BansheeEngine/CamelotUtility/Source/CmDataStream.cpp

#include "CmDataStream.h"
#include "CmDebug.h"
#include "CmException.h"

namespace CamelotFramework 
{
    template <typename T> DataStream& DataStream::operator >>(T& val)
    {
        read(static_cast<void*>(&val), sizeof(T));
        return *this;
    }

    String DataStream::getLine(bool trimAfter)
    {
        char tmpBuf[OGRE_STREAM_TEMP_SIZE];
        String retString;
        size_t readCount;
        // Keep looping while not hitting delimiter
        while ((readCount = read(tmpBuf, OGRE_STREAM_TEMP_SIZE-1)) != 0)
        {
            // Terminate string
            tmpBuf[readCount] = '\0';

            char* p = strchr(tmpBuf, '\n');
            if (p != 0)
            {
                // Reposition backwards
                skip((long)(p + 1 - tmpBuf - readCount));
                *p = '\0';
            }

            retString += tmpBuf;

            if (p != 0)
            {
                // Trim off trailing CR if this was a CR/LF entry
                if (retString.length() && retString[retString.length()-1] == '\r')
                {
                    retString.erase(retString.length()-1, 1);
                }

                // Found terminator, break out
                break;
            }
        }

        if (trimAfter)
        {
            StringUtil::trim(retString);
        }

        return retString;
    }

    size_t DataStream::readLine(char* buf, size_t maxCount, const String& delim)
    {
		// Deal with both Unix & Windows LFs
		bool trimCR = false;
		if (delim.find_first_of('\n') != String::npos)
		{
			trimCR = true;
		}

        char tmpBuf[OGRE_STREAM_TEMP_SIZE];
        size_t chunkSize = std::min(maxCount, (size_t)OGRE_STREAM_TEMP_SIZE-1);
        size_t totalCount = 0;
        size_t readCount; 
        while (chunkSize && (readCount = read(tmpBuf, chunkSize)) != 0)
        {
            // Terminate
            tmpBuf[readCount] = '\0';

            // Find first delimiter
            size_t pos = strcspn(tmpBuf, delim.c_str());

            if (pos < readCount)
            {
                // Found terminator, reposition backwards
                skip((long)(pos + 1 - readCount));
            }

            // Are we genuinely copying?
            if (buf)
            {
                memcpy(buf+totalCount, tmpBuf, pos);
            }
            totalCount += pos;

            if (pos < readCount)
            {
                // Trim off trailing CR if this was a CR/LF entry
                if (trimCR && totalCount && buf[totalCount-1] == '\r')
                {
                    --totalCount;
                }

                // Found terminator, break out
                break;
            }

            // Adjust chunkSize for next time
            chunkSize = std::min(maxCount-totalCount, (size_t)OGRE_STREAM_TEMP_SIZE-1);
        }

        // Terminate
        buf[totalCount] = '\0';

        return totalCount;
    }

    size_t DataStream::skipLine(const String& delim)
    {
        char tmpBuf[OGRE_STREAM_TEMP_SIZE];
        size_t total = 0;
        size_t readCount;
        // Keep looping while not hitting delimiter
        while ((readCount = read(tmpBuf, OGRE_STREAM_TEMP_SIZE-1)) != 0)
        {
            // Terminate string
            tmpBuf[readCount] = '\0';

            // Find first delimiter
            size_t pos = strcspn(tmpBuf, delim.c_str());

            if (pos < readCount)
            {
                // Found terminator, reposition backwards
                skip((long)(pos + 1 - readCount));

                total += pos + 1;

                // break out
                break;
            }

            total += readCount;
        }

        return total;
    }

    String DataStream::getAsString()
    {
        // Read the entire buffer - ideally in one read, but if the size of
        // the buffer is unknown, do multiple fixed size reads.
        size_t bufSize = (mSize > 0 ? mSize : 4096);
        char* pBuf = (char*)malloc(sizeof(char) * bufSize);
        // Ensure read from begin of stream
        seek(0);
        String result;
        while (!eof())
        {
            size_t nr = read(pBuf, bufSize);
            result.append(pBuf, nr);
        }
        free(pBuf);
        return result;
    }

    MemoryDataStream::MemoryDataStream(void* pMem, size_t inSize, bool freeOnClose, bool readOnly)
		: DataStream(static_cast<UINT16>(readOnly ? READ : (READ | WRITE)))
    {
        mData = mPos = static_cast<UINT8*>(pMem);
        mSize = inSize;
        mEnd = mData + mSize;
        mFreeOnClose = freeOnClose;
        assert(mEnd >= mPos);
    }

