napi系列学习高阶篇——通过IDE集成C/C++三方库并开发napi接口

简介

应用在调用系统固件集成的C/C++三方库时,可能会由于系统固件集成端与IDE的NDK中libc++版本不一致导致调用失败,而且系统固件集成的C/C++三方库对于应用的调式也很不友好,需要多方编译调试,很不方便。因此本文将通过在IDE上适配openjpeg 三方库为例介绍IDE上适配一个C/C++三方库的具体流程。

创建工程

在开发进行三方库适配以及napi接口开发前,我们需要创建一个三方库对应的工程,具体创建工程方法可以参照文档通过IDE开发一个Napi工程。

IDE上三方库的适配

本文中我们以适配 openjpeg 为例介绍整个适配流程 。

原生库准备

下载代码

通过openjpeg github网址,通过Code>>Download ZIP选项下载最新版本的源码包,并将其解压后放在IDE工程中的CPP目录下。

  • 下载openjpeg 2.5.0版本的库:

  • 将库放在IDE工程:

分析编译依赖
  • 分析CMakeLists.txt 对于库不是很复杂且目录结构简单的库可以通过分析CMakeLists.txt文件来获取库的依赖。在openjpeg库中, 通过分析最外层CMakeLists.txt文件,可以得知编译openjpeg核心代码以及需要依赖编译库自带thirdparty,如下图:

而分析thirdparty/CMakeLists.txt文件,如果BUILD_THIRDPARTY开关未打开,将会通过FindPkgConfig自动搜索系统(IDE工具的SDK编译链)中的库文件,如下图:

并由此文件可以分析出该库非强制依赖了libz, libpng, libtiff以及liblcms2,如对libpng依赖的分析中:

IDE工具的SDK编译链中只有libz库,其他三个库是没有的,所以如果需要其他三个库的功能,我们需要将BUILD_THIRDPARTY开关打开,此开关在库顶层目录的CMakeLists.txt文件中,如下图:

到此,本库的依赖就已经分析完了。

  • 通过运行cmake分析 我们除了分析CMakeLists.txt文件外,也可以通过在linux中通过cmake过程来分析对应的依赖。

我们在执行cmake的时候,会有对相关的依赖库的提示:

-- Large File support - found
-- Looking for include file malloc.h
-- Looking for include file malloc.h - found
-- Looking for _aligned_malloc
-- Looking for _aligned_malloc - not found
-- Looking for posix_memalign
-- Looking for posix_memalign - found
-- Looking for memalign
-- Looking for memalign - found
-- Found PkgConfig: /usr/bin/pkg-config (found version "0.29.1")
-- Found ZLIB: /usr/lib/x86_64-linux-gnu/libz.so (found version "1.2.11")
-- Your system seems to have a Z lib available, we will use it to generate PNG lib
-- Found PNG: /usr/lib/x86_64-linux-gnu/libpng.so (found version "1.6.37")
-- Your system seems to have a PNG lib available, we will use it
-- Found TIFF: /usr/lib/x86_64-linux-gnu/libtiff.so (found version "4.1.0")
-- Your system seems to have a TIFF lib available, we will use it
-- Could NOT find LCMS2 (missing: LCMS2_LIBRARY LCMS2_INCLUDE_DIR)
-- Could NOT find LCMS (missing: LCMS_LIBRARY LCMS_INCLUDE_DIR)
-- LCMS2 or LCMS lib not found, activate BUILD_THIRDPARTY if you want build it
-- Configuring done
-- Generating done

由以上信息可以查看到,编译此库需要依赖libz(found version “1.2.11”),libpng(found version “1.6.37”),libtiff(found version “4.1.0”)以及liblcms2(LCMS2 or LCMS lib not found, activate BUILD_THIRDPARTY if you want build it)。从提示中可以看到,如果想要使能对应的功能且系统库中未包含该依赖的话,需要打开BUILD_THIRDPARTY 开关。

除了cmake中获取的依赖,我们也可以通过分析make编译过程获取更多的信息,具体方法可以参照三方库适配依赖分析。

重构CMakeLists

对于不复杂的库且没有其他四方库依赖的三方库,我们可以使用原生库的CMakeLists.txt文件,但是对于一些复杂的,且强制依赖其他四方库的库,使用其原生CMakeLists.txt文件,无法解决四方库依赖的问题。此时,我们就需要对三方库的CMakeLists.txt文件进行重构。
重构CMakeLists文件主要需涉及以下几点:

