Class: Mneme::CompressedViewport

Inherits:
Object
  • Object
show all
Defined in:
lib/mneme/compressed_viewport.rb

Overview

Builds a compressed viewport for Mneme’s LLM context. Mneme sees conversation (user/agent messages and think events) but not mechanical execution (tool calls and responses). Tool calls are compressed to aggregate counters like ‘[4 tools called]`.

The viewport is split into three zones separated by delimiters:

  • **Eviction zone** — messages about to leave the viewport (upper third)

  • **Middle zone** — messages in the middle of the viewport

  • **Recent zone** — the most recent messages (lower third)

Zone boundaries are calculated WITH tool call tokens (they affect position), then tool calls are removed and replaced with counters.

Examples:

viewport = Mneme::CompressedViewport.new(session, token_budget: 60_000)
viewport.render  #=> "── EVICTION ZONE ──\nmessage 42 User: ..."

Constant Summary collapse

ZONE_DELIMITERS = 
{
  eviction: "── EVICTION ZONE (upper third) ──",
  middle: "── MIDDLE ZONE ──",
  recent: "── RECENT ZONE (lower third) ──"
}.freeze

Instance Method Summary collapse

Constructor Details

#initialize(session, token_budget:, from_message_id: nil) ⇒ CompressedViewport

Returns a new instance of CompressedViewport.

Parameters:

  • session (Session) —

    the session to build viewport for

  • token_budget (Integer) —

    total tokens available for Mneme’s viewport

  • from_message_id (Integer, nil) (defaults to: nil) —

    start from this message ID (inclusive); when nil, uses the session’s full viewport



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# File 'lib/mneme/compressed_viewport.rb', line 31

def initialize(session, token_budget:, from_message_id: nil)
  @session = session
  @token_budget = token_budget
  @from_message_id = from_message_id
end

Instance Method Details

#messages ⇒ Array<Message>

Returns the raw messages selected for this viewport.

Returns:

  • (Array<Message>) —

    the raw messages selected for this viewport



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# File 'lib/mneme/compressed_viewport.rb', line 48

def messages
  @messages ||= fetch_messages
end

#render ⇒ String

Renders the compressed viewport as a string ready for Mneme’s LLM context.

Returns:

  • (String) —

    compressed viewport with zone delimiters



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# File 'lib/mneme/compressed_viewport.rb', line 40

def render
  return "" if messages.empty?

  zones = split_into_zones(messages)
  render_zones(zones)
end