教程 » Rust:使用ElasticSearch构建全文检索API » 3. 搜索文档 » 3.3 中文搜索

中文搜索

列出索引

curl 'http://localhost:9200/_cat/indices?v'

如下结果：

health status index    uuid                   pri rep docs.count docs.deleted store.size pri.store.size dataset.size
yellow open   book_idx c1a4fmDyRkyLQoKMcDlvLw   1   1         10            0     21.9kb         21.9kb       21.9kb

现有的默认索引 books_idx 对英文处理效果不错，但是对中文的效果不理想。可以尝试使用上一节安装的 smartcn 分词器。

创建基于 smartcn 的索引

curl -X PUT "http://localhost:9200/book_idx_cn?pretty" -H 'Content-Type: application/json' -d'
{
  "settings": {
    "analysis": {
      "analyzer": {
        "default": {
          "type": "smartcn"
        }
      }
    }
  }
}'

创建结果：

{
  "acknowledged" : true,
  "shards_acknowledged" : true,
  "index" : "book_idx_cn"
}

更新代码

修改 src/infrastructure/config/mod.rs：

@@ -11,6 +11,7 @@ pub struct Config {
 #[derive(Debug, Deserialize, Serialize)]
 pub struct SearchConfig {
     pub address: String,
+    pub index: String,
 }
 
 #[derive(Debug, Deserialize, Serialize)]

修改 config.toml:

@@ -4,3 +4,4 @@ page_size = 10
 
 [search]
 address = "http://localhost:9200"
+index = "book_idx_cn"

修改 src/infrastructure/search/es.rs：

@@ -8,18 +8,21 @@ use serde_json::{json, Value};
 use crate::domain::gateway::BookManager;
 use crate::domain::model;
 
-const INDEX_BOOK: &str = "book_idx";
-
 pub struct ElasticSearchEngine {
     client: Elasticsearch,
+    index: String,
     page_size: u32,
 }
 
 impl ElasticSearchEngine {
-    pub fn new(address: &str, page_size: u32) -> Result<Self, Box<dyn Error>> {
+    pub fn new(address: &str, index: &str, page_size: u32) -> Result<Self, Box<dyn Error>> {
         let transport = Transport::single_node(address)?;
         let client = Elasticsearch::new(transport);
-        Ok(ElasticSearchEngine { client, page_size })
+        Ok(ElasticSearchEngine {
+            client,
+            index: index.to_string(),
+            page_size,
+        })
     }
 }
 
@@ -28,7 +31,7 @@ impl BookManager for ElasticSearchEngine {
     async fn index_book(&self, b: &model::Book) -> Result<String, Box<dyn Error>> {
         let response = self
             .client
-            .index(IndexParts::Index(INDEX_BOOK))
+            .index(IndexParts::Index(&self.index))
             .body(b)
             .send()
             .await?;
@@ -39,7 +42,7 @@ impl BookManager for ElasticSearchEngine {
     async fn search_books(&self, q: &str) -> Result<Vec<model::Book>, Box<dyn Error>> {
         let response = self
             .client
-            .search(SearchParts::Index(&[INDEX_BOOK]))
+            .search(SearchParts::Index(&[&self.index]))
             .from(0)
             .size(self.page_size as i64)
             .body(json!({

修改 src/application/wire_helper.rs：

@@ -12,6 +12,7 @@ impl WireHelper {
     pub fn new(c: &Config) -> Result<Self, Box<dyn std::error::Error>> {
         let engine = Arc::new(search::ElasticSearchEngine::new(
             &c.search.address,
+            &c.search.index,
             c.app.page_size,
         )?);
         Ok(WireHelper { engine })

编辑完成后，重新启动服务器。

填入中文测试数据

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"title":"哈利·波特与魔法石","author":"J.K. 罗琳","published_at":"1997-06-26","content":"一个年轻男孩发现自己是一名巫师，并开始在霍格沃茨魔法学校接受教育，在那里他揭开了“魔法石”的秘密。"}' \
  http://localhost:3000/books

