第 18 章： 发布与订阅

客户端订阅频道。

digraph { label = "\n 图 18-1 news.it 频道和它的三个订阅者"; rankdir = BT; // news_it [label = "news.it 频道", shape = box, width = 3.0]; client_1 [label = "客户端 A"]; client_2 [label = "客户端 B"]; client_3 [label = "客户端 C"]; // edge [label = "订阅"]; client_1 -> news_it; client_2 -> news_it; client_3 -> news_it; }

客户端向频道发送消息， 消息被传递至各个订阅者。

digraph { label = "\n 图 18-2 向 news.it 频道发送消息"; // publish [label = "PUBLISH \"news.it\" \"hello\"", shape = plaintext]; news_it [label = "news.it 频道", shape = box, width = 3.0]; client_1 [label = "客户端 A"]; client_2 [label = "客户端 B"]; client_3 [label = "客户端 C"]; // edge [style = dashed]; publish -> news_it; edge [label = "\"hello\""]; news_it -> client_1; news_it -> client_2; news_it -> client_3; }

客户端订阅模式。

digraph { label = "\n 图 18-3 频道和模式的订阅状态"; rankdir = BT; // news_et [label = "news.et 频道", shape = box, width = 3.0]; news_it [label = "news.it 频道", shape = box, width = 3.0]; news_iet [label = "news.[ie]t 模式", shape = hexagon, width = 3.0]; node [shape = ellipse]; client_1 [label = "客户端 A"]; client_2 [label = "客户端 B"]; client_3 [label = "客户端 C"]; client_4 [label = "客户端 D"]; // client_1 -> news_it [label = "订阅"]; client_2 -> news_et [label = "订阅"]; news_iet -> news_et [dir = back, label = "匹配"]; news_iet -> news_it [dir = back, label = "匹配"]; edge [label = "订阅"]; client_3 -> news_iet; client_4 -> news_iet; }

客户端向频道发送消息， 消息被传递给正在订阅匹配模式的订阅者。

digraph { label = "\n 图 18-4 将消息发送给频道的订阅者和匹配模式的订阅者"; rankdir = BT; // news_et [label = "news.et 频道", shape = box, width = 3.0]; news_it [label = "news.it 频道", shape = box, width = 3.0]; news_iet [label = "news.[ie]t 模式", shape = hexagon, width = 3.0]; publish [label = "PUBLISH \"news.it\" \"hello\"", shape = plaintext]; node [shape = ellipse]; client_1 [label = "客户端 A"]; client_2 [label = "客户端 B"]; client_3 [label = "客户端 C"]; client_4 [label = "客户端 D"]; // client_1 -> news_it [dir = back, label = "\"hello\"", style = dashed]; client_2 -> news_et [label = "订阅"]; news_iet -> news_et [dir = back, label = "匹配"]; news_iet -> news_it [dir = back, label = "匹配", style = dashed]; edge [dir = back, label = "\"hello\"", style = dashed]; client_3 -> news_iet; client_4 -> news_iet; news_it -> publish [dir = back, style = dashed, label =""]; }

另一个模式被匹配的例子。

digraph { label = "\n 图 18-5 将消息发送给频道的订阅者和匹配模式的订阅者"; rankdir = BT; // news_et [label = "news.et 频道", shape = box, width = 3.0]; news_it [label = "news.it 频道", shape = box, width = 3.0]; news_iet [label = "news.[ie]t 模式", shape = hexagon, width = 3.0]; publish [label = "PUBLISH \"news.et\" \"world\"", shape = plaintext]; node [shape = ellipse]; client_1 [label = "客户端 A"]; client_2 [label = "客户端 B"]; client_3 [label = "客户端 C"]; client_4 [label = "客户端 D"]; // client_1 -> news_it [label = "订阅"]; client_2 -> news_et [dir = back, label = "\"world\"", style = dashed]; news_iet -> news_et [dir = back, label = "匹配", style = dashed]; news_iet -> news_it [dir = back, label = "匹配"]; edge [dir = back, label = "\"world\"", style = dashed]; client_3 -> news_iet; client_4 -> news_iet; news_et -> publish [dir = back, style = dashed, label =""]; }

pubsub_channels 字典示例。

digraph { label = "\n 图 18-6 一个 pubsub_channels 字典示例"; rankdir = LR; // node [shape = record]; pubsub_channels [label = " pubsub_channels | <news_it> \"news.it\" | <news_sport> \"news.sport\" | <news_business> \"news.business\" ", height = 3, width = 2.2]; client_1 [label = "client-1"]; client_2 [label = "client-2"]; client_3 [label = "client-3"]; client_4 [label = "client-4"]; client5 [label = "client-5"]; client6 [label = "client-6"]; // pubsub_channels:news_it -> client_1; client_1 -> client_2; client_2 -> client_3; pubsub_channels:news_sport -> client_4; pubsub_channels:news_business -> client5 -> client6; }

pubsubPattern 结构示例。

digraph { label = "\n 图 18-10 pubsubPattern 结构示例"; rankdir = LR; // node [shape =record]; pubsubPattern [label = " pubsubPattern | client \n client-9 | pattern \n \"news.*\" "]; }

pubsub_patterns 链表的示例。

digraph { label = "\n 图 18-11 pubsub_patterns 链表示例"; rankdir = LR; // node [shape = record]; redisServer [label = "redisServer | ... | <pubsub_patterns> pubsub_patterns | ...", height = 2.2, width = 2.2]; all_music [label = " pubsubPattern | client \n client-7 | pattern \n \"music.*\" "]; all_book [label = " pubsubPattern | client \n client-8 | pattern \n \"book.*\" "]; all_news [label = " pubsubPattern | client \n client-9 | pattern \n \"news.*\" "]; // redisServer:pubsub_patterns -> all_music; all_music -> all_book; all_book -> all_news; }