1 /*
2  * Copyright 2015 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "GrTextBlobCache.h"
9 
10 DECLARE_SKMESSAGEBUS_MESSAGE(GrTextBlobCache::PurgeBlobMessage)
11 
12 static inline bool SkShouldPostMessageToBus(
13         const GrTextBlobCache::PurgeBlobMessage& msg, uint32_t msgBusUniqueID) {
14     return msg.fContextID == msgBusUniqueID;
15 }
16 
17 GrTextBlobCache::~GrTextBlobCache() {
18     this->freeAll();
19 }
20 
21 void GrTextBlobCache::freeAll() {
22     fBlobIDCache.foreach([this](uint32_t, BlobIDCacheEntry* entry) {
23         for (const auto& blob : entry->fBlobs) {
24             fBlobList.remove(blob.get());
25         }
26     });
27 
28     fBlobIDCache.reset();
29 
30     fCurrentSize = 0;
31 
32     // There should be no allocations in the memory pool at this point
33     SkASSERT(fBlobList.isEmpty());
34 }
35 
36 void GrTextBlobCache::PostPurgeBlobMessage(uint32_t blobID, uint32_t cacheID) {
37     SkASSERT(blobID != SK_InvalidGenID);
38     SkMessageBus<PurgeBlobMessage>::Post(PurgeBlobMessage(blobID, cacheID));
39 }
40 
41 void GrTextBlobCache::purgeStaleBlobs() {
42     SkTArray<PurgeBlobMessage> msgs;
43     fPurgeBlobInbox.poll(&msgs);
44 
45     for (const auto& msg : msgs) {
46         auto* idEntry = fBlobIDCache.find(msg.fBlobID);
47         if (!idEntry) {
48             // no cache entries for id
49             continue;
50         }
51 
52         // remove all blob entries from the LRU list
53         for (const auto& blob : idEntry->fBlobs) {
54             fCurrentSize -= blob->size();
55             fBlobList.remove(blob.get());
56         }
57 
58         // drop the idEntry itself (unrefs all blobs)
59         fBlobIDCache.remove(msg.fBlobID);
60     }
61 }
62 
63 void GrTextBlobCache::checkPurge(GrTextBlob* blob) {
64     // First, purge all stale blob IDs.
65     this->purgeStaleBlobs();
66 
67     // If we are still over budget, then unref until we are below budget again
68     if (fCurrentSize > fSizeBudget) {
69         BitmapBlobList::Iter iter;
70         iter.init(fBlobList, BitmapBlobList::Iter::kTail_IterStart);
71         GrTextBlob* lruBlob = nullptr;
72         while (fCurrentSize > fSizeBudget && (lruBlob = iter.get()) && lruBlob != blob) {
73             // Backup the iterator before removing and unrefing the blob
74             iter.prev();
75 
76             this->remove(lruBlob);
77         }
78 
79         // If we break out of the loop with lruBlob == blob, then we haven't purged enough
80         // use the call back and try to free some more.  If we are still overbudget after this,
81         // then this single textblob is over our budget
82         if (blob && lruBlob == blob) {
83             (*fCallback)(fData);
84         }
85 
86 #ifdef SPEW_BUDGET_MESSAGE
87         if (fCurrentSize > fSizeBudget) {
88             SkDebugf("Single textblob is larger than our whole budget");
89         }
90 #endif
91     }
92 }
93 
94 
95 
96