE ON)
     target_compile_definitions(llama PRIVATE LLAMA_SHARED LLAMA_BUILD)
+
+    set_target_properties(rwkv PROPERTIES POSITION_INDEPENDENT_CODE ON)
+    target_compile_definitions(rwkv PRIVATE LLAMA_SHARED LLAMA_BUILD)
 endif()
 
 #

Makefile

@@ -243,6 +243,9 @@ main: examples/main/main.cpp ggml.o llama.o common.o
 	@echo '====  Run ./main -h for help.  ===='
 	@echo
 
+main_rwkv: examples/main_rwkv/main_rwkv.cpp ggml.o rwkv.o common.o
+	$(CXX) $(CXXFLAGS) examples/main_rwkv/main_rwkv.cpp ggml.o rwkv.o common.o -o main_rwkv $(LDFLAGS)
+
 quantize: examples/quantize/quantize.cpp ggml.o llama.o
 	$(CXX) $(CXXFLAGS) examples/quantize/quantize.cpp ggml.o llama.o -o quantize $(LDFLAGS)
 

README.md

@@ -2,21 +2,21 @@
 
 This is a port of [BlinkDL/RWKV-LM](https://github.com/BlinkDL/RWKV-LM) to [ggerganov/ggml](https://github.com/ggerganov/ggml). The end goal is to allow 4-bit quanized inference on CPU.
 
-**WORK IN PROGRESS!** **Status**: FP32 and FP16 inference work correctly. Currently, I'm working on creating usable C library interface and Python wrapper for it.
+**WORK IN PROGRESS!** **Status**: There is a Python wrapper, FP32 and FP16 inference work correctly. Currently, I'm working on INT4 quantization support.
 
 ## Plan
 
-1. Create proper interface (probably, C library)
-2. Create Python wrapper with sampling and simple chat interface
-3. Write a good `README.md` and publish links to this repo
-4. Make INT4 inference work
+1. Make INT4 inference work
+2. Create Python script with sampling and simple chat interface
+3. Clean up the repo (remove llama related files and mentions)
+4. Write a good `README.md` and publish links to this repo
 5. Create pull request to main `ggml` repo with all improvements made here
 
 ## Structure
 
 This repo is based on the [llama.cpp repo](https://github.com/ggerganov/llama.cpp). RWKV-related code is in these directories:
 
-- `./rwkv`: directory containing Python scripts for conversion and validation
+- `./rwkv`: directory containing Python scripts for conversion, inference and validation
 - `./examples/main_rwkw`: directory containing script that loads and infers RWKV model
 
 Please do not change files in other directories — this will make pulling recent changes easier.
@@ -27,25 +27,39 @@ Please do not change files in other directories — this will make pulling recen
 
 Requirements: [git](https://gitforwindows.org/), [CMake](https://cmake.org/download/), MSVC compiler, Python 3.x with PyTorch.
 
-Clone the repo and set it up for build:
+#### 1. Clone the repo and build it:
 
 ```commandline
 git clone https://github.com/saharNooby/rwkv.cpp.git
 cd rwkv.cpp
-cmake .
+cmake -DBUILD_SHARED_LIBS=ON -DLLAMA_BUILD_TESTS=OFF -DLLAMA_BUILD_EXAMPLES=OFF .
+cmake --build . --config Release
 ```
 
-Download an RWKV model from [Huggingface](https://huggingface.co/BlinkDL) and convert it into `ggml` format:
+If everything went OK, `bin\Release\rwkv.dll` file should appear.
+
+#### 2. Download an RWKV model from [Huggingface](https://huggingface.co/BlinkDL) and convert it into `ggml` format:
 
 ```commandline
 python rwkv\convert_pytorch_rwkv_to_ggml.py C:\RWKV-4-Pile-169M-20220807-8023.pth C:\rwkv.cpp-169M.bin float32
 ```
 
-Compile and run the script:
+#### 3. Use the model in Python:
+
+```python
+# This file is located at rwkv/rwkv_cpp.py
+import rwkv_cpp
+
+model = rwkv_cpp.RWKVModel(r'bin\Release\rwkv.dll', r'C:\rwkv.cpp-169M.bin')
+
+logits, state = None, None
+
+for token in [1, 2, 3]:
+    logits, state = model.eval(token, state)
+    
+    print(f'Output logits: {logits}')
+
+# Don't forget to free memory after you've done working with the model
+model.free()
 
