llvfile.cpp

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#include "linden_common.h"

#include "llvfile.h"

#include "llerror.h"
#include "llthread.h"
#include "llvfs.h"

const S32 LLVFile::READ                 = 0x00000001;
const S32 LLVFile::WRITE                = 0x00000002;
const S32 LLVFile::READ_WRITE   = 0x00000003;  // LLVFile::READ & LLVFile::WRITE
const S32 LLVFile::APPEND               = 0x00000006;  // 0x00000004 & LLVFile::WRITE

//----------------------------------------------------------------------------
LLVFSThread* LLVFile::sVFSThread = NULL;
BOOL LLVFile::sAllocdVFSThread = FALSE;
//----------------------------------------------------------------------------

//============================================================================

LLVFile::LLVFile(LLVFS *vfs, const LLUUID &file_id, const LLAssetType::EType file_type, S32 mode)
{
        mFileType =     file_type;

        mFileID =       file_id;
        mPosition = 0;
        mMode =         mode;
        mVFS =          vfs;

        mBytesRead = 0;
        mHandle = LLVFSThread::nullHandle();
        mPriority = 128.f;

        mVFS->incLock(mFileID, mFileType, VFSLOCK_OPEN);
}

LLVFile::~LLVFile()
{
        if (!isReadComplete())
        {
                if (mHandle != LLVFSThread::nullHandle())
                {
                        if (!(mMode & LLVFile::WRITE))
                        {
                                //llwarns << "Destroying LLVFile with pending async read/write, aborting..." << llendl;
                                sVFSThread->setFlags(mHandle, LLVFSThread::FLAG_AUTO_COMPLETE | LLVFSThread::FLAG_ABORT);
                        }
                        else // WRITE
                        {
                                sVFSThread->setFlags(mHandle, LLVFSThread::FLAG_AUTO_COMPLETE);
                        }
                }
        }
        mVFS->decLock(mFileID, mFileType, VFSLOCK_OPEN);
}

BOOL LLVFile::read(U8 *buffer, S32 bytes, BOOL async, F32 priority)
{
        if (! (mMode & READ))
        {
                llwarns << "Attempt to read from file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << llendl;
                return FALSE;
        }

        if (mHandle != LLVFSThread::nullHandle())
        {
                llwarns << "Attempt to read from vfile object " << mFileID << " with pending async operation" << llendl;
                return FALSE;
        }
        mPriority = priority;
        
        BOOL success = TRUE;

        // We can't do a read while there are pending async writes
        waitForLock(VFSLOCK_APPEND);
        
        // *FIX: (???)
        if (async)
        {
                mHandle = sVFSThread->read(mVFS, mFileID, mFileType, buffer, mPosition, bytes, threadPri());
        }
        else
        {
                // We can't do a read while there are pending async writes on this file
                mBytesRead = sVFSThread->readImmediate(mVFS, mFileID, mFileType, buffer, mPosition, bytes);
                mPosition += mBytesRead;
                if (! mBytesRead)
                {
                        success = FALSE;
                }
        }

        return success;
}

//static
U8* LLVFile::readFile(LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type, S32* bytes_read)
{
        U8 *data;
        LLVFile file(vfs, uuid, type, LLVFile::READ);
        S32 file_size = file.getSize();
        if (file_size == 0)
        {
                // File is empty.
                data = NULL;
        }
        else
        {
                data = new U8[file_size];
                file.read(data, file_size);     /* Flawfinder: ignore */ 
                
                if (file.getLastBytesRead() != (S32)file_size)
                {
                        delete[] data;
                        data = NULL;
                        file_size = 0;
                }
        }
        if (bytes_read)
        {
                *bytes_read = file_size;
        }
        return data;
}
        
void LLVFile::setReadPriority(const F32 priority)
{
        mPriority = priority;
        if (mHandle != LLVFSThread::nullHandle())
        {
                sVFSThread->setPriority(mHandle, threadPri());
        }
}

BOOL LLVFile::isReadComplete()
{
        BOOL res = TRUE;
        if (mHandle != LLVFSThread::nullHandle())
        {
                LLVFSThread::Request* req = (LLVFSThread::Request*)sVFSThread->getRequest(mHandle);
                LLVFSThread::status_t status = req->getStatus();
                if (status == LLVFSThread::STATUS_COMPLETE)
                {
                        mBytesRead = req->getBytesRead();
                        mPosition += mBytesRead;
                        sVFSThread->completeRequest(mHandle);
                        mHandle = LLVFSThread::nullHandle();
                }
                else
                {
                        res = FALSE;
                }
        }
        return res;
}

S32 LLVFile::getLastBytesRead()
{
        return mBytesRead;
}

BOOL LLVFile::eof()
{
        return mPosition >= getSize();
}

BOOL LLVFile::write(const U8 *buffer, S32 bytes)
{
        if (! (mMode & WRITE))
        {
                llwarns << "Attempt to write to file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << llendl;
        }
        if (mHandle != LLVFSThread::nullHandle())
        {
                llerrs << "Attempt to write to vfile object " << mFileID << " with pending async operation" << llendl;
                return FALSE;
        }
        BOOL success = TRUE;
        
        // *FIX: allow async writes? potential problem wit mPosition...
        if (mMode == APPEND) // all appends are async (but WRITEs are not)
        {       
                U8* writebuf = new U8[bytes];
                memcpy(writebuf, buffer, bytes);
                S32 offset = -1;
                mHandle = sVFSThread->write(mVFS, mFileID, mFileType,
                                                                        writebuf, offset, bytes,
                                                                        LLVFSThread::FLAG_AUTO_COMPLETE | LLVFSThread::FLAG_AUTO_DELETE);
                mHandle = LLVFSThread::nullHandle(); // FLAG_AUTO_COMPLETE means we don't track this
        }
        else
        {
                // We can't do a write while there are pending reads or writes on this file
                waitForLock(VFSLOCK_READ);
                waitForLock(VFSLOCK_APPEND);

