kvStore

键值数据库

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1存储能力强于用户首选项，不能存储复杂数据
2json作为存储对象，覆盖存储，直接存储到硬盘不用flush
3实现多个设备终端协同
4
5设备协同数据库：单条记录 key<=896B, value<4MB
6单版本数据库 key<=1KB, value<4MB
7最多支持同时打开16个键值型分布式数据库

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 1import { AbilityConstant, ConfigurationConstant, UIAbility, Want } from '@kit.AbilityKit';
 2import { hilog } from '@kit.PerformanceAnalysisKit';
 3import { window } from '@kit.ArkUI';
 4import { cardDBUtils } from '../utils/CardDBUtils';
 5import preferencesUtil from '../utils/PreferencesUtils';
 6import kvStore from '../utils/KVStore';
 7
 8const DOMAIN = 0x0000;
 9
10export default class EntryAbility extends UIAbility {
11  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam): void {
12    this.context.getApplicationContext().setColorMode(ConfigurationConstant.ColorMode.COLOR_MODE_NOT_SET);
13    hilog.info(DOMAIN, 'testTag', '%{public}s', 'Ability onCreate');
14  }
15
16  onDestroy(): void {
17    hilog.info(DOMAIN, 'testTag', '%{public}s', 'Ability onDestroy');
18  }
19
20  onWindowStageCreate(windowStage: window.WindowStage): void {
21    // 加载数据库
22    cardDBUtils.initCardDB(this.context, 'goodcard')
23    preferencesUtil.init(this.context, 'goodMail')
24    preferencesUtil.insertData('theme', 'pink')
25
26    kvStore.init(this.context)
27    kvStore.createStore('myStore')
28....

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 1import { distributedKVStore } from "@kit.ArkData";
 2import { BusinessError } from "@kit.BasicServicesKit";
 3
 4export class KVStore {
 5  // 代表数据库管理对象
 6  private kvManager: distributedKVStore.KVManager | undefined = undefined
 7  // 管理数据库里面数据列表
 8  private kvStore: distributedKVStore.SingleKVStore | undefined = undefined
 9
10  init(context: Context) {
11    // 定义数据库初始化需要的字段
12    const kvManagerConfig: distributedKVStore.KVManagerConfig = {
13      context: context,
14      bundleName: 'com.example.snailmall'
15    }
16
17    try {
18      this.kvManager = distributedKVStore.createKVManager(kvManagerConfig)
19      console.log('success create kvManager')
20    } catch (e) {
21      let error = e as BusinessError
22      console.log(`failed to create kvManager, ${error.name}-${error.message}`)
23    }
24  }
25
26  createStore(storeId: string) {
27    try {
28      // 定义store参数
29      const options: distributedKVStore.Options = {
30        createIfMissing: true,
31        encrypt: false,
32        backup: false,
33        autoSync: false,
34        // kvStoreType不填时，默认创建多设备协同数据库
35        kvStoreType: distributedKVStore.KVStoreType.SINGLE_VERSION,
36        // 多设备协同数据库 kvStoreType:distributedKVStore.KVStoreType.DEVICE_COLLABORATION
37        securityLevel: distributedKVStore.SecurityLevel.S1
38      }
39
40      this.kvManager?.getKVStore<distributedKVStore.SingleKVStore>(storeId, options,
41        (err, store: distributedKVStore.SingleKVStore) => {
42          if (err) {
43            console.log('create kvStore failed')
44            return
45          }
46          console.log('create kvStore success')
47          this.kvStore = store
48        })
49    } catch (e) {
50      let error = e as BusinessError
51      console.log(`failed to create kvStore, ${error.name}-${error.message}`)
52    }
53  }
54
55  putData(key: string, value: string) {
56    try {
57      this.kvStore?.put(key, value, (err) => {
58        if (err) {
59          console.log(`kvStore insert data failed, ${err.name}-${err.code}`)
60          return
61        }
62        console.log('kvStore insert data success')
63      })
64    } catch (e) {
65      let error = e as BusinessError
66      console.log(`kvStore insert data failed, ${error.name}-${error.message}`)
67    }
68  }
69
70  getData(key: string) {
71    return new Promise((resolve: (value: string | number | boolean | Uint8Array) => void,
72      reject: (value?: string) => void) => {
73      this.kvStore?.get(key, (err, data) => {
74        if (err) {
75          console.log(`kvStore get data failed, ${err.name}-${err.code}`)
76          reject('kvStore get data failed')
77          return
78        }
79        console.log(`kvStore get data success, ${data}`)
80        resolve(data)
81      })
82    })
83  }
84
85  deleteData(key: string) {
86    this.kvStore?.delete(key, (err, data) => {
87      if (err) {
88        console.log(`kvStore get data failed, ${err.name}-${err.code}`)
89        return
90      }
91      console.log(`kvStore get data success, ${data}`)
92    })
93  }
94}
95
96const kvStore = new KVStore()
97
98export default kvStore

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1kvStore insert data success
2kvStore get data success, Lining
3kvStore get data success, {"id":1,"name":"Wyoming"}

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