#include "common/ISegmentStream.h"

ISegmentStream::ISegmentStream()

{

streamLength = 0;

}

ISegmentStream::~ISegmentStream()

{

}

void ISegmentStream::AttachStream(IDataStream * inStream)

{

parent = inStream;

streamLength = 0;

streamOffset = 0;

}

void ISegmentStream::AddSegment(UInt64 offset, UInt64 length, UInt64 parentOffset)

{

segmentInfo.push_back(SegmentInfo(offset, length, parentOffset));

if(streamLength < (parentOffset + length))

streamLength = parentOffset + length;

}

void ISegmentStream::ReadBuf(void * buf, UInt32 inLength)

{

UInt32 remain = inLength;

UInt8 * out = (UInt8 *)buf;

while(remain > 0)

{

SegmentInfo * info = LookupInfo(streamOffset);

ASSERT(info);

UInt64 segmentOffset = streamOffset - info->offset;

UInt64 transferLength = info->length - segmentOffset;

if(transferLength > remain)

transferLength = remain;

parent->SetOffset(info->parentOffset + segmentOffset);

parent->ReadBuf(out, transferLength);

streamOffset += transferLength;

remain -= transferLength;

}

}

void ISegmentStream::WriteBuf(const void * buf, UInt32 inLength)

{

HALT("ISegmentStream::WriteBuf: writing unsupported");

}

void ISegmentStream::SetOffset(SInt64 inOffset)

{

SegmentInfo * info = LookupInfo(inOffset);

ASSERT(info);

UInt64 segmentOffset = inOffset - info->offset;

parent->SetOffset(info->parentOffset + segmentOffset);

streamOffset = inOffset;

}

ISegmentStream::SegmentInfo * ISegmentStream::LookupInfo(UInt64 offset)

{

for(SegmentInfoListType::iterator iter = segmentInfo.begin(); iter != segmentInfo.end(); iter++)

if((offset >= (*iter).offset) && (offset < (*iter).offset + (*iter).length))

return &(*iter);

return NULL;

}