[&](widget& w, rect r) { widget.place(r); } ); } void center_bitmaps() { std::array<bitmap, 3> = { , , }; // What now? } 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 6void vertical_ce center_bitmaps() { std::array<bitmap, 3> = { , , }; // What now? } 1 2 3 4 5 6 7 8 7struct widget { rect bounding_box(); void place(rect r); }; struct bitmap { std::array data; std::array<bitmap, 3> = { , , }; 16 // What now? 17 } 18 8void vertical_center(auto const& c) { struct widget { 1 rect bounding_box(); 2 void place(rect r); 3 }; 4 5 struct bitmap { 6 std::array

0 码力 | 132 页 | 14.20 MB | 6 月前

3

Example Bitmap Functions ● All of these functions are related to operating on ‘bitmap images’ -- they are a provided common set of functions ○ Load Bitmap Filename ○ Load Bitmap Filename, Bitmap Number Number ○ Set Current Bitmap Bitmap Number ■ etc. 20A Monumental Moment! (3/3) 21 ● Loops and functions are somewhat related -- both help us reuse blocks of code for computation ● All of these functions related to operating on ‘bitmap images’ -- they are a provided common set of functions ○ Load Bitmap Filename ○ Load Bitmap Filename, Bitmap Number ○ Set Current Bitmap Bitmap Number ■ etc. Again

字段 类型 说明 version uint8_t 文件格式协议 版本号 demaged bool 损坏标记 sn uint64_t 快照版本号 bits uint32_t 位图的位数 bitmap char[] 位图 crc uint32_t 上述字段的crc 校验码 padding / 填0，以补足 4KBCHUNKSERVER端快照实现-写时复制原理  写时复制通常使用版本号实现 快照实现-写时复制  使用copy-on-write  当前写请求的sn > chunk的cur_sn时触发复制  拷贝的单位是一个Page，即4KB  使用snapfile中的bitmap标记复制过的PageCHUNKSERVER端快照实现-转储内部快照 a) 打快照后未写过，未触发cow， 无snap file产生，直接读取chunk file b) 打快照后写过，触发了cow， location占用的字节数 location char[] 可缺省，当前为CloneChunk时表示 克隆源字段 bits uint32_t 可缺省，当前为CloneChunk时表示 bitmap的位数 bitmap char[] 可缺省，位图表 crc uint32_t 上述字段的crc校验码 padding / 填0，以补足4KB location定义为A@B的形式: • 如果源卷在s3

on a bitmap management system. • The XOffsetDatastructure maintains a block of memory space with contiguous virtual addresses. • This memory block is divided into chunks, and we use a bitmap to track track the usage status of each chunk. Fanchen Su, XOffsetDatastructure, CppCon 2024 78 Bitmap AllocatorBitmap Allocator (After mallocN) 5.1 Custom Allocator • mallocN • This function is used to find mallocN to allocate a block of 3 contiguous chunks. Fanchen Su, XOffsetDatastructure, CppCon 2024 79Bitmap Allocator (After freeN) 5.1 Custom Allocator • freeN • This function is used to release N consecutive

reserved Page 116 2 "use strict"; 3 var game_over_panel, game_over_position, game_over_bitmap, panel_text_style; 4 // if current score is higher than highest score, update it 5 if ( score; 7 } 8 9 // create a bitmap do show the game over panel 10 game_over_position = new Phaser.Point(0, this.game.world.height); 11 game_over_bitmap = this.add.bitmapData(this.game.world world.width, this.game.world.height); 12 game_over_bitmap.ctx.fillStyle = "#000"; 13 game_over_bitmap.ctx.fillRect(0, 0, this.game.world.width, this.game.world.height); 14 panel_text_style

blustore/polarfs 直接在块设备上构建分布式fs。一个文件的数据对应块设备上某个空间，因此需要知道块设备的哪些空间是空闲的，哪些是已经分配出去的, 需要一个空间分配管理器。blustore有两个空间分配器bitmap和stupid。polarfs开源部分有空间映射关系，但空间分配器没有公布。 当前curve已经实现了块设备。curve的数据节点采用了chunkfilepool实现性能优化，同时也绕过了文件 blk的粒度为多少？ 从调研的系统来看，如果chunk是固定的分配力度，会选择64k，以一个20TB的盘为例： blk=4k, 需要bitmap的大小为640MB blk=64k, 需要bitmap的大小为40MB 在设计过程中，对于每个文件系统，blk应该是可以根据业务形态来配置的 bitmap重建时间？ 如果通过获取所有inode，重建出当前的空间分配情况，我们常见的业务形态有以下两种： ① 在AI训练等场景

void (*init) (void *userdata, struct fuse_conn_info *conn); 根据挂载信息，从mds获取文件系统信息（或superblock），块分配器（bitmap）和root inode所在的copyset、 metaserver ip等信息 去metaserver获取文件系统信息（super block），缓存到client端。 destroy void 因此不是必须接口，也先不实现。 功能分析 根据上述接口的分析，可以把client端的功能进行汇总，client需实现的功能主要有： 缓存文件系统元数据（包括super block， bitmap & allocator等） 缓存文件和目录信息（包括inode struct，dentry struct） 缓存metaserver copyset 和 topo信息（目前先支持单metase 根据上述功能模块，将client划分模块 fs cache inode cache dentry cache location cache （inode location、dentry location、fs location、bitmap location，目前都在同一meta server，可先不实现） copyset cache & topo cache （可先不实现） mds client meta server client

[out] IDisplaySourceBitmap displaySourceBitmap) screenId displaySourceBitmap Obtains the guest screen bitmap parameters. 5.18.14 setScreenLayout void IDisplay::setScreenLayout( [in] ScreenLayoutMode screenLayoutMode allocated by the caller and pointed to by address. The buffer size must be enough for a 32 bits per pixel bitmap, i.e. width * height * 4 bytes. Note: This API can be used only locally by a VM process through the bitmapFormat) address width height bitsPerPixel bytesPerLine bitmapFormat Information about the screen bitmap. 5.20 IDnDBase Base abstract interface for drag’n drop. 5.20.1 Attributes 5.20.1.1 formats (read-only)

[out] IDisplaySourceBitmap displaySourceBitmap) screenId displaySourceBitmap Obtains the guest screen bitmap parameters. 5.18.14 setScreenLayout void IDisplay::setScreenLayout( [in] ScreenLayoutMode screenLayoutMode allocated by the caller and pointed to by address. The buffer size must be enough for a 32 bits per pixel bitmap, i.e. width * height * 4 bytes. Note: This API can be used only locally by a VM process through the bitmapFormat) address width height bitsPerPixel bytesPerLine bitmapFormat Information about the screen bitmap. 5.20 IDnDBase Base abstract interface for drag’n drop. 5.20.1 Attributes 5.20.1.1 formats (read-only)

size Size of buffer required to store the bitmap. width Bitmap width. height Bitmap height. Returns size in bytes and dimensions in pixels of a saved thumbnail bitmap from saved state. 5.44.44 readLog octet[] is: B, G, R, 0xFF. If this parameter is false, then bytes order is: R, G, B, 0xFF. width Bitmap width. height Bitmap height. Thumbnail is retrieved to an array of bytes in uncompressed 32-bit BGRA or RGBA support alpha, the pointer could be displayed as a normal color pointer. The AND mask is a 1-bpp bitmap with byte aligned scanlines. The size of the AND mask therefore is cbAnd = (width + 7) / 8 * height