Method readStream

src/parser/indirect-object-parser.ts:148–200

* Read stream data after the dict has been parsed. * The "stream" keyword has been detected by ObjectParser's lookahead, * and the scanner is positioned right after "stream".

(dict: PdfDict)

   * and the scanner is positioned right after "stream".
   */
  private readStream(dict: PdfDict): PdfStream {
    // The scanner is positioned right after "stream" keyword
    // (ObjectParser consumed it during lookahead but didn't use it)

    // Skip EOL after "stream" (required: LF or CRLF)
    this.skipStreamEOL();

    const startPos = this.scanner.position;

    // Try to resolve /Length from the dict. If that fails (e.g. indirect
    // ref during brute-force recovery with no resolver), fall back to
    // scanning for the "endstream" keyword to determine the length.
    let length = -1;

    try {
      length = this.resolveLength(dict);
    } catch {
      length = -1;
    }

    // Validate /Length: the "endstream" keyword must follow the data.
    // Malformed PDFs often carry a wrong /Length — recover by scanning
    // for endstream instead of trusting the declared value.
    if (length >= 0 && !this.isEndstreamAt(startPos + length)) {
      this.warn(
        `Stream /Length ${length} does not point at endstream, scanning for actual end`,
        startPos,
      );

      length = -1;
    }

    length = length < 0 ? this.findEndStream(startPos) : length;

    if (length < 0) {
      throw new ObjectParseError("Stream has no valid /Length and no endstream found");
    }

    // Read exactly `length` bytes.
    // Use subarray (zero-copy view) since the underlying PDF bytes
    // are kept alive by the PDF object for the document's lifetime.
    const data = this.scanner.bytes.subarray(startPos, startPos + length);

    this.scanner.moveTo(startPos + length);

    // Skip optional EOL before "endstream"
    this.skipOptionalEOL();

    // Consume "endstream" keyword directly from scanner
    this.expectKeyword("endstream");

    return new PdfStream(dict, data);
  }

  /**
   * Check whether the "endstream" keyword appears at the given position,