Method readObject

cmd/pdftext/reader.go:458–514

(ref pdfRef)

}

func (r *pdfReader) readObject(ref pdfRef) (any, error) {
	if val, ok := r.cache[ref]; ok {
		return val, nil
	}
	obj, ok := r.objects[ref]
	if !ok {
		return nil, fmt.Errorf("unknown object %v", ref)
	} else if obj.free {
		return nil, fmt.Errorf("bad object %v is free", ref)
	} else if obj.compressed {
		iobjectStream, err := r.readObject(pdfRef{obj.object, 0})
		if err != nil {
			return nil, err
		}
		objectStream, ok := iobjectStream.(pdfStream)
		if !ok {
			return nil, fmt.Errorf("compressed object %v must refer to stream", ref)
		}

		b, i := objectStream.data, 0
		object, offset := 0, 0
		for index := 0; index <= obj.offset; index++ {
			val, n, err := pdfReadContentVal(b[i:])
			if err != nil {
				return nil, fmt.Errorf("invalid stream: %w", err)
			}
			object, _ = val.(int)
			i = moveWhiteSpace(b, i+n)

			val, n, err = pdfReadContentVal(b[i:])
			if err != nil {
				return nil, fmt.Errorf("invalid stream: %w", err)
			}
			offset, _ = val.(int)
			i = moveWhiteSpace(b, i+n)
		}
		if uint32(object) != ref[0] {
			return nil, fmt.Errorf("bad object %v: invalid index in compressed object", ref)
		}

		first, _ := r.GetInt(objectStream.dict["First"])
		offset += first
		if len(b) <= offset {
			return nil, fmt.Errorf("bad object %v: invalid offset in compressed object", ref)
		}

		val, _, err := pdfReadVal(r, ref, b[offset:])
		if err != nil {
			return nil, fmt.Errorf("bad object %v: %w", ref, err)
		}
		r.cache[ref] = val
		return val, nil
	}
	val, err := r.readObjectAt(ref, obj.offset)
	r.cache[ref] = val
	return val, err
}