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Documentation for easy-llama

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Note

The documentation assumes you have imported easy-llama with import easy_llama as ez.

class ez.Model

A high-level abstraction of a llama model

The following attributes are available:

  • .bos_token - The model's beginning-of-stream token ID
  • .context_length - The model's loaded context length
  • .flash_attn - Whether the model was loaded with flash_attn=True
  • .eos_token - The model's end-of-stream token ID
  • .llama - The underlying llama_cpp.Llama instance
  • .metadata - The GGUF metadata of the model
  • .n_ctx_train - The native context length of the model
  • .rope_freq_base - The model's loaded RoPE frequency base
  • .rope_freq_base_train - The model's native RoPE frequency base
  • .tokens - A list of all the tokens in the model's tokenizer
  • .verbose - Whether the model was loaded with verbose=True

Model.__init__()

Given the path to a GGUF file, construct a Model instance.

The following parameter is required:

  • model_path: str - The path to the GGUF model you wish to load

The following parameters are optional:

  • context_length: int - The context length at which to load the model, in tokens. May be less than or greater than the native context length of the model. A warning will be displayed if the chosen context length is large enough to cause a loss of quality. Modifies rope_freq_base for context scaling, which does not degrade quality as much as linear RoPE scaling. Defaults to None, which will use the native context length of the model.
  • n_gpu_layers: int - The number of layers to offload to the GPU. Defaults to 0.
  • offload_kqv: bool - Whether to offload the K, Q, and V caches (i.e. context) to the GPU. Defaults to True.
  • flash_attn: bool - Whether to use Flash Attention (ref). Defaults to False.
  • verbose: bool - Whether to show output from llama-cpp-python/llama.cpp or not. This is lots of very detailed output.

Example usage

# load a model from a GGUF file
Mistral = ez.Model(
	'mistral-7b-instruct-v0.1.Q4_K_S.gguf',
	n_gpu_layers=-1,
	flash_attn=True
)

Model.unload() -> None

Unload the Model from memory. If the Model is already unloaded, do nothing.

If you attempt to use a Model after it has been unloaded, easy_llama.model.ModelUnloadedException will be raised.

Example usage

# load a model (allocates memory)
Mistral = ez.Model('mistral-7b-instruct-v0.1.Q4_K_S.gguf')

# returns ' the sun is shining, and blah blah blah...'
Mistral.generate('The sky is blue, and')

# unload model (frees memory)
Mistral.unload()

# raises ez.model.ModelUnloadedException
Mistral.generate('The girl walked down')

Model.get_length() -> int

Get the length of a given text in tokens according to this Model, including the appended BOS token.

The following parameter is required:

  • text: str - The text to read

Example usage

>>> Mistral.get_length('Gentlemen, owing to lack of time and adverse circumstances, most people leave this world without thinking too much about it. Those who try get a headache and move on to something else. I belong to the second group. As my career progressed, the amount of space dedicated to me in Who’s Who grew and grew, but neither the last issue nor any future ones will explain why I abandoned journalism. This will be the subject of my story, which I wouldn’t tell you under other circumstances anyway.')
109

Model.generate() -> str

Given a prompt, return a generated string.

The following parameter is required:

  • prompt: str - The text from which to generate

The following parameters are optional:

  • stops: list[Union[str, int]] - A list of strings and/or token IDs at which to end the generation early. Defaults to [].
  • sampler: SamplerSettings - The ez.samplers.SamplerSettings object used to control text generation. Defaults to ez.samplers.DefaultSampling.

Model.stream() -> Generator

Given a prompt, return a Generator that yields dicts containing tokens. To get the token string itself, subscript the dict with: ['choices'][0]['text'].

The following parameter is required:

  • prompt: str - The text from which to generate

The following parameters are optional:

  • stops: list[Union[str, int]] - A list of strings and/or token IDs at which to end the generation early. Defaults to [].
  • sampler: SamplerSettings - The ez.samplers.SamplerSettings object used to control text generation. Defaults to ez.samplers.DefaultSampling.

Model.stream_print() -> str

Given a prompt, stream text to a file as it is generated, and return the generated string. The returned string does not include the end parameter.

