VBoxServicePropCache.cpp@ 68080

Last change on this file since 68080 was 64766, checked in by vboxsync, 8 years ago
src/VBox: Make the use of the iterator for RTListForEach()/RTListForEachSafe() more obvious. There is no need to initialize the iterator and we also must not depend on the iterator being NULL if the list was empty.
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 14.4 KB

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1	/* $Id: VBoxServicePropCache.cpp 64766 2016-11-30 10:59:48Z vboxsync $ */
2	/** @file
3	* VBoxServicePropCache - Guest property cache.
4	*/
5
6	/*
7	* Copyright (C) 2010-2016 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
34	/** @todo Docs */
35	static PVBOXSERVICEVEPROPCACHEENTRY vgsvcPropCacheFindInternal(PVBOXSERVICEVEPROPCACHE pCache, const char *pszName,
36	uint32_t fFlags)
37	{
38	RT_NOREF1(fFlags);
39	AssertPtrReturn(pCache, NULL);
40	AssertPtrReturn(pszName, NULL);
41
42	/** @todo This is a O(n) lookup, maybe improve this later to O(1) using a
43	* map.
44	* r=bird: Use a string space (RTstrSpace*). That is O(log n) in its current
45	* implementation (AVL tree). However, this is not important at the
46	* moment. */
47	PVBOXSERVICEVEPROPCACHEENTRY pNode = NULL;
48	if (RT_SUCCESS(RTCritSectEnter(&pCache->CritSect)))
49	{
50	PVBOXSERVICEVEPROPCACHEENTRY pNodeIt;
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 */
66	static PVBOXSERVICEVEPROPCACHEENTRY vgsvcPropCacheInsertEntryInternal(PVBOXSERVICEVEPROPCACHE pCache, const char *pszName)
67	{
68	AssertPtrReturn(pCache, NULL);
69	AssertPtrReturn(pszName, NULL);
70
71	PVBOXSERVICEVEPROPCACHEENTRY pNode = (PVBOXSERVICEVEPROPCACHEENTRY)RTMemAlloc(sizeof(VBOXSERVICEVEPROPCACHEENTRY));
72	if (pNode)
73	{
74	pNode->pszName = RTStrDup(pszName);
75	if (!pNode->pszName)
76	{
77	RTMemFree(pNode);
78	return NULL;
79	}
80	pNode->pszValue = NULL;
81	pNode->fFlags = 0;
82	pNode->pszValueReset = NULL;
83
84	int rc = RTCritSectEnter(&pCache->CritSect);
85	if (RT_SUCCESS(rc))
86	{
87	RTListAppend(&pCache->NodeHead, &pNode->NodeSucc);
88	rc = RTCritSectLeave(&pCache->CritSect);
89	}
90	}
91	return pNode;
92	}
93
94
95	/** @todo Docs */
96	static int vgsvcPropCacheWritePropF(uint32_t u32ClientId, const char pszName, uint32_t fFlags, const char pszValueFormat, ...)
97	{
98	AssertPtrReturn(pszName, VERR_INVALID_POINTER);
99
100	int rc;
101	if (pszValueFormat != NULL)
102	{
103	va_list va;
104	va_start(va, pszValueFormat);
105
106	char *pszValue;
107	if (RTStrAPrintfV(&pszValue, pszValueFormat, va) >= 0)
108	{
109	if (fFlags & VGSVCPROPCACHE_FLAGS_TRANSIENT)
110	{
111	/*
112	* Because a value can be temporary we have to make sure it also
113	* gets deleted when the property cache did not have the chance to
114	* gracefully clean it up (due to a hard VM reset etc), so set this
115	* guest property using the TRANSRESET flag..
