1import Module from '../../artifacts/graphviz/graphviz-backend'2import { renderInput } from '../../artifacts/graphviz/graphviz-wrapper'3import { RenderError } from '../runtime/errors'4import type { RendererAdapter } from '../runtime/types'5import { edgeResult } from './types'67const VERSION = 'graphviz@15.1.1'8const LAYOUT_ENGINES = new Set(['circo', 'dot', 'fdp', 'neato', 'nop', 'nop1', 'nop2', 'osage', 'patchwork', 'sfdp', 'twopi'])9const RESOURCE_ATTRIBUTES = new Set(['fontpath', 'image', 'imagepath', 'shapefile', 'stylesheet'])1011let modulePromise: ReturnType<typeof Module> | undefined12let renderTail: Promise<void> = Promise.resolve()1314export function graphvizModule(): ReturnType<typeof Module> {15 modulePromise ??= Module()16 return modulePromise17}1819async function withGraphvizLock<T>(operation: () => T): Promise<T> {20 const previous = renderTail21 let release!: () => void22 renderTail = new Promise(resolve => { release = resolve })23 await previous24 try {25 return operation()26 } finally {27 release()28 }29}3031function withoutQuotedContent(source: string): string {32 let result = ''33 let quote = ''34 let escaped = false35 for (const char of source) {36 if (quote) {37 if (escaped) escaped = false38 else if (char === '\\') escaped = true39 else if (char === quote) {40 quote = ''41 result += char42 }43 continue44 }45 if (char === '"' || char === "'") quote = char46 result += char47 }48 return result49}5051function hasResourceAttribute(source: string): boolean {52 return /\b(?:fontpath|image|imagepath|shapefile|stylesheet)\s*=|<\s*img\b/i.test(withoutQuotedContent(source))53}5455export function optionsFor(options: Record<string, string>): Record<string, unknown> {56 const engine = options.layout ?? 'dot'57 if (!LAYOUT_ENGINES.has(engine)) throw new RenderError(400, 'invalid_options', `Unsupported GraphViz layout engine: ${engine}.`)58 const graphAttributes: Record<string, string> = {}59 const nodeAttributes: Record<string, string> = {}60 const edgeAttributes: Record<string, string> = {}61 for (const [name, value] of Object.entries(options)) {62 if (name === 'layout') continue63 if (name === 'scale') throw new RenderError(400, 'unsupported_options', 'GraphViz scale is not supported by the edge-Wasm adapter.')64 const attributeName = name.replace(/^(?:graph|node|edge)-attribute-/, '')65 if (attributeName !== name && RESOURCE_ATTRIBUTES.has(attributeName.toLowerCase())) {66 throw new RenderError(400, 'unsafe_options', `GraphViz resource attribute '${attributeName}' is not supported by the edge renderer.`)67 }68 if (name.startsWith('graph-attribute-')) graphAttributes[attributeName] = value69 if (name.startsWith('node-attribute-')) nodeAttributes[attributeName] = value70 if (name.startsWith('edge-attribute-')) edgeAttributes[attributeName] = value71 if (!name.startsWith('graph-attribute-') && !name.startsWith('node-attribute-') && !name.startsWith('edge-attribute-')) {72 throw new RenderError(400, 'invalid_options', `Unsupported GraphViz option: ${name}.`)73 }74 }75 return {76 engine,77 format: 'svg',78 yInvert: false,79 reduce: false,80 graphAttributes,81 nodeAttributes,82 edgeAttributes,83 }84}8586/** Shared in-process GraphViz runtime for translators such as ERD and WireViz. */87export async function renderGraphvizSource(source: string, options: Record<string, string> = {}): Promise<string> {88 const module = await graphvizModule()89 const result: any = await withGraphvizLock(() => renderInput(module, source, ['svg'], optionsFor(options)))90 if (result.status !== 'success' || typeof result.output?.svg !== 'string') {91 const message = result.errors?.find((entry: { level?: string }) => entry.level === 'error')?.message ?? 'GraphViz could not render this source.'92 throw new RenderError(422, 'render_failed', message)93 }94 return result.output.svg95}9697export const graphvizAdapter: RendererAdapter = {98 id: 'graphviz',99 runtime: 'edge-wasm',100 version: VERSION,101 async render(request, signal) {102 if (signal.aborted) throw signal.reason103 if (hasResourceAttribute(request.source)) {104 throw new RenderError(422, 'unsafe_include', 'GraphViz resource-loading attributes are not supported by the edge renderer.')105 }106 try {107 return edgeResult('graphviz', VERSION, await renderGraphvizSource(request.source, request.options), 'edge-wasm')108 } catch (error) {109 if (error instanceof RenderError) throw error110 const message = error instanceof Error ? error.message : String(error)111 throw new RenderError(422, 'render_failed', message.slice(0, 500) || 'GraphViz could not render this source.')112 }113 },114}