diff options
Diffstat (limited to 'LibOVR/Src/Kernel/OVR_File.cpp')
| -rw-r--r-- | LibOVR/Src/Kernel/OVR_File.cpp | 571 |
1 files changed, 571 insertions, 0 deletions
diff --git a/LibOVR/Src/Kernel/OVR_File.cpp b/LibOVR/Src/Kernel/OVR_File.cpp new file mode 100644 index 0000000..7620e37 --- /dev/null +++ b/LibOVR/Src/Kernel/OVR_File.cpp @@ -0,0 +1,571 @@ +/**************************************************************************
+
+Filename : OVR_File.cpp
+Content : File wrapper class implementation (Win32)
+
+Created : April 5, 1999
+Authors : Michael Antonov
+
+Copyright : Copyright 2012 Oculus VR, Inc. All Rights reserved.
+
+Use of this software is subject to the terms of the Oculus license
+agreement provided at the time of installation or download, or which
+otherwise accompanies this software in either electronic or hard copy form.
+
+**************************************************************************/
+
+#define GFILE_CXX
+
+// Standard C library (Captain Obvious guarantees!)
+#include <stdio.h>
+
+#include "OVR_File.h"
+
+namespace OVR {
+
+// Buffered file adds buffering to an existing file
+// FILEBUFFER_SIZE defines the size of internal buffer, while
+// FILEBUFFER_TOLERANCE controls the amount of data we'll effectively try to buffer
+#define FILEBUFFER_SIZE (8192-8)
+#define FILEBUFFER_TOLERANCE 4096
+
+// ** Constructor/Destructor
+
+// Hidden constructor
+// Not supposed to be used
+BufferedFile::BufferedFile() : DelegatedFile(0)
+{
+ pBuffer = (UByte*)OVR_ALLOC(FILEBUFFER_SIZE);
+ BufferMode = NoBuffer;
+ FilePos = 0;
+ Pos = 0;
+ DataSize = 0;
+}
+
+// Takes another file as source
+BufferedFile::BufferedFile(File *pfile) : DelegatedFile(pfile)
+{
+ pBuffer = (UByte*)OVR_ALLOC(FILEBUFFER_SIZE);
+ BufferMode = NoBuffer;
+ FilePos = pfile->LTell();
+ Pos = 0;
+ DataSize = 0;
+}
+
+
+// Destructor
+BufferedFile::~BufferedFile()
+{
+ // Flush in case there's data
+ if (pFile)
+ FlushBuffer();
+ // Get rid of buffer
+ if (pBuffer)
+ OVR_FREE(pBuffer);
+}
+
+/*
+bool BufferedFile::VCopy(const Object &source)
+{
+ if (!DelegatedFile::VCopy(source))
+ return 0;
+
+ // Data members
+ BufferedFile *psource = (BufferedFile*)&source;
+
+ // Buffer & the mode it's in
+ pBuffer = psource->pBuffer;
+ BufferMode = psource->BufferMode;
+ Pos = psource->Pos;
+ DataSize = psource->DataSize;
+ return 1;
+}
+*/
+
+// Initializes buffering to a certain mode
+bool BufferedFile::SetBufferMode(BufferModeType mode)
+{
+ if (!pBuffer)
+ return false;
+ if (mode == BufferMode)
+ return true;
+
+ FlushBuffer();
+
+ // Can't set write mode if we can't write
+ if ((mode==WriteBuffer) && (!pFile || !pFile->IsWritable()) )
+ return 0;
+
+ // And SetMode
+ BufferMode = mode;
+ Pos = 0;
+ DataSize = 0;
+ return 1;
+}
+
+// Flushes buffer
+void BufferedFile::FlushBuffer()
+{
+ switch(BufferMode)
+ {
+ case WriteBuffer:
+ // Write data in buffer
+ FilePos += pFile->Write(pBuffer,Pos);
+ Pos = 0;
+ break;
+
+ case ReadBuffer:
+ // Seek back & reset buffer data
+ if ((DataSize-Pos)>0)
+ FilePos = pFile->LSeek(-(int)(DataSize-Pos), Seek_Cur);
+ DataSize = 0;
+ Pos = 0;
+ break;
+ default:
+ // not handled!
+ break;
+ }
+}
+
+// Reloads data for ReadBuffer
+void BufferedFile::LoadBuffer()
+{
+ if (BufferMode == ReadBuffer)
+ {
+ // We should only reload once all of pre-loaded buffer is consumed.
