Class: Clacky::AnthropicStreamAggregator

Inherits:
Object
  • Object
show all
Defined in:
lib/clacky/anthropic_stream_aggregator.rb

Overview

Reassembles an Anthropic Messages SSE stream (event: message_start / content_block_start / content_block_delta / content_block_stop / message_delta / message_stop / ping) into the same hash shape that MessageFormat::Anthropic.parse_response expects from a non-streaming response, while invoking on_chunk(input_tokens:, output_tokens:) as usage accumulates.

Wire reference: docs.anthropic.com/en/api/messages-streaming

Instance Method Summary collapse

Constructor Details

#initialize(on_chunk: nil) ⇒ AnthropicStreamAggregator

Returns a new instance of AnthropicStreamAggregator.



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# File 'lib/clacky/anthropic_stream_aggregator.rb', line 15

def initialize(on_chunk: nil)
  @on_chunk = on_chunk
  @blocks = {}
  @stop_reason = nil
  @usage = {}
  @last_input_tokens = 0
  @last_output_tokens = 0
end

Instance Method Details

#handle(event, data_str) ⇒ Object 



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# File 'lib/clacky/anthropic_stream_aggregator.rb', line 24

def handle(event, data_str)
  data = parse_or_nil(data_str)
  return unless data

  case event
  when "message_start"
    msg = data["message"] || {}
    if (u = msg["usage"])
      @usage.merge!(u)
      emit_usage_progress
    end
  when "content_block_start"
    idx = data["index"] || @blocks.size
    cb = data["content_block"] || {}
    case cb["type"]
    when "tool_use"
      @blocks[idx] = { kind: :tool_use, id: cb["id"], name: cb["name"], input_str: +"" }
    else
      @blocks[idx] = { kind: :text, text: +"" }
    end
  when "content_block_delta"
    idx = data["index"] || 0
    delta = data["delta"] || {}
    block = (@blocks[idx] ||= { kind: :text, text: +"" })
    case delta["type"]
    when "text_delta"
      block[:kind] ||= :text
      block[:text] ||= +""
      block[:text] << delta["text"].to_s
    when "input_json_delta"
      block[:kind] = :tool_use
      block[:input_str] ||= +""
      block[:input_str] << delta["partial_json"].to_s
    when "thinking_delta"
      block[:kind] = :thinking
      block[:thinking] ||= +""
      block[:thinking] << delta["thinking"].to_s
    end
    emit_estimate_progress
  when "content_block_stop"
    # Nothing to do: blocks are finalised in to_h.
  when "message_delta"
    if (d = data["delta"])
      @stop_reason = d["stop_reason"] if d["stop_reason"]
    end
    if (u = data["usage"])
      @usage.merge!(u)
      emit_usage_progress
    end
  when "message_stop", "ping", "error"
    # no-op
  end
end

#to_h ⇒ Object

Canonical non-streaming Anthropic response shape consumed by MessageFormat::Anthropic.parse_response.



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# File 'lib/clacky/anthropic_stream_aggregator.rb', line 80

def to_h
  content_blocks = @blocks.keys.sort.map do |idx|
    b = @blocks[idx]
    case b[:kind]
    when :tool_use
      input_value =
        if b[:input_str].to_s.empty?
          {}
        else
          JSON.parse(b[:input_str]) rescue b[:input_str]
        end
      { "type" => "tool_use", "id" => b[:id], "name" => b[:name], "input" => input_value }
    else
      { "type" => "text", "text" => b[:text].to_s }
    end
  end

  { "content" => content_blocks, "stop_reason" => @stop_reason, "usage" => @usage }
end