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"title":"杀死一只知更鸟","author":"哈珀·李","published_at":"1960-07-11","content":"小说设置在大萧条期间的美国南部，通过年轻的斯考特·芬奇的眼睛探索了种族不义和道德成长的主题。"}' \
  http://localhost:3000/books

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"title":"魔戒","author":"J.R.R. 托尔金","published_at":"1954-07-29","content":"一个名叫弗罗多·巴金斯的霍比特人踏上了一场艰险的旅程，摧毁一枚强大的戒指，并拯救中土世界，免受黑暗领主索伦的侵害。"}' \
  http://localhost:3000/books

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"title":"麦田里的守望者","author":"J.D. 赛林格","published_at":"1951-07-16","content":"霍尔顿·考菲尔德在被驱逐出预备学校后，讲述了他在纽约市的经历，探讨了疏远、身份和纯真等主题。"}' \
  http://localhost:3000/books

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"title":"牧羊少年奇幻之旅","author":"保罗·柯艾略","published_at":"1988-01-01","content":"牧羊人圣地亚哥从西班牙前往埃及，寻找埋在金字塔附近的宝藏。沿途，他学到了追随梦想的重要性。"}' \
  http://localhost:3000/books

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"title":"饥饿游戏","author":"苏珊·柯林斯","published_at":"2008-09-14","content":"在一个反乌托邦的未来，青少年被迫参加名为饥饿游戏的电视死斗。凯特尼斯·艾弗丁自愿代替妹妹参加，并成为叛乱的象征。"}' \
  http://localhost:3000/books

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"title":"1984","author":"乔治·奥威尔","published_at":"1949-06-08","content":"温斯顿·史密斯生活在一个由党领导的极权社会中。他反抗压迫性的政权，但最终屈服于其控制。"}' \
  http://localhost:3000/books

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"title":"龙纹身的女孩","author":"斯蒂格·拉尔森","published_at":"2005-08-01","content":"记者米卡埃尔·布隆奎斯特和黑客丽斯贝特·萨兰德调查了一个富裕家庭的年轻女子失踪案，揭示了黑暗的秘密和腐败。"}' \
  http://localhost:3000/books

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{"title":"消失的女孩","author":"吉莲·弗林","published_at":"2012-06-05","content":"在他们的第五个结婚纪念日上，尼克·邓恩的妻子艾米失踪了。随着媒体的狂热报道和怀疑的增加，尼克发现自己陷入了一场欺骗和背叛的旋涡中。"}' \
  http://localhost:3000/books

验证效果

用 ”记者牧羊人“ 进行检索验证。

Query 的分词结果

curl -X POST 'http://localhost:9200/_analyze' -H 'Content-Type: application/json' -d '{
  "analyzer": "smartcn",
  "text": "记者牧羊人"
}'

{"tokens":[{"token":"记者","start_offset":0,"end_offset":2,"type":"word","position":0},{"token":"牧羊人","start_offset":2,"end_offset":5,"type":"word","position":1}]}

Query 的查询结果

curl 'http://localhost:3000/books?q=%E8%AE%B0%E8%80%85%E7%89%A7%E7%BE%8A%E4%BA%BA'

%E8%AE%B0%E8%80%85%E7%89%A7%E7%BE%8A%E4%BA%BA 是“记者牧羊人”URL 编码后的值。

[
	{
		"title": "牧羊少年奇幻之旅",
		"author": "保罗·柯艾略",
		"published_at": "1988-01-01",
		"content": "牧羊人圣地亚哥从西班牙前往埃及，寻找埋在金字塔附近的宝藏。沿途，他学到了追随梦想的重要性。"
	},
	{
		"title": "龙纹身的女孩",
		"author": "斯蒂格·拉尔森",
		"published_at": "2005-08-01",
		"content": "记者米卡埃尔·布隆奎斯特和黑客丽斯贝特·萨兰德调查了一个富裕家庭的年轻女子失踪案，揭示了黑暗的秘密和腐败。"
	}
]

