VirtualBox

source: vbox/trunk/src/VBox/Additions/common/VBoxService/VBoxServicePropCache.cpp@ 36219

Last change on this file since 36219 was 36219, checked in by vboxsync, 14 years ago

Addressed some guest property (transient reset) todos.
  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 13.5 KB
Line 
1/* $Id: VBoxServicePropCache.cpp 36219 2011-03-09 10:57:28Z vboxsync $ */
2/** @file
3 * VBoxServicePropCache - Guest property cache.
4 */
5
6/*
7 * Copyright (C) 2010 Oracle Corporation
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.virtualbox.org. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 */
17
18
19/*******************************************************************************
20* Header Files *
21*******************************************************************************/
22#include <iprt/assert.h>
23#include <iprt/list.h>
24#include <iprt/mem.h>
25#include <iprt/string.h>
26
27#include <VBox/VBoxGuestLib.h>
28#include "VBoxServiceInternal.h"
29#include "VBoxServiceUtils.h"
30#include "VBoxServicePropCache.h"
31
32
33/** Internal functions, not for public use. */
34PVBOXSERVICEVEPROPCACHEENTRY vboxServicePropCacheFindInternal(PVBOXSERVICEVEPROPCACHE pCache, const char *pszName, uint32_t uFlags);
35PVBOXSERVICEVEPROPCACHEENTRY vboxServicePropCacheInsertEntryInternal(PVBOXSERVICEVEPROPCACHE pCache, const char *pszName);
36
37
38/** @todo Docs */
39PVBOXSERVICEVEPROPCACHEENTRY vboxServicePropCacheFindInternal(PVBOXSERVICEVEPROPCACHE pCache, const char *pszName, uint32_t uFlags)
40{
41 AssertPtr(pCache);
42 AssertPtr(pszName);
43 /** @todo This is a O(n) lookup, maybe improve this later to O(1) using a
44 * map.
45 * r=bird: Use a string space (RTstrSpace*). That is O(log n) in its current
46 * implementation (AVL tree). However, this is not important at the
47 * moment. */
48 PVBOXSERVICEVEPROPCACHEENTRY pNodeIt, pNode = NULL;
49 if (RT_SUCCESS(RTCritSectEnter(&pCache->CritSect)))
50 {
51 RTListForEach(&pCache->NodeHead, pNodeIt, VBOXSERVICEVEPROPCACHEENTRY, NodeSucc)
52 {
53 if (strcmp(pNodeIt->pszName, pszName) == 0)
54 {
55 pNode = pNodeIt;
56 break;
57 }
58 }
59 RTCritSectLeave(&pCache->CritSect);
60 }
61 return pNode;
62}
63
64
65/** @todo Docs */
66PVBOXSERVICEVEPROPCACHEENTRY vboxServicePropCacheInsertEntryInternal(PVBOXSERVICEVEPROPCACHE pCache, const char *pszName)
67{
68 AssertPtr(pszName);
69 PVBOXSERVICEVEPROPCACHEENTRY pNode = (PVBOXSERVICEVEPROPCACHEENTRY)RTMemAlloc(sizeof(VBOXSERVICEVEPROPCACHEENTRY));
70 if (pNode)
71 {
72 pNode->pszName = RTStrDup(pszName);
73 pNode->pszValue = NULL;
74 pNode->fFlags = 0;
75 pNode->pszValueReset = NULL;
76
77 int rc = RTCritSectEnter(&pCache->CritSect);
78 if (RT_SUCCESS(rc))
79 {
80 /*rc =*/ RTListAppend(&pCache->NodeHead, &pNode->NodeSucc);
81 rc = RTCritSectLeave(&pCache->CritSect);
82 }
83 }
84 return pNode;
85}
86
87
88/** @todo Docs */
89int vboxServicePropCacheWritePropF(uint32_t u32ClientId, const char *pszName, uint32_t fFlags, const char *pszValueFormat, ...)
