This document describes how to use the native Rawfile APIs to manage raw file directories and files in OpenHarmony. You can use Rawfile APIs to perform operations such as traversing the file list, opening, searching for, reading, and closing raw files.
This document describes how to use Native Rawfile APIs to manage the directories and files in the **rawfile** directory in OpenHarmony. You can use the APIs to perform operations, such as traversing a directory and opening, searching for, reading, and closing a file in the the **rawfile** directory.
| RawDir *OH_ResourceManager_OpenRawDir(const NativeResourceManager *mgr, const char *dirName) | Opens a raw file directory. |
| int OH_ResourceManager_GetRawFileCount(RawDir *rawDir) | Obtains the number of raw files in the specified directory.|
| const char *OH_ResourceManager_GetRawFileName(RawDir *rawDir, int index) | Obtains the name of a raw file. |
| RawFile *OH_ResourceManager_OpenRawFile(const NativeResourceManager *mgr, const char *fileName) | Opens a raw file. |
| long OH_ResourceManager_GetRawFileSize(RawFile *rawFile) | Obtains the size of a raw file. |
| int OH_ResourceManager_SeekRawFile(const RawFile *rawFile, long offset, int whence) | Seeks a read/write position in a raw file based on the specified offset. |
| long OH_ResourceManager_GetRawFileOffset(const RawFile *rawFile) | Obtains the offset. |
| int OH_ResourceManager_ReadRawFile(const RawFile *rawFile, void *buf, size_t length) | Reads a raw file. |
| void OH_ResourceManager_CloseRawFile(RawFile *rawFile) | Closes a raw file to release resources. |
| void OH_ResourceManager_CloseRawDir(RawDir *rawDir) | Closes a raw file directory to release resources. |
| bool OH_ResourceManager_GetRawFileDescriptor(const RawFile *rawFile, RawFileDescriptor &descriptor) | Obtains the file descriptor (FD) of a raw file. |
| bool OH_ResourceManager_ReleaseRawFileDescriptor(const RawFileDescriptor &descriptor) | Releases the FD of a raw file. |
| RawDir *OH_ResourceManager_OpenRawDir(const NativeResourceManager *mgr, const char *dirName) | Opens a directory in the **rawfile** directory. |
| int OH_ResourceManager_GetRawFileCount(RawDir *rawDir) | Obtains the number of files in the specified directory. |
| const char *OH_ResourceManager_GetRawFileName(RawDir *rawDir, int index) | Obtains the name of a file in the **rawfile** directory. |
| RawFile *OH_ResourceManager_OpenRawFile(const NativeResourceManager *mgr, const char *fileName) | Opens a file in the **rawfile** directory. |
| long OH_ResourceManager_GetRawFileSize(RawFile *rawFile) | Obtains the size of a file in the **rawfile** directory. |
| int OH_ResourceManager_SeekRawFile(const RawFile *rawFile, long offset, int whence) | Seeks for the read/write position in a file in the **rawfile** directory based on the specified offset. |
| long OH_ResourceManager_GetRawFileOffset(const RawFile *rawFile) | Obtains the offset of a file. |
| int OH_ResourceManager_ReadRawFile(const RawFile *rawFile, void *buf, size_t length) | Reads data from a file in the **rawfile** directory. |
| void OH_ResourceManager_CloseRawFile(RawFile *rawFile) | Closes a file in the **rawfile** directory to release resources. |
| void OH_ResourceManager_CloseRawDir(RawDir *rawDir) | Closes a directory in the **rawfile** directory to release resources. |
| bool OH_ResourceManager_GetRawFileDescriptor(const RawFile *rawFile, RawFileDescriptor &descriptor) | Obtains the file descriptor (FD) of a file in the **rawfile** directory. |
| bool OH_ResourceManager_ReleaseRawFileDescriptor(const RawFileDescriptor &descriptor) | Releases the FD of a file in the **rawfile** directory. |
The following describes how to obtain the raw file list, raw file content, and raw file descriptor on the JavaScript side as an example.
The following describes how to obtain the file list in the **rawfile** directory, file content, and FD {fd, offset, length} on the JavaScript side as an example.
