sdk/lib/drivers/sound/mment4/registry.c

   1 /*
   2  * PROJECT:     ReactOS Sound System "MME Buddy" NT4 Library
   3  * LICENSE:     GPL - See COPYING in the top level directory
   4  * FILE:        lib/drivers/sound/mment4/registry.c
   5  *
   6  * PURPOSE:     Registry operation helper for audio device drivers.
   7  *
   8  * PROGRAMMERS: Andrew Greenwood (silverblade@reactos.org)
   9 */
  10
  11 #include "precomp.h"
  12
  13 #include <mmebuddy_debug.h>
  14
  15 /*
  16     Open the parameters key of a sound driver.
  17     NT4 only.
  18 */
  19 MMRESULT
  20 OpenSoundDriverParametersRegKey(
  21     IN  LPWSTR ServiceName,
  22     OUT PHKEY KeyHandle)
  23 {
  24     SIZE_T KeyLength;
  25     PWCHAR ParametersKeyName;
  26
  27     VALIDATE_MMSYS_PARAMETER( ServiceName );
  28     VALIDATE_MMSYS_PARAMETER( KeyHandle );
  29
  30     /* Work out how long the string will be */
  31     KeyLength = wcslen(REG_SERVICES_KEY_NAME_U) + 1
  32               + wcslen(ServiceName) + 1
  33               + wcslen(REG_PARAMETERS_KEY_NAME_U);
  34
  35     /* Allocate memory for the string */
  36     ParametersKeyName = AllocateWideString(KeyLength);
  37
  38     if ( ! ParametersKeyName )
  39         return MMSYSERR_NOMEM;
  40
  41     /* Construct the registry path */
  42     wsprintf(ParametersKeyName,
  43              L"%s\\%s\\%s",
  44              REG_SERVICES_KEY_NAME_U,
  45              ServiceName,
  46              REG_PARAMETERS_KEY_NAME_U);
  47
  48     SND_TRACE(L"Opening reg key: %wS\n", ParametersKeyName);
  49
  50     /* Perform the open */
  51     if ( RegOpenKeyEx(HKEY_LOCAL_MACHINE,
  52                       ParametersKeyName,
  53                       0,
  54                       KEY_READ,
  55                       KeyHandle) != ERROR_SUCCESS )
  56     {
  57         /* Couldn't open the key */
  58         SND_ERR(L"Failed to open reg key: %wS\n", ParametersKeyName);
  59         FreeMemory(ParametersKeyName);
  60         return MMSYSERR_ERROR;
  61     }
  62
  63     FreeMemory(ParametersKeyName);
  64
  65     return MMSYSERR_NOERROR;
  66 }
  67
  68 /*
  69     Open one of the Device sub-keys belonging to the sound driver.
  70     NT4 only.
  71 */
  72 MMRESULT
  73 OpenSoundDeviceRegKey(
  74     IN  LPWSTR ServiceName,
  75     IN  DWORD DeviceIndex,
  76     OUT PHKEY KeyHandle)
  77 {
  78     SIZE_T PathLength;
  79     PWCHAR RegPath;
  80
  81     VALIDATE_MMSYS_PARAMETER( ServiceName );
  82     VALIDATE_MMSYS_PARAMETER( KeyHandle );
  83
  84     /*
  85         Work out the space required to hold the path:
  86
  87         HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\
  88             sndblst\
  89                 Parameters\
  90                     Device123\
  91     */
  92     PathLength = wcslen(REG_SERVICES_KEY_NAME_U) + 1
  93                + wcslen(ServiceName) + 1
  94                + wcslen(REG_PARAMETERS_KEY_NAME_U) + 1
  95                + wcslen(REG_DEVICE_KEY_NAME_U)
  96                + GetDigitCount(DeviceIndex);
  97
  98     /* Allocate storage for the string */
  99     RegPath = AllocateWideString(PathLength);
 100
 101     if ( ! RegPath )
 102     {
 103         return MMSYSERR_NOMEM;
 104     }
 105
 106     /* Write the path */
 107     wsprintf(RegPath,
 108              L"%ls\\%ls\\%ls\\%ls%d",
 109              REG_SERVICES_KEY_NAME_U,
 110              ServiceName,
 111              REG_PARAMETERS_KEY_NAME_U,
 112              REG_DEVICE_KEY_NAME_U,
 113              DeviceIndex);
 114
 115     SND_TRACE(L"Opening reg key: %wS\n", RegPath);
 116
 117     /* Perform the open */
 118     if ( RegOpenKeyEx(HKEY_LOCAL_MACHINE,
 119                       RegPath,
 120                       0,
 121                       KEY_READ,
 122                       KeyHandle) != ERROR_SUCCESS )
 123     {
 124         /* Couldn't open the key */
 125         SND_ERR(L"Failed to open reg key: %wS\n", RegPath);
 126         FreeMemory(RegPath);
 127         return MMSYSERR_ERROR;
 128     }
 129
 130     FreeMemory(RegPath);
 131
 132     return MMSYSERR_NOERROR;
 133 }