90{
91 AssertPtr(pszName);
92 int rc;
93 if (pszValueFormat != NULL)
94 {
95 va_list va;
96 va_start(va, pszValueFormat);
97
98 char *pszValue;
99 if (RTStrAPrintfV(&pszValue, pszValueFormat, va) >= 0)
100 {
101 if (fFlags & VBOXSERVICEPROPCACHEFLAG_TEMPORARY)
102 {
103 /*
104 * Because a value can be temporary we have to make sure it also
105 * gets deleted when the property cache did not have the chance to
106 * gracefully clean it up (due to a hard VM reset etc), so set this
107 * guest property using the TRANSRESET flag..
108 */
109 rc = VbglR3GuestPropWrite(u32ClientId, pszName, pszValue, "TRANSRESET");
110 if (rc == VERR_PARSE_ERROR)
111 {
112 /* Host does not support the "TRANSRESET" flag, so only
113 * use the "TRANSIENT" flag -- better than nothing :-). */
114 rc = VbglR3GuestPropWrite(u32ClientId, pszName, pszValue, "TRANSIENT");
115 /** @todo r=bird: Remember that the host doesn't support
116 * this. */
117 }
118 }
119 else
120 rc = VbglR3GuestPropWriteValue(u32ClientId, pszName, pszValue);
121 RTStrFree(pszValue);
122 }
123 else
124 rc = VERR_NO_MEMORY;
125 va_end(va);
126 }
127 else
128 {
129 rc = VbglR3GuestPropWriteValue(u32ClientId, pszName, NULL);
130 }
131 return rc;
132}
133
134
135/**
136 * Creates a property cache.
137 *
138 * @returns IPRT status code.
139 * @param pCache Pointer to the cache.
140 * @param uClientId The HGCM handle of to the guest property service.
141 */
142int VBoxServicePropCacheCreate(PVBOXSERVICEVEPROPCACHE pCache, uint32_t uClientId)
143{
144 AssertPtr(pCache);
145 /** @todo Prevent init the cache twice!
146 * r=bird: Use a magic. */
147 RTListInit(&pCache->NodeHead);
148 pCache->uClientID = uClientId;
149 return RTCritSectInit(&pCache->CritSect);
150}
151
152
153/**
154 * Updates a cache entry without submitting any changes to the host.
155 * This is handy for defining default values/flags.
156 *
157 * @returns VBox status code.
158 *
159 * @param pCache The property cache.
160 * @param pszName The property name.
161 * @param fFlags The property flags to set.
162 * @param pszValueReset The property reset value.
163 */
164int VBoxServicePropCacheUpdateEntry(PVBOXSERVICEVEPROPCACHE pCache,
165 const char *pszName, uint32_t fFlags, const char *pszValueReset)
166{
167 AssertPtr(pCache);
168 AssertPtr(pszName);
169 PVBOXSERVICEVEPROPCACHEENTRY pNode = vboxServicePropCacheFindInternal(pCache, pszName, 0);
170 if (pNode == NULL)
171 pNode = vboxServicePropCacheInsertEntryInternal(pCache, pszName);
172
173 int rc;
174 if (pNode != NULL)
175 {
176 rc = RTCritSectEnter(&pCache->CritSect);
177 if (RT_SUCCESS(rc))
178 {
179 pNode->fFlags = fFlags;
180 if (pszValueReset)
181 {
182 if (pNode->pszValueReset)
183 RTStrFree(pNode->pszValueReset);
184 pNode->pszValueReset = RTStrDup(pszValueReset);
185 }
186 rc = RTCritSectLeave(&pCache->CritSect);
187 }
188 }
189 else
190 rc = VERR_NO_MEMORY;
191 return rc;
192}
193
194
195/**
196 * Updates the local guest property cache and writes it to HGCM if outdated.
197 *
198 * @returns VBox status code.
199 *
200 * @param pCache The property cache.
201 * @param pszName The property name.
202 * @param pszValueFormat The property format string. If this is NULL then
203 * the property will be deleted (if possible).
204 * @param ... Format arguments.