    MemoryDataStream::MemoryDataStream(const String& name, void* pMem, size_t inSize, 
        bool freeOnClose, bool readOnly)
        : DataStream(name, static_cast<UINT16>(readOnly ? READ : (READ | WRITE)))
    {
        mData = mPos = static_cast<UINT8*>(pMem);
        mSize = inSize;
        mEnd = mData + mSize;
        mFreeOnClose = freeOnClose;
        assert(mEnd >= mPos);
    }

    MemoryDataStream::MemoryDataStream(DataStream& sourceStream, 
        bool freeOnClose, bool readOnly)
        : DataStream(static_cast<UINT16>(readOnly ? READ : (READ | WRITE)))
    {
        // Copy data from incoming stream
        mSize = sourceStream.size();
        if (mSize == 0 && !sourceStream.eof())
        {
            // size of source is unknown, read all of it into memory
            String contents = sourceStream.getAsString();
            mSize = contents.size();
            mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
            mPos = mData;
            memcpy(mData, contents.data(), mSize);
            mEnd = mData + mSize;
        }
        else
        {
            mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
            mPos = mData;
            mEnd = mData + sourceStream.read(mData, mSize);
            mFreeOnClose = freeOnClose;
        }
        assert(mEnd >= mPos);
    }

    MemoryDataStream::MemoryDataStream(DataStreamPtr& sourceStream, 
        bool freeOnClose, bool readOnly)
        : DataStream(static_cast<UINT16>(readOnly ? READ : (READ | WRITE)))
    {
        // Copy data from incoming stream
        mSize = sourceStream->size();
        if (mSize == 0 && !sourceStream->eof())
        {
            // size of source is unknown, read all of it into memory
            String contents = sourceStream->getAsString();
            mSize = contents.size();
            mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
            mPos = mData;
            memcpy(mData, contents.data(), mSize);
            mEnd = mData + mSize;
        }
        else
        {
            mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
            mPos = mData;
            mEnd = mData + sourceStream->read(mData, mSize);
            mFreeOnClose = freeOnClose;
        }
        assert(mEnd >= mPos);
    }

    MemoryDataStream::MemoryDataStream(const String& name, DataStream& sourceStream, 
        bool freeOnClose, bool readOnly)
        : DataStream(name, static_cast<UINT16>(readOnly ? READ : (READ | WRITE)))
    {
        // Copy data from incoming stream
        mSize = sourceStream.size();
        if (mSize == 0 && !sourceStream.eof())
        {
            // size of source is unknown, read all of it into memory
            String contents = sourceStream.getAsString();
            mSize = contents.size();
            mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
            mPos = mData;
            memcpy(mData, contents.data(), mSize);
            mEnd = mData + mSize;
        }
        else
        {
            mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
            mPos = mData;
            mEnd = mData + sourceStream.read(mData, mSize);
            mFreeOnClose = freeOnClose;
        }
        assert(mEnd >= mPos);
    }

    MemoryDataStream::MemoryDataStream(const String& name, const DataStreamPtr& sourceStream, 
        bool freeOnClose, bool readOnly)
        : DataStream(name, static_cast<UINT16>(readOnly ? READ : (READ | WRITE)))
    {
        // Copy data from incoming stream
        mSize = sourceStream->size();
        if (mSize == 0 && !sourceStream->eof())
        {
            // size of source is unknown, read all of it into memory
            String contents = sourceStream->getAsString();
            mSize = contents.size();
            mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
            mPos = mData;
            memcpy(mData, contents.data(), mSize);
            mEnd = mData + mSize;
        }
        else
        {
            mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
            mPos = mData;
            mEnd = mData + sourceStream->read(mData, mSize);
            mFreeOnClose = freeOnClose;
        }
        assert(mEnd >= mPos);
    }

    MemoryDataStream::MemoryDataStream(size_t inSize, bool freeOnClose, bool readOnly)
        : DataStream(static_cast<UINT16>(readOnly ? READ : (READ | WRITE)))
    {
        mSize = inSize;
        mFreeOnClose = freeOnClose;
        mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
        mPos = mData;
        mEnd = mData + mSize;
        assert(mEnd >= mPos);
    }

    MemoryDataStream::MemoryDataStream(const String& name, size_t inSize, 
        bool freeOnClose, bool readOnly)
        : DataStream(name, static_cast<UINT16>(readOnly ? READ : (READ | WRITE)))
    {
        mSize = inSize;
        mFreeOnClose = freeOnClose;
        mData = (UINT8*)malloc(sizeof(UINT8) * mSize);
        mPos = mData;
        mEnd = mData + mSize;
        assert(mEnd >= mPos);
    }

