LibPDF: Convert CFF::parse_dict & co to Stream

No behavior change.
This commit is contained in:
Nico Weber 2024-04-13 21:58:06 -04:00 committed by Andreas Kling
parent 1f7924e14c
commit cc3d4b6adb
Notes: sideshowbarker 2024-07-17 08:27:05 +09:00
2 changed files with 30 additions and 29 deletions

View file

@ -301,7 +301,7 @@ PDFErrorOr<Vector<CFF::TopDict>> CFF::parse_top_dicts(Reader& reader, ReadonlyBy
TRY(parse_index(reader, [&](ReadonlyBytes const& element_data) -> PDFErrorOr<void> {
TopDict top_dict;
Reader element_reader { element_data };
FixedMemoryStream element_reader { element_data };
TRY(parse_dict<TopDictOperator>(element_reader, [&](TopDictOperator op, Vector<DictOperand> const& operands) -> PDFErrorOr<void> {
switch (op) {
case TopDictOperator::Version:
@ -353,7 +353,7 @@ PDFErrorOr<Vector<CFF::TopDict>> CFF::parse_top_dicts(Reader& reader, ReadonlyBy
case TopDictOperator::Private: {
auto private_dict_size = operands[0].get<int>();
auto private_dict_offset = operands[1].get<int>();
Reader priv_dict_reader { cff_bytes.slice(private_dict_offset, private_dict_size) };
FixedMemoryStream priv_dict_reader { cff_bytes.slice(private_dict_offset, private_dict_size) };
TRY(parse_dict<PrivDictOperator>(priv_dict_reader, [&](PrivDictOperator op, Vector<DictOperand> const& operands) -> PDFErrorOr<void> {
switch (op) {
case PrivDictOperator::BlueValues:
@ -997,12 +997,12 @@ PDFErrorOr<Vector<u8>> CFF::parse_encoding(Stream&& reader, HashMap<Card8, SID>&
}
template<typename OperatorT>
PDFErrorOr<void> CFF::parse_dict(Reader& reader, DictEntryHandler<OperatorT>&& handler)
PDFErrorOr<void> CFF::parse_dict(Stream& reader, DictEntryHandler<OperatorT>&& handler)
{
// CFF spec, "4 DICT data"
Vector<DictOperand> operands;
while (reader.remaining() > 0) {
auto b0 = reader.read<u8>();
while (!reader.is_eof()) {
auto b0 = TRY(reader.read_value<u8>());
// "Operators and operands may be distinguished by inspection of their first byte: 0-21 specify operators"
if (b0 <= 21) {
auto op = TRY(parse_dict_operator<OperatorT>(b0, reader));
@ -1016,11 +1016,11 @@ PDFErrorOr<void> CFF::parse_dict(Reader& reader, DictEntryHandler<OperatorT>&& h
return {};
}
template PDFErrorOr<void> CFF::parse_dict<CFF::TopDictOperator>(Reader&, DictEntryHandler<TopDictOperator>&&);
template PDFErrorOr<void> CFF::parse_dict<CFF::PrivDictOperator>(Reader&, DictEntryHandler<PrivDictOperator>&&);
template PDFErrorOr<void> CFF::parse_dict<CFF::TopDictOperator>(Stream&, DictEntryHandler<TopDictOperator>&&);
template PDFErrorOr<void> CFF::parse_dict<CFF::PrivDictOperator>(Stream&, DictEntryHandler<PrivDictOperator>&&);
template<typename OperatorT>
PDFErrorOr<OperatorT> CFF::parse_dict_operator(u8 b0, Reader& reader)
PDFErrorOr<OperatorT> CFF::parse_dict_operator(u8 b0, Stream& reader)
{
// CFF spec, "4 DICT data"
VERIFY(b0 <= 21);
@ -1028,11 +1028,11 @@ PDFErrorOr<OperatorT> CFF::parse_dict_operator(u8 b0, Reader& reader)
// "Two-byte operators have an initial escape byte of 12."
if (b0 != 12)
return OperatorT { (int)b0 };
auto b1 = TRY(reader.try_read<u8>());
auto b1 = TRY(reader.read_value<u8>());
return OperatorT { b0 << 8 | b1 };
}
template PDFErrorOr<CFF::TopDictOperator> CFF::parse_dict_operator(u8, Reader&);
template PDFErrorOr<CFF::TopDictOperator> CFF::parse_dict_operator(u8, Stream&);
PDFErrorOr<void> CFF::parse_index(Reader& reader, IndexDataHandler&& data_handler)
{
@ -1075,36 +1075,36 @@ PDFErrorOr<void> CFF::parse_index_data(OffSize offset_size, Card16 count, Reader
return {};
}
int CFF::load_int_dict_operand(u8 b0, Reader& reader)
ErrorOr<int> CFF::load_int_dict_operand(u8 b0, Stream& reader)
{
// CFF spec, "Table 3 Operand Encoding"
if (b0 >= 32 && b0 <= 246) {
return b0 - 139;
}
if (b0 >= 247 && b0 <= 250) {
auto b1 = reader.read<u8>();
auto b1 = TRY(reader.read_value<u8>());
return (b0 - 247) * 256 + b1 + 108;
}
if (b0 >= 251 && b0 <= 254) {
auto b1 = reader.read<u8>();
auto b1 = TRY(reader.read_value<u8>());
return -(b0 - 251) * 256 - b1 - 108;
}
if (b0 == 28) {
auto b1 = reader.read<u8>();
auto b2 = reader.read<u8>();
auto b1 = TRY(reader.read_value<u8>());
auto b2 = TRY(reader.read_value<u8>());
return b1 << 8 | b2;
}
if (b0 == 29) {
auto b1 = reader.read<u8>();
auto b2 = reader.read<u8>();
auto b3 = reader.read<u8>();
auto b4 = reader.read<u8>();
auto b1 = TRY(reader.read_value<u8>());
auto b2 = TRY(reader.read_value<u8>());
auto b3 = TRY(reader.read_value<u8>());
auto b4 = TRY(reader.read_value<u8>());
return b1 << 24 | b2 << 16 | b3 << 8 | b4;
}
VERIFY_NOT_REACHED();
}
float CFF::load_float_dict_operand(Reader& reader)
ErrorOr<float> CFF::load_float_dict_operand(Stream& reader)
{
// CFF spec, "Table 5 Nibble Definitions"
StringBuilder sb;
@ -1121,7 +1121,7 @@ float CFF::load_float_dict_operand(Reader& reader)
sb.append('-');
};
while (true) {
auto byte = reader.read<u8>();
auto byte = TRY(reader.read_value<u8>());
char nibble1 = (byte & 0xf0) >> 4;
char nibble2 = byte & 0x0f;
if (nibble1 == 0xf)
@ -1135,13 +1135,14 @@ float CFF::load_float_dict_operand(Reader& reader)
return result.release_value();
}
PDFErrorOr<CFF::DictOperand> CFF::load_dict_operand(u8 b0, Reader& reader)
PDFErrorOr<CFF::DictOperand> CFF::load_dict_operand(u8 b0, Stream& reader)
{
// CFF spec, "4 DICT data"
if (b0 == 30)
return load_float_dict_operand(reader);
return DictOperand { TRY(load_float_dict_operand(reader)) };
if (b0 >= 28)
return load_int_dict_operand(b0, reader);
return DictOperand { TRY(load_int_dict_operand(b0, reader)) };
return Error { Error::Type::MalformedPDF, ByteString::formatted("Unknown CFF dict element prefix: {}", b0) };
}
}