The following parameter is required:

  • prompt: str - The text from which to generate

The following parameters are optional:

  • stops: list[Union[str, int]] - A list of strings and/or token IDs at which to end the generation early. Defaults to [].
  • sampler: SamplerSettings - The ez.samplers.SamplerSettings object used to control text generation. Defaults to ez.samplers.DefaultSampling.
  • end: str - A string to print after the generated text. Defaults to \n.
  • file: _SupportsWriteAndFlush - The file where text should be printed. Defaults to sys.stdout.
  • flush: bool - Whether to flush the stream after each token. The stream is always flushed at the end of generation.

Model.ingest() -> None

Ingest the given text into the model's cache, to reduce latency of future generations that start with the same text.

The following parameter is required:

  • text: str - The text to ingest

Model.candidates() -> list[tuple[str, np.floating]]

Given prompt str and k int, return a sorted list of the top k candidates for most likely next token, along with their normalized probabilities.

The following parameters are required:

  • prompt: str - The text to evaluate
  • k: int - The number of candidate tokens to return

Example usage

>>> Mixtral.candidates('The dog says woof, but the cat says', 5)
[('▁me', 0.512151), ('▁“', 0.048059467), (',', 0.029822024), ('▁wo', 0.023914132), ('…', 0.023838354)]

Model.print_candidates() -> None

Like Model.candidates(), but print the values instead of returning them.

The following parameters are required:

  • prompt: str - The text to evaluate
  • k: int - The number of candidate tokens to return

The following parameter is optional:

  • file: _SupportsWriteAndFlush - The file where text should be printed. Defaults to sys.stdout.

Example usage

>>> Mixtral.print_candidates('The dog says woof, but the cat says', 5)
token '▁me' has probability 0.5121510028839111
token '▁“' has probability 0.04805946722626686
token ',' has probability 0.02982202358543873
token '▁wo' has probability 0.02391413226723671
token '…' has probability 0.023838354274630547

class ez.Thread

Provide functionality to facilitate easy interactions with a Model

The following attributes are available:

  • .format - The format being used for messages in this thread
  • .messages - The list of messages in this thread
  • .model - The ez.Model instance used by this thread
  • .sampler - The ez.SamplerSettings object used in this thread

`Thread.create_message() -> Message

Construct a message using the format of this thread. If you are looking to create a message and also add it to the Thread's message history, see Thread.add_message().

The following parameters are required:

  • role: str - The role of the message. Must be one of 'system', 'user', or 'bot'. Case-insensitive.
  • content: str - The content of the message.

Thread.len_messages() -> int

Return the total length of all messages in this thread, in tokens. Equivalent to len(Thread).

Thread.add_message() -> None

Create a message and append it to Thread.messages.

Thread.add_message(...) is a shorthand for Thread.messages.append(Thread.create_message(...))

The following parameters are required:

  • role: str - The role of the message. Must be one of 'system', 'user', or 'bot'. Case-insensitive.
  • content: str - The content of the message.

Thread.inference_str_from_messages() -> str

Using the list of messages, construct a string suitable for inference, respecting the format and context length of this thread.

Thread.send() -> str

Send a message in this thread. This adds your message and the bot's response to the list of messages. Returns a string containing the response to your message.

The following parameter is required:

  • prompt: str - The content of the message to send

Thread.interact() -> None

Start an interactive chat session using this Thread.

While text is being generated, press ^C to interrupt the bot. Then you have the option to press ENTER to re-roll, or to simply type another message.

At the prompt, press ^C to end the chat session.

End your input with a backslash \ for multi-line input.

Type ! and press ENTER to enter a basic command prompt. For a list of commands, type help at this prompt.

Type < and press ENTER to prefix the bot's next message, for example with Sure!.

Type !! at the prompt and press ENTER to insert a system message.

The following parameters are optional:

  • color: bool - Whether to use colored text to differentiate user / bot. Defaults to True.
  • header: str - Header text to print at the start of the interaction. Defaults to None.
  • stream: bool - Whether to stream text as it is generated. If False, then print generated messages all at once. Defaults to True.

