discourse-ai/lib/completions/endpoints/vllm.rb

103 lines
3.0 KiB
Ruby

# frozen_string_literal: true
module DiscourseAi
module Completions
module Endpoints
class Vllm < Base
def self.can_contact?(model_provider)
model_provider == "vllm"
end
def normalize_model_params(model_params)
model_params = model_params.dup
# max_tokens, temperature are already supported
if model_params[:stop_sequences]
model_params[:stop] = model_params.delete(:stop_sequences)
end
model_params
end
def default_options
{ max_tokens: 2000, model: llm_model.name }
end
def provider_id
AiApiAuditLog::Provider::Vllm
end
private
def model_uri
if llm_model.url.to_s.starts_with?("srv://")
service = DiscourseAi::Utils::DnsSrv.lookup(llm_model.url.sub("srv://", ""))
api_endpoint = "https://#{service.target}:#{service.port}/v1/chat/completions"
else
api_endpoint = llm_model.url
end
@uri ||= URI(api_endpoint)
end
def prepare_payload(prompt, model_params, dialect)
payload = default_options.merge(model_params).merge(messages: prompt)
if @streaming_mode
payload[:stream] = true if @streaming_mode
payload[:stream_options] = { include_usage: true }
end
payload
end
def prepare_request(payload)
headers = { "Referer" => Discourse.base_url, "Content-Type" => "application/json" }
api_key = llm_model&.api_key || SiteSetting.ai_vllm_api_key
headers["X-API-KEY"] = api_key if api_key.present?
Net::HTTP::Post.new(model_uri, headers).tap { |r| r.body = payload }
end
def xml_tools_enabled?
true
end
def final_log_update(log)
log.request_tokens = @prompt_tokens if @prompt_tokens
log.response_tokens = @completion_tokens if @completion_tokens
end
def decode(response_raw)
json = JSON.parse(response_raw, symbolize_names: true)
@prompt_tokens = json.dig(:usage, :prompt_tokens)
@completion_tokens = json.dig(:usage, :completion_tokens)
[json.dig(:choices, 0, :message, :content)]
end
def decode_chunk(chunk)
@json_decoder ||= JsonStreamDecoder.new
(@json_decoder << chunk)
.map do |parsed|
# vLLM keeps sending usage over and over again
prompt_tokens = parsed.dig(:usage, :prompt_tokens)
completion_tokens = parsed.dig(:usage, :completion_tokens)
@prompt_tokens = prompt_tokens if prompt_tokens
@completion_tokens = completion_tokens if completion_tokens
text = parsed.dig(:choices, 0, :delta, :content)
if text.to_s.empty?
nil
else
text
end
end
.compact
end
end
end
end
end