205 */
206int VBoxServicePropCacheUpdate(PVBOXSERVICEVEPROPCACHE pCache, const char *pszName, const char *pszValueFormat, ...)
207{
208 AssertPtr(pCache);
209 Assert(pCache->uClientID);
210 AssertPtr(pszName);
211
212 /*
213 * Format the value first.
214 */
215 char *pszValue = NULL;
216 if (pszValueFormat)
217 {
218 va_list va;
219 va_start(va, pszValueFormat);
220 RTStrAPrintfV(&pszValue, pszValueFormat, va);
221 va_end(va);
222 if (!pszValue)
223 return VERR_NO_STR_MEMORY;
224 }
225
226 PVBOXSERVICEVEPROPCACHEENTRY pNode = vboxServicePropCacheFindInternal(pCache, pszName, 0);
227
228 /* Lock the cache. */
229 int rc = RTCritSectEnter(&pCache->CritSect);
230 if (RT_SUCCESS(rc))
231 {
232 if (pNode == NULL)
233 pNode = vboxServicePropCacheInsertEntryInternal(pCache, pszName);
234
235 AssertPtr(pNode);
236 if (pszValue) /* Do we have a value to check for? */
237 {
238 bool fUpdate = false;
239 /* Always update this property, no matter what? */
240 if (pNode->fFlags & VBOXSERVICEPROPCACHEFLAG_ALWAYS_UPDATE)
241 fUpdate = true;
242 /* Did the value change so we have to update? */
243 else if (pNode->pszValue && strcmp(pNode->pszValue, pszValue) != 0)
244 fUpdate = true;
245 /* No value stored at the moment but we have a value now? */
246 else if (pNode->pszValue == NULL)
247 fUpdate = true;
248
249 if (fUpdate)
250 {
251 /* Write the update. */
252 rc = vboxServicePropCacheWritePropF(pCache->uClientID, pNode->pszName, pNode->fFlags, pszValue);
253 RTStrFree(pNode->pszValue);
254 pNode->pszValue = RTStrDup(pszValue);
255 }
256 else
257 rc = VINF_NO_CHANGE; /* No update needed. */
258 }
259 else
260 {
261 /* No value specified. Deletion (or no action required). */
262 if (pNode->pszValue) /* Did we have a value before? Then the value needs to be deleted. */
263 {
264 /* Delete property (but do not remove from cache) if not deleted yet. */
265 RTStrFree(pNode->pszValue);
266 pNode->pszValue = NULL;
267 rc = vboxServicePropCacheWritePropF(pCache->uClientID, pNode->pszName,
268 0, /* Flags */ NULL /* Value */);
269 }
270 else
271 rc = VINF_NO_CHANGE; /* No update needed. */
272 }
273
274 /* Release cache. */
275 RTCritSectLeave(&pCache->CritSect);
276 }
277
278 /* Delete temp stuff. */
279 RTStrFree(pszValue);
280 return rc;
281}
282
283
284/**
285 * Updates all cache values which are matching the specified path.
286 *
287 * @returns VBox status code.
288 *
289 * @param pCache The property cache.
290 * @param pszValue The value to set. A NULL will delete the value.
291 * @param fFlags Flags to set.
292 * @param pszPathFormat The path format string. May not be null and has
293 * to be an absolute path.
294 * @param ... Format arguments.
295 */
296int VBoxServicePropCacheUpdateByPath(PVBOXSERVICEVEPROPCACHE pCache, const char *pszValue, uint32_t fFlags, const char *pszPathFormat, ...)
297{
298 AssertPtr(pCache);
299 AssertPtr(pszPathFormat);
300 int rc = VERR_NOT_FOUND;
301 PVBOXSERVICEVEPROPCACHEENTRY pNodeIt = NULL;
302 if (RT_SUCCESS(RTCritSectEnter(&pCache->CritSect)))
303 {
304 /*
305 * Format the value first.
