xref: /third_party/lzma/CPP/7zip/IStream.h (revision 370b324c)

// IStream.h

#ifndef ZIP7_INC_ISTREAM_H
#define ZIP7_INC_ISTREAM_H

#include "../Common/MyTypes.h"
#include "../Common/MyWindows.h"

#include "IDecl.h"

Z7_PURE_INTERFACES_BEGIN

#define Z7_IFACE_CONSTR_STREAM_SUB(i, base, n) \
  Z7_DECL_IFACE_7ZIP_SUB(i, base, 3, n) \
  { Z7_IFACE_COM7_PURE(i) };

#define Z7_IFACE_CONSTR_STREAM(i, n) \
        Z7_IFACE_CONSTR_STREAM_SUB(i, IUnknown, n)


/*
ISequentialInStream::Read()
  The requirement for caller: (processedSize != NULL).
  The callee can allow (processedSize == NULL) for compatibility reasons.

  if (size == 0), this function returns S_OK and (*processedSize) is set to 0.

  if (size != 0)
  {
    Partial read is allowed: (*processedSize <= avail_size && *processedSize <= size),
      where (avail_size) is the size of remaining bytes in stream.
    If (avail_size != 0), this function must read at least 1 byte: (*processedSize > 0).
    You must call Read() in loop, if you need to read exact amount of data.
  }

  If seek pointer before Read() call was changed to position past the end of stream:
    if (seek_pointer >= stream_size), this function returns S_OK and (*processedSize) is set to 0.

  ERROR CASES:
    If the function returns error code, then (*processedSize) is size of
    data written to (data) buffer (it can be data before error or data with errors).
    The recommended way for callee to work with reading errors:
      1) write part of data before error to (data) buffer and return S_OK.
      2) return error code for further calls of Read().
*/
#define Z7_IFACEM_ISequentialInStream(x) \
  x(Read(void *data, UInt32 size, UInt32 *processedSize))
Z7_IFACE_CONSTR_STREAM(ISequentialInStream, 0x01)


/*
ISequentialOutStream::Write()
  The requirement for caller: (processedSize != NULL).
  The callee can allow (processedSize == NULL) for compatibility reasons.

  if (size != 0)
  {
    Partial write is allowed: (*processedSize <= size),
    but this function must write at least 1 byte: (*processedSize > 0).
    You must call Write() in loop, if you need to write exact amount of data.
  }

  ERROR CASES:
    If the function returns error code, then (*processedSize) is size of
    data written from (data) buffer.
*/
#define Z7_IFACEM_ISequentialOutStream(x) \
  x(Write(const void *data, UInt32 size, UInt32 *processedSize))
Z7_IFACE_CONSTR_STREAM(ISequentialOutStream, 0x02)


#ifdef _WIN32

#ifdef __HRESULT_FROM_WIN32
#define HRESULT_WIN32_ERROR_NEGATIVE_SEEK __HRESULT_FROM_WIN32(ERROR_NEGATIVE_SEEK)
#else
#define HRESULT_WIN32_ERROR_NEGATIVE_SEEK   HRESULT_FROM_WIN32(ERROR_NEGATIVE_SEEK)
#endif

#else

#define HRESULT_WIN32_ERROR_NEGATIVE_SEEK   MY_E_ERROR_NEGATIVE_SEEK

#endif


/*
IInStream::Seek() / IOutStream::Seek()
  If you seek to position before the beginning of the stream,
  Seek() function returns error code:
      Recommended error code is __HRESULT_FROM_WIN32(ERROR_NEGATIVE_SEEK).
      or STG_E_INVALIDFUNCTION
  It is allowed to seek past the end of the stream.
  if Seek() returns error, then the value of *newPosition is undefined.
*/

#define Z7_IFACEM_IInStream(x) \
  x(Seek(Int64 offset, UInt32 seekOrigin, UInt64 *newPosition))
Z7_IFACE_CONSTR_STREAM_SUB(IInStream, ISequentialInStream, 0x03)