两个结果的匹配得分及其原因解释。

2.2704897
{"description":"max of:","details":[{"description":"sum of:","details":[{"description":"weight(content:牧羊人 in 4) [PerFieldSimilarity], result of:","details":[{"description":"score(freq=1.0), computed as boost * idf * tf from:","details":[{"description":"boost","details":[],"value":2.2},{"description":"idf, computed as log(1 + (N - n + 0.5) / (n + 0.5)) from:","details":[{"description":"n, number of documents containing term","details":[],"value":1},{"description":"N, total number of documents with field","details":[],"value":10}],"value":1.9924302},{"description":"tf, computed as freq / (freq + k1 * (1 - b + b * dl / avgdl)) from:","details":[{"description":"freq, occurrences of term within document","details":[],"value":1.0},{"description":"k1, term saturation parameter","details":[],"value":1.2},{"description":"b, length normalization parameter","details":[],"value":0.75},{"description":"dl, length of field","details":[],"value":22.0},{"description":"avgdl, average length of field","details":[],"value":31.4}],"value":0.5179809}],"value":2.2704897}],"value":2.2704897}],"value":2.2704897}],"value":2.2704897}
1.8797743
{"description":"max of:","details":[{"description":"sum of:","details":[{"description":"weight(content:记者 in 7) [PerFieldSimilarity], result of:","details":[{"description":"score(freq=1.0), computed as boost * idf * tf from:","details":[{"description":"boost","details":[],"value":2.2},{"description":"idf, computed as log(1 + (N - n + 0.5) / (n + 0.5)) from:","details":[{"description":"n, number of documents containing term","details":[],"value":1},{"description":"N, total number of documents with field","details":[],"value":10}],"value":1.9924302},{"description":"tf, computed as freq / (freq + k1 * (1 - b + b * dl / avgdl)) from:","details":[{"description":"freq, occurrences of term within document","details":[],"value":1.0},{"description":"k1, term saturation parameter","details":[],"value":1.2},{"description":"b, length normalization parameter","details":[],"value":0.75},{"description":"dl, length of field","details":[],"value":36.0},{"description":"avgdl, average length of field","details":[],"value":31.4}],"value":0.42884457}],"value":1.8797743}],"value":1.8797743}],"value":1.8797743}],"value":1.8797743}

再用 ”麦田龙女孩“ 进行检索验证。

Query 的分词结果

curl -X POST 'http://localhost:9200/_analyze' -H 'Content-Type: application/json' -d '{
  "analyzer": "smartcn",
  "text": "麦田龙女孩"
}'

{"tokens":[{"token":"麦田","start_offset":0,"end_offset":2,"type":"word","position":0},{"token":"龙","start_offset":2,"end_offset":3,"type":"word","position":1},{"token":"女孩","start_offset":3,"end_offset":5,"type":"word","position":2}]}

Query 的查询结果

curl 'http://localhost:3000/books?q=%E9%BA%A6%E7%94%B0%E9%BE%99%E5%A5%B3%E5%AD%A9'

[
	{
		"title": "龙纹身的女孩",
		"author": "斯蒂格·拉尔森",
		"published_at": "2005-08-01",
		"content": "记者米卡埃尔·布隆奎斯特和黑客丽斯贝特·萨兰德调查了一个富裕家庭的年轻女子失踪案，揭示了黑暗的秘密和腐败。"
	},
	{
		"title": "麦田里的守望者",
		"author": "J.D. 赛林格",
		"published_at": "1951-07-16",
		"content": "霍尔顿·考菲尔德在被驱逐出预备学校后，讲述了他在纽约市的经历，探讨了疏远、身份和纯真等主题。"
	},
	{
		"title": "消失的女孩",
		"author": "吉莲·弗林",
		"published_at": "2012-06-05",
		"content": "在他们的第五个结婚纪念日上，尼克·邓恩的妻子艾米失踪了。随着媒体的狂热报道和怀疑的增加，尼克发现自己陷入了一场欺骗和背叛的旋涡中。"
	}
]