  • 动态生成配置文件 查看原生CMakeLists.txt文件中是否有configure_file配置项,如果没有可直接跳过此步骤。
    在openjpeg库的原生CMakeLists.txt文件中,有2个配置文件需要动态生成:
# opj_config.h generation (2/2)
configure_file(${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_config.h.cmake.in${CMAKE_CURRENT_BINARY_DIR}/src/lib/openjp2/opj_config.h@ONLY)configure_file(${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_config_private.h.cmake.in${CMAKE_CURRENT_BINARY_DIR}/src/lib/openjp2/opj_config_private.h@ONLY)

configure_file带了@ONLY参数,该参数限制了变量替换,让其只替换被@VAR@引用的变量。因此我们需要分析两个文件中对应的@VAR@配置规则。首先在opj_config.h.cmake.in文件定义的对应@VAR@的定义:

/* create opj_config.h for CMake */
#cmakedefine OPJ_HAVE_STDINT_H   @OPJ_HAVE_STDINT_H@
/*--------------------------------------------------------------------------*/
/* OpenJPEG Versioning                                                      *//* Version number. */
#define OPJ_VERSION_MAJOR @OPENJPEG_VERSION_MAJOR@
#define OPJ_VERSION_MINOR @OPENJPEG_VERSION_MINOR@
#define OPJ_VERSION_BUILD @OPENJPEG_VERSION_BUILD@

在分析@VAR@的赋值规则,在顶层CMakeLists.txt中:

# opj_config.h generation (1/2)# Check if some include files are provided by the system
include(EnsureFileInclude)
# These files are mandatory
ensure_file_include("string.h"   HAVE_STRING_H YES)
ensure_file_include("memory.h"   HAVE_MEMORY_H YES)
ensure_file_include("stdlib.h"   HAVE_STDLIB_H YES)
ensure_file_include("stdio.h"    HAVE_STDIO_H  YES)
ensure_file_include("math.h"     HAVE_MATH_H   YES)
ensure_file_include("float.h"    HAVE_FLOAT_H  YES)
ensure_file_include("time.h"     HAVE_TIME_H   YES)
ensure_file_include("stdarg.h"   HAVE_STDARG_H YES)
ensure_file_include("ctype.h"    HAVE_CTYPE_H  YES)
ensure_file_include("assert.h"   HAVE_ASSERT_H YES)# For the following files, we provide an alternative, they are not mandatory
ensure_file_include("stdint.h"   OPJ_HAVE_STDINT_H   NO)
ensure_file_include("inttypes.h" OPJ_HAVE_INTTYPES_H NO)

从以上内容通过分析ensure_file_include可以知道,在执行cmake时从系统中查找stdint.h文件,如果查找到则将OPJ_HAVE_STDINT_H置起,否则不会改变。而IDE上是没有stdint.h文件的,因此我们需要在配置文件之前手动将OPJ_HAVE_STDINT_H置起,如下:

set(OPJ_HAVE_STDINT_H TRUE)