+ OVR_ASSERT(Pos == DataSize);
+
+ // WARNING: Right now LoadBuffer() assumes the buffer's empty
+ int sz = pFile->Read(pBuffer,FILEBUFFER_SIZE);
+ DataSize = sz<0 ? 0 : (unsigned)sz;
+ Pos = 0;
+ FilePos += DataSize;
+ }
+}
+
+
+// ** Overridden functions
+
+// We override all the functions that can possibly
+// require buffer mode switch, flush, or extra calculations
+
+// Tell() requires buffer adjustment
+int BufferedFile::Tell()
+{
+ if (BufferMode == ReadBuffer)
+ return int (FilePos - DataSize + Pos);
+
+ int pos = pFile->Tell();
+ // Adjust position based on buffer mode & data
+ if (pos!=-1)
+ {
+ OVR_ASSERT(BufferMode != ReadBuffer);
+ if (BufferMode == WriteBuffer)
+ pos += Pos;
+ }
+ return pos;
+}
+
+SInt64 BufferedFile::LTell()
+{
+ if (BufferMode == ReadBuffer)
+ return FilePos - DataSize + Pos;
+
+ SInt64 pos = pFile->LTell();
+ if (pos!=-1)
+ {
+ OVR_ASSERT(BufferMode != ReadBuffer);
+ if (BufferMode == WriteBuffer)
+ pos += Pos;
+ }
+ return pos;
+}
+
+int BufferedFile::GetLength()
+{
+ int len = pFile->GetLength();
+ // If writing through buffer, file length may actually be bigger
+ if ((len!=-1) && (BufferMode==WriteBuffer))
+ {
+ int currPos = pFile->Tell() + Pos;
+ if (currPos>len)
+ len = currPos;
+ }
+ return len;
+}
+SInt64 BufferedFile::LGetLength()
+{
+ SInt64 len = pFile->LGetLength();
+ // If writing through buffer, file length may actually be bigger
+ if ((len!=-1) && (BufferMode==WriteBuffer))
+ {
+ SInt64 currPos = pFile->LTell() + Pos;
+ if (currPos>len)
+ len = currPos;
+ }
+ return len;
+}
+
+/*
+bool BufferedFile::Stat(FileStats *pfs)
+{
+ // Have to fix up length is stat
+ if (pFile->Stat(pfs))
+ {
+ if (BufferMode==WriteBuffer)
+ {
+ SInt64 currPos = pFile->LTell() + Pos;
+ if (currPos > pfs->Size)
+ {
+ pfs->Size = currPos;
+ // ??
+ pfs->Blocks = (pfs->Size+511) >> 9;
+ }
+ }
+ return 1;
+ }
+ return 0;
+}
+*/
+
+int BufferedFile::Write(const UByte *psourceBuffer, int numBytes)
+{
+ if ( (BufferMode==WriteBuffer) || SetBufferMode(WriteBuffer))
+ {
+ // If not data space in buffer, flush
+ if ((FILEBUFFER_SIZE-(int)Pos)<numBytes)
+ {
+ FlushBuffer();
+ // If bigger then tolerance, just write directly
+ if (numBytes>FILEBUFFER_TOLERANCE)
+ {
+ int sz = pFile->Write(psourceBuffer,numBytes);
+ if (sz > 0)
+ FilePos += sz;
+ return sz;
+ }
+ }
+
+ // Enough space in buffer.. so copy to it
+ memcpy(pBuffer+Pos, psourceBuffer, numBytes);
+ Pos += numBytes;
+ return numBytes;
+ }
+ int sz = pFile->Write(psourceBuffer,numBytes);
+ if (sz > 0)
+ FilePos += sz;
+ return sz;
+}
+
+int BufferedFile::Read(UByte *pdestBuffer, int numBytes)
+{
+ if ( (BufferMode==ReadBuffer) || SetBufferMode(ReadBuffer))
+ {
+ // Data in buffer... copy it
+ if ((int)(DataSize-Pos) >= numBytes)
+ {
+ memcpy(pdestBuffer, pBuffer+Pos, numBytes);
+ Pos += numBytes;
+ return numBytes;
+ }
+
+ // Not enough data in buffer, copy buffer
+ int readBytes = DataSize-Pos;
+ memcpy(pdestBuffer, pBuffer+Pos, readBytes);
+ numBytes -= readBytes;
+ pdestBuffer += readBytes;
+ Pos = DataSize;
+
+ // Don't reload buffer if more then tolerance
+ // (No major advantage, and we don't want to write a loop)
+ if (numBytes>FILEBUFFER_TOLERANCE)
+ {
+ numBytes = pFile->Read(pdestBuffer,numBytes);
+ if (numBytes > 0)
+ {
+ FilePos += numBytes;
+ Pos = DataSize = 0;
+ }
+ return readBytes + ((numBytes==-1) ? 0 : numBytes);
+ }
+
+ // Reload the buffer
+ // WARNING: Right now LoadBuffer() assumes the buffer's empty
+ LoadBuffer();
+ if ((int)(DataSize-Pos) < numBytes)
+ numBytes = (int)DataSize-Pos;
+
+ memcpy(pdestBuffer, pBuffer+Pos, numBytes);
+ Pos += numBytes;
+ return numBytes + readBytes;
+
+ /*
+ // Alternative Read implementation. The one above is probably better
+ // due to FILEBUFFER_TOLERANCE.
