dlls/combase/string.c

   1 /*
   2  * Copyright 2014 Martin Storsjo
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18
  19 #include <string.h>
  20
  21 #include "windows.h"
  22 #include "winerror.h"
  23 #include "hstring.h"
  24 #include "wine/debug.h"
  25
  26 WINE_DEFAULT_DEBUG_CHANNEL(combase);
  27
  28 struct hstring_private
  29 {
  30     LPWSTR buffer;
  31     UINT32 length;
  32     BOOL   reference;
  33     LONG   refcount;
  34 };
  35
  36 static const WCHAR empty[1];
  37
  38 C_ASSERT(sizeof(struct hstring_private) <= sizeof(HSTRING_HEADER));
  39
  40 static inline struct hstring_private *impl_from_HSTRING(HSTRING string)
  41 {
  42    return (struct hstring_private *)string;
  43 }
  44
  45 static inline struct hstring_private *impl_from_HSTRING_HEADER(HSTRING_HEADER *header)
  46 {
  47    return (struct hstring_private *)header;
  48 }
  49
  50 static BOOL alloc_string(UINT32 len, HSTRING *out)
  51 {
  52     struct hstring_private *priv;
  53     priv = HeapAlloc(GetProcessHeap(), 0, sizeof(*priv) + (len + 1) * sizeof(*priv->buffer));
  54     if (!priv)
  55         return FALSE;
  56     priv->buffer = (LPWSTR)(priv + 1);
  57     priv->length = len;
  58     priv->reference = FALSE;
  59     priv->refcount = 1;
  60     priv->buffer[len] = '\0';
  61     *out = (HSTRING)priv;
  62     return TRUE;
  63 }
  64
  65 /***********************************************************************
  66  *      WindowsCreateString (combase.@)
  67  */
  68 HRESULT WINAPI WindowsCreateString(LPCWSTR ptr, UINT32 len,
  69                                    HSTRING *out)
  70 {
  71     struct hstring_private *priv;
  72     if (out == NULL)
  73         return E_INVALIDARG;
  74     if (ptr == NULL && len > 0)
  75         return E_POINTER;
  76     if (len == 0)
  77     {
  78         *out = NULL;
  79         return S_OK;
  80     }
  81     if (!alloc_string(len, out))
  82         return E_OUTOFMEMORY;
  83     priv = impl_from_HSTRING(*out);
  84     memcpy(priv->buffer, ptr, len * sizeof(*priv->buffer));
  85     return S_OK;
  86 }
  87
  88 /***********************************************************************
  89  *      WindowsCreateStringReference (combase.@)
  90  */
  91 HRESULT WINAPI WindowsCreateStringReference(LPCWSTR ptr, UINT32 len,
  92                                             HSTRING_HEADER *header, HSTRING *out)
  93 {
  94     struct hstring_private *priv = impl_from_HSTRING_HEADER(header);
  95     if (out == NULL || header == NULL)
  96         return E_INVALIDARG;
  97     if (ptr == NULL && len > 0)
  98         return E_POINTER;
  99     if (ptr[len] != '\0')
 100         return E_INVALIDARG;
 101     if (len == 0)
 102     {
 103         *out = NULL;
 104         return S_OK;
 105     }
 106     priv->buffer = (LPWSTR)ptr;
 107     priv->length = len;
 108     priv->reference = TRUE;
 109     *out = (HSTRING)header;
 110     return S_OK;
 111 }
 112
 113 /***********************************************************************
 114  *      WindowsDeleteString (combase.@)
 115  */
 116 HRESULT WINAPI WindowsDeleteString(HSTRING str)
 117 {
 118     struct hstring_private *priv = impl_from_HSTRING(str);
 119     if (str == NULL)
 120         return S_OK;
 121     if (priv->reference)
 122         return S_OK;
 123     if (InterlockedDecrement(&priv->refcount) == 0)
 124         HeapFree(GetProcessHeap(), 0, priv);
 125     return S_OK;
 126 }
 127
 128 /***********************************************************************
 129  *      WindowsDuplicateString (combase.@)
 130  */
 131 HRESULT WINAPI WindowsDuplicateString(HSTRING str, HSTRING *out)
 132 {
 133     struct hstring_private *priv = impl_from_HSTRING(str);
 134     if (out == NULL)
 135         return E_INVALIDARG;
 136     if (str == NULL)
 137     {
 138         *out = NULL;
 139         return S_OK;
 140     }
 141     if (priv->reference)
 142         return WindowsCreateString(priv->buffer, priv->length, out);
 143     InterlockedIncrement(&priv->refcount);
 144     *out = str;
 145     return S_OK;
 146 }
 147
 148 /***********************************************************************
 149  *      WindowsGetStringLen (combase.@)
 150  */
 151 UINT32 WINAPI WindowsGetStringLen(HSTRING str)
 152 {
 153     struct hstring_private *priv = impl_from_HSTRING(str);
 154     if (str == NULL)
 155         return 0;
 156     return priv->length;
 157 }
 158
 159 /***********************************************************************
 160  *      WindowsGetStringRawBuffer (combase.@)
 161  */
 162 LPCWSTR WINAPI WindowsGetStringRawBuffer(HSTRING str, UINT32 *len)
 163 {
 164     struct hstring_private *priv = impl_from_HSTRING(str);
 165     if (str == NULL)
 166     {
 167         if (len)
 168             *len = 0;
 169         return empty;
 170     }
 171     if (len)
 172         *len = priv->length;
 173     return priv->buffer;
 174 }
 175
 176 /***********************************************************************
 177  *      WindowsStringHasEmbeddedNull (combase.@)
 178  */
 179 HRESULT WINAPI WindowsStringHasEmbeddedNull(HSTRING str, BOOL *out)
 180 {
 181     UINT32 i;
 182     struct hstring_private *priv = impl_from_HSTRING(str);
 183     if (out == NULL)
 184         return E_INVALIDARG;
 185     if (str == NULL)
 186     {
 187         *out = FALSE;
 188         return S_OK;
 189     }
 190     for (i = 0; i < priv->length; i++)
 191     {
 192         if (priv->buffer[i] == '\0')
 193         {
 194             *out = TRUE;
 195             return S_OK;
 196         }
 197     }
 198     *out = FALSE;
 199     return S_OK;
 200 }
 201
 202 /***********************************************************************
 203  *      WindowsIsStringEmpty (combase.@)
 204  */
 205 BOOL WINAPI WindowsIsStringEmpty(HSTRING str)
 206 {
 207     struct hstring_private *priv = impl_from_HSTRING(str);
 208     if (str == NULL)
 209         return TRUE;
 210     return priv->length == 0;
 211 }