dart::ReadStream Class Reference

#include <datastream.h>

Inheritance diagram for dart::ReadStream:

Classes
class	Raw
class	Raw< 1, T >
class	Raw< 2, T >
class	Raw< 4, T >
class	Raw< 8, T >

Public Member Functions
	ReadStream (const uint8_t *buffer, intptr_t size)
	ReadStream (const uint8_t *buffer, intptr_t size, intptr_t pos)
void	ReadBytes (void *addr, intptr_t len)
template<typename T = intptr_t>
T	ReadUnsigned ()
intptr_t	ReadRefId ()
intptr_t	Position () const
void	SetPosition (intptr_t value)
void	Align (intptr_t alignment, intptr_t offset=0)
const uint8_t *	AddressOfCurrentPosition () const
void	Advance (intptr_t value)
intptr_t	PendingBytes () const
template<typename T >
T	Read ()
uword	ReadWordWith32BitReads ()
template<typename T = uintptr_t>
C::only_if_unsigned< T, T >	ReadLEB128 ()
template<typename T >
C::only_if_signed< T, T >	ReadLEB128 ()
template<typename T >
C::only_if_unsigned< T, T >	ReadSLEB128 ()
template<typename T = intptr_t>
C::only_if_signed< T, T >	ReadSLEB128 ()
Public Member Functions inherited from dart::ValueObject
	ValueObject ()
	~ValueObject ()

Friends
class	Deserializer

Detailed Description

Definition at line 51 of file datastream.h.

Constructor & Destructor Documentation

ReadStream() [1/2]

dart::ReadStream::ReadStream ( const uint8_t *  buffer, intptr_t  size  )

inline

Definition at line 53 of file datastream.h.

      : buffer_(buffer), current_(buffer), end_(buffer + size) {}

ReadStream() [2/2]

dart::ReadStream::ReadStream ( const uint8_t *  buffer, intptr_t  size, intptr_t  pos  )

inline

Definition at line 57 of file datastream.h.

      : ReadStream(buffer, size) {
    SetPosition(pos);
  }

Member Function Documentation

AddressOfCurrentPosition()

const uint8_t * dart::ReadStream::AddressOfCurrentPosition ( ) const

inline

Definition at line 140 of file datastream.h.

{ return current_; }

Advance()

void dart::ReadStream::Advance ( intptr_t  value )

inline

Definition at line 142 of file datastream.h.

                               {
    ASSERT((end_ - current_) >= value);
    current_ = current_ + value;
  }

Align()

void dart::ReadStream::Align ( intptr_t  alignment, intptr_t  offset = 0  )

inline

Definition at line 133 of file datastream.h.

                                                      {
    intptr_t position_before = Position();
    intptr_t position_after =
        Utils::RoundUp(position_before, alignment, offset);
    Advance(position_after - position_before);
  }

PendingBytes()

intptr_t dart::ReadStream::PendingBytes ( ) const

inline

Definition at line 147 of file datastream.h.

                                {
    ASSERT(end_ >= current_);
    return (end_ - current_);
  }

Position()

intptr_t dart::ReadStream::Position ( ) const

inline

Definition at line 127 of file datastream.h.

{ return current_ - buffer_; }

Read()

template<typename T >

T dart::ReadStream::Read ( )

inline

Definition at line 153 of file datastream.h.

           {
    return Read<T>(kEndByteMarker);
  }

ReadBytes()

void dart::ReadStream::ReadBytes ( void *  addr, intptr_t  len  )

inline

Definition at line 90 of file datastream.h.

                                           {
    ASSERT((end_ - current_) >= len);
    if (len != 0) {
      memmove(addr, current_, len);
    }
    current_ += len;
  }

ReadLEB128() [1/2]

template<typename T = uintptr_t>

C::only_if_unsigned< T, T > dart::ReadStream::ReadLEB128 ( )

inline

Definition at line 173 of file datastream.h.

                                       {
    constexpr intptr_t kBitsPerT = kBitsPerByte * sizeof(T);
    T r = 0;
    uint8_t s = 0;
    uint8_t b;
    do {
      ASSERT(s < kBitsPerT);
      b = ReadByte();
      r |= static_cast<T>(b & C::kDataByteMask) << s;
      s += C::kDataBitsPerByte;
    } while ((b & C::kMoreDataMask) != 0);
    ASSERT(s < C::kDataBitsPerByte + kBitsPerT);
    return r;
  }

ReadLEB128() [2/2]

template<typename T >

C::only_if_signed< T, T > dart::ReadStream::ReadLEB128 ( )

inline

Definition at line 189 of file datastream.h.