306 */
307 char *pszPath = NULL;
308 va_list va;
309 va_start(va, pszPathFormat);
310 RTStrAPrintfV(&pszPath, pszPathFormat, va);
311 va_end(va);
312 if (!pszPath)
313 {
314 rc = VERR_NO_STR_MEMORY;
315 }
316 else
317 {
318 /* Iterate through all nodes and compare their paths. */
319 RTListForEach(&pCache->NodeHead, pNodeIt, VBOXSERVICEVEPROPCACHEENTRY, NodeSucc)
320 {
321 if (RTStrStr(pNodeIt->pszName, pszPath) == pNodeIt->pszName)
322 {
323 /** @todo Use some internal function to update the node directly, this is slow atm. */
324 rc = VBoxServicePropCacheUpdate(pCache, pNodeIt->pszName, pszValue);
325 }
326 if (RT_FAILURE(rc))
327 break;
328 }
329 RTStrFree(pszPath);
330 }
331 RTCritSectLeave(&pCache->CritSect);
332 }
333 return rc;
334}
335
336
337/**
338 * Flushes the cache by writing every item regardless of its state.
339 *
340 * @param pCache The property cache.
341 */
342int VBoxServicePropCacheFlush(PVBOXSERVICEVEPROPCACHE pCache)
343{
344 AssertPtr(pCache);
345 int rc = VINF_SUCCESS;
346 PVBOXSERVICEVEPROPCACHEENTRY pNodeIt = NULL;
347 if (RT_SUCCESS(RTCritSectEnter(&pCache->CritSect)))
348 {
349 RTListForEach(&pCache->NodeHead, pNodeIt, VBOXSERVICEVEPROPCACHEENTRY, NodeSucc)
350 {
351 rc = vboxServicePropCacheWritePropF(pCache->uClientID, pNodeIt->pszName,
352 pNodeIt->fFlags, pNodeIt->pszValue);
353 if (RT_FAILURE(rc))
354 break;
355 }
356 RTCritSectLeave(&pCache->CritSect);
357 }
358 return rc;
359}
360
361
362/**
363 * Reset all temporary properties and destroy the cache.
364 *
365 * @param pCache The property cache.
366 */
367void VBoxServicePropCacheDestroy(PVBOXSERVICEVEPROPCACHE pCache)
368{
369 AssertPtr(pCache);
370 Assert(pCache->uClientID);
371
372 /* Lock the cache. */
373 int rc = RTCritSectEnter(&pCache->CritSect);
374 if (RT_SUCCESS(rc))
375 {
376 PVBOXSERVICEVEPROPCACHEENTRY pNode = RTListGetFirst(&pCache->NodeHead, VBOXSERVICEVEPROPCACHEENTRY, NodeSucc);
377 while (pNode)
378 {
379 PVBOXSERVICEVEPROPCACHEENTRY pNext = RTListNodeIsLast(&pCache->NodeHead, &pNode->NodeSucc)
380 ? NULL :
381 RTListNodeGetNext(&pNode->NodeSucc,
382 VBOXSERVICEVEPROPCACHEENTRY, NodeSucc);
383 RTListNodeRemove(&pNode->NodeSucc);
384
385 /*
386 * When destroying the cache and we have a temporary value, remove the
387 * (eventually) set TRANSIENT_RESET flag from it so that it doesn't get deleted
388 * by the host side in order to put the actual reset value in it.
389 */
390 if (pNode->fFlags & VBOXSERVICEPROPCACHEFLAG_TEMPORARY)
391 vboxServicePropCacheWritePropF(pCache->uClientID, pNode->pszName, 0 /* Flags, clear all */, pNode->pszValueReset);
392
393 AssertPtr(pNode->pszName);
394 RTStrFree(pNode->pszName);
395 RTStrFree(pNode->pszValue);
396 RTStrFree(pNode->pszValueReset);
397 pNode->fFlags = 0;
398
399 RTMemFree(pNode);
400
401 pNode = pNext;
402 }
403 RTCritSectLeave(&pCache->CritSect);
404 }
405
406 /* Destroy critical section. */
407 RTCritSectDelete(&pCache->CritSect);
408}
409
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