> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
Double-ended queue (deque) is a sequence container implemented based on the queue data structure that follows the principles of First In First Out (FIFO) and Last In First Out (LIFO). It allows insertion and removal of elements at both the ends. **Deque** can dynamically adjust the capacity based on project requirements. It doubles the capacity each time. **Deque** differs from **[Queue](js-apis-queue.md)** and **[Vector](js-apis-vector.md)** mainly in the following aspects:
The **distributedBundle** module provides APIs for managing distributed bundles.
> **NOTE**
>
> The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
>
> The APIs provided by this module are system APIs.
## Modules to Import
```
import distributedBundle from '@ohos.bundle.distributedBundleManager';
| callback | AsyncCallback<[RemoteAbilityInfo](js-apis-bundleManager-remoteAbilityInfo.md)> | Yes | Callback used to return the result. If the operation is successful, **err** is **null** and **data** is the **RemoteAbilityInfo** object obtained. Otherwise, **err** is an error object and **data** is **undefined**.|
**Error codes**
For details about the error codes, see [Bundle Error Codes](../errorcodes/errorcode-bundle.md).
| Promise\<[RemoteAbilityInfo](js-apis-bundleManager-remoteAbilityInfo.md)> | Promise used to return the result. If the operation is successful, the **RemoteAbilityInfo** object is returned. Otherwise, an error object is returned.|
**Error codes**
For details about the error codes, see [Bundle Error Codes](../errorcodes/errorcode-bundle.md).
| ID| Error Message |
|----------|-------------------------|
| 17700001 | The specified bundle name is not found. |
| 17700003 | The specified ability name is not found. |
| 17700007 | The specified device ID is not found. |
| 17700027 | The distributed service is not running. |
| elementNames | Array<[ElementName](js-apis-bundleManager-elementName.md)> | Yes | **ElementName** array, whose maximum length is 10. |
| callback | AsyncCallback\<Array\<[RemoteAbilityInfo](js-apis-bundleManager-remoteAbilityInfo.md)>> | Yes | Callback used to return the result. If the operation is successful, **err** is **null** and **data** is the array of **RemoteAbilityInfo** objects obtained. Otherwise, **err** is an error object and **data** is **undefined**.|
**Error codes**
For details about the error codes, see [Bundle Error Codes](../errorcodes/errorcode-bundle.md).
| ID| Error Message |
|----------|-------------------------|
| 17700001 | The specified bundle name is not found. |
| 17700003 | The specified ability name is not found. |
| 17700007 | The specified device ID is not found. |
| 17700027 | The distributed service is not running. |
**Example**
```ts
try{
distributedBundle.getRemoteAbilityInfo(
[
{
deviceId:'1',
bundleName:'com.example.application1',
abilityName:'MainAbility1'
},
{
deviceId:'1',
bundleName:'com.example.application2',
abilityName:'MainAbility'
}
],(err,data)=>{
if(err){
console.error('Operation failed: error code is '+err.code+'and error message is '+err.message);
| Promise\<Array<[RemoteAbilityInfo](js-apis-bundleManager-remoteAbilityInfo.md)>> | Promise used to return the result. If the operation is successful, an array of **RemoteAbilityInfo** objects is returned. Otherwise, an error object is returned.|
**Error codes**
For details about the error codes, see [Bundle Error Codes](../errorcodes/errorcode-bundle.md).
| ID| Error Message |
|----------|-------------------------|
| 17700001 | The specified bundle name is not found. |
| 17700003 | The specified ability name is not found. |
| 17700007 | The specified device ID is not found. |
| 17700027 | The distributed service is not running. |
Obtains information about the remote ability that matches the given element name and locale. This API uses an asynchronous callback to return the result.
| callback | AsyncCallback<[RemoteAbilityInfo](js-apis-bundleManager-remoteAbilityInfo.md)> | Yes | Callback used to return the result. If the operation is successful, **err** is **null** and **data** is the **RemoteAbilityInfo** object obtained. Otherwise, **err** is an error object and **data** is **undefined**.|
**Error codes**
For details about the error codes, see [Bundle Error Codes](../errorcodes/errorcode-bundle.md).