-```commandline
-cmake --build . --config Release
-bin\Release\main_rwkv.exe "C:\rwkv.cpp-169M.bin" 123 "C:\state_in.bin" "C:\state_out.bin" "C:\logits_out.bin"
 ```
-
-The script will read state from `state_in.bin`, do single inference using the state and token `123` as an input, save new state into `state_out.bin` and logits into `logits_out.bin`.

rwkv.h

@@ -29,13 +29,13 @@ extern "C" {
 
     struct rwkv_context;
 
-    // Loads the model from a file and prepares it for inference by allocating memory and building computation graph.
+    // Loads the model from a file and prepares it for inference.
     // Returns NULL on any error. Error messages would be printed to stderr.
     RWKV_API struct rwkv_context * rwkv_init_from_file(const char * model_file_path, int n_threads);
 
-    // Evaluates the model for a single pass.
+    // Evaluates the model for a single token.
     // Returns false on any error. Error messages would be printed to stderr.
-    // - token: next token index, in range 0..n_vocab - 1.
+    // - token: next token index, in range 0 <= token < n_vocab.
     // - state_in: FP32 buffer of size rwkv_get_state_buffer_element_count; or NULL, if this is a first pass.
     // - state_out: FP32 buffer of size rwkv_get_state_buffer_element_count. This buffer will be written to.
     // - logits_out: FP32 buffer of size rwkv_get_logits_buffer_element_count. This buffer will be written to.

rwkv/compare_cpp_with_reference_implementation.py

@@ -9,11 +9,12 @@ import argparse
 import subprocess
 import torch
 import numpy as np
+import rwkv_cpp
 from typing import List, Tuple, Any
 
 def parse_args():
     parser = argparse.ArgumentParser(description='Compare logits from rwkv.cpp implementation of RWKV with logits from reference implementation of RWKV')
-    parser.add_argument('main_executable_path', help='Path to main rwkv.cpp executable file')
+    parser.add_argument('main_executable_path', help='Path to main rwkv.cpp executable file or shared library')
     parser.add_argument('ggml_model_path', help='Path to rwkv.cpp checkpoint file')
     return parser.parse_args()
 
@@ -48,28 +49,42 @@ def main() -> None:
             # FP16, lower precision, so higher threshold
             threshold = 0.003
 
+    model = None
+
+    if args.main_executable_path.lower().endswith('.dll') or args.main_executable_path.lower().endswith('.so'):
+        print('Testing shared library')
+
+        model = rwkv_cpp.RWKVModel(args.main_executable_path, args.ggml_model_path)
+    else:
+        print('Testing main_rwkv executable')
+
     def compare_logits(tokens_subset: List[int]) -> None:
         token_count: int = len(tokens_subset)
         state_path: str = './state.bin'
         logits_path: str = './logits.bin'
 
+        logits, state = None, None
+
         for i in range(token_count):
             token: int = tokens_subset[i]
 
             print(f'{i + 1}/{token_count}')
 
-            subprocess.run(
-                [
-                    args.main_executable_path,
-                    args.ggml_model_path,
-                    str(token),
-                    # If this is the first token, let the script create a new state.
-                    '' if i == 0 else state_path,
-                    state_path,
-                    logits_path
-                ],
-                check=True
-            )
+            if model is not None:
+                logits, state = model.eval(token, state)
+            else:
+                subprocess.run(
+                    [
+                        args.main_executable_path,
+                        args.ggml_model_path,
+                        str(token),
+                        # If this is the first token, let the script create a new state.
+                        '' if i == 0 else state_path,
+                        state_path,
+                        logits_path
+                    ],
+                    check=True
+                )
 
         expected_logits_path: str = f'expected_logits_169M_20220807_8023_{len(tokens_subset)}_tokens.bin'
 
@@ -79,8 +94,11 @@ def main() -> None:
         with open(expected_logits_path, 'rb') as logits_file:
             expected_logits = torch.tensor(np.frombuffer(logits_file.read(), dtype=np.single))
 
-        with open(logits_path, 'rb') as logits_file:
-            actual_logits = torch.tensor(np.frombuffer(logits_file.read(), dtype=np.single))
+        if model is not None:
+            actual_logits = logits
+        else:
+            with open(logits_path, 'rb') as logits_file:
+                actual_logits = torch.tensor(np.frombuffer(logits_file.read(), dtype=np.single))
 
         difference: float = (torch.sum(expected_logits - actual_logits) / len(expected_logits)).item()
 
@@ -97,5 +115,8 @@ def main() -> None:
     print()
     print('Test passes')
 
