1 /* 2 * Copyright (c) 2020-2022 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 /* 17 * Font cache is used for managing font bitmap. 18 * Each bitmap is contained in a chunk block which can be searched quickly in a hash-table. 19 * All the struct and memory block are force-aligned to ALIGNMENT_BYTES. 20 * To make the most frequently used memroy hot, chunk blocks are managed with an easy lru algorithm. 21 * Memory maps of font cache is shown below: 22 * 23 * aligned bitmapCache ─────────►┌────────────────────┐ 24 * (FONT_BITMAP_CACHE_SIZE) │ HashTable │ 25 * │ (ListHead*32) │ 26 * UIFontAllocator::free_ ──────────┼────────────────────┼───────────► ┌──────────────┐ 27 * │ chunk block │ │ struct Chunk │ 28 * ├────────────────────┼──────┐ ├──────────────┤ 29 * │ ... │ │ │ struct Bitmap│ 30 * ├────────────────────┤ │ ├──────────────┤ 31 * │ chunk block │ │ │ FontCache │ 32 * ├────────────────────┤ │ │ (20*20*n) │ 33 * │ last_chunk │ └────► └──────────────┘ 34 * │ (Head only) │ 35 * └────────────────────┘ 36 */ 37 #ifndef UI_FONT_CACHE_H 38 #define UI_FONT_CACHE_H 39 40 #include "ui_font_allocator.h" 41 #include "font/ui_font_header.h" 42 43 namespace OHOS { 44 class UIFontCache : public HeapBase { 45 public: 46 static constexpr uint8_t FONT_CACHE_HASH_NR = 32; 47 static constexpr uint32_t FONT_CACHE_MIN_SIZE = 20 * 20; 48 struct UI_STRUCT_ALIGN ListHead { 49 ListHead* prev; 50 ListHead* next; 51 }; 52 struct UI_STRUCT_ALIGN Bitmap { 53 ListHead hashHead; 54 ListHead lruHead; 55 uint32_t fontId; // bitmap font: fontId vector font: fontKey ttfId + fontsize 56 uint32_t unicode; 57 uint32_t reserve1; 58 uint32_t reserve2; 59 #if defined(ENABLE_SPANNABLE_STRING) && ENABLE_SPANNABLE_STRING 60 TextStyle textStyle; 61 #endif 62 uint8_t data[]; 63 }; 64 65 UIFontCache(uint8_t* ram, uint32_t size); 66 67 ~UIFontCache(); 68 69 uint8_t* GetSpace(uint16_t fontKey, uint32_t unicode, uint32_t size, TextStyle textStyle = TEXT_STYLE_NORMAL); 70 void PutSpace(uint8_t* addr); 71 uint8_t* GetBitmap(uint16_t fontKey, uint32_t unicode, TextStyle textStyle = TEXT_STYLE_NORMAL); 72 73 private: 74 void UpdateLru(Bitmap* bitmap); ListInit(ListHead * head)75 void ListInit(ListHead* head) 76 { 77 head->prev = head; 78 head->next = head; 79 } ListAdd(ListHead * node,ListHead * head)80 void ListAdd(ListHead* node, ListHead* head) 81 { 82 head->next->prev = node; 83 node->next = head->next; 84 node->prev = head; 85 head->next = node; 86 } ListDel(ListHead * node)87 void ListDel(ListHead* node) 88 { 89 node->next->prev = node->prev; 90 node->prev->next = node->next; 91 } 92 93 UIFontAllocator allocator_; 94 ListHead* hashTable_ = nullptr; 95 ListHead lruList_ = {}; 96 }; 97 } // namespace OHOS 98 #endif /* UI_FONT_CACHE_H */ 99