| ID| Error Message |
|----------|-------------------------|
| 17700001 | The specified bundle name is not found. |
| 17700003 | The specified ability name is not found. |
| 17700007 | The specified device ID is not found. |
| 17700027 | The distributed service is not running. |
**Example**
```ts
try{
distributedBundle.getRemoteAbilityInfo(
{
deviceId:'1',
bundleName:'com.example.application',
abilityName:'MainAbility'
},'zh-Hans-CN',(err,data)=>{
if(err){
console.error('Operation failed: error code is '+err.code+'and error message is '+err.message);
| Promise\<[RemoteAbilityInfo](js-apis-bundleManager-remoteAbilityInfo.md)> | Promise used to return the result. If the operation is successful, the **RemoteAbilityInfo** object is returned. Otherwise, an error object is returned.|
**Error codes**
For details about the error codes, see [Bundle Error Codes](../errorcodes/errorcode-bundle.md).
| ID| Error Message |
|----------|-------------------------|
| 17700001 | The specified bundle name is not found. |
| 17700003 | The specified ability name is not found. |
| 17700007 | The specified device ID is not found. |
| 17700027 | The distributed service is not running. |
Obtains information about the remote abilities that match the given element names and locale. This API uses an asynchronous callback to return the result.
| elementNames | Array<[ElementName](js-apis-bundleManager-elementName.md)> | Yes | **ElementName** array, whose maximum length is 10. |
| locale | string |Yes| Target locale.|
| callback | AsyncCallback\<Array\<[RemoteAbilityInfo](js-apis-bundleManager-remoteAbilityInfo.md)>> | Yes | Callback used to return the result. If the operation is successful, **err** is **null** and **data** is the array of **RemoteAbilityInfo** objects obtained. Otherwise, **err** is an error object and **data** is **undefined**.|
**Error codes**
For details about the error codes, see [Bundle Error Codes](../errorcodes/errorcode-bundle.md).
| ID | Error Message |
|---------------|-------------------------|
| 17700001 | The specified bundle name is not found. |
| 17700003 | The specified ability name is not found. |
| 17700007 | The specified device ID is not found. |
| 17700027 | The distributed service is not running. |
**Example**
```ts
try{
distributedBundle.getRemoteAbilityInfo(
[
{
deviceId:'1',
bundleName:'com.example.application1',
abilityName:'MainAbility1'
},
{
deviceId:'1',
bundleName:'com.example.application2',
abilityName:'MainAbility'
}
],'zh-Hans-CN',(err,data)=>{
if(err){
console.error('Operation failed: error code is '+err.code+'and error message is '+err.message);
| Promise\<Array<[RemoteAbilityInfo](js-apis-bundleManager-remoteAbilityInfo.md)>> | Promise used to return the result. If the operation is successful, an array of **RemoteAbilityInfo** objects is returned. Otherwise, an error object is returned.|
**Error codes**
For details about the error codes, see [Bundle Error Codes](../errorcodes/errorcode-bundle.md).
| ID| Error Message |
|----------|-------------------------|
| 17700001 | The specified bundle name is not found. |
| 17700003 | The specified ability name is not found. |
| 17700007 | The specified device ID is not found. |
| 17700027 | The distributed service is not running. |
> - The initial APIs of this module are supported since API version 6. Newly added APIs will be marked with a superscript to indicate their earliest API version.
# @ohos.file.fileAccess (User File Access and Management)
The **fileAccess** module is a framework for accessing and operating user files based on the Extension ability mechanism. This module interacts with diverse file management services, such as the media library and external storage management service, and provides a set of file access and management APIs for system applications. The media library service allows access to user files on local devices and distributed devices. The external storage management service allows access to the user files stored on devices such as shared disks, USB flash drives, and SD cards.
The **fileio** module provides APIs for file storage and management, including basic file management, directory management, file information statistics, and stream read and write.
...
...
@@ -40,7 +40,7 @@ FA Model
letpathDir=data;
})
```
For details about how to obtain the context of the FA model, see [FA Model](https://gitee.com/openharmony/docs/blob/master/en/application-dev/reference/apis/js-apis-Context.md#context).
The **bundle.launcherBundleManager** module providers APIs for the **Home Screen** application to obtain the launcher ability information and shortcut information.
The **Screenshot** module provides APIs for you to set information such as the region to capture and the size of the screen region when capturing a screen.
The statfs module provides APIs for obtaining file system information, including the total number of bytes and the number of idle bytes of the file system.
> - The APIs of this module are no longer maintained since API version 7. You are advised to use [`@ohos.i18n`](js-apis-i18n.md) and [`@ohos.intl`](js-apis-intl.md) instead.
> - The APIs of this module are no longer maintained since API version 6. You are advised to use [`@ohos.net.http`](js-apis-http.md) instead.
