/*
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * Copyright (c) 1999-2001 Apple Computer, Inc.  All Rights Reserved. The
 * contents of this file constitute Original Code as defined in and are
 * subject to the Apple Public Source License Version 1.2 (the 'License').
 * You may not use this file except in compliance with the License.  Please
 * obtain a copy of the License at http://www.apple.com/publicsource and
 * read it before using this file.
 *
 * This Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.  Please
 * see the License for the specific language governing rights and
 * limitations under the License.
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 * @APPLE_LICENSE_HEADER_END@
 *
 */
/*
	File:		osfile.cpp

	Contains:	simple file abstraction
					
	
	
	
*/

#include <stdio.h>
#include <string.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>

#ifndef __Win32__
#include <unistd.h>
#endif

#include "OSFileSource.h"
#include "OSMemory.h"
#include "OSThread.h"
#include "OS.h"
#include "OSQueue.h"

#if __MACOS__
#include "OSArrayObjectDeleter.h"
#endif

#define FILE_SOURCE_DEBUG 0
#define FILE_SOURCE_BUFFTEST 0
#define TEST_TIME 0

#if TEST_TIME
static SInt64 startTime = 0;
static SInt64 durationTime = 0;
static SInt32 sReadCount = 0;
static SInt32 sByteCount = 0;
static Bool16 sMovie = false;

#endif


#if READ_LOG
extern UInt32 xTrackID;
void OSFileSource::SetLog(const char *inPath)
{
	fFilePath[0] =0;
	::strcpy(fFilePath,inPath);
	
	if (fFile != -1 && fFileLog == NULL)
	{
		::strcat(fFilePath,inPath);
		::strcat(fFilePath,".readlog");
		fFileLog = ::fopen(fFilePath,"w+");
		if (fFileLog && IsValid())
		{	::fprintf(fFileLog, "%s","QTFILE_READ_LOG\n");
			::fprintf(fFileLog, "size: %qu\n",GetLength());
			printf("OSFileSource::SetLog=%s\n",fFilePath);
			
		}
		::fclose(fFileLog);
	}
}
#else
void OSFileSource::SetLog(const char *inPath)
{

#if FILE_SOURCE_DEBUG
	printf("OSFileSource::SetLog=%s\n",inPath);
#endif
	
}
#endif



FileBlockBuffer::~FileBlockBuffer(void)
{
	if (fDataBuffer != NULL)
	{
		Assert (fDataBuffer[fBufferSize] == 0);
		
#if FILE_SOURCE_DEBUG
	::memset( (char *)fDataBuffer,0, fBufferSize);
	printf("FileBlockBuffer::~FileBlockBuffer delete %lu this=%lu\n",fDataBuffer, this);
#endif
		delete fDataBuffer;
		fDataBuffer = NULL;
		fArrayIndex = -1;
	}
	else 
		Assert(false);
}

void FileBlockBuffer::AllocateBuffer(UInt32 buffSize)
{
	fBufferSize = buffSize;
	fDataBuffer = NEW char[buffSize + 1];
	fDataBuffer[buffSize] = 0;
	
#if FILE_SOURCE_DEBUG
	this->CleanBuffer();
	printf("FileBlockBuffer::FileBlockBuffer allocate buff ptr =%lu len=%lu this=%lu\n",fDataBuffer,buffSize,this);
#endif

}

void FileBlockBuffer::TestBuffer(void)
{

#if FILE_SOURCE_BUFFTEST	
	if (fDataBuffer != NULL)
		Assert (fDataBuffer[fBufferSize] == 0);	
#endif

}

void FileBlockPool::MarkUsed(FileBlockBuffer* inBuffPtr)
{
	if (NULL == inBuffPtr)
		return;
		
	if (fQueue.GetTail() != inBuffPtr->GetQElem()) // Least Recently Used tail is last accessed
	{
		fQueue.Remove(inBuffPtr->GetQElem());
		fQueue.EnQueue(inBuffPtr->GetQElem()); // put on tail
	}
}  

