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#include "stdafx.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[] = __FILE__; #endif // _DEBUG
#ifndef _CTMPFILE_INCLUDED
#include "ctmpfile.h"
#endif
const int CB_COPY_BUFFER = 4096 * 8; // 64K
// If memory exceeds LARGEST_ALLOC then we switch to a real file
static int LARGEST_ALLOC = (1024 * 1024 * 8) - 4096L; // 8 megs
CTmpFile::CTmpFile(void) { cbAlloc = 4096; pmem = (PBYTE) VirtualAlloc(NULL, LARGEST_ALLOC, MEM_RESERVE, PAGE_READWRITE); if (!pmem) OOM(); if (!VirtualAlloc(pmem, cbAlloc, MEM_COMMIT, PAGE_READWRITE)) OOM();
cbFile = 0; FilePtr = 0; hf = HFILE_ERROR; pszFileName = NULL; }
CTmpFile::~CTmpFile(void) { if (pszFileName) { _lclose(hf); remove(pszFileName); lcFree(pszFileName); } if (pmem) { VirtualFree(pmem, LARGEST_ALLOC, MEM_DECOMMIT); VirtualFree(pmem, 0, MEM_RELEASE); } }
int STDCALL CTmpFile::seek(int lPos, int Origin) { if (pszFileName) return _llseek(hf, lPos, Origin);
// REVIEW (niklasb): Seeking past the end of a real file does
// not grow the file until the next write operation. We should
// probably do the same here, especially since the code in this
// function chokes if we grow past LARGEST_ALLOC.
//
switch (Origin) { case SEEK_SET:
#if 0 // don't grow file until next write
if (lPos > cbAlloc) {
// Create more memory, aligned on a 4K page boundary
int cbNew = lPos / 4096 * 4096 + 4096; ASSERT(cbNew < LARGEST_ALLOC);
if (!VirtualAlloc(pmem + cbAlloc, cbNew - cbAlloc, MEM_COMMIT, PAGE_READWRITE)) OOM(); cbAlloc = cbNew; } #endif
FilePtr = lPos; break;
case SEEK_CUR: #if 0 // don't grow file until next write
if (FilePtr + lPos > cbAlloc) { // Create more memory, aligned on a 4K page boundary
int cbNew = (FilePtr + lPos) / 4096 * 4096 + 4096; ASSERT(cbNew < LARGEST_ALLOC);
if (!VirtualAlloc(pmem + cbAlloc, cbNew - cbAlloc, MEM_COMMIT, PAGE_READWRITE)) OOM(); cbAlloc = cbNew; } #endif
FilePtr += lPos; break;
case SEEK_END: ASSERT(cbFile + lPos < cbAlloc); FilePtr = cbFile + lPos; break;
default: ASSERT(TRUE); break; } return FilePtr; }
int STDCALL CTmpFile::write(void* qv, int lcb) { ASSERT(qv);
// If this is a real file, just write the data; we no
// longer track cbFile in this case.
if (pszFileName) return (int) _lwrite(hf, (LPCSTR) qv, lcb);
// Grow the pseudo-file if necessary.
if (FilePtr + lcb > cbAlloc) {
// Calculate the new committed size (always 4K aligned).
int cbNew = (FilePtr + lcb) / 4096 * 4096 + 4096;
// If > reserved size, create a real file.
if (cbNew > LARGEST_ALLOC) { DBWIN("Switching CTmpFile to a real file.");
pszFileName = (PSTR) FmNewTemp(); if (!pszFileName) OOM();
hf = _lcreat(pszFileName, 0); if (hf == HFILE_ERROR) return HFILE_ERROR;
// Write all of our current data to the temp file.
_lwrite(hf, (LPCSTR) pmem, cbFile);
// Free all of the current memory
VirtualFree(pmem, cbAlloc, MEM_DECOMMIT); VirtualFree(pmem, 0, MEM_RELEASE); pmem = NULL;
// Add the new data
_llseek(hf, FilePtr, SEEK_SET); return (int) _lwrite(hf, (LPCSTR) qv, lcb); }
// We're still a pseudo-file: commit more memory.