其他变量也是通过类似的方法分析。

  • 相关宏定义的设置 通过add_definitions设置三方库的相关宏定义,如下所示:
add_definitions(-DOPJ_HAVE_PNG_H=0 -DOPJ_HAVE_TIFF_H=1 -DOPJ_HAVE_LCMS2_H=1)
  • 源码文件编译 三方库编译的源码可以通过在linux执行make的时候查看分析到:
[  0%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/thread.c.o
[  1%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/bio.c.o
[  1%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/cio.c.o
[  2%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/dwt.c.o
[  3%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/event.c.o
[  3%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/ht_dec.c.o
[  4%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/image.c.o
[  5%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/invert.c.o
[  5%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/j2k.c.o
[  6%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/jp2.c.o
[  7%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/mct.c.o
[  7%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/mqc.c.o
[  8%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/openjpeg.c.o
[  9%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/opj_clock.c.o
[  9%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/pi.c.o
[ 10%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/t1.c.o
[ 10%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/t2.c.o
[ 11%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/tcd.c.o
[ 12%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/tgt.c.o
[ 12%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/function_list.c.o
[ 13%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/opj_malloc.c.o
[ 14%] Building C object src/lib/openjp2/CMakeFiles/openjp2_static.dir/sparse_array.c.o
[ 14%] Linking C static library ../../../bin/libopenjp2.a
[ 14%] Built target openjp2_static
Scanning dependencies of target openjp2
[ 14%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/thread.c.o
[ 15%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/bio.c.o
[ 16%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/cio.c.o
[ 16%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/dwt.c.o
[ 17%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/event.c.o
[ 18%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/ht_dec.c.o
[ 18%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/image.c.o
[ 19%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/invert.c.o
[ 20%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/j2k.c.o
[ 20%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/jp2.c.o
[ 21%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/mct.c.o
[ 22%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/mqc.c.o
[ 22%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/openjpeg.c.o
[ 23%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/opj_clock.c.o
[ 23%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/pi.c.o
[ 24%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/t1.c.o
[ 25%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/t2.c.o
[ 25%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/tcd.c.o
[ 26%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/tgt.c.o
[ 27%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/function_list.c.o
[ 27%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/opj_malloc.c.o
[ 28%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/sparse_array.c.o
[ 29%] Linking C shared library ../../../bin/libopenjp2.so
[ 29%] Built target openjp2
Scanning dependencies of target z
[ 30%] Building C object thirdparty/libz/CMakeFiles/z.dir/adler32.c.o
[ 31%] Building C object thirdparty/libz/CMakeFiles/z.dir/compress.c.o
[ 31%] Building C object thirdparty/libz/CMakeFiles/z.dir/crc32.c.o
[ 32%] Building C object thirdparty/libz/CMakeFiles/z.dir/deflate.c.o
[ 32%] Building C object thirdparty/libz/CMakeFiles/z.dir/gzclose.c.o
[ 33%] Building C object thirdparty/libz/CMakeFiles/z.dir/gzlib.c.o
[ 34%] Building C object thirdparty/libz/CMakeFiles/z.dir/gzread.c.o
[ 34%] Building C object thirdparty/libz/CMakeFiles/z.dir/gzwrite.c.o
[ 35%] Building C object thirdparty/libz/CMakeFiles/z.dir/inflate.c.o
[ 36%] Building C object thirdparty/libz/CMakeFiles/z.dir/infback.c.o
[ 36%] Building C object thirdparty/libz/CMakeFiles/z.dir/inftrees.c.o
[ 37%] Building C object thirdparty/libz/CMakeFiles/z.dir/inffast.c.o
[ 38%] Building C object thirdparty/libz/CMakeFiles/z.dir/trees.c.o
[ 38%] Building C object thirdparty/libz/CMakeFiles/z.dir/uncompr.c.o
[ 39%] Building C object thirdparty/libz/CMakeFiles/z.dir/zutil.c.o
[ 40%] Linking C static library ../lib/libz.a
[ 40%] Built target z
Scanning dependencies of target tiff
[ 40%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_aux.c.o
[ 41%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_close.c.o
[ 42%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_codec.c.o
[ 42%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_color.c.o
[ 43%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_compress.c.o
[ 43%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_dir.c.o
[ 44%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_dirinfo.c.o
[ 45%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_dirread.c.o
[ 45%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_dirwrite.c.o
[ 46%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_dumpmode.c.o
[ 47%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_error.c.o
[ 47%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_extension.c.o
[ 48%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_fax3.c.o
[ 49%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_fax3sm.c.o
[ 49%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_flush.c.o
[ 50%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_getimage.c.o
[ 51%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_jbig.c.o
[ 51%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_jpeg.c.o
[ 52%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_luv.c.o
[ 52%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_lzw.c.o
[ 53%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_next.c.o
[ 54%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_ojpeg.c.o
[ 54%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_open.c.o
[ 55%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_packbits.c.o
[ 56%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_pixarlog.c.o
[ 56%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_predict.c.o
[ 57%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_print.c.o
[ 58%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_read.c.o
[ 58%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_strip.c.o
[ 59%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_swab.c.o
[ 59%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_thunder.c.o
[ 60%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_tile.c.o
[ 61%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_version.c.o
[ 61%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_warning.c.o
[ 62%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_write.c.o
[ 63%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_zip.c.o
[ 63%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_jpeg_12.c.o
[ 64%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_lzma.c.o
[ 65%] Building C object thirdparty/libtiff/CMakeFiles/tiff.dir/tif_unix.c.o
[ 65%] Linking C static library ../lib/libtiff.a
[ 65%] Built target tiff
Scanning dependencies of target lcms2
[ 65%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsalpha.c.o
[ 66%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmscam02.c.o
[ 66%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmscgats.c.o
[ 67%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmscnvrt.c.o
[ 68%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmserr.c.o
[ 68%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsgamma.c.o
[ 69%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsgmt.c.o
[ 70%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmshalf.c.o
[ 70%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsintrp.c.o
[ 71%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsio0.c.o
[ 72%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsio1.c.o
[ 72%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmslut.c.o
[ 73%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsmd5.c.o
[ 73%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsmtrx.c.o
[ 74%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsnamed.c.o
[ 75%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsopt.c.o
[ 75%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmspack.c.o
[ 76%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmspcs.c.o
[ 77%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsplugin.c.o
[ 77%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsps2.c.o
[ 78%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmssamp.c.o
[ 79%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmssm.c.