C++ LLAPRFile::seek方法代码示例

bool LLLFSThread::Request::processRequest()
{
	bool complete = false;
	if (mOperation ==  FILE_READ)
	{
		llassert(mOffset >= 0);
		LLAPRFile infile ;
		infile.open(mFileName, LL_APR_RB, LLAPRFile::local);
		if (!infile.getFileHandle())
		{
			llwarns << "LLLFS: Unable to read file: " << mFileName << llendl;
			mBytesRead = 0; // fail
			return true;
		}
		S32 off;
		if (mOffset < 0)
			off = infile.seek(APR_END, 0);
		else
			off = infile.seek(APR_SET, mOffset);
		llassert_always(off >= 0);
		mBytesRead = infile.read(mBuffer, mBytes );
		complete = true;
		infile.close() ;
// 		llinfos << "LLLFSThread::READ:" << mFileName << " Bytes: " << mBytesRead << llendl;
	}
	else if (mOperation ==  FILE_WRITE)
	{
		apr_int32_t flags = APR_CREATE|APR_WRITE|APR_BINARY;
		if (mOffset < 0)
			flags |= APR_APPEND;
		LLAPRFile outfile ;
		outfile.open(mFileName, flags, LLAPRFile::local);
		if (!outfile.getFileHandle())
		{
			llwarns << "LLLFS: Unable to write file: " << mFileName << llendl;
			mBytesRead = 0; // fail
			return true;
		}
		if (mOffset >= 0)
		{
			S32 seek = outfile.seek(APR_SET, mOffset);
			if (seek < 0)
			{
				llwarns << "LLLFS: Unable to write file (seek failed): " << mFileName << llendl;
				mBytesRead = 0; // fail
				return true;
			}
		}
		mBytesRead = outfile.write(mBuffer, mBytes );
		complete = true;

// 		llinfos << "LLLFSThread::WRITE:" << mFileName << " Bytes: " << mBytesRead << "/" << mBytes << " Offset:" << mOffset << llendl;
	}
	else
	{
		llwarns << "LLLFSThread::unknown operation: " << (S32)mOperation << llendl;
	}
	return complete;
}

S32 check_for_invalid_wav_formats(const std::string& in_fname, std::string& error_msg)
{
	U16 num_channels = 0;
	U32 sample_rate = 0;
	U32 bits_per_sample = 0;
	U32 physical_file_size = 0;
	U32 chunk_length = 0;
	U32 raw_data_length = 0;
	U32 bytes_per_sec = 0;
	BOOL uncompressed_pcm = FALSE;

	unsigned char wav_header[44];		/*Flawfinder: ignore*/

	error_msg.clear();

	// ********************************
	LLAPRFile infile ;
	infile.open(in_fname,LL_APR_RB);
	// ********************************
	if (!infile.getFileHandle())
	{
		error_msg = "CannotUploadSoundFile";
		return(LLVORBISENC_SOURCE_OPEN_ERR);
	}

	infile.read(wav_header, 44);
	physical_file_size = infile.seek(APR_END,0);

	if (strncmp((char *)&(wav_header[0]),"RIFF",4))
	{
		error_msg = "SoundFileNotRIFF";
		return(LLVORBISENC_WAV_FORMAT_ERR);
	}

	if (strncmp((char *)&(wav_header[8]),"WAVE",4))
	{
		error_msg = "SoundFileNotRIFF";
		return(LLVORBISENC_WAV_FORMAT_ERR);
	}
	
	// parse the chunks
	
	U32 file_pos = 12;  // start at the first chunk (usually fmt but not always)
	
	while ((file_pos + 8)< physical_file_size)
	{
		infile.seek(APR_SET,file_pos);
		infile.read(wav_header, 44);

		chunk_length = ((U32) wav_header[7] << 24) 
			+ ((U32) wav_header[6] << 16) 
			+ ((U32) wav_header[5] << 8) 
			+ wav_header[4];

		if (chunk_length > physical_file_size - file_pos - 4)
		{
			infile.close();
			error_msg = "SoundFileInvalidChunkSize";
			return(LLVORBISENC_CHUNK_SIZE_ERR);
		}