116	*/
117	rc = VbglR3GuestPropWrite(u32ClientId, pszName, pszValue, "TRANSRESET");
118	if (rc == VERR_PARSE_ERROR)
119	{
120	/* Host does not support the "TRANSRESET" flag, so only
121	* use the "TRANSIENT" flag -- better than nothing :-). */
122	rc = VbglR3GuestPropWrite(u32ClientId, pszName, pszValue, "TRANSIENT");
123	/** @todo r=bird: Remember that the host doesn't support
124	* this. */
125	}
126	}
127	else
128	rc = VbglR3GuestPropWriteValue(u32ClientId, pszName, pszValue /* No transient flags set */);
129	RTStrFree(pszValue);
130	}
131	else
132	rc = VERR_NO_MEMORY;
133	va_end(va);
134	}
135	else
136	rc = VbglR3GuestPropWriteValue(u32ClientId, pszName, NULL);
137	return rc;
138	}
139
140
141	/**
142	* Creates a property cache.
143	*
144	* @returns IPRT status code.
145	* @param pCache Pointer to the cache.
146	* @param uClientId The HGCM handle of to the guest property service.
147	*/
148	int VGSvcPropCacheCreate(PVBOXSERVICEVEPROPCACHE pCache, uint32_t uClientId)
149	{
150	AssertPtrReturn(pCache, VERR_INVALID_POINTER);
151	/** @todo Prevent init the cache twice!
152	* r=bird: Use a magic. */
153	RTListInit(&pCache->NodeHead);
154	pCache->uClientID = uClientId;
155	return RTCritSectInit(&pCache->CritSect);
156	}
157
158
159	/**
160	* Updates a cache entry without submitting any changes to the host.
161	*
162	* This is handy for defining default values/flags.
163	*
164	* @returns VBox status code.
165	*
166	* @param pCache The property cache.
167	* @param pszName The property name.
168	* @param fFlags The property flags to set.
169	* @param pszValueReset The property reset value.
170	*/
171	int VGSvcPropCacheUpdateEntry(PVBOXSERVICEVEPROPCACHE pCache, const char pszName, uint32_t fFlags, const char pszValueReset)
172	{
173	AssertPtrReturn(pCache, VERR_INVALID_POINTER);
174	AssertPtrReturn(pszName, VERR_INVALID_POINTER);
175	PVBOXSERVICEVEPROPCACHEENTRY pNode = vgsvcPropCacheFindInternal(pCache, pszName, 0);
176	if (pNode == NULL)
177	pNode = vgsvcPropCacheInsertEntryInternal(pCache, pszName);
178
179	int rc;
180	if (pNode != NULL)
181	{
182	rc = RTCritSectEnter(&pCache->CritSect);
183	if (RT_SUCCESS(rc))
184	{
185	pNode->fFlags = fFlags;
186	if (pszValueReset)
187	{
188	if (pNode->pszValueReset)
189	RTStrFree(pNode->pszValueReset);
190	pNode->pszValueReset = RTStrDup(pszValueReset);
191	AssertPtr(pNode->pszValueReset);
192	}
193	rc = RTCritSectLeave(&pCache->CritSect);
194	}
195	}
196	else
197	rc = VERR_NO_MEMORY;
198	return rc;
199	}
200
201
202	/**
203	* Updates the local guest property cache and writes it to HGCM if outdated.
204	*
205	* @returns VBox status code.
206	*
207	* @param pCache The property cache.
208	* @param pszName The property name.
209	* @param pszValueFormat The property format string. If this is NULL then
210	* the property will be deleted (if possible).
211	* @param ... Format arguments.
212	*/
213	int VGSvcPropCacheUpdate(PVBOXSERVICEVEPROPCACHE pCache, const char pszName, const char pszValueFormat, ...)
214	{
215	AssertPtrReturn(pCache, VERR_INVALID_POINTER);
216	AssertPtrReturn(pszName, VERR_INVALID_POINTER);
217
218	Assert(pCache->uClientID);
219
220	/*
221	* Format the value first.
