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Diffstat (limited to 'LibOVR/Src/Kernel/OVR_File.cpp')
| -rw-r--r-- | LibOVR/Src/Kernel/OVR_File.cpp | 582 |
1 files changed, 582 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..31ab516 --- /dev/null +++ b/LibOVR/Src/Kernel/OVR_File.cpp @@ -0,0 +1,582 @@ +/************************************************************************** + +Filename : OVR_File.cpp +Content : File wrapper class implementation (Win32) + +Created : April 5, 1999 +Authors : Michael Antonov + +Copyright : Copyright 2014 Oculus VR, Inc. All Rights reserved. + +Licensed under the Oculus VR Rift SDK License Version 3.1 (the "License"); +you may not use the Oculus VR Rift SDK except in compliance with the License, +which is provided at the time of installation or download, or which +otherwise accompanies this software in either electronic or hard copy form. + +You may obtain a copy of the License at + +http://www.oculusvr.com/licenses/LICENSE-3.1 + +Unless required by applicable law or agreed to in writing, the Oculus VR SDK +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. + +**************************************************************************/ + +#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 + |