README.md

    Utils

    Overview

    The Utils repository stores basic components of OpenHarmony. These basic components are used by OpenHarmony subsystems and upper-layer applications.

    The Utils library provides the following capabilities on different platforms:

    • LiteOS Cortex-M (Hi3861 platform): key value (KV) store, file operations, timer, and system attribute dumping
    • LiteOS Cortex-A (Hi3516 or Hi3518 platform): KV store, timer, JavaScript APIs for device query and data storage, and system attribute dumping

    Table 1 Utils capabilities

    Module

    Platform

    Description

    KV store

    LiteOS Cortex-M and LiteOS Cortex-A

    Provides KV storage for applications.

    File operation

    LiteOS Cortex-M

    Provides unified file operation interfaces that can be used on different underlying chip components.

    Timer

    LiteOS Cortex-M and LiteOS Cortex-A

    Provides unified timer operation interfaces that can be used on different underlying chip components.

    JavaScript API

    LiteOS Cortex-A

    Provides JavaScript APIs for obtaining device information and storing data.

    System attribute dumping

    LiteOS Cortex-M and LiteOS Cortex-A

    Provides the command line tool for dumping system attributes.

    Directory Structure

    utils/native/lite/              # Root directory
    ├── file                        # Implementation of the file system APIs
    ├── hals                        # HAL directory
    │   └── file                    # Header files of the hardware abstraction layer for file operations
    ├── include                     # Header files of external APIs
    ├── js                          # JavaScript APIs
    │   └── builtin
    │       ├── common
    │       ├── deviceinfokit       # Device information kit
    │       ├── filekit             # File kit
    │       └── kvstorekit          # KV store kit
    ├── kal                         # KAL directory
    │   └── timer                   # KAL implementation of the timer
    ├── kv_store	                # KV store implementation
    │   ├── innerkits               # Internal KV store APIs
    │   └── src	                    # KV store source file
    ├── memory
    │   └── include                 # Memory pool management APIs
    ├── os_dump                     # System attribute dumping
    └── timer_task                  # Timer implementation

    Usage

    • KV store

      // Store or update the value of a key.
      const char key1[] = "key_sample";
      const char defValue[] = "test case of key value store.";
      int ret = UtilsSetValue(key1, defValue);
      
      // Obtain the value of the key.
      char value1[32] = {0};
      ret = UtilsGetValue(key1, value1, 32);
      
      // Delete the value of the key.
      UtilsDeleteValue(key1);
    • File operation

      // Open or create a file.
      const char fileName[] = "testfile";
      int fd = UtilsFileOpen(fileName, O_RDWR_FS | O_CREAT_FS | O_TRUNC_FS, 0);
      
      // Write a specified length of data into a file with the specified file descriptor.
      const char defValue[] = "test case of file system.";
      int ret = UtilsFileWrite(fd, defValue, strlen(defValue));
      
      // Close a file with a specified file descriptor.
      UtilsFileClose(fd);
      
      // Obtain the file size.
      int fileLen = 0;
      ret = UtilsFileStat(fileName, &fileLen);
      printf("file size = %d\n", fileLen);
      
      // Adjust the read and write position offset in a file.
      int fd1 = UtilsFileOpen(fileName, O_RDWR_FS, 0);
      ret = UtilsFileSeek(fd1, 5, SEEK_SET_FS);
      
      // Read a specified length of data from a file with the specified file descriptor and write the data into the buffer.
      char buf[32] = {0};
      int readLen = UtilsFileRead(fd1, buf, 32);
      ret = UtilsFileClose(fd1);
      printf("read len = %d : buf = %s\n", readLen, buf);
      
      // Delete a specified file.
      ret = UtilsFileDelete(fileName);
    • System attribute dumping

      LiteOS Cortex-M kernel: Run the following command over the serial port to dump the current system parameters:

      AT+SYSPARA

      LiteOS Cortex-A kernel: Run the os_dump command in the bin directory to dump the current system parameters:

      ./bin/os_dump syspara

    Repositories Involved

    Utils

    utils_native_lite

    项目简介

    公共基础库

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    开发语言

    • C 71.4 %
    • C++ 26.9 %
    • CMake 1.8 %