Implement basic search api

Author: velopert

GUIDELINES.md

@@ -61,7 +61,11 @@ $ psql postgres
 psql (10.4)
 Type "help" for help.
 
-postgres=# CREATE DATABASE velog;
+postgres=# CREATE DATABASE velog
+  LC_COLLATE 'C'
+  LC_CTYPE 'C'
+  ENCODING 'UTF8'
+  TEMPLATE template0;
 CREATE DATABASE
 postgres=# CREATE USER velog WITH ENCRYPTED PASSWORD 'velogpw';
 CREATE ROLE

velog-backend/sql/posts_tsv.sql

@@ -0,0 +1,17 @@
+alter table posts 
+add column tsv tsvector;
+
+create index posts_tsv on posts using gin(tsv);
+
+update posts set tsv = to_tsvector(coalesce(title)) || to_tsvector(coalesce(body));
+
+create or replace function posts_tsv_trigger() returns trigger as $$
+begin
+	new.tsv := to_tsvector(coalesce(new.title)) || to_tsvector(coalesce(new.body));
+	return new;
+end
+$$ language plpgsql;
+
+
+create trigger tsvectorupdate before insert or update on posts
+for each row execute procedure posts_tsv_trigger();

velog-backend/src/database/rawQuery/search.js

@@ -0,0 +1,63 @@
+// @flow
+import Sequelize from 'sequelize';
+import db from 'database/db';
+
+type SearchParameter = {
+  tsquery: string,
+  fk_user_id?: string,
+  authorized?: boolean,
+  page?: number,
+};
+
+type SearchDataRow = {
+  id: string,
+  rank: number,
+};
+
+export const searchPosts = async ({
+  tsquery,
+  fk_user_id,
+  authorized,
+  page = 1,
+}: SearchParameter): Promise<SearchDataRow[]> => {
+  const query = `
+SELECT id, ts_rank(tsv, TO_TSQUERY($tsquery)) * 1000 + total_score AS rank
+FROM posts 
+JOIN (select fk_post_id, SUM(score) as total_score from post_scores group by fk_post_id) as q on q.fk_post_id = posts.id 
+WHERE tsv @@ TO_TSQUERY($tsquery)
+ORDER BY rank DESC
+OFFSET ${10 * (page - 1)}
+LIMIT 10
+  `;
+
+  try {
+    const rows = await db.query(query, {
+      bind: { tsquery },
+    });
+    return rows[0];
+  } catch (e) {
+    throw e;
+  }
+};
+
+export const countSearchPosts = async ({
+  tsquery,
+  fk_user_id,
+  authorized,
+  page = 1,
+}: SearchParameter): Promise<number> => {
+  const query = `
+SELECT COUNT(*) as count
+FROM posts 
+WHERE tsv @@ TO_TSQUERY($tsquery)
+  `;
+
+  try {
+    const rows = await db.query(query, {
+      bind: { tsquery },
+    });
+    return rows[0][0].count;
+  } catch (e) {
+    throw e;
+  }
+};

velog-backend/src/router/index.js

@@ -2,9 +2,6 @@
 import Router from 'koa-router';
 import type { Context } from 'koa';
 import needsAuth from 'lib/middlewares/needsAuth';
-import downloadImage from 'lib/downloadImage';
-import crypto from 'crypto';
-import { PostReadcounts } from 'database/views';
 import auth from './auth';
 import posts from './posts';
 import files from './files';
@@ -15,8 +12,7 @@ import common from './common';
 import sitemaps from './sitemaps';
 import internal from './internal';
 import atom from './atom';
-import Post from '../database/models/Post';
-import { getTagsList } from '../database/rawQuery/tags';
+import search from './search/search';
 
 const router: Router = new Router();
 
@@ -30,11 +26,12 @@ router.use('/common', common.routes());
 router.use('/sitemaps', sitemaps.routes());
 router.use('/internal', internal.routes());
 router.use('/atom', atom.routes());
+router.use('/search', search.routes());
 
 router.get('/check', (ctx: Context) => {
   console.log('avoiding cold start...');
   ctx.body = {
-    version: '1.0.0-alpha.0',
+    version: '1.0.0',
     origin: ctx.origin,
     env: process.env.NODE_ENV,
   };

velog-backend/src/router/posts/posts.ctrl.js

@@ -457,25 +457,19 @@ export const listTrendingPosts = async (ctx: Context) => {
 
   // check cursor
   try {
-    console.time('getTrendingPosts');
     const postIds = await getTrendingPosts(offset || 0);
-    console.timeEnd('getTrendingPosts');
     if (!postIds || postIds.length === 0) {
       ctx.body = [];
       return;
     }
-    console.time('readPostsByIds');
     const posts = await Post.readPostsByIds(postIds.map(postId => postId.post_id));
     const filtered = posts.filter(p => !p.is_private);
-    console.timeEnd('readPostsByIds');
     const data = filtered
       .map(serializePost)
       .map(post => ({ ...post, body: formatShortDescription(post.body) }));
 
     // retrieve commentCounts and inject
-    console.time('getCommentCounts');
     const commentCounts = await getCommentCountsOfPosts(filtered.map(p => p.id));
-    console.timeEnd('getCommentCounts');
     ctx.body = injectCommentCounts(data, commentCounts);
   } catch (e) {
     ctx.throw(500, e);

velog-backend/src/router/search/search.ctrl.js

@@ -0,0 +1,32 @@
+// @flow
+import type { Context } from 'koa';
+import Post, { serializePost } from 'database/models/Post';
+import { searchPosts, countSearchPosts } from 'database/rawQuery/search';
+import { formatShortDescription } from 'lib/common';
+
+export const publicSearch = async (ctx: Context) => {
+  const { q } = ctx.query;
+  const transformed = `${q.replace(/ /, '|')}:*`;
+  try {
+    const [count, searchResult] = await Promise.all([
+      countSearchPosts({
+        tsquery: transformed,
+      }),
+      searchPosts({
+        tsquery: transformed,
+      }),
+    ]);
+
+    const postIds = searchResult.map(r => r.id);
+    const posts = await Post.readPostsByIds(postIds);
+    const data = posts
+      .map(serializePost)
+      .map(post => ({ ...post, body: formatShortDescription(post.body) }));
+    ctx.body = {
+      count,
+      data,
+    };
+  } catch (e) {
+    ctx.throw(500, e);
+  }
+};

velog-backend/src/router/search/search.js

@@ -0,0 +1,8 @@
+// @flow
+import Router from 'koa-router';
+import { publicSearch } from './search.ctrl';
+
+const search = new Router();
+
+search.get('/public', publicSearch);
+export default search;