222	*/
223	char *pszValue = NULL;
224	if (pszValueFormat)
225	{
226	va_list va;
227	va_start(va, pszValueFormat);
228	RTStrAPrintfV(&pszValue, pszValueFormat, va);
229	va_end(va);
230	if (!pszValue)
231	return VERR_NO_STR_MEMORY;
232	}
233
234	PVBOXSERVICEVEPROPCACHEENTRY pNode = vgsvcPropCacheFindInternal(pCache, pszName, 0);
235
236	/* Lock the cache. */
237	int rc = RTCritSectEnter(&pCache->CritSect);
238	if (RT_SUCCESS(rc))
239	{
240	if (pNode == NULL)
241	pNode = vgsvcPropCacheInsertEntryInternal(pCache, pszName);
242
243	AssertPtr(pNode);
244	if (pszValue) /* Do we have a value to check for? */
245	{
246	bool fUpdate = false;
247	/* Always update this property, no matter what? */
248	if (pNode->fFlags & VGSVCPROPCACHE_FLAGS_ALWAYS_UPDATE)
249	fUpdate = true;
250	/* Did the value change so we have to update? */
251	else if (pNode->pszValue && strcmp(pNode->pszValue, pszValue) != 0)
252	fUpdate = true;
253	/* No value stored at the moment but we have a value now? */
254	else if (pNode->pszValue == NULL)
255	fUpdate = true;
256
257	if (fUpdate)
258	{
259	/* Write the update. */
260	rc = vgsvcPropCacheWritePropF(pCache->uClientID, pNode->pszName, pNode->fFlags, pszValue);
261	VGSvcVerbose(4, "[PropCache %p]: Written '%s'='%s' (flags: %x), rc=%Rrc\n",
262	pCache, pNode->pszName, pszValue, pNode->fFlags, rc);
263	if (RT_SUCCESS(rc)) /* Only update the node's value on successful write. */
264	{
265	RTStrFree(pNode->pszValue);
266	pNode->pszValue = RTStrDup(pszValue);
267	if (!pNode->pszValue)
268	rc = VERR_NO_MEMORY;
269	}
270	}
271	else
272	rc = VINF_NO_CHANGE; /* No update needed. */
273	}
274	else
275	{
276	/* No value specified. Deletion (or no action required). */
277	if (pNode->pszValue) /* Did we have a value before? Then the value needs to be deleted. */
278	{
279	rc = vgsvcPropCacheWritePropF(pCache->uClientID, pNode->pszName,
280	0, /* Flags / NULL / Value */);
281	VGSvcVerbose(4, "[PropCache %p]: Deleted '%s'='%s' (flags: %x), rc=%Rrc\n",
282	pCache, pNode->pszName, pNode->pszValue, pNode->fFlags, rc);
283	if (RT_SUCCESS(rc)) /* Only delete property value on successful Vbgl deletion. */
284	{
285	/* Delete property (but do not remove from cache) if not deleted yet. */
286	RTStrFree(pNode->pszValue);
287	pNode->pszValue = NULL;
288	}
289	}
290	else
291	rc = VINF_NO_CHANGE; /* No update needed. */
292	}
293
294	/* Release cache. */
295	RTCritSectLeave(&pCache->CritSect);
296	}
297
298	VGSvcVerbose(4, "[PropCache %p]: Updating '%s' resulted in rc=%Rrc\n", pCache, pszName, rc);
299
300	/* Delete temp stuff. */
301	RTStrFree(pszValue);
302	return rc;
303	}
304
305
306	/**
307	* Updates all cache values which are matching the specified path.
308	*
309	* @returns VBox status code.
310	*
311	* @param pCache The property cache.
312	* @param pszValue The value to set. A NULL will delete the value.
313	* @param fFlags Flags to set.
314	* @param pszPathFormat The path format string. May not be null and has
315	* to be an absolute path.
316	* @param ... Format arguments.
317	*/
318	int VGSvcPropCacheUpdateByPath(PVBOXSERVICEVEPROPCACHE pCache, const char *pszValue, uint32_t fFlags,
319	const char *pszPathFormat, ...)
320	{
321	RT_NOREF1(fFlags);
322	AssertPtrReturn(pCache, VERR_INVALID_POINTER);
323	AssertPtrReturn(pszPathFormat, VERR_INVALID_POINTER);
324
325	int rc = VERR_NOT_FOUND;
326	if (RT_SUCCESS(RTCritSectEnter(&pCache->CritSect)))
327	{
328	/*
329	* Format the value first.