>
>
> - The initial APIs of this module are supported since API version 3. Newly added APIs will be marked with a superscript to indicate their earliest API version.
> - The APIs of this module are no longer maintained since API version 7. You are advised to use [`@ohos.geolocation`](js-apis-geolocation.md).
> - The initial APIs of this module are supported since API version 3. Newly added APIs will be marked with a superscript to indicate their earliest API version.
The task pool provides a multi-thread running environment for applications. It helps reduce resource consumption and improve system performance. It also frees you from caring about the lifecycle of thread instances. You can use the **TaskPool** APIs to create background tasks and perform operations on them, for example, executing or canceling a task. Theoretically, you can create an unlimited number of tasks, but this is not recommended for memory considerations. In addition, you are not advised performing blocking operations in a task, especially indefinite blocking. Long-time blocking operations occupy worker threads and may block other task scheduling, adversely affecting your application performance.
You can determine the execution sequence of tasks with the same priority. They are executed in the same sequence as you call the task execution APIs. The default task priority is **MEDIUM**. (The task priority mechanism is not supported yet.)
If the number of tasks to be executed is greater than the number of worker threads in the task pool, the task pool scales out based on load balancing to minimize the waiting duration. Similarly, when the number of tasks to be executed falls below the number of worker threads, the task pool scales in to reduce the number of worker threads. (The load balancing mechanism is not supported yet.)
The **TaskPool** APIs return error codes in numeric format. For details about the error codes, see [Utils Error Codes](../errorcodes/errorcode-utils.md).
> **NOTE**<br>
> The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
## Modules to Import
```js
importtaskpoolfrom'@ohos.taskpool';
```
## Priority
Enumerates the priorities available for created tasks. (This enum is not supported yet.)
| func | Function | Yes | Function to be passed in for task execution. For details about the supported return value types of the function, see [Sequenceable Data Types](#sequenceable-data-types). |
| args | unknown[] | No | Arguments of the function. For details about the supported parameter types, see [Sequenceable Data Types](#sequenceable-data-types).|
**Error codes**
For details about the error codes, see [Utils Error Codes](../errorcodes/errorcode-utils.md).
| function | Function | Yes | Yes | Function to be passed in during task creation. For details about the supported return value types of the function, see [Sequenceable Data Types](#sequenceable-data-types). |
| arguments | unknown[] | Yes | Yes | Arguments of the function. For details about the supported parameter types, see [Sequenceable Data Types](#sequenceable-data-types).|
Executes a task in the task pool. You must pass in a function and arguments to execute the task, and the task executed in this mode cannot be canceled.
| func | Function | Yes | Function used to execute the task. For details about the supported return value types of the function, see [Sequenceable Data Types](#sequenceable-data-types). |
| args | unknown[] | No | Arguments of the function. For details about the supported parameter types, see [Sequenceable Data Types](#sequenceable-data-types).|
For details about the error codes, see [Utils Error Codes](../errorcodes/errorcode-utils.md).
| ID| Error Message |
| -------- | ------------------------- |
| 10200015 | If the task is not exist. |
| 10200016 | If the task is running. |
**Example**
```js
functionfunc(args){
"use concurrent"
console.log("func: "+args);
returnargs;
}
lettask=newtaskpool.Task(func,"this is first Task");
letvalue=taskpool.execute(task);
taskpool.cancel(task);
```
## Additional Information
### Sequenceable Data Types
The following sequenceable data types are supported: All Primitive Type (excluding symbol), Date, String, RegExp, Array, Map, Set, Object, ArrayBuffer, and TypedArray.
### Precautions
A task in the task pool can reference only variables passed in by input parameters or imported variables. It does not support closure variables.
```js
// 1. Reference a variable passed in by the input parameter.
functionfunc(args){
"use concurrent"
console.log("func: "+args);
returnargs;
}
lettask=newtaskpool.Task(func,"create task, then execute");
letval1=taskpool.execute(task);
letval2=taskpool.execute(func,"execute task by func");
```
```js
// 2. Reference an imported variable.
// b.ts
exportvarc=2000;
// a.ts
import{c}from'./b'
functiontest(a){
"use concurrent"
console.log(a);
console.log(c);
returna;
}
lettask=newtaskpool.Task(test,"create task, then execute");
letval1=taskpool.execute(task);
letval2=taskpool.execute(test,"execute task by func");
The **WantAgent** module provides APIs for creating and comparing **WantAgent** objects, and obtaining the user ID and bundle name of a **WantAgent** object.