FileBlockBuffer *FileBlockPool::GetBufferElement(UInt32 bufferSizeBytes)
{
	FileBlockBuffer* theNewBuf = NULL;
	if ( fNumCurrentBuffers < fMaxBuffers)
	{
#if FILE_SOURCE_DEBUG
			printf("FileBlockPool::GetBufferElement NEW element fNumCurrentBuffers=%lu fMaxBuffers=%lu fBufferUnitSizeBytes=%lu bufferSizeBytes=%lu\n",fNumCurrentBuffers,fMaxBuffers,fBufferUnitSizeBytes,bufferSizeBytes);
#endif
		theNewBuf = NEW FileBlockBuffer();
		theNewBuf->AllocateBuffer(bufferSizeBytes);
		fNumCurrentBuffers++;
		theNewBuf->fQElem.SetEnclosingObject(theNewBuf);
		fQueue.EnQueue(theNewBuf->GetQElem()); // put on tail
		Assert(theNewBuf != NULL);
		return theNewBuf;
	}
	
	OSQueueElem *theElem = fQueue.DeQueue(); // get head

	Assert(theElem != NULL);
	
	if (theElem == NULL)
		return NULL;
		
	theNewBuf = (FileBlockBuffer*) theElem->GetEnclosingObject();
	Assert(theNewBuf != NULL);
	//printf("FileBlockPool::GetBufferElement reuse buffer theNewBuf=%lu fDataBuffer=%lu fArrayIndex=%ld\n",theNewBuf,theNewBuf->fDataBuffer,theNewBuf->fArrayIndex);

	return theNewBuf;

}  
 
void FileBlockPool::DeleteBlockPool(void) 
{

	FileBlockBuffer *buffer = NULL;
	OSQueueElem* theElem = fQueue.DeQueue();
	while (theElem != NULL)
	{	buffer = (FileBlockBuffer *) theElem->GetEnclosingObject();
		delete buffer;
		theElem = fQueue.DeQueue();	
	}
	
	fMaxBuffers = 1;
	fNumCurrentBuffers = 0; 
	fBufferUnitSizeBytes = kBufferUnitSize;
}

FileBlockPool::~FileBlockPool(void) 
{

	this->DeleteBlockPool();
}


void FileMap::AllocateBufferMap(UInt32 inUnitSizeInK, UInt32 inNumBuffSizeUnits, UInt32 inBufferIncCount, UInt32 inMaxBitRateBuffSizeInBlocks, UInt64 fileLen, UInt32 inBitRate)
{
	
	if (fFileMapArray != NULL && fNumBuffSizeUnits == inNumBuffSizeUnits && inBufferIncCount == fBlockPool.GetMaxBuffers())
		return;
		
	if( inUnitSizeInK < 1 )
		inUnitSizeInK = 1;
		
	fBlockPool.SetBufferUnitSize(inUnitSizeInK);
	
	if (inBitRate == 0) // just use the maximum possible size
		inBitRate = inMaxBitRateBuffSizeInBlocks * fBlockPool.GetBufferUnitSizeBytes();
		
	if (inNumBuffSizeUnits == 0) // calculate the buffer size ourselves
	{
		inNumBuffSizeUnits = inBitRate / fBlockPool.GetBufferUnitSizeBytes();
		
		if( inNumBuffSizeUnits > inMaxBitRateBuffSizeInBlocks) // max is 8 * buffUnit Size (32k) = 256K
		{	inNumBuffSizeUnits = inMaxBitRateBuffSizeInBlocks;
		}
	} //else the inNumBuffSizeUnits is explicitly defined so just use that value
	
	if( inNumBuffSizeUnits < 1 )
		inNumBuffSizeUnits = 1;
		
	this->DeleteMap();	
	fBlockPool.DeleteBlockPool();
	
	fNumBuffSizeUnits = inNumBuffSizeUnits;
	fDataBufferSize = fBlockPool.GetBufferUnitSizeBytes() * inNumBuffSizeUnits;
	
    fBlockPool.SetMaxBuffers(inBufferIncCount);
    fBlockPool.SetBuffIncValue(inBufferIncCount);

	fMapArraySize = (fileLen / fDataBufferSize) + 1;	
	fFileMapArray = NEW FileBlockBuffer *[fMapArraySize + 1];
	
	this->Clean(); // required because fFileMapArray's array is used to store buffer pointers.
#if FILE_SOURCE_DEBUG
	printf("FileMap::AllocateBufferMap shared buffers fFileMapArray=%lu fDataBufferSize= %lu fMapArraySize=%lu fileLen=%qu \n",fFileMapArray, fDataBufferSize, fMapArraySize,fileLen);   
#endif