    MemoryDataStream::~MemoryDataStream()
    {
        close();
    }

    size_t MemoryDataStream::read(void* buf, size_t count)
    {
        size_t cnt = count;
        // Read over end of memory?
        if (mPos + cnt > mEnd)
            cnt = mEnd - mPos;
        if (cnt == 0)
            return 0;

        assert (cnt<=count);

        memcpy(buf, mPos, cnt);
        mPos += cnt;
        return cnt;
    }

	size_t MemoryDataStream::write(const void* buf, size_t count)
	{
		size_t written = 0;
		if (isWriteable())
		{
			written = count;
			// we only allow writing within the extents of allocated memory
			// check for buffer overrun & disallow
			if (mPos + written > mEnd)
				written = mEnd - mPos;
			if (written == 0)
				return 0;

			memcpy(mPos, buf, written);
			mPos += written;
		}
		return written;
	}

    size_t MemoryDataStream::readLine(char* buf, size_t maxCount, const String& delim)
    {
        // Deal with both Unix & Windows LFs
		bool trimCR = false;
		if (delim.find_first_of('\n') != String::npos)
		{
			trimCR = true;
		}

        size_t pos = 0;

        // Make sure pos can never go past the end of the data 
        while (pos < maxCount && mPos < mEnd)
        {
            if (delim.find(*mPos) != String::npos)
            {
                // Trim off trailing CR if this was a CR/LF entry
                if (trimCR && pos && buf[pos-1] == '\r')
                {
                    // terminate 1 character early
                    --pos;
                }

                // Found terminator, skip and break out
                ++mPos;
                break;
            }

            buf[pos++] = *mPos++;
        }

        // terminate
        buf[pos] = '\0';

        return pos;
    }

    size_t MemoryDataStream::skipLine(const String& delim)
    {
        size_t pos = 0;

        // Make sure pos can never go past the end of the data 
        while (mPos < mEnd)
        {
            ++pos;
            if (delim.find(*mPos++) != String::npos)
            {
                // Found terminator, break out
                break;
            }
        }

        return pos;

    }

    void MemoryDataStream::skip(long count)
    {
        size_t newpos = (size_t)( ( mPos - mData ) + count );
        assert( mData + newpos <= mEnd );        

        mPos = mData + newpos;
    }

    void MemoryDataStream::seek( size_t pos )
    {
        assert( mData + pos <= mEnd );
        mPos = mData + pos;
    }

    size_t MemoryDataStream::tell(void) const
	{
		//mData is start, mPos is current location
		return mPos - mData;
	}

    bool MemoryDataStream::eof(void) const
    {
        return mPos >= mEnd;
    }

    void MemoryDataStream::close(void)    
    {
        if (mFreeOnClose && mData)
        {
            free(mData);
            mData = 0;
        }
    }

    FileDataStream::FileDataStream(std::shared_ptr<std::ifstream> s, bool freeOnClose)
        : DataStream(), mpInStream(s), mpFStreamRO(s), mpFStream(0), mFreeOnClose(freeOnClose)
    {
        // calculate the size
        mpInStream->seekg(0, std::ios_base::end);
        mSize = (size_t)mpInStream->tellg();
        mpInStream->seekg(0, std::ios_base::beg);
		determineAccess();
    }

    FileDataStream::FileDataStream(const String& name, 
        std::shared_ptr<std::ifstream> s, bool freeOnClose)
        : DataStream(name), mpInStream(s), mpFStreamRO(s), mpFStream(0), mFreeOnClose(freeOnClose)
    {
        // calculate the size
        mpInStream->seekg(0, std::ios_base::end);
        mSize = (size_t)mpInStream->tellg();
        mpInStream->seekg(0, std::ios_base::beg);
		determineAccess();
    }

    FileDataStream::FileDataStream(const String& name, 
        std::shared_ptr<std::ifstream> s, size_t inSize, bool freeOnClose)
        : DataStream(name), mpInStream(s), mpFStreamRO(s), mpFStream(0), mFreeOnClose(freeOnClose)
    {
        // Size is passed in
        mSize = inSize;
		determineAccess();
    }

	FileDataStream::FileDataStream(std::shared_ptr<std::fstream> s, bool freeOnClose)
		: DataStream(false), mpInStream(s), mpFStreamRO(0), mpFStream(s), mFreeOnClose(freeOnClose)
	{
		// writeable!
		// calculate the size
		mpInStream->seekg(0, std::ios_base::end);
		mSize = (size_t)mpInStream->tellg();
		mpInStream->seekg(0, std::ios_base::beg);
		determineAccess();

	}

	FileDataStream::FileDataStream(const String& name, 
		std::shared_ptr<std::fstream> s, bool freeOnClose)
		: DataStream(name, false), mpInStream(s), mpFStreamRO(0), mpFStream(s), mFreeOnClose(freeOnClose)
	{
		// writeable!
		// calculate the size
		mpInStream->seekg(0, std::ios_base::end);
		mSize = (size_t)mpInStream->tellg();
		mpInStream->seekg(0, std::ios_base::beg);
		determineAccess();
	}