ASSERT(cbNew <= LARGEST_ALLOC); if (!VirtualAlloc(pmem + cbAlloc, cbNew - cbAlloc, MEM_COMMIT, PAGE_READWRITE)) OOM();
cbAlloc = cbNew; }
// We're still a pseudo-file; and we either already
// reallocated or don't need to.
ASSERT(pmem && FilePtr + lcb <= cbAlloc);
// Copy the new data to the pseudo-file.
memcpy(pmem + FilePtr, qv, lcb); FilePtr += lcb; if (FilePtr > cbFile) cbFile = FilePtr; return lcb; }
int STDCALL CTmpFile::read(void* qv, int lcb) { if (pszFileName) return _lread(hf, qv, lcb); else { if (lcb > cbFile) lcb = cbFile; memcpy(qv, pmem + FilePtr, lcb); FilePtr += lcb; return lcb; } }
/***************************************************************************
FUNCTION: CTmpFile::copyfromfile
PURPOSE: Copy lcb bytes from a file into our temporary file buffer
PARAMETERS: hfSrc lcb
RETURNS:
COMMENTS: REVIEW: now that we can handle up to 8 megs, we should read from the file directly into our memory rather then going through a temporary buffer.
MODIFICATION DATES: 06-Jan-1994 [ralphw]
***************************************************************************/
RC_TYPE STDCALL CTmpFile::copyfromfile(HFILE hfSrc, DWORD lcb) { CMem buf(CB_COPY_BUFFER);
int cbRead = CB_COPY_BUFFER;
while (lcb > CB_COPY_BUFFER) { if ((cbRead = _lread(hfSrc, buf.pb, CB_COPY_BUFFER)) == HFILE_ERROR) break;
if (write(buf.pb, cbRead) != cbRead) { cbRead = HFILE_ERROR; break; }
lcb -= cbRead; }
if (cbRead != HFILE_ERROR && lcb && (cbRead = _lread(hfSrc, buf.pb, lcb)) != HFILE_ERROR) { if (write(buf.pb, cbRead) != cbRead) cbRead = HFILE_ERROR; }
if (cbRead == HFILE_ERROR) { if (SetFSErrorRc(RcGetIOError()) == RC_Success) SetFSErrorRc(RC_Invalid); } else SetFSErrorRc(RC_Success);
return rcFSError; }
/***************************************************************************
FUNCTION: CTmpFile::copytofile
PURPOSE: Copy from our temporary buffer into a real file
PARAMETERS: hfDst lcb
RETURNS:
COMMENTS:
MODIFICATION DATES: 06-Jan-1994 [ralphw]
***************************************************************************/
RC_TYPE STDCALL CTmpFile::copytofile(HFILE hfDst, DWORD lcb) { int cbRead = CB_COPY_BUFFER;;
if (hf == HFILE_ERROR) {
// Not a real file, so just copy our entire buffer
ASSERT(FilePtr == 0);
if (_lwrite(hfDst, (LPCSTR) pmem, cbFile) != (UINT) cbFile) cbRead = HFILE_ERROR; } else { CMem buf(CB_COPY_BUFFER);
#ifdef _DEBUG
if (lcb > CB_COPY_BUFFER) DBWIN("CB_COPY_BUFFER wasn't large enough in copytofile."); #endif
while (lcb > CB_COPY_BUFFER) { if ((cbRead = read(buf.pb, CB_COPY_BUFFER)) == HFILE_ERROR) break;
if (_lwrite(hfDst, (LPCSTR) buf.pb, cbRead) != (UINT) cbRead) { cbRead = HFILE_ERROR; break; }
lcb -= cbRead; }
if (cbRead != HFILE_ERROR && lcb && (cbRead = read(buf.pb, lcb)) != HFILE_ERROR) { if (_lwrite(hfDst, (LPCSTR) buf.pb, cbRead) != (UINT) cbRead) cbRead = HFILE_ERROR; } }
if (cbRead == HFILE_ERROR) { if (SetFSErrorRc(RcGetIOError()) == RC_Success) SetFSErrorRc(RC_Invalid); } else SetFSErrorRc(RC_Success);
return rcFSError; }
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