}    

void FileMap::DeleteOldBuffs()
{
 	while (fBlockPool.GetNumCurrentBuffers() > fBlockPool.GetMaxBuffers()) // delete any old buffers
	{
		FileBlockBuffer *theElem =  fBlockPool.GetBufferElement(fDataBufferSize);
		fFileMapArray[theElem->fArrayIndex] = NULL; 
		delete theElem;
		fBlockPool.DecCurBuffers();
	}
}	

char *FileMap::GetBuffer(SInt32 buffIndex, Bool16 *outFillBuff)
{
	Assert(outFillBuff != NULL);
    *outFillBuff = true; // we are re-using or just created a buff

	this->DeleteOldBuffs();
 	Assert(buffIndex < (SInt32) fMapArraySize);
 	
 	FileBlockBuffer *theElem = fFileMapArray[buffIndex];
    if ( NULL == theElem)
    {
    	#if FILE_SOURCE_DEBUG
    		printf("FileMap::GetBuffer call fBlockPool.GetBufferElement(); buffIndex=%ld\n",buffIndex);
    	#endif
    	
    	 theElem =  fBlockPool.GetBufferElement(fDataBufferSize);
    	 Assert(theElem);
    }
        
	fBlockPool.MarkUsed(theElem); // must happen here after getting a pre-allocated or used buffer.

    if (theElem->fArrayIndex == buffIndex) // found a pre-allocated and filled buffer
    {
    	#if FILE_SOURCE_DEBUG
   			//printf("FileMap::GetBuffer pre-allocated buff buffIndex=%ld\n",buffIndex);
     	#endif
     	
	   	*outFillBuff = false;
    	return theElem->fDataBuffer;
    }

    if (theElem->fArrayIndex >= 0)
    {
		fFileMapArray[theElem->fArrayIndex] = NULL; // reset the old map location
	}
    fFileMapArray[buffIndex] = theElem; // a new buffer
	theElem->fArrayIndex = buffIndex; // record the index
	
#if FILE_SOURCE_DEBUG
	theElem->CleanBuffer();
#endif
	
    return theElem->fDataBuffer;
 	
}



void	FileMap::Clean(void)
{
	if (fFileMapArray != NULL)
		::memset( (char *)fFileMapArray,0, sizeof(FileBlockBuffer *) * fMapArraySize);
}

void	FileMap::DeleteMap(void)
{
	if (NULL == fFileMapArray)
		return;
		
#if FILE_SOURCE_DEBUG
	printf("FileMap::DeleteMap fFileMapArray=%lu fMapArraySize=%ld \n",fFileMapArray, fMapArraySize);   
	this->Clean();
#endif

	delete fFileMapArray;
	fFileMapArray = NULL;

}


void OSFileSource::Set(const char *inPath)
{
	Close();
	
#if __Win32__
	fFile = open(inPath, O_RDONLY | O_BINARY);
#else
	fFile = open(inPath, O_RDONLY);
#endif

	if (fFile != -1)
	{
		struct stat buf;
		if (::fstat(fFile, &buf) >= 0)
		{
			fLength = buf.st_size;
			fModDate = buf.st_mtime;
#ifdef __Win32__
			fIsDir = buf.st_mode & _S_IFDIR;
#else
			fIsDir = S_ISDIR(buf.st_mode);
#endif
			this->SetLog(inPath);
		}
		else
			this->Close();
	}	
}



#if __MacOSXServer__
void OSFileSource::Advise(UInt64 advisePos, UInt32 adviseAmt)
{
	//if the caller wants us to, issue an advise. Advise for the file area
	//immediately following the current read area
	struct radvisory radv;
	memset(&radv, 0, sizeof(radv));
	radv.ra_offset = (off_t)advisePos;
	radv.ra_count = (int)adviseAmt;
	::fcntl(fFile, F_RDADVISE, &radv);
}
#else
void OSFileSource::Advise(UInt64 , UInt32 )
{
// does nothing on platforms other than MacOSXServer
}
#endif

OS_Error	OSFileSource::FillBuffer(char* ioBuffer, char *buffStart, SInt32 buffIndex)
{
	UInt32 buffSize = fFileMap.GetMaxBufSize();
	UInt64 startPos = buffIndex * buffSize;
	UInt32 readLen = 0;
	
