import os
import sys
import ctypes
import pathlib
from typing import Optional
P_FLOAT = ctypes.POINTER(ctypes.c_float)
class RWKVContext:
def __init__(self, ptr: ctypes.pointer):
self.ptr = ptr
class RWKVSharedLibrary:
"""
Python wrapper around rwkv.cpp shared library.
"""
def __init__(self, shared_library_path: str):
"""
Loads the shared library from specified file.
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'.
"""
self.library = ctypes.cdll.LoadLibrary(shared_library_path)
self.library.rwkv_init_from_file.argtypes = [ctypes.c_char_p, ctypes.c_uint32]
self.library.rwkv_init_from_file.restype = ctypes.c_void_p
self.library.rwkv_eval.argtypes = [
ctypes.c_void_p, # ctx
ctypes.c_int32, # 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_uint32
self.library.rwkv_get_logits_buffer_element_count.argtypes = [ctypes.c_void_p]
self.library.rwkv_get_logits_buffer_element_count.restype = ctypes.c_uint32
self.library.rwkv_free.argtypes = [ctypes.c_void_p]
self.library.rwkv_free.restype = None
self.library.rwkv_free.argtypes = [ctypes.c_void_p]
self.library.rwkv_free.restype = None
self.library.rwkv_quantize_model_file.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_uint32]
self.library.rwkv_quantize_model_file.restype = ctypes.c_bool
self.library.rwkv_get_system_info_string.argtypes = []
self.library.rwkv_get_system_info_string.restype = ctypes.c_char_p
def rwkv_init_from_file(self, model_file_path: str, thread_count: int) -> RWKVContext:
"""
Loads the model from a file and prepares it for inference.
Throws an exception in case of any error. Error messages would be printed to stderr.
Parameters
----------
model_file_path : str
Path to model file in ggml format.
thread_count : int
Count of threads to use, must be positive.
"""
ptr = self.library.rwkv_init_from_file(model_file_path.encode('utf-8'), ctypes.c_uint32(thread_count))
assert ptr is not None, 'rwkv_init_from_file failed, check stderr'
return RWKVContext(ptr)
def rwkv_eval(
self,
ctx: RWKVContext,
token: int,
state_in_address: Optional[int],
state_out_address: int,
logits_out_address: int
) -> None:
"""
Evaluates the model for a single token.
Throws an exception in case of any error. Error messages would be printed to stderr.
Parameters
----------
ctx : RWKVContext
RWKV context obtained from rwkv_init_from_file.
token : int
Next token index, in range 0 <= token < n_vocab.
state_in_address : int
Address of the first element of a FP32 buffer of size rwkv_get_state_buffer_element_count; or None, if this is a first pass.
state_out_address : int
Address of the first element of a FP32 buffer of size rwkv_get_state_buffer_element_count. This buffer will be written to.
logits_out_address : int
Address of the first element of a FP32 buffer of size rwkv_get_logits_buffer_element_count. This buffer will be written to.
"""
assert self.library.rwkv_eval(
ctx.ptr,
ctypes.c_int32(token),
ctypes.cast(0 if state_in_address is None else state_in_address, P_FLOAT),
ctypes.cast(state_out_address, P_FLOAT),
ctypes.cast(logits_out_address, P_FLOAT)
), 'rwkv_eval failed, check stderr'
def rwkv_get_state_buffer_element_count(self, ctx: RWKVContext) -> int:
"""
Returns count of FP32 elements in state buffer.
Parameters
----------
ctx : RWKVContext
RWKV context obtained from rwkv_init_from_file.
"""
return self.library.rwkv_get_state_buffer_element_count(ctx.ptr)
def rwkv_get_logits_buffer_element_count(self, ctx: RWKVContext) -> int:
"""
Returns count of FP32 elements in logits buffer.
Parameters
----------
ctx : RWKVContext
RWKV context obtained from rwkv_init_from_file.
"""
return self.library.rwkv_get_logits_buffer_element_count(ctx.ptr)
def rwkv_free(self, ctx: RWKVContext) -> None:
"""
Frees all allocated memory and the context.
Parameters
----------
ctx : RWKVContext
RWKV context obtained from rwkv_init_from_file.
"""
self.library.rwkv_free(ctx.ptr)
ctx.ptr = ctypes.cast(0, ctypes.c_void_p)
def rwkv_quantize_model_file(self, model_file_path_in: str, model_file_path_out: str, q_type: int) -> None:
"""
Quantizes FP32 or FP16 model to one of INT4 formats.
Throws an exception in case of any error. Error messages would be printed to stderr.
Parameters
----------
model_file_path_in : str
Path to model file in ggml format, must be either FP32 or FP16.
model_file_path_out : str
Quantized model will be written here.
q_type : int
Set to 2 for GGML_TYPE_Q4_0, set to 3 for GGML_TYPE_Q4_1.
"""
assert self.library.rwkv_quantize_model_file(
model_file_path_in.encode('utf-8'),
model_file_path_out.encode('utf-8'),
ctypes.c_uint32(q_type)
), 'rwkv_quantize_model_file failed, check stderr'
def rwkv_get_system_info_string(self) -> str:
"""
Returns system information string.
"""
return self.library.rwkv_get_system_info_string().decode('utf-8')
def load_rwkv_shared_library() -> RWKVSharedLibrary:
"""
Attempts to find rwkv.cpp shared library and load it.
To specify exact path to the library, create an instance of RWKVSharedLibrary explicitly.
"""
file_name: str
if 'win32' in sys.platform or 'cygwin' in sys.platform:
file_name = 'rwkv.dll'
elif 'darwin' in sys.platform:
file_name = 'librwkv.dylib'
else:
file_name = 'librwkv.so'
repo_root_dir: pathlib.Path = pathlib.Path(os.path.abspath(__file__)).parent.parent
paths = [
# If we are in "rwkv" directory
f'../bin/Release/{file_name}',
# If we are in repo root directory
f'bin/Release/{file_name}',
# Search relative to this file
str(repo_root_dir / 'bin' / 'Release' / file_name),
# Fallback
str(repo_root_dir / file_name)
]
for path in paths:
if os.path.isfile(path):
return RWKVSharedLibrary(path)
return RWKVSharedLibrary(paths[-1])