//		llinfos << "chunk found: '" << wav_header[0] << wav_header[1] << wav_header[2] << wav_header[3] << "'" << llendl;

		if (!(strncmp((char *)&(wav_header[0]),"fmt ",4)))
		{
			if ((wav_header[8] == 0x01) && (wav_header[9] == 0x00))
			{
				uncompressed_pcm = TRUE;
			}
			num_channels = ((U16) wav_header[11] << 8) + wav_header[10];
			sample_rate = ((U32) wav_header[15] << 24) 
				+ ((U32) wav_header[14] << 16) 
				+ ((U32) wav_header[13] << 8) 
				+ wav_header[12];
			bits_per_sample = ((U16) wav_header[23] << 8) + wav_header[22];
			bytes_per_sec = ((U32) wav_header[19] << 24) 
				+ ((U32) wav_header[18] << 16) 
				+ ((U32) wav_header[17] << 8) 
				+ wav_header[16];
		}
		else if (!(strncmp((char *)&(wav_header[0]),"data",4)))
		{
			raw_data_length = chunk_length;			
		}
		file_pos += (chunk_length + 8);
		chunk_length = 0;
	} 
	// ****************
	infile.close();
	// ****************

	if (!uncompressed_pcm)
	{	
		 error_msg = "SoundFileNotPCM";
		  return(LLVORBISENC_PCM_FORMAT_ERR);
	}
	
	if ((num_channels < 1) || (num_channels > LLVORBIS_CLIP_MAX_CHANNELS))
	{	
		error_msg = "SoundFileInvalidChannelCount";
//.........这里部分代码省略.........

S32 encode_vorbis_file(const std::string& in_fname, const std::string& out_fname)
{
#define READ_BUFFER 1024
	unsigned char readbuffer[READ_BUFFER*4+44];   /* out of the data segment, not the stack */	/*Flawfinder: ignore*/

	ogg_stream_state os; /* take physical pages, weld into a logical stream of packets */
	ogg_page         og; /* one Ogg bitstream page.  Vorbis packets are inside */
	ogg_packet       op; /* one raw packet of data for decode */
	
	vorbis_info      vi; /* struct that stores all the static vorbis bitstream settings */
	vorbis_comment   vc; /* struct that stores all the user comments */
	
	vorbis_dsp_state vd; /* central working state for the packet->PCM decoder */
	vorbis_block     vb; /* local working space for packet->PCM decode */
	
	int eos=0;
	int result;

	U16 num_channels = 0;
	U32 sample_rate = 0;
	U32 bits_per_sample = 0;

	S32 format_error = 0;
	std::string error_msg;
	if ((format_error = check_for_invalid_wav_formats(in_fname, error_msg)))
	{
		llwarns << error_msg << ": " << in_fname << llendl;
		return(format_error);
	}

#if 1
	unsigned char wav_header[44];	/*Flawfinder: ignore*/

	S32 data_left = 0;

	LLAPRFile infile ;
	infile.open(in_fname,LL_APR_RB);
	if (!infile.getFileHandle())
	{
		llwarns << "Couldn't open temporary ogg file for writing: " << in_fname
			<< llendl;
		return(LLVORBISENC_SOURCE_OPEN_ERR);
	}

	LLAPRFile outfile ;
	outfile.open(out_fname,LL_APR_WPB);
	if (!outfile.getFileHandle())
	{
		llwarns << "Couldn't open upload sound file for reading: " << in_fname
			<< llendl;
		return(LLVORBISENC_DEST_OPEN_ERR);
	}
	
	 // parse the chunks
	 U32 chunk_length = 0;
	 U32 file_pos = 12;  // start at the first chunk (usually fmt but not always)
	 
	 while (infile.eof() != APR_EOF)
	 {
		 infile.seek(APR_SET,file_pos);
		 infile.read(wav_header, 44);
		 
		 chunk_length = ((U32) wav_header[7] << 24) 
			 + ((U32) wav_header[6] << 16) 
			 + ((U32) wav_header[5] << 8) 
			 + wav_header[4];
		 
//		 llinfos << "chunk found: '" << wav_header[0] << wav_header[1] << wav_header[2] << wav_header[3] << "'" << llendl;
		 
		 if (!(strncmp((char *)&(wav_header[0]),"fmt ",4)))
		 {
			 num_channels = ((U16) wav_header[11] << 8) + wav_header[10];
			 sample_rate = ((U32) wav_header[15] << 24) 
				 + ((U32) wav_header[14] << 16) 
				 + ((U32) wav_header[13] << 8) 
				 + wav_header[12];
			 bits_per_sample = ((U16) wav_header[23] << 8) + wav_header[22];
		 }
	 	 else if (!(strncmp((char *)&(wav_header[0]),"data",4)))
		 {
			 infile.seek(APR_SET,file_pos+8);
			 // leave the file pointer at the beginning of the data chunk data
			 data_left = chunk_length;			
			 break;
		 }
		 file_pos += (chunk_length + 8);
		 chunk_length = 0;
	 } 
	 

	 /********** Encode setup ************/
	 
	 /* choose an encoding mode */
	 /* (mode 0: 44kHz stereo uncoupled, roughly 128kbps VBR) */
	 vorbis_info_init(&vi);

	 // always encode to mono

	 // SL-52913 & SL-53779 determined this quality level to be our 'good
	 // enough' general-purpose quality level with a nice low bitrate.
//.........这里部分代码省略.........