chore: import upstream snapshot with attribution

apps/sim/executor/utils/run-from-block.ts

@@ -0,0 +1,257 @@
+import { LOOP, PARALLEL } from '@/executor/constants'
+import type { DAG } from '@/executor/dag/builder'
+
+/**
+ * Builds the sentinel-start node ID for a loop.
+ */
+function buildLoopSentinelStartId(loopId: string): string {
+  return `${LOOP.SENTINEL.PREFIX}${loopId}${LOOP.SENTINEL.START_SUFFIX}`
+}
+
+/**
+ * Builds the sentinel-start node ID for a parallel.
+ */
+function buildParallelSentinelStartId(parallelId: string): string {
+  return `${PARALLEL.SENTINEL.PREFIX}${parallelId}${PARALLEL.SENTINEL.START_SUFFIX}`
+}
+
+/**
+ * Checks if a block ID is a loop or parallel container and returns the sentinel-start ID if so.
+ * Returns null if the block is not a container.
+ */
+export function resolveContainerToSentinelStart(blockId: string, dag: DAG): string | null {
+  if (dag.loopConfigs.has(blockId)) {
+    return buildLoopSentinelStartId(blockId)
+  }
+  if (dag.parallelConfigs.has(blockId)) {
+    return buildParallelSentinelStartId(blockId)
+  }
+  return null
+}
+
+/**
+ * Result of validating a block for run-from-block execution.
+ */
+export interface RunFromBlockValidation {
+  valid: boolean
+  error?: string
+}
+
+/**
+ * Context for run-from-block execution mode.
+ */
+export interface RunFromBlockContext {
+  /** The block ID to start execution from */
+  startBlockId: string
+  /** Set of block IDs that need re-execution (start block + all downstream) */
+  dirtySet: Set<string>
+}
+
+/**
+ * Result of computing execution sets for run-from-block mode.
+ */
+export interface ExecutionSets {
+  /** Blocks that need re-execution (start block + all downstream) */
+  dirtySet: Set<string>
+  /** Blocks that are upstream (ancestors) of the start block */
+  upstreamSet: Set<string>
+  /** Blocks that are upstream of any dirty block (for snapshot preservation) */
+  reachableUpstreamSet: Set<string>
+}
+
+/**
+ * Computes the dirty set, upstream set, and reachable upstream set.
+ * - Dirty set: start block + all blocks reachable via outgoing edges (need re-execution)
+ * - Upstream set: all blocks reachable via incoming edges from the start block
+ * - Reachable upstream set: all non-dirty blocks that are upstream of ANY dirty block
+ *   (includes sibling branches that dirty blocks may reference)
+ *
+ * For loop/parallel containers, starts from the sentinel-start node and includes
+ * the container ID itself in the dirty set.
+ *
+ * @param dag - The workflow DAG
+ * @param startBlockId - The block to start execution from
+ * @returns Object containing dirtySet, upstreamSet, and reachableUpstreamSet
+ */
+export function computeExecutionSets(dag: DAG, startBlockId: string): ExecutionSets {
+  const dirty = new Set<string>([startBlockId])
+  const upstream = new Set<string>()
+  const sentinelStartId = resolveContainerToSentinelStart(startBlockId, dag)
+  const traversalStartId = sentinelStartId ?? startBlockId
+
+  if (sentinelStartId) {
+    dirty.add(sentinelStartId)
+  }
+
+  // BFS downstream for dirty set
+  const downstreamQueue = [traversalStartId]
+  while (downstreamQueue.length > 0) {
+    const nodeId = downstreamQueue.shift()!
+    const node = dag.nodes.get(nodeId)
+    if (!node) continue
+
+    for (const [, edge] of node.outgoingEdges) {
+      if (!dirty.has(edge.target)) {
+        dirty.add(edge.target)
+        downstreamQueue.push(edge.target)
+      }
+    }
+  }
+
+  // BFS upstream from start block for upstream set
+  const upstreamQueue = [traversalStartId]
+  while (upstreamQueue.length > 0) {
+    const nodeId = upstreamQueue.shift()!
+    const node = dag.nodes.get(nodeId)
+    if (!node) continue
+
+    for (const sourceId of node.incomingEdges) {
+      if (!upstream.has(sourceId)) {
+        upstream.add(sourceId)
+        upstreamQueue.push(sourceId)
+      }
+    }
+  }
+
+  // Compute reachable upstream: all non-dirty blocks upstream of ANY dirty block
+  // This handles the case where a dirty block (like C in A->C, B->C) may reference
+  // sibling branches (like B when running from A)
+  const reachableUpstream = new Set<string>()
+  for (const dirtyNodeId of dirty) {
+    const node = dag.nodes.get(dirtyNodeId)
+    if (!node) continue
+
+    // BFS upstream from this dirty node
+    const queue = [...node.incomingEdges]
+    while (queue.length > 0) {
+      const sourceId = queue.shift()!