	OS_Error theErr = this->ReadFromPos(startPos, buffStart, buffSize, &readLen);	

	fFileMap.SetIndexBuffFillSize(buffIndex, readLen);
	fFileMap.TestBuffer(buffIndex);	
				
	return theErr;
}

#if FILE_SOURCE_BUFFTEST
static SInt32 sBuffCount = 1;	
#endif

OS_Error	OSFileSource::Read(UInt64 inPosition, void* inBuffer, UInt32 inLength, UInt32* outRcvLen)
{ 
		
	if	(	( !fFileMap.Initialized() )
		 	|| ( !fCacheEnabled )
		 	|| ( fFileMap.GetBuffIndex(inPosition+inLength) > fFileMap.GetMaxBuffIndex() ) 
	 	)
		return  this->ReadFromPos(inPosition, inBuffer, inLength, outRcvLen);
  	
	return  this->ReadFromCache(inPosition, inBuffer, inLength, outRcvLen);
}


OS_Error	OSFileSource::ReadFromCache(UInt64 inPosition, void* inBuffer, UInt32 inLength, UInt32* outRcvLen)
{ 
 	OSMutexLocker locker(&fMutex);
	
	if (!fFileMap.Initialized() || !fCacheEnabled)
	{	Assert(0);
	}
	
	Assert(outRcvLen != NULL);
   	*outRcvLen = 0;
   		
   if (inPosition >= fLength) // eof
   		return OS_NoErr;

	SInt32 buffIndex = fFileMap.GetBuffIndex(inPosition);	
	SInt32 buffSize = 0;
	SInt32 maxBuffSize = fFileMap.GetMaxBufSize();
    SInt32 endIndex = fFileMap.GetBuffIndex(inPosition+inLength);
    SInt32 maxIndex = fFileMap.GetMaxBuffIndex();
    UInt32 buffPos =  inPosition - fFileMap.GetBuffOffset(buffIndex);
    SInt32 buffOffsetLen = 0;
    char *buffStart = NULL;
    SInt32 buffCopyLen = inLength;
    SInt32 bytesToCopy = inLength;
  	char *buffOut = (char*)inBuffer;
	Bool16 fillBuff = true;
 	char *buffOffset = NULL;
 	
#if FILE_SOURCE_BUFFTEST
	char testBuff[inLength + 1];
 	buffOut = (char*)testBuff;
 	sBuffCount ++;
 	::memset(inBuffer,0,inLength);	
 	::memset(testBuff,0,inLength);
#endif
    
    if (buffIndex > endIndex || endIndex > maxIndex)
    {
#if FILE_SOURCE_DEBUG

		printf("OSFileSource::ReadFromCache bad index: buffIndex=%ld endIndex=%ld maxIndex=%ld\n",buffIndex,endIndex,maxIndex);
		printf("OSFileSource::ReadFromCache inPosition =%qu buffSize = %lu index=%ld\n",inPosition, fFileMap.GetMaxBufSize(),buffIndex);
#endif
	   	Assert(0);
    }
    	
   while (buffIndex <= endIndex && buffIndex <= maxIndex)
   {	
#if FILE_SOURCE_DEBUG
		printf("OSFileSource::ReadFromCache inPosition =%qu buffSize = %lu index=%ld\n",inPosition, fFileMap.GetMaxBufSize(),buffIndex);
#endif

  		buffStart = fFileMap.GetBuffer(buffIndex, &fillBuff);
   		Assert(buffStart != NULL);
   		
    	if (fillBuff)
    	{
			OS_Error theErr = this->FillBuffer( (char *) inBuffer, (char *) buffStart, (SInt32) buffIndex);
			if (theErr != OS_NoErr)
				return theErr;
			
		}
		
		
		buffSize = fFileMap.GetBuffSize(buffIndex);
		buffOffset = &buffStart[buffPos];
		
		if	( 	(buffPos == 0) && 
				(bytesToCopy <= maxBuffSize) && 
				(buffSize < bytesToCopy)
			) // that's all there is in the file
		{
				
			#if FILE_SOURCE_DEBUG
				printf("OSFileSource::ReadFromCache end of file reached buffIndex=%lu buffSize = %ld bytesToCopy=%lu\n",buffIndex, buffSize,bytesToCopy);
			#endif
			
			::memcpy(buffOut,buffOffset,buffSize);
			*outRcvLen += buffSize;
			break;
		}

		buffOffsetLen = buffSize - buffPos;
		if (buffCopyLen >= buffOffsetLen)
			buffCopyLen = buffOffsetLen;
			