+ int total = 0;
+
+ do {
+ int bufferBytes = (int)(DataSize-Pos);
+ int copyBytes = (bufferBytes > numBytes) ? numBytes : bufferBytes;
+
+ memcpy(pdestBuffer, pBuffer+Pos, copyBytes);
+ numBytes -= copyBytes;
+ pdestBuffer += copyBytes;
+ Pos += copyBytes;
+ total += copyBytes;
+
+ if (numBytes == 0)
+ break;
+ LoadBuffer();
+
+ } while (DataSize > 0);
+
+ return total;
+ */
+ }
+ int sz = pFile->Read(pdestBuffer,numBytes);
+ if (sz > 0)
+ FilePos += sz;
+ return sz;
+}
+
+
+int BufferedFile::SkipBytes(int numBytes)
+{
+ int skippedBytes = 0;
+
+ // Special case for skipping a little data in read buffer
+ if (BufferMode==ReadBuffer)
+ {
+ skippedBytes = (((int)DataSize-(int)Pos) >= numBytes) ? numBytes : (DataSize-Pos);
+ Pos += skippedBytes;
+ numBytes -= skippedBytes;
+ }
+
+ if (numBytes)
+ {
+ numBytes = pFile->SkipBytes(numBytes);
+ // Make sure we return the actual number skipped, or error
+ if (numBytes!=-1)
+ {
+ skippedBytes += numBytes;
+ FilePos += numBytes;
+ Pos = DataSize = 0;
+ }
+ else if (skippedBytes <= 0)
+ skippedBytes = -1;
+ }
+ return skippedBytes;
+}
+
+int BufferedFile::BytesAvailable()
+{
+ int available = pFile->BytesAvailable();
+ // Adjust available size based on buffers
+ switch(BufferMode)
+ {
+ case ReadBuffer:
+ available += DataSize-Pos;
+ break;
+ case WriteBuffer:
+ available -= Pos;
+ if (available<0)
+ available= 0;
+ break;
+ default:
+ break;
+ }
+ return available;
+}
+
+bool BufferedFile::Flush()
+{
+ FlushBuffer();
+ return pFile->Flush();
+}
+
+// Seeking could be optimized better..
+int BufferedFile::Seek(int offset, int origin)
+{
+ if (BufferMode == ReadBuffer)
+ {
+ if (origin == Seek_Cur)
+ {
+ // Seek can fall either before or after Pos in the buffer,
+ // but it must be within bounds.
+ if (((unsigned(offset) + Pos)) <= DataSize)
+ {
+ Pos += offset;
+ return int (FilePos - DataSize + Pos);
+ }
+
+ // Lightweight buffer "Flush". We do this to avoid an extra seek
+ // back operation which would take place if we called FlushBuffer directly.