+    if model is not None:
+        model.free()
+
 if __name__ == "__main__":
     main()

rwkv/rwkv_cpp.py

@@ -0,0 +1,127 @@
+import os
+import ctypes
+import torch
+import multiprocessing
+from typing import Tuple, Optional
+
+P_FLOAT = ctypes.POINTER(ctypes.c_float)
+
+class RWKVModel:
+    """
+    PyTorch wrapper around rwkv.cpp shared library.
+    """
+
+    def __init__(
+            self,
+            shared_library_path: str,
+            model_path: str,
+            thread_count: int = max(1, multiprocessing.cpu_count() // 2)
+    ):
+        """
+        Loads the model and prepares it for inference.
+        In case of any error, this method will throw an exception.
+
+        Parameters
+        ----------
+        shared_library_path : str
+            Path to rwkv.cpp shared library. On Windows, it would look like 'rwkv.dll'. On UNIX, 'rwkv.so'.
+        model_path : str
+            Path to RWKV model file in ggml format.
+        thread_count : int
+            Thread count to use. If not set, defaults to CPU count / 2.
+        """
+
+        assert os.path.isfile(shared_library_path), f'{shared_library_path} is not a file'
+        assert os.path.isfile(model_path), f'{model_path} is not a file'
+        assert thread_count > 0, 'Thread count must be positive'
+
+        self.library = ctypes.cdll.LoadLibrary(shared_library_path)
+
+        self.library.rwkv_init_from_file.argtypes = [ctypes.c_char_p, ctypes.c_int]
+        self.library.rwkv_init_from_file.restype = ctypes.c_void_p
+
+        self.library.rwkv_eval.argtypes = [
+            ctypes.c_void_p, # ctx
+            ctypes.c_long, # token
+            P_FLOAT, # state_in
+            P_FLOAT, # state_out
+            P_FLOAT  # logits_out
+        ]
+        self.library.rwkv_eval.restype = ctypes.c_bool
+
+        self.library.rwkv_get_state_buffer_element_count.argtypes = [ctypes.c_void_p]
+        self.library.rwkv_get_state_buffer_element_count.restype = ctypes.c_size_t
+
+        self.library.rwkv_get_logits_buffer_element_count.argtypes = [ctypes.c_void_p]
+        self.library.rwkv_get_logits_buffer_element_count.restype = ctypes.c_size_t
+
+        self.library.rwkv_free.argtypes = [ctypes.c_void_p]
+        self.library.rwkv_free.restype = None
+
+        self.ctx = self.library.rwkv_init_from_file(model_path.encode('utf-8'), ctypes.c_int(thread_count))
+
+        assert self.ctx is not None, 'Failed to load the model, see stderr'
+
+        self.state_buffer_element_count = self.library.rwkv_get_state_buffer_element_count(self.ctx)
+        self.logits_buffer_element_count = self.library.rwkv_get_logits_buffer_element_count(self.ctx)
+
+        self.valid = True
+
+    def eval(self, token: int, state_in: Optional[torch.Tensor]) -> Tuple[torch.Tensor, torch.Tensor]:
+        """
+        Evaluates the model for a single token.
+        In case of any error, this method will throw an exception.
+
+        Parameters
+        ----------
+        token : int
+            Index of next token to be seen by the model. Must be in range 0 <= token < n_vocab.
+        state_in : Optional[torch.Tensor]
+            State from previous call of this method. If this is a first pass, set it to None.
+
+        Returns
+        -------
+        logits, state
+            Logits vector of shape (n_vocab); state for the next step.
+        """
+
+        assert self.valid, 'Model was freed'
+
+        if state_in is None:
+            state_in_ptr = 0
+        else:
+            expected_shape = (self.state_buffer_element_count,)
+
+            assert state_in.is_contiguous(), 'State tensor is not contiguous'
+            assert state_in.shape == expected_shape, f'Invalid state shape {state_in.shape}, expected {expected_shape}'
+
+            state_in_ptr = state_in.storage().data_ptr()
+
+        # TODO Probably these allocations can be optimized away
+        state_out: torch.Tensor = torch.zeros(self.state_buffer_element_count, dtype=torch.float32, device='cpu')
+        logits_out: torch.Tensor = torch.zeros(self.logits_buffer_element_count, dtype=torch.float32, device='cpu')
+
+        result = self.library.rwkv_eval(
+            self.ctx,
+            ctypes.c_long(token),
+            ctypes.cast(state_in_ptr, P_FLOAT),
+            ctypes.cast(state_out.storage().data_ptr(), P_FLOAT),
+            ctypes.cast(logits_out.storage().data_ptr(), P_FLOAT)
+        )
+
+        assert result, 'Inference failed, see stderr'
+
+        return logits_out, state_out
+
+    def free(self):
+        """
+        Frees all allocated resources.
+        In case of any error, this method will throw an exception.
+        The object must not be used anymore after calling this method.
+        """
+
+        assert self.valid, 'Already freed'
+
+        self.valid = False
+
+        self.library.rwkv_free(self.ctx)