		Assert(buffCopyLen <= buffSize);

		::memcpy(buffOut,buffOffset,buffCopyLen);
		buffOut += buffCopyLen;
    	*outRcvLen += buffCopyLen;
		bytesToCopy -= buffCopyLen;
		Assert(bytesToCopy >= 0);
		
		buffCopyLen = bytesToCopy;
   		buffPos = 0;
   		buffIndex ++;
    		
    } 
    
#if FILE_SOURCE_DEBUG
		//printf("OSFileSource::ReadFromCache inLength= %lu *outRcvLen=%lu\n",inLength, *outRcvLen);
#endif

#if FILE_SOURCE_BUFFTEST	
	{	UInt32 outLen = 0;
		OS_Error theErr = this->ReadFromPos(inPosition, inBuffer, inLength, &outLen);		
		
		Assert(*outRcvLen == outLen);
		if (*outRcvLen != outLen)
			printf("OSFileSource::ReadFromCache *outRcvLen != outLen *outRcvLen=%lu outLen=%lu\n",*outRcvLen,outLen);
			
		for (int i = 0; i < inLength; i++)
		{	if ( ((char*)inBuffer)[i] != testBuff[i])
			{	printf("OSFileSource::ReadFromCache byte pos %d of %lu failed len=%lu inPosition=%qu sBuffCount=%ld\n",i,inLength,outLen,inPosition,sBuffCount);
				break;
			}
		}
	}
#endif

	return OS_NoErr;
}

OS_Error	OSFileSource::ReadFromDisk(void* inBuffer, UInt32 inLength, UInt32* outRcvLen)
{
	#if FILE_SOURCE_BUFFTEST
		printf("OSFileSource::Read inLength=%lu fFile=%d\n",inLength,fFile);
	#endif
	
	if (lseek(fFile, fPosition, SEEK_SET) == -1)
		return OSThread::GetErrno();
		
	int rcvLen = ::read(fFile, (char*)inBuffer, inLength);
	if (rcvLen == -1)
		return OSThread::GetErrno();

	if (outRcvLen != NULL)
		*outRcvLen = rcvLen;

	fPosition += rcvLen;
	fReadPos = fPosition;
	
 	return OS_NoErr;
}

OS_Error	OSFileSource::ReadFromPos(UInt64 inPosition, void* inBuffer, UInt32 inLength, UInt32* outRcvLen)
{	
#if TEST_TIME
	{	
		startTime = OS::Milliseconds();
		sReadCount++;
		if (outRcvLen)
			*outRcvLen = 0;
		printf("OSFileSource::Read sReadCount = %ld totalbytes=%ld readsize=%lu\n",sReadCount,sByteCount,inLength);
	}
#endif

    this->Seek(inPosition);
    OS_Error err =  this->ReadFromDisk(inBuffer,inLength,outRcvLen);
    
#if READ_LOG
		if (fFileLog)
		{	fFileLog = ::fopen(fFilePath,"a");
			if (fFileLog)
			{	::fprintf(fFileLog, "read: %qu %lu %lu\n",inPosition, *outRcvLen, xTrackID);
				::fclose(fFileLog);
			}
		}
			
#endif
#if TEST_TIME
	{
		durationTime += OS::Milliseconds() - startTime;
		sByteCount += *outRcvLen;
	}
#endif

	return err;
}

void OSFileSource::SetTrackID(UInt32 trackID) 	
{ 
#if READ_LOG
	fTrackID = trackID;
//	printf("OSFileSource::SetTrackID = %lu this=%lu\n",fTrackID,(UInt32) this);
#endif
}


void	OSFileSource::Close()
{
	if ((fFile != -1) && (fShouldClose))
	{	::close(fFile);
	
		#if READ_LOG
			if ( 0 && fFileLog != NULL )
			{	::fclose(fFileLog);
				fFileLog = NULL;
				fFilePath[0] =0;
			}
		#endif
	}
	
	fFile = -1;
	fModDate = 0;
	fLength = 0;
	fPosition = 0;
	fReadPos = 0;
	
#if TEST_TIME	
	if (fShouldClose)
	{	sMovie = 0;
//		printf("OSFileSource::Close sReadCount = %ld totalbytes=%ld\n",sReadCount,sByteCount);
//		printf("OSFileSource::Close durationTime = %qd\n",durationTime);
	}
#endif
	
}