1. Create a project.
2. Add dependencies.
After a project is created, the **cpp** directory is created under the project. The directory contains files such as **libentry/index.d.ts**, **hello.cpp**, and **CMakeLists.txt**.
After the project is created, the **cpp** directory is created under the project. The directory contains files such as **libentry/index.d.ts**, **hello.cpp**, and **CMakeLists.txt**.
1. Open the **src/main/cpp/CMakeLists.txt** file, and add **librawfile.z.so** and **libhilog_ndk.z.so** to **target_link_libraries**.
1. Open the **src/main/cpp/CMakeLists.txt** file, and add **librawfile.z.so** and **libhilog_ndk.z.so** to **target_link_libraries**.
```c++
```
target_link_libraries(entry PUBLIC libace_napi.z.so libhilog_ndk.z.so librawfile.z.so)
```
2. Open the **src/main/cpp/types/libentry/index.d.ts** file, and declare the application functions **getFileList**, **getRawFileContent**, and **getRawFileDescriptor**.
2. Open the **src/main/cpp/types/libentry/index.d.ts** file, and declare the application functions **getFileList**, **getRawFileContent**, and **getRawFileDescriptor**.
```c++
import resourceManager from '@ohos.resourceManager';
...
...
@@ -50,9 +138,11 @@ After a project is created, the **cpp** directory is created under the project.
1. Open the **src/main/cpp/hello.cpp** file. During initialization, the file maps the external JavaScript APIs **getFileList**, **getRawFileContent**, and **getRawFileDescriptor** to C++ native APIs **GetFileList**, **GetRawFileContent**, and **GetRawFileDescriptor**.
1. Open the **src/main/cpp/hello.cpp** file. During initialization, the file maps the external JavaScript APIs **getFileList**, **getRawFileContent**, and **getRawFileDescriptor** to C++ native APIs **GetFileList**, **GetRawFileContent**, and **GetRawFileDescriptor**.
```c++
EXTERN_C_START
...
...
@@ -70,7 +160,9 @@ After a project is created, the **cpp** directory is created under the project.
EXTERN_C_END
```
2. Add the three functions to the **src/main/cpp/hello.cpp** file.
2. Add the three functions to the **src/main/cpp/hello.cpp** file.
3. Obtain JavaScript resource objects from the **hello.cpp** file, and convert them to native resource objects. Then, call the native APIs to obtain the raw file list, raw file content, and raw file descriptor {fd, offset, length}. The sample code is as follows:
3. Obtain JavaScript resource objects from the **hello.cpp** file, and convert them to Native resource objects. Then, call the Native APIs to obtain the file list, file content, and FD {fd, offset, length}.
The sample code is as follows:
```c++
// Example 1: Use GetFileList to obtain the raw file list.
...
...
@@ -174,7 +270,7 @@ After a project is created, the **cpp** directory is created under the project.
// Convert the native object to a JavaScript object.
...
...
@@ -254,13 +350,17 @@ After a project is created, the **cpp** directory is created under the project.
}
```
4. Call APIs on the JavaScript side.
1. Open **src\main\ets\pages\index.ets**, and import **libentry.so**.
2. Obtain the JavaScript resource object, that is, **resourceManager**.
4. Call JavaScript APIs.
1. Open **src\main\ets\pages\index.ets**, and import **libentry.so**.
2. Obtain the JavaScript resource object, that is, **resourceManager**.
3. Call **getFileList**, that is, the native API declared in **src/main/cpp/types/libentry/index.d.ts**. When calling the API, pass the JavaScript resource object and the relative path of the raw file. The sample code is as follows:
3. Call **getFileList**, that is, the Native API declared in **src/main/cpp/types/libentry/index.d.ts**. When calling the API, pass in the JavaScript resource object and the relative path of the file.
The sample code is as follows:
```js
import hilog from '@ohos.hilog';
...
...
@@ -293,88 +393,5 @@ After a project is created, the **cpp** directory is created under the project.
}
```
## Using C++ Functions
1. Call **OH_ResourceManager_OpenRawDir** to obtain a **RawDir** instance based on the **NativeResourceManager** instance.