                S32 pos = (mMode & APPEND) == APPEND ? -1 : mPosition;

                S32 wrote = sVFSThread->writeImmediate(mVFS, mFileID, mFileType, (U8*)buffer, pos, bytes);

                mPosition += wrote;
                
                if (wrote < bytes)
                {       
                        llwarns << "Tried to write " << bytes << " bytes, actually wrote " << wrote << llendl;

                        success = FALSE;
                }
        }
        return success;
}

//static
BOOL LLVFile::writeFile(const U8 *buffer, S32 bytes, LLVFS *vfs, const LLUUID &uuid, LLAssetType::EType type)
{
        LLVFile file(vfs, uuid, type, LLVFile::WRITE);
        file.setMaxSize(bytes);
        return file.write(buffer, bytes);
}

BOOL LLVFile::seek(S32 offset, S32 origin)
{
        if (mMode == APPEND)
        {
                llwarns << "Attempt to seek on append-only file" << llendl;
                return FALSE;
        }

        if (-1 == origin)
        {
                origin = mPosition;
        }

        S32 new_pos = origin + offset;

        S32 size = getSize(); // Calls waitForLock(VFSLOCK_APPEND)

        if (new_pos > size)
        {
                llwarns << "Attempt to seek past end of file" << llendl;

                mPosition = size;
                return FALSE;
        }
        else if (new_pos < 0)
        {
                llwarns << "Attempt to seek past beginning of file" << llendl;

                mPosition = 0;
                return FALSE;
        }

        mPosition = new_pos;
        return TRUE;
}

S32 LLVFile::tell() const
{
        return mPosition;
}

S32 LLVFile::getSize()
{
        waitForLock(VFSLOCK_APPEND);
        S32 size = mVFS->getSize(mFileID, mFileType);

        return size;
}

S32 LLVFile::getMaxSize()
{
        S32 size = mVFS->getMaxSize(mFileID, mFileType);

        return size;
}

BOOL LLVFile::setMaxSize(S32 size)
{
        if (! (mMode & WRITE))
        {
                llwarns << "Attempt to change size of file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << llendl;

                return FALSE;
        }

        if (!mVFS->checkAvailable(size))
        {
                LLFastTimer t(LLFastTimer::FTM_VFILE_WAIT);
                S32 count = 0;
                while (sVFSThread->getPending() > 1000)
                {
                        if (count % 100 == 0)
                        {
                                llinfos << "VFS catching up... Pending: " << sVFSThread->getPending() << llendl;
                        }
                        if (sVFSThread->isPaused())
                        {
                                sVFSThread->update(0);
                        }
                        ms_sleep(10);
                }
        }
        return mVFS->setMaxSize(mFileID, mFileType, size);
}

BOOL LLVFile::rename(const LLUUID &new_id, const LLAssetType::EType new_type)
{
        if (! (mMode & WRITE))
        {
                llwarns << "Attempt to rename file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << llendl;

                return FALSE;
        }

        if (mHandle != LLVFSThread::nullHandle())
        {
                llwarns << "Renaming file with pending async read" << llendl;
        }

        waitForLock(VFSLOCK_READ);
        waitForLock(VFSLOCK_APPEND);

        // we need to release / replace our own lock
        // since the renamed file will inherit locks from the new name
        mVFS->decLock(mFileID, mFileType, VFSLOCK_OPEN);
        mVFS->renameFile(mFileID, mFileType, new_id, new_type);
        mVFS->incLock(new_id, new_type, VFSLOCK_OPEN);
        
        mFileID = new_id;
        mFileType = new_type;

        return TRUE;
}

BOOL LLVFile::remove()
{
//      llinfos << "Removing file " << mFileID << llendl;
        
        if (! (mMode & WRITE))
        {
                // Leaving paranoia warning just because this should be a very infrequent
                // operation.
                llwarns << "Remove file " << mFileID << " opened with mode " << std::hex << mMode << std::dec << llendl;
        }

        if (mHandle != LLVFSThread::nullHandle())
        {
                llwarns << "Removing file with pending async read" << llendl;
        }
        
        // why not seek back to the beginning of the file too?
        mPosition = 0;

        waitForLock(VFSLOCK_READ);
        waitForLock(VFSLOCK_APPEND);
        mVFS->removeFile(mFileID, mFileType);

        return TRUE;
}

// static
void LLVFile::initClass(LLVFSThread* vfsthread)
{
        if (!vfsthread)
        {
                if (LLVFSThread::sLocal != NULL)
                {
                        vfsthread = LLVFSThread::sLocal;
                }
                else
                {
                        vfsthread = new LLVFSThread();
                        sAllocdVFSThread = TRUE;
                }
        }
        sVFSThread = vfsthread;
}

// static
void LLVFile::cleanupClass()
{
        if (sAllocdVFSThread)
        {
                delete sVFSThread;
        }
        sVFSThread = NULL;
}

bool LLVFile::isLocked(EVFSLock lock)
{
        return mVFS->isLocked(mFileID, mFileType, lock) ? true : false;
}

void LLVFile::waitForLock(EVFSLock lock)
{
        LLFastTimer t(LLFastTimer::FTM_VFILE_WAIT);
        // spin until the lock clears
        while (isLocked(lock))
        {
                if (sVFSThread->isPaused())
                {
                        sVFSThread->update(0);
                }
                ms_sleep(1);
        }
}

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