+ origin = Seek_Set;
+ OVR_ASSERT(((FilePos - DataSize + Pos) + (UInt64)offset) < ~(UInt64)0);
+ offset = (int)(FilePos - DataSize + Pos) + offset;
+ Pos = DataSize = 0;
+ }
+ else if (origin == Seek_Set)
+ {
+ if (((unsigned)offset - (FilePos-DataSize)) <= DataSize)
+ {
+ OVR_ASSERT((FilePos-DataSize) < ~(UInt64)0);
+ Pos = (unsigned)offset - (unsigned)(FilePos-DataSize);
+ return offset;
+ }
+ Pos = DataSize = 0;
+ }
+ else
+ {
+ FlushBuffer();
+ }
+ }
+ else
+ {
+ FlushBuffer();
+ }
+
+ /*
+ // Old Seek Logic
+ if (origin == Seek_Cur && offset + Pos < DataSize)
+ {
+ //OVR_ASSERT((FilePos - DataSize) >= (FilePos - DataSize + Pos + offset));
+ Pos += offset;
+ OVR_ASSERT(int (Pos) >= 0);
+ return int (FilePos - DataSize + Pos);
+ }
+ else if (origin == Seek_Set && unsigned(offset) >= FilePos - DataSize && unsigned(offset) < FilePos)
+ {
+ Pos = unsigned(offset - FilePos + DataSize);
+ OVR_ASSERT(int (Pos) >= 0);
+ return int (FilePos - DataSize + Pos);
+ }
+
+ FlushBuffer();
+ */
+
+
+ FilePos = pFile->Seek(offset,origin);
+ return int (FilePos);
+}
+
+SInt64 BufferedFile::LSeek(SInt64 offset, int origin)
+{
+ if (BufferMode == ReadBuffer)
+ {
+ if (origin == Seek_Cur)
+ {
+ // Seek can fall either before or after Pos in the buffer,
+ // but it must be within bounds.
+ if (((unsigned(offset) + Pos)) <= DataSize)
+ {
+ Pos += (unsigned)offset;
+ return SInt64(FilePos - DataSize + Pos);
+ }
+
+ // Lightweight buffer "Flush". We do this to avoid an extra seek
+ // back operation which would take place if we called FlushBuffer directly.
+ origin = Seek_Set;
+ offset = (SInt64)(FilePos - DataSize + Pos) + offset;
+ Pos = DataSize = 0;
+ }
+ else if (origin == Seek_Set)
+ {
+ if (((UInt64)offset - (FilePos-DataSize)) <= DataSize)
+ {
+ Pos = (unsigned)((UInt64)offset - (FilePos-DataSize));
+ return offset;
+ }
+ Pos = DataSize = 0;
+ }
+ else
+ {
+ FlushBuffer();
+ }
+ }
+ else
+ {
+ FlushBuffer();
+ }
+
+/*
+ OVR_ASSERT(BufferMode != NoBuffer);
+
+ if (origin == Seek_Cur && offset + Pos < DataSize)
+ {
+ Pos += int (offset);
+ return FilePos - DataSize + Pos;
+ }
+ else if (origin == Seek_Set && offset >= SInt64(FilePos - DataSize) && offset < SInt64(FilePos))
+ {
+ Pos = unsigned(offset - FilePos + DataSize);
+ return FilePos - DataSize + Pos;
+ }
+
+ FlushBuffer();
+ */
+
+ FilePos = pFile->LSeek(offset,origin);
+ return FilePos;
+}
+
+int BufferedFile::CopyFromStream(File *pstream, int byteSize)
+{
+ // We can't rely on overridden Write()
+ // because delegation doesn't override virtual pointers
+ // So, just re-implement
+ UByte buff[0x4000];
+ int count = 0;
+ int szRequest, szRead, szWritten;
+
+ while(byteSize)
+ {
+ szRequest = (byteSize > int(sizeof(buff))) ? int(sizeof(buff)) : byteSize;
+
+ szRead = pstream->Read(buff,szRequest);
+ szWritten = 0;
+ if (szRead > 0)
+ szWritten = Write(buff,szRead);
+
+ count +=szWritten;
+ byteSize-=szWritten;
+ if (szWritten < szRequest)
+ break;
+ }
+ return count;
+}
+
+// Closing files
+bool BufferedFile::Close()
+{
+ switch(BufferMode)
+ {
+ case WriteBuffer:
+ FlushBuffer();
+ break;
+ case ReadBuffer:
+ // No need to seek back on close
+ BufferMode = NoBuffer;
+ break;
+ default:
+ break;
+ }
+ return pFile->Close();
+}
+
+
+// ***** Global path helpers
+
+// Find trailing short filename in a path.
+const char* OVR_CDECL GetShortFilename(const char* purl)
+{
+ UPInt len = OVR_strlen(purl);
+ for (UPInt i=len; i>0; i--)
+ if (purl[i]=='\\' || purl[i]=='/')
+ return purl+i+1;
+ return purl;
+}
+
+} // OVR
+
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