Thread.reset() -> None

Clear the list of messages, which resets the thread to its original state.

Thread.as_string() -> str

Return the thread's message history as a string

Thread.print_stats() -> None

Print stats about the context usage in this thread. For example:

443 / 8192 tokens
5% of context used
7 messages

The following parameters are optional:

  • file: _SupportsWriteAndFlush - The file where text should be printed. Defaults to sys.stdout.

class ez.thread.Message

A dictionary representing a single message within a Thread

Normally, there is no need to interface with this class directly. Just use the methods of Thread to manage messages.

Works just like a normal dict, but adds a new method:

  • .as_string - Return the full message string

Generally, messages have these keys:

  • role - The role of the speaker: 'system', 'user', or 'bot'
  • prefix - The text that prefixes the message content
  • content - The actual content of the message
  • postfix - The text that postfixes the message content

Message.as_string() -> str

Return the full text of a message, including the prefix, content, and postfix.

class ez.samplers.SamplerSettings

A SamplerSettings object specifies the sampling parameters that will be used to control text generation. It is passed as an optional parameter to Thread(), Model.generate(), Model.stream(), and Model.stream_print().

ez.samplers.SamplerSettings.__init__()

Construct a SamplerSettings object.

The following parameters are optional. If not specified, values will default to the current llama.cpp defaults.

  • max_len_tokens: int - The maximum length of generations, in tokens. Set to less than 1 for unlimited.
  • temp: float - The temperature value to use, which control randomness
  • top_p: float - Nucleus sampling
  • min_p: float - Min-P sampling
  • frequency_penalty: float - Penalty applied to tokens based on the frequency with which they appear in the input
  • presence_penalty: float - Flat penalty applied to tokens if they appear in the input
  • repeat_penalty: float - Penalty applied to repetitive tokens
  • top_k: int - The number of most likely tokens to consider when sampling

Preset samplers

easy-llama comes with several built-in SamplerSettings objects that can be used out of the box for different purposes:

  • ez.samplers.GreedyDecoding - Most likely next token is always chosen (temperature = 0.0)
  • ez.samplers.DefaultSampling - Use llama.cpp default values for sampling (recommended for most cases)
  • ez.samplers.ClassicSampling - Reflects old llama.cpp defaults
  • ez.samplers.SimpleSampling - Original probability distribution
  • ez.samplers.SemiSampling - Halfway between DefaultSampling and SimpleSampling
  • ez.samplers.TikTokenSampling - Recommended for models with a large vocabulary, such as Llama 3 or Yi, which tend to run hot
  • ez.samplers.LowMinPSampling - Use Min-P as the only active sampler (weak)
  • ez.samplers.MinPSampling - Use Min-P as the only active sampler (moderate)
  • ez.samplers.StrictMinPSampling - Use Min-P as the only active sampler (strict)
  • ez.samplers.ContrastiveSearch - Use contrastive search with a moderate alpha value (arXiv)
  • ez.samplers.WarmContrastiveSearch - Use contrastive search with a high alpha value (arXiv)
  • ez.samplers.RandomSampling - Output completely random tokens from vocab (useless)
  • ez.samplers.LowTempSampling - Default sampling with reduced temperature
  • ez.samplers.HighTempSampling - Default sampling with increased temperature

ez.formats

easy-llama comes with several built-in prompt formats that correspond to well-known language models or families of language models, such as Llama 3, Mistral Instruct, Vicuna, Guanaco, and many more. For a complete list of available formats, see formats.py.

Formats are instances of dict, and they look like this:

# https://github.com/tatsu-lab/stanford_alpaca
alpaca: dict[str, Union[str, list]] = {
	"system_prefix": "",
	"system_prompt": "Below is an instruction that describes a task. Write a response that appropriately completes the request.",
	"system_suffix": "\n\n",
	"user_prefix": "### Instruction:\n",
	"user_suffix": "\n\n",
	"bot_prefix": "### Response:\n",
	"bot_suffix": "\n\n",
	"stops": ['###', 'Instruction:', '\n\n\n']
}