View file

@ -99,9 +99,9 @@ public:
return operand.get<float>();
}
static int load_int_dict_operand(u8 b0, Reader&);
static float load_float_dict_operand(Reader&);
static PDFErrorOr<DictOperand> load_dict_operand(u8, Reader&);
static ErrorOr<int> load_int_dict_operand(u8 b0, Stream&);
static ErrorOr<float> load_float_dict_operand(Stream&);
static PDFErrorOr<DictOperand> load_dict_operand(u8, Stream&);
using IndexDataHandler = Function<PDFErrorOr<void>(ReadonlyBytes const&)>;
static PDFErrorOr<void> parse_index(Reader& reader, IndexDataHandler&&);
@ -112,10 +112,10 @@ public:
using DictEntryHandler = Function<PDFErrorOr<void>(OperatorT, Vector<DictOperand> const&)>;
template<typename OperatorT>
static PDFErrorOr<void> parse_dict(Reader& reader, DictEntryHandler<OperatorT>&& handler);
static PDFErrorOr<void> parse_dict(Stream&, DictEntryHandler<OperatorT>&& handler);
template<typename OperatorT>
static PDFErrorOr<OperatorT> parse_dict_operator(u8, Reader&);
static PDFErrorOr<OperatorT> parse_dict_operator(u8, Stream&);
// CFF spec, "8 Top DICT INDEX"
struct TopDict {