fix: resolve workspace integration blockers (#5)

apps/viewer-2d-sample/src/cadInputPolicy.ts

@@ -0,0 +1,72 @@
+export const MAX_CAD_BYTES = 50 * 1024 * 1024;
+export const CAD_FETCH_TIMEOUT_MS = 15_000;
+
+export function assertCadByteLength(byteLength: number): void {
+  if (!Number.isFinite(byteLength) || byteLength < 0) {
+    throw new Error('CAD 파일 크기를 확인할 수 없습니다.');
+  }
+  if (byteLength > MAX_CAD_BYTES) {
+    throw new Error('CAD 파일은 50 MiB 이하여야 합니다.');
+  }
+}
+
+export function resolveCadUrl(input: string, base: URL): URL {
+  const url = new URL(input, base);
+  if (!['http:', 'https:'].includes(url.protocol)) {
+    throw new Error('CAD URL은 HTTP(S)만 허용합니다.');
+  }
+  if (url.origin !== base.origin) {
+    throw new Error('CAD URL은 viewer와 같은 origin만 허용합니다.');
+  }
+  return url;
+}
+
+export async function fetchCadBuffer(url: URL): Promise<ArrayBuffer> {
+  const controller = new AbortController();
+  const timeout = window.setTimeout(() => controller.abort(), CAD_FETCH_TIMEOUT_MS);
+
+  try {
+    const response = await fetch(url, {
+      credentials: 'same-origin',
+      signal: controller.signal,
+    });
+    if (!response.ok) throw new Error(`HTTP ${response.status}`);
+
+    const declaredLength = Number(response.headers.get('content-length'));
+    if (Number.isFinite(declaredLength) && declaredLength > 0) {
+      assertCadByteLength(declaredLength);
+    }
+
+    if (!response.body) {
+      const buffer = await response.arrayBuffer();
+      assertCadByteLength(buffer.byteLength);
+      return buffer;
+    }
+
+    const reader = response.body.getReader();
+    const chunks: Uint8Array[] = [];
+    let total = 0;
+    while (true) {
+      const { done, value } = await reader.read();
+      if (done) break;
+      total += value.byteLength;
+      assertCadByteLength(total);
+      chunks.push(value);
+    }
+
+    const data = new Uint8Array(total);
+    let offset = 0;
+    for (const chunk of chunks) {
+      data.set(chunk, offset);
+      offset += chunk.byteLength;
+    }
+    return data.buffer;
+  } catch (error) {
+    if (controller.signal.aborted) {
+      throw new Error('CAD 파일 요청 시간이 초과되었습니다.');
+    }
+    throw error;
+  } finally {
+    window.clearTimeout(timeout);
+  }
+}