Function buildChildDrafts

packages/node-runtime/src/semantic-index/chunker.ts:260–291

(parent: ChunkMessageInput[], config: ChunkerConfig)

}

function buildChildDrafts(parent: ChunkMessageInput[], config: ChunkerConfig): ChunkMessageInput[][] {
  const drafts: ChunkMessageInput[][] = []
  let current: ChunkMessageInput[] = []
  let newCount = 0

  const closeAndSeed = () => {
    drafts.push(current)
    const seed = config.overlapMessages > 0 ? current.slice(-config.overlapMessages) : []
    current = [...seed]
    newCount = 0
  }

  for (const m of parent) {
    current.push(m)
    newCount++
    const effectiveChars = sumEffectiveChars(current)
    const messageCount = current.length
    const overChars = effectiveChars >= config.childTargetMaxChars
    const overTokens = estimateTokens(current.map((x) => effectiveContentOf(x)).join('\n')) >= config.childHardMaxTokens
    // 消息数软上限：高频短消息群聊里，攒够消息数且有效字符达标即关闭，避免单 chunk 混入过多消息
    const overSoftMessages = messageCount >= config.childSoftMaxMessages && effectiveChars >= config.childTargetMinChars
    // 消息数硬上限：即使有效字符不足 min 也强制关闭，避免极端短消息无限堆积
    const overHardMessages = messageCount >= config.childHardMaxMessages
    if (overChars || overTokens || overSoftMessages || overHardMessages) closeAndSeed()
  }

  // flush：仅当还有新消息（避免重复上一个 child 的 overlap 尾巴）
  if (current.length > 0 && (newCount > 0 || drafts.length === 0)) {
    drafts.push(current)
  }
  return drafts
}

export function chunkMessages(input: ChunkMessagesInput): ChunkResult {
  const config = input.config ?? DEFAULT_CHUNKER_CONFIG