三个结果的匹配得分及其原因解释。

3.1877713
{"description":"max of:","details":[{"description":"sum of:","details":[{"description":"weight(title:龙 in 7) [PerFieldSimilarity], result of:","details":[{"description":"score(freq=1.0), computed as boost * idf * tf from:","details":[{"description":"boost","details":[],"value":2.2},{"description":"idf, computed as log(1 + (N - n + 0.5) / (n + 0.5)) from:","details":[{"description":"n, number of documents containing term","details":[],"value":1},{"description":"N, total number of documents with field","details":[],"value":10}],"value":1.9924302},{"description":"tf, computed as freq / (freq + k1 * (1 - b + b * dl / avgdl)) from:","details":[{"description":"freq, occurrences of term within document","details":[],"value":1.0},{"description":"k1, term saturation parameter","details":[],"value":1.2},{"description":"b, length normalization parameter","details":[],"value":0.75},{"description":"dl, length of field","details":[],"value":5.0},{"description":"avgdl, average length of field","details":[],"value":4.1}],"value":0.41709054}],"value":1.8282523}],"value":1.8282523},{"description":"weight(title:女孩 in 7) [PerFieldSimilarity], result of:","details":[{"description":"score(freq=1.0), computed as boost * idf * tf from:","details":[{"description":"boost","details":[],"value":2.2},{"description":"idf, computed as log(1 + (N - n + 0.5) / (n + 0.5)) from:","details":[{"description":"n, number of documents containing term","details":[],"value":2},{"description":"N, total number of documents with field","details":[],"value":10}],"value":1.4816046},{"description":"tf, computed as freq / (freq + k1 * (1 - b + b * dl / avgdl)) from:","details":[{"description":"freq, occurrences of term within document","details":[],"value":1.0},{"description":"k1, term saturation parameter","details":[],"value":1.2},{"description":"b, length normalization parameter","details":[],"value":0.75},{"description":"dl, length of field","details":[],"value":5.0},{"description":"avgdl, average length of field","details":[],"value":4.1}],"value":0.41709054}],"value":1.3595191}],"value":1.3595191}],"value":3.1877713}],"value":3.1877713}
1.8282523
{"description":"max of:","details":[{"description":"sum of:","details":[{"description":"weight(title:麦田 in 3) [PerFieldSimilarity], result of:","details":[{"description":"score(freq=1.0), computed as boost * idf * tf from:","details":[{"description":"boost","details":[],"value":2.2},{"description":"idf, computed as log(1 + (N - n + 0.5) / (n + 0.5)) from:","details":[{"description":"n, number of documents containing term","details":[],"value":1},{"description":"N, total number of documents with field","details":[],"value":10}],"value":1.9924302},{"description":"tf, computed as freq / (freq + k1 * (1 - b + b * dl / avgdl)) from:","details":[{"description":"freq, occurrences of term within document","details":[],"value":1.0},{"description":"k1, term saturation parameter","details":[],"value":1.2},{"description":"b, length normalization parameter","details":[],"value":0.75},{"description":"dl, length of field","details":[],"value":5.0},{"description":"avgdl, average length of field","details":[],"value":4.1}],"value":0.41709054}],"value":1.8282523}],"value":1.8282523}],"value":1.8282523}],"value":1.8282523}
1.6642681
{"description":"max of:","details":[{"description":"sum of:","details":[{"description":"weight(title:女孩 in 8) [PerFieldSimilarity], result of:","details":[{"description":"score(freq=1.0), computed as boost * idf * tf from:","details":[{"description":"boost","details":[],"value":2.2},{"description":"idf, computed as log(1 + (N - n + 0.5) / (n + 0.5)) from:","details":[{"description":"n, number of documents containing term","details":[],"value":2},{"description":"N, total number of documents with field","details":[],"value":10}],"value":1.4816046},{"description":"tf, computed as freq / (freq + k1 * (1 - b + b * dl / avgdl)) from:","details":[{"description":"freq, occurrences of term within document","details":[],"value":1.0},{"description":"k1, term saturation parameter","details":[],"value":1.2},{"description":"b, length normalization parameter","details":[],"value":0.75},{"description":"dl, length of field","details":[],"value":3.0},{"description":"avgdl, average length of field","details":[],"value":4.1}],"value":0.5105853}],"value":1.6642681}],"value":1.6642681}],"value":1.6642681}],"value":1.6642681}

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