The **Window** module provides basic window management capabilities, such as creating and destroying the current window, setting properties for the current window, and managing and scheduling windows.
...
...
@@ -54,7 +54,7 @@ Defines the parameters for creating a subwindow or system window.
| windowType | [WindowType](#windowtype7) | Yes| Type of the window. |
| ctx | BaseContext | No| Current application context.<br>For details about the context in the FA model, see [Context](js-apis-inner-app-context.md).<br>For details about the context in the stage model, see [ServiceExtensionContext](js-apis-inner-application-serviceExtensionContext.md). If this parameter is not set, no context is used.<br>A system window is created when **Context** is [ServiceExtensionContext](js-apis-inner-application-serviceExtensionContext.md).|
| ctx | [BaseContext](js-apis-inner-application-baseContext.md) | No| Current application context. If this parameter is not set, no context is used.<br>You do not need to set this parameter to create a subwindow in the FA model or a system window in the stage model. |
| displayId | number | No| ID of the current physical screen. If this parameter is not set, the default value **-1** is used.|
| parentId | number | No| ID of the parent window. If this parameter is not set, the default value **-1** is used. |
...
...
@@ -430,7 +430,7 @@ Obtains the top window of the current application. This API uses an asynchronous
| ctx | BaseContext | Yes| Current application context.<br>For details about the context in the FA model, see [Context](js-apis-inner-app-context.md).<br>For details about the context in the stage model, see [Context](js-apis-ability-context.md).|
| ctx | [BaseContext](js-apis-inner-application-baseContext.md) | Yes| Current application context.|
| callback | AsyncCallback<[Window](#window)> | Yes| Callback used to return the top window obtained.|
**Error codes**
...
...
@@ -472,7 +472,7 @@ Obtains the top window of the current application. This API uses a promise to re
| ctx | BaseContext | Yes | Current application context.<br>For details about the context in the FA model, see [Context](js-apis-inner-app-context.md).<br>For details about the context in the stage model, see [Context](js-apis-ability-context.md).|
| ctx | [BaseContext](js-apis-inner-application-baseContext.md) | Yes | Current application context.|
| ctx | BaseContext | Yes | Current application context.<br>For details about the context in the FA model, see [Context](js-apis-inner-app-context.md).<br>For details about the context in the stage model, see [ServiceExtensionContext](js-apis-inner-application-serviceExtensionContext.md).|
| id | string | Yes | Window ID. |
| type | [WindowType](#windowtype7)| Yes | Window type. |
| callback | AsyncCallback<[Window](#window)>| Yes | Callback used to return the subwindow created. |
| ctx | BaseContext | Yes | Current application context.<br>For details about the context in the FA model, see [Context](js-apis-inner-app-context.md).<br>For details about the context in the stage model, see [ServiceExtensionContext](js-apis-inner-application-serviceExtensionContext.md).|
| ctx | [BaseContext](js-apis-inner-application-baseContext.md) | Yes | Current application context.|
| id | string | Yes | Window ID. |
| type | [WindowType](#windowtype7) | Yes | Window type. |
...
...
@@ -1121,7 +1121,7 @@ Obtains the top window of the current application. This API uses an asynchronous
| ctx | BaseContext | Yes | Current application context.<br>For details about the context in the FA model, see [Context](js-apis-inner-app-context.md).<br>For details about the context in the stage model, see [Context](js-apis-ability-context.md).|
| ctx | [BaseContext](js-apis-inner-application-baseContext.md) | Yes | Current application context.|
| callback | AsyncCallback<[Window](#window)> | Yes | Callback used to return the top window obtained. |
**Example**
...
...
@@ -1154,7 +1154,7 @@ Obtains the top window of the current application. This API uses a promise to re
| ctx | BaseContext | Yes | Current application context.<br>For details about the context in the FA model, see [Context](js-apis-inner-app-context.md).<br>For details about the context in the stage model, see [Context](js-apis-ability-context.md).|
| ctx | [BaseContext](js-apis-inner-application-baseContext.md) | Yes | Current application context.|
**Return value**
...
...
@@ -1864,7 +1864,7 @@ Obtains the area where this window cannot be displayed, for example, the system
| callback | AsyncCallback<[ColorSpace](#colorspace8)> | Yes | Callback used to return the result. When the color space is obtained successfully, **err** is **undefined**, and **data** is the current color space. |