	FileDataStream::FileDataStream(const String& name, 
		std::shared_ptr<std::fstream> s, size_t inSize, bool freeOnClose)
		: DataStream(name, false), mpInStream(s), mpFStreamRO(0), mpFStream(s), mFreeOnClose(freeOnClose)
	{
		// writeable!
		// Size is passed in
		mSize = inSize;
		determineAccess();
	}

	void FileDataStream::determineAccess()
	{
		mAccess = 0;
		if (mpInStream)
			mAccess |= READ;
		if (mpFStream)
			mAccess |= WRITE;
	}

    FileDataStream::~FileDataStream()
    {
        close();
    }

    size_t FileDataStream::read(void* buf, size_t count)
    {
		mpInStream->read(static_cast<char*>(buf), static_cast<std::streamsize>(count));
        return (size_t)mpInStream->gcount();
    }

	size_t FileDataStream::write(const void* buf, size_t count)
	{
		size_t written = 0;
		if (isWriteable() && mpFStream)
		{
			mpFStream->write(static_cast<const char*>(buf), static_cast<std::streamsize>(count));
			written = count;
		}
		return written;
	}

    size_t FileDataStream::readLine(char* buf, size_t maxCount,  const String& delim)
    {
		if (delim.empty())
		{
			CM_EXCEPT(InvalidParametersException, "No delimiter provided");
		}
		if (delim.size() > 1)
		{
			gDebug().log("WARNING: FileStreamDataStream::readLine - using only first delimeter", "DataStream");
		}
		// Deal with both Unix & Windows LFs
		bool trimCR = false;
		if (delim.at(0) == '\n') 
		{
			trimCR = true;
		}
		// maxCount + 1 since count excludes terminator in getline
		mpInStream->getline(buf, static_cast<std::streamsize>(maxCount+1), delim.at(0));
		size_t ret = (size_t)mpInStream->gcount();
		// three options
		// 1) we had an eof before we read a whole line
		// 2) we ran out of buffer space
		// 3) we read a whole line - in this case the delim character is taken from the stream but not written in the buffer so the read data is of length ret-1 and thus ends at index ret-2
		// in all cases the buffer will be null terminated for us

		if (mpInStream->eof()) 
		{
			// no problem
		}
		else if (mpInStream->fail())
		{
			// Did we fail because of maxCount hit? No - no terminating character
			// in included in the count in this case
			if (ret == maxCount)
			{
				// clear failbit for next time 
				mpInStream->clear();
			}
			else
			{
				CM_EXCEPT(InternalErrorException, "Streaming error occurred");
			}
		}
		else 
		{
			// we need to adjust ret because we want to use it as a
			// pointer to the terminating null character and it is
			// currently the length of the data read from the stream
			// i.e. 1 more than the length of the data in the buffer and
			// hence 1 more than the _index_ of the NULL character
			--ret;
		}

		// trim off CR if we found CR/LF
		if (trimCR && buf[ret-1] == '\r')
		{
			--ret;
			buf[ret] = '\0';
		}
		return ret;
	}

    void FileDataStream::skip(long count)
    {
#if defined(STLPORT)
		// Workaround for STLport issues: After reached eof of file stream,
		// it's seems the stream was putted in intermediate state, and will be
		// fail if try to repositioning relative to current position.
		// Note: tellg() fail in this case too.
		if (mpInStream->eof())
		{
			mpInStream->clear();
			// Use seek relative to either begin or end to bring the stream
			// back to normal state.
			mpInStream->seekg(0, std::ios::end);
		}
#endif 		
		mpInStream->clear(); //Clear fail status in case eof was set
		mpInStream->seekg(static_cast<std::ifstream::pos_type>(count), std::ios::cur);
    }

    void FileDataStream::seek( size_t pos )
    {
		mpInStream->clear(); //Clear fail status in case eof was set
		mpInStream->seekg(static_cast<std::streamoff>(pos), std::ios::beg);
	}

    size_t FileDataStream::tell(void) const
	{
		mpInStream->clear(); //Clear fail status in case eof was set
		return (size_t)mpInStream->tellg();
	}

    bool FileDataStream::eof(void) const
    {
        return mpInStream->eof();
    }

    void FileDataStream::close(void)
    {
        if (mpInStream)
        {
			// Unfortunately, there is no file-specific shared class hierarchy between fstream and ifstream (!!)
			if (mpFStreamRO)
	            mpFStreamRO->close();
			if (mpFStream)
			{
				mpFStream->flush();
				mpFStream->close();
			}

            if (mFreeOnClose)
            {
				mpInStream = nullptr;
				mpFStreamRO = nullptr; 
				mpFStream = nullptr; 
            }
        }
    }
}