330	*/
331	char *pszPath = NULL;
332	va_list va;
333	va_start(va, pszPathFormat);
334	RTStrAPrintfV(&pszPath, pszPathFormat, va);
335	va_end(va);
336	if (!pszPath)
337	{
338	rc = VERR_NO_STR_MEMORY;
339	}
340	else
341	{
342	/* Iterate through all nodes and compare their paths. */
343	PVBOXSERVICEVEPROPCACHEENTRY pNodeIt;
344	RTListForEach(&pCache->NodeHead, pNodeIt, VBOXSERVICEVEPROPCACHEENTRY, NodeSucc)
345	{
346	if (RTStrStr(pNodeIt->pszName, pszPath) == pNodeIt->pszName)
347	{
348	/** @todo Use some internal function to update the node directly, this is slow atm. */
349	rc = VGSvcPropCacheUpdate(pCache, pNodeIt->pszName, pszValue);
350	}
351	if (RT_FAILURE(rc))
352	break;
353	}
354	RTStrFree(pszPath);
355	}
356	RTCritSectLeave(&pCache->CritSect);
357	}
358	return rc;
359	}
360
361
362	/**
363	* Flushes the cache by writing every item regardless of its state.
364	*
365	* @param pCache The property cache.
366	*/
367	int VGSvcPropCacheFlush(PVBOXSERVICEVEPROPCACHE pCache)
368	{
369	AssertPtrReturn(pCache, VERR_INVALID_POINTER);
370
371	int rc = VINF_SUCCESS;
372	if (RT_SUCCESS(RTCritSectEnter(&pCache->CritSect)))
373	{
374	PVBOXSERVICEVEPROPCACHEENTRY pNodeIt;
375	RTListForEach(&pCache->NodeHead, pNodeIt, VBOXSERVICEVEPROPCACHEENTRY, NodeSucc)
376	{
377	rc = vgsvcPropCacheWritePropF(pCache->uClientID, pNodeIt->pszName, pNodeIt->fFlags, pNodeIt->pszValue);
378	if (RT_FAILURE(rc))
379	break;
380	}
381	RTCritSectLeave(&pCache->CritSect);
382	}
383	return rc;
384	}
385
386
387	/**
388	* Reset all temporary properties and destroy the cache.
389	*
390	* @param pCache The property cache.
391	*/
392	void VGSvcPropCacheDestroy(PVBOXSERVICEVEPROPCACHE pCache)
393	{
394	AssertPtrReturnVoid(pCache);
395	Assert(pCache->uClientID);
396
397	/* Lock the cache. */
398	int rc = RTCritSectEnter(&pCache->CritSect);
399	if (RT_SUCCESS(rc))
400	{
401	PVBOXSERVICEVEPROPCACHEENTRY pNode = RTListGetFirst(&pCache->NodeHead, VBOXSERVICEVEPROPCACHEENTRY, NodeSucc);
402	while (pNode)
403	{
404	PVBOXSERVICEVEPROPCACHEENTRY pNext = RTListNodeIsLast(&pCache->NodeHead, &pNode->NodeSucc)
405	? NULL :
406	RTListNodeGetNext(&pNode->NodeSucc,
407	VBOXSERVICEVEPROPCACHEENTRY, NodeSucc);
408	RTListNodeRemove(&pNode->NodeSucc);
409
410	if (pNode->fFlags & VGSVCPROPCACHE_FLAGS_TEMPORARY)
411	rc = vgsvcPropCacheWritePropF(pCache->uClientID, pNode->pszName, pNode->fFlags, pNode->pszValueReset);
412
413	AssertPtr(pNode->pszName);
414	RTStrFree(pNode->pszName);
415	RTStrFree(pNode->pszValue);
416	RTStrFree(pNode->pszValueReset);
417	pNode->fFlags = 0;
418
419	RTMemFree(pNode);
420
421	pNode = pNext;
422	}
423	RTCritSectLeave(&pCache->CritSect);
424	}
425
426	/* Destroy critical section. */
427	RTCritSectDelete(&pCache->CritSect);
428	}
429

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source: vbox/trunk/src/VBox/Additions/common/VBoxService/VBoxServicePropCache.cpp@ 68080

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