reactos/win32ss/printing/base/spoolss/monitors.c

70 lines
2.1 KiB
C

/*
* PROJECT: ReactOS Spooler Router
* LICENSE: GPL-2.0+ (https://spdx.org/licenses/GPL-2.0+)
* PURPOSE: Functions related to Print Monitors
* COPYRIGHT: Copyright 2015-2017 Colin Finck (colin@reactos.org)
*/
#include "precomp.h"
BOOL WINAPI
EnumMonitorsW(PWSTR pName, DWORD Level, PBYTE pMonitors, DWORD cbBuf, PDWORD pcbNeeded, PDWORD pcReturned)
{
BOOL bReturnValue = TRUE;
DWORD cbCallBuffer;
DWORD cbNeeded;
DWORD dwReturned;
PBYTE pCallBuffer;
PSPOOLSS_PRINT_PROVIDER pPrintProvider;
PLIST_ENTRY pEntry;
// Sanity checks.
if (cbBuf && !pMonitors)
{
SetLastError(ERROR_INVALID_USER_BUFFER);
return FALSE;
}
// Begin counting.
*pcbNeeded = 0;
*pcReturned = 0;
// At the beginning, we have the full buffer available.
cbCallBuffer = cbBuf;
pCallBuffer = pMonitors;
// Loop through all Print Provider.
for (pEntry = PrintProviderList.Flink; pEntry != &PrintProviderList; pEntry = pEntry->Flink)
{
pPrintProvider = CONTAINING_RECORD(pEntry, SPOOLSS_PRINT_PROVIDER, Entry);
// Check if this Print Provider provides an EnumMonitors function.
if (!pPrintProvider->PrintProvider.fpEnumMonitors)
continue;
// Call the EnumMonitors function of this Print Provider.
cbNeeded = 0;
dwReturned = 0;
bReturnValue = pPrintProvider->PrintProvider.fpEnumMonitors(pName, Level, pCallBuffer, cbCallBuffer, &cbNeeded, &dwReturned);
// Add the returned counts to the total values.
*pcbNeeded += cbNeeded;
*pcReturned += dwReturned;
// Reduce the available buffer size for the next call without risking an underflow.
if (cbNeeded < cbCallBuffer)
cbCallBuffer -= cbNeeded;
else
cbCallBuffer = 0;
// Advance the buffer if the caller provided it.
if (pCallBuffer)
pCallBuffer += cbNeeded;
// Check if we shall not ask other Print Providers.
if (bReturnValue == ROUTER_STOP_ROUTING)
break;
}
return bReturnValue;
}