refactor: consolidate shared analysis boundaries (#10293)

src/artifacts/nodeSea/NodeSeaLocation.ts

@@ -1,3 +1,7 @@
+import {
+  hashArtifactRange,
+  readArtifactRange as readExact,
+} from "../ArtifactCarrierRange.js";
 import { readMachoSegmentHeader } from "../../domain/apple/machoSegmentHeader.js";
 import { readMachoSectionHeader } from "../../domain/apple/machoSectionHeader.js";
 import { readElfSectionHeader } from "../../domain/elfSectionHeader.js";
@@ -214,8 +218,11 @@ const collapseRanges = async (
   if (chosen === undefined) return undefined;
   if (unique.length > 1) {
     const hashes = new Set<string>();
-    for (const range of unique)
-      hashes.add(await digestRange(carrier, range.offset, range.length));
+    for (const range of unique) {
+      const hash = await hashArtifactRange(carrier, range.offset, range.length);
+      if (hash === undefined) throw formatFailure(NODE_SEA_TRUNCATED);
+      hashes.add(hash);
+    }
     if (hashes.size !== 1) throw formatFailure(NODE_SEA_DUPLICATE_BLOB);
   }
   return {
@@ -694,58 +701,6 @@ const locatePeResources = async (carrier: Carrier): Promise<BlobRange[]> => {
   });
 };
 
-const digestRange = async (
-  carrier: Carrier,
-  offset: number,
-  length: number,
-): Promise<string> => {
-  const hash = createHash("sha256");
-  let remaining = length;
-  let position = offset;
-  while (remaining > 0) {
-    const chunkLength = Math.min(64 * 1024, remaining);
-    const chunk = await readExact(carrier, position, chunkLength);
-    if (chunk === undefined) throw formatFailure(NODE_SEA_TRUNCATED);
-    hash.update(chunk);
-    position += chunkLength;
-    remaining -= chunkLength;
-  }
-  return hash.digest("hex");
-};
-
-const readExact = async (
-  carrier: Carrier,
-  offset: number,
-  length: number,
-): Promise<Buffer | undefined> => {
-  abortIfNeeded(carrier.signal);
-  if (
-    !Number.isSafeInteger(offset) ||
-    !Number.isSafeInteger(length) ||
-    offset < 0 ||
-    length < 0 ||
-    offset > carrier.fileSize ||
-    length > carrier.fileSize - offset
-  )
-    return undefined;
-  if (length === 0) return Buffer.alloc(0);
-  const bytes = Buffer.alloc(length);
-  let filled = 0;
-  while (filled < length) {
-    abortIfNeeded(carrier.signal);
-    const read = await carrier.handle.read(
-      bytes,
-      filled,
-      length - filled,
-      offset + filled,
-    );
-    abortIfNeeded(carrier.signal);
-    if (read.bytesRead === 0) return undefined;
-    filled += read.bytesRead;
-  }
-  return bytes;
-};
-
 const cString = (bytes: Buffer, offset: number, length: number): string => {
   let end = offset;
   const limit = Math.min(bytes.length, offset + length);