#define Z7_IFACEM_IOutStream(x) \
  x(Seek(Int64 offset, UInt32 seekOrigin, UInt64 *newPosition)) \
  x(SetSize(UInt64 newSize))
Z7_IFACE_CONSTR_STREAM_SUB(IOutStream, ISequentialOutStream, 0x04)

#define Z7_IFACEM_IStreamGetSize(x) \
  x(GetSize(UInt64 *size))
Z7_IFACE_CONSTR_STREAM(IStreamGetSize, 0x06)

#define Z7_IFACEM_IOutStreamFinish(x) \
  x(OutStreamFinish())
Z7_IFACE_CONSTR_STREAM(IOutStreamFinish, 0x07)

#define Z7_IFACEM_IStreamGetProps(x) \
  x(GetProps(UInt64 *size, FILETIME *cTime, FILETIME *aTime, FILETIME *mTime, UInt32 *attrib))
Z7_IFACE_CONSTR_STREAM(IStreamGetProps, 0x08)


struct CStreamFileProps
{
  UInt64 Size;
  UInt64 VolID;
  UInt64 FileID_Low;
  UInt64 FileID_High;
  UInt32 NumLinks;
  UInt32 Attrib;
  FILETIME CTime;
  FILETIME ATime;
  FILETIME MTime;
};


#define Z7_IFACEM_IStreamGetProps2(x) \
  x(GetProps2(CStreamFileProps *props))
Z7_IFACE_CONSTR_STREAM(IStreamGetProps2, 0x09)

#define Z7_IFACEM_IStreamGetProp(x) \
  x(GetProperty(PROPID propID, PROPVARIANT *value)) \
  x(ReloadProps())
Z7_IFACE_CONSTR_STREAM(IStreamGetProp, 0x0a)


/*
IStreamSetRestriction::SetRestriction(UInt64 begin, UInt64 end)

  It sets region of data in output stream that is restricted.
  For restricted region it's expected (or allowed)
  to change data with different calls of Write()/SetSize().
  Another regions of output stream will be supposed as non-restricted:
    - The callee usually doesn't flush the data in restricted region.
    - The callee usually can flush data from non-restricted region.

inputs:

  (begin > end) is not allowed, and returns E_FAIL;

  if (begin == end)
  {
    it means that there is no region restriction for flushing.
    The callee is allowed to flush already written data and
    is allowed to flush all data in future calls of
    ISequentialOutStream::Write(), but before next call of SetRestriction().
    The pair of values (begin == 0 && end == 0) is recommended to
    remove all restrictions.
  }

  if (begin < end)
  {
    it means that callee must NOT to flush any data in region [begin, end).
    The caller is allowed to Seek() to that region and rewrite the
    data in that restriction region.
    if (end == (UInt64(Int64)-1)
    {
      there is no upper bound for restricted region.
      So non-restricted region will be [0, begin) in that case
    }

    Note: it's not expected that some already written region was marked as
    non-restricted by old call SetRestriction() and later the part of
    that region was marked as restricted with new call SetRestriction().
    For example, for different calls with non-empty restricted regions:
     (begin_new >= begin_old) is expected :
     {
       SetRestriction(begin_old, ...)
       ...
       SetRestriction(begin_new, ...)
     }
  }

 returns:
  - if (begin > end) it return ERROR code (E_FAIL)
  - S_OK : if no errors.
  - Also the call of SetRestriction() can initiate the flushing of already written data.
    So it can return the result of that flushing.

 Note: IOutStream::SetSize() also can change the data.
    So it's not expected the call
    IOutStream::SetSize() to unrestricted already written region.
*/

#define Z7_IFACEM_IStreamSetRestriction(x) \
  x(SetRestriction(UInt64 begin, UInt64 end)) \

Z7_IFACE_CONSTR_STREAM(IStreamSetRestriction, 0x10)

Z7_PURE_INTERFACES_END
#endif