feat: doc search infra (#7166)

detail in `packages/common/infra/src/sync/indexer/README.md`

packages/common/infra/package.json

@@ -18,6 +18,9 @@
     "@blocksuite/store": "0.15.0-canary-202407011031-17e7b65",
     "@datastructures-js/binary-search-tree": "^5.3.2",
     "foxact": "^0.2.33",
+    "fuse.js": "^7.0.0",
+    "graphemer": "^1.4.0",
+    "idb": "^8.0.0",
     "jotai": "^2.8.0",
     "jotai-effect": "^1.0.0",
     "lodash-es": "^4.17.21",
@@ -33,6 +36,7 @@
     "@blocksuite/presets": "0.15.0-canary-202407011031-17e7b65",
     "@testing-library/react": "^16.0.0",
     "async-call-rpc": "^6.4.0",
+    "fake-indexeddb": "^6.0.0",
     "react": "^18.2.0",
     "rxjs": "^7.8.1",
     "vite": "^5.2.8",

packages/common/infra/src/sync/indexer/README.md

@@ -0,0 +1,147 @@
+# index
+
+Search engine abstraction layer for AFFiNE.
+
+## Using
+
+1. Define schema
+
+First, we need to define the shape of the data. Currently, there are the following data types.
+
+- 'Integer'
+- 'Boolean'
+- 'FullText': for full-text search, it will be tokenized and stemmed.
+- 'String': for exact match search, e.g. tags, ids.
+
+```typescript
+const schema = defineSchema({
+  title: 'FullText',
+  tag: 'String',
+  size: 'Integer',
+});
+```
+
+> **Array type**
+> All types can contain one or more values, so each field can store an array.
+
+2. Pick a backend
+
+Currently, there are two backends available.
+
+- `MemoryIndex`: in-memory indexer, useful for testing.
+- `IndexedDBIndex`: persistent indexer using IndexedDB.
+
+> **Underlying Data Table**
+> Some back-end processes need to maintain underlying data tables, including table creation and migration. This operation should be silently executed the first time the indexer is invoked.
+> Callers do not need to worry about these details.
+>
+> This design conforms to the usual conventions of search engine APIs, such as in Elasticsearch: https://www.elastic.co/guide/en/elasticsearch/reference/current/array.html
+
+3. Write data
+
+Write data to the indexer. you need to start a write transaction by `await index.write()` first and then complete the batch write through `await writer.commit()`.
+
+> **Transactional**
+> Typically, the indexer does not provide transactional guarantees; reliable locking logic needs to be implemented at a higher level.
+
+```typescript
+const indexer = new IndexedDBIndex(schema);
+
+const writer = await index.write();
+writer.insert(
+  Document.from('id', {
+    title: 'hello world',
+    tag: ['doc', 'page'],
+    size: '100',
+  })
+);
+await writer.commit();
+```
+
+4. Search data
+
+To search for content in the indexer, you need to use a specific **query language**. Here are some examples:
+
+```typescript
+// match title == 'hello world'
+{
+  type: 'match',
+  field: 'title',
+  match: 'hello world',
+}
+
+// match title == 'hello world' && tag == 'doc'
+{
+    type: 'boolean',
+    occur: 'must',
+    queries: [
+        {
+            type: 'match',
+            field: 'title',
+            match: 'hello world',
+        },
+        {
+            type: 'match',
+            field: 'tag',
+            match: 'doc',
+        },
+    ],
+}
+```
+
+There are two ways to perform the search, `index.search()` and `index.aggregate()`.
+
+- **search**: return each matched node and pagination information.
+- **aggregate**: aggregate all matched results based on a certain field into buckets, and return the count and score of items in each bucket.
+
+Examples:
+
+```typescript
+const result = await index.search({
+  type: 'match',
+  field: 'title',
+  match: 'hello world',
+});
+// result = {
+//   nodes: [
+//     {
+//       id: '1',
+//       score: 1,
+//     },
+//   ],
+//   pagination: {
+//     count: 1,
+//     hasMore: false,
+//     limit: 10,
+//     skip: 0,
+//   },
+// }
+```
+
+```typescript
+const result = await index.aggregate(
+  {
+    type: 'match',
+    field: 'title',
+    match: 'affine',
+  },
+  'tag'
+);
+// result = {
+//   buckets: [
+//     { key: 'motorcycle', count: 2, score: 1 },
+//     { key: 'bike', count: 1, score: 1 },
+//     { key: 'airplane', count: 1, score: 1 },
+//   ],
+//   pagination: {
+//     count: 3,
+//     hasMore: false,
+//     limit: 10,
+//     skip: 0,
+//   },
+// }
+```
+
+More uses:
+
+[black-box.spec.ts](./__tests__/black-box.spec.ts)