                                     {
    return bit_cast<T>(ReadLEB128<typename std::make_unsigned<T>::type>());
  }

ReadRefId()

intptr_t dart::ReadStream::ReadRefId ( )

inline

Definition at line 103 of file datastream.h.

                       {
    const int8_t* cursor = reinterpret_cast<const int8_t*>(current_);
    intptr_t result = 0;
    intptr_t byte;
    // clang-format off
#define STAGE                                                                  \
    byte = *cursor++;              /* ldrsb byte, [result], 1  */              \
    result = byte + (result << 7); /* add result, byte, result lsl 7 */        \
    if (byte < 0) goto done;       /* tbnz byte, 63, done */
    STAGE  // 0-7
    STAGE  // 8-14
    STAGE  // 15-21
    STAGE  // 22-28
#undef STAGE
    ASSERT(byte < 0);  // 256MB is enough for anyone...
    // clang-format on
  done:
    current_ = reinterpret_cast<const uint8_t*>(cursor);
    // With big-endian order and the has-more marker being 0, the correction
    // factor to remove the last-byte marker is a constant, which can be folded
    // into subsequent load offsets.
    return result + 128;
  }

ReadSLEB128() [1/2]

template<typename T >

C::only_if_unsigned< T, T > dart::ReadStream::ReadSLEB128 ( )

inline

Definition at line 194 of file datastream.h.

                                        {
    constexpr intptr_t kBitsPerT = kBitsPerByte * sizeof(T);
    T r = 0;
    uint8_t s = 0;
    uint8_t b;
    do {
      ASSERT(s < kBitsPerT);
      b = ReadByte();
      r |= static_cast<T>(b & C::kDataByteMask) << s;
      s += C::kDataBitsPerByte;
    } while ((b & C::kMoreDataMask) != 0);
    ASSERT(s < C::kDataBitsPerByte + kBitsPerT);
    // At this point, [s] contains how many data bits have made it into the
    // value. If the value is negative and the count of data bits is less than
    // the size of the value, then we need to extend the sign by setting the
    // remaining (unset) most significant bits (MSBs).
    T sign_bits = 0;
    if ((b & C::kSignMask) != 0 && s < kBitsPerT) {
      // Create a bitmask for the current data bits and invert it.
      sign_bits = ~((static_cast<T>(1) << s) - 1);
    }
    return r | sign_bits;
  }

ReadSLEB128() [2/2]

template<typename T = intptr_t>

C::only_if_signed< T, T > dart::ReadStream::ReadSLEB128 ( )

inline

Definition at line 219 of file datastream.h.

                                      {
    return bit_cast<T>(ReadSLEB128<typename std::make_unsigned<T>::type>());
  }

ReadUnsigned()

template<typename T = intptr_t>

T dart::ReadStream::ReadUnsigned ( )

inline

Definition at line 99 of file datastream.h.

                   {
    return Read<T>(kEndUnsignedByteMarker);
  }

ReadWordWith32BitReads()

uword dart::ReadStream::ReadWordWith32BitReads ( )

inline

Definition at line 157 of file datastream.h.

                                 {
    constexpr intptr_t kNumRead32PerWord = kBitsPerWord / kBitsPerInt32;
 
    uword value = 0;
    for (intptr_t j = 0; j < kNumRead32PerWord; j++) {
      const auto partial_value = Raw<kInt32Size, uint32_t>::Read(this);
      value |= (static_cast<uword>(partial_value) << (j * kBitsPerInt32));
    }
    return value;
  }

SetPosition()

void dart::ReadStream::SetPosition ( intptr_t  value )

inline

Definition at line 128 of file datastream.h.

                                   {
    ASSERT((end_ - buffer_) >= value);
    current_ = buffer_ + value;
  }

Friends And Related Function Documentation

Deserializer

friend class Deserializer

friend

Definition at line 326 of file datastream.h.

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The documentation for this class was generated from the following file:

• third_party/dart-lang/sdk/runtime/vm/datastream.h