p7zip-rar/CPP/7zip/IStream.h
2017-10-11 12:40:22 +02:00

128 lines
3.6 KiB
C

// IStream.h
#ifndef __ISTREAM_H
#define __ISTREAM_H
#include "../Common/MyTypes.h"
#include "../Common/MyWindows.h"
#include "IDecl.h"
#define STREAM_INTERFACE_SUB(i, base, x) DECL_INTERFACE_SUB(i, base, 3, x)
#define STREAM_INTERFACE(i, x) STREAM_INTERFACE_SUB(i, IUnknown, x)
STREAM_INTERFACE(ISequentialInStream, 0x01)
{
STDMETHOD(Read)(void *data, UInt32 size, UInt32 *processedSize) PURE;
/*
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().
*/
};
STREAM_INTERFACE(ISequentialOutStream, 0x02)
{
STDMETHOD(Write)(const void *data, UInt32 size, UInt32 *processedSize) PURE;
/*
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.
*/
};
#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
/* Seek() Function
If you seek 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.
*/
STREAM_INTERFACE_SUB(IInStream, ISequentialInStream, 0x03)
{
STDMETHOD(Seek)(Int64 offset, UInt32 seekOrigin, UInt64 *newPosition) PURE;
};
STREAM_INTERFACE_SUB(IOutStream, ISequentialOutStream, 0x04)
{
STDMETHOD(Seek)(Int64 offset, UInt32 seekOrigin, UInt64 *newPosition) PURE;
STDMETHOD(SetSize)(UInt64 newSize) PURE;
};
STREAM_INTERFACE(IStreamGetSize, 0x06)
{
STDMETHOD(GetSize)(UInt64 *size) PURE;
};
STREAM_INTERFACE(IOutStreamFinish, 0x07)
{
STDMETHOD(OutStreamFinish)() PURE;
};
STREAM_INTERFACE(IStreamGetProps, 0x08)
{
STDMETHOD(GetProps)(UInt64 *size, FILETIME *cTime, FILETIME *aTime, FILETIME *mTime, UInt32 *attrib) PURE;
};
struct CStreamFileProps
{
UInt64 Size;
UInt64 VolID;
UInt64 FileID_Low;
UInt64 FileID_High;
UInt32 NumLinks;
UInt32 Attrib;
FILETIME CTime;
FILETIME ATime;
FILETIME MTime;
};
STREAM_INTERFACE(IStreamGetProps2, 0x09)
{
STDMETHOD(GetProps2)(CStreamFileProps *props) PURE;
};
#endif