+      if (reachableUpstream.has(sourceId) || dirty.has(sourceId)) continue
+
+      reachableUpstream.add(sourceId)
+      const sourceNode = dag.nodes.get(sourceId)
+      if (sourceNode) {
+        queue.push(...sourceNode.incomingEdges)
+      }
+    }
+  }
+
+  return { dirtySet: dirty, upstreamSet: upstream, reachableUpstreamSet: reachableUpstream }
+}
+
+/**
+ * Validates that a block can be used as a run-from-block starting point.
+ *
+ * Validation rules:
+ * - Block must exist in the DAG (or be a loop/parallel container)
+ * - Block cannot be inside a loop (but loop containers are allowed)
+ * - Block cannot be inside a parallel (but parallel containers are allowed)
+ * - Block cannot be a sentinel node
+ * - All upstream dependencies must have been executed (have cached outputs)
+ *
+ * @param blockId - The block ID to validate
+ * @param dag - The workflow DAG
+ * @param executedBlocks - Set of blocks that were executed in the source run
+ * @returns Validation result with error message if invalid
+ */
+export function validateRunFromBlock(
+  blockId: string,
+  dag: DAG,
+  executedBlocks: Set<string>
+): RunFromBlockValidation {
+  const node = dag.nodes.get(blockId)
+  const isLoopContainer = dag.loopConfigs.has(blockId)
+  const isParallelContainer = dag.parallelConfigs.has(blockId)
+  const isContainer = isLoopContainer || isParallelContainer
+  let validationNode = node
+
+  if (!node && !isContainer) {
+    return { valid: false, error: `Block not found in workflow: ${blockId}` }
+  }
+
+  if (isContainer) {
+    const parentLoopId = findParentLoop(blockId, dag)
+    if (parentLoopId) {
+      return {
+        valid: false,
+        error: `Cannot run from block inside loop: ${parentLoopId}`,
+      }
+    }
+
+    const parentParallelId = findParentParallel(blockId, dag)
+    if (parentParallelId) {
+      return {
+        valid: false,
+        error: `Cannot run from block inside parallel: ${parentParallelId}`,
+      }
+    }
+
+    const sentinelStartId = resolveContainerToSentinelStart(blockId, dag)
+    if (!sentinelStartId || !dag.nodes.has(sentinelStartId)) {
+      return {
+        valid: false,
+        error: `Container sentinel not found for: ${blockId}`,
+      }
+    }
+    validationNode = dag.nodes.get(sentinelStartId)
+  }
+
+  if (node) {
+    if (node.metadata.isLoopNode) {
+      return {
+        valid: false,
+        error: `Cannot run from block inside loop: ${node.metadata.subflowId}`,
+      }
+    }
+
+    if (node.metadata.isParallelBranch) {
+      return {
+        valid: false,
+        error: `Cannot run from block inside parallel: ${node.metadata.subflowId}`,
+      }
+    }
+
+    if (node.metadata.isSentinel) {
+      return { valid: false, error: 'Cannot run from sentinel node' }
+    }
+  }
+
+  if (validationNode) {
+    // Check immediate upstream dependencies were executed
+    for (const sourceId of validationNode.incomingEdges) {
+      const sourceNode = dag.nodes.get(sourceId)
+      // Skip sentinel nodes - they're internal and not in executedBlocks
+      if (sourceNode?.metadata.isSentinel) continue
+
+      // Skip trigger nodes - they're entry points and don't need prior execution
+      // A trigger node has no incoming edges
+      if (sourceNode && sourceNode.incomingEdges.size === 0) continue
+
+      if (!executedBlocks.has(sourceId)) {
+        return {
+          valid: false,
+          error: `Upstream dependency not executed: ${sourceId}`,
+        }
+      }
+    }
+  }
+
+  return { valid: true }
+}
+
+function findParentLoop(blockId: string, dag: DAG): string | undefined {
+  for (const [loopId, config] of dag.loopConfigs) {
+    if (loopId !== blockId && config.nodes?.includes(blockId)) {
+      return loopId
+    }
+  }
+  return undefined
+}
+
+function findParentParallel(blockId: string, dag: DAG): string | undefined {
+  for (const [parallelId, config] of dag.parallelConfigs) {
+    if (parallelId !== blockId && config.nodes?.includes(blockId)) {
+      return parallelId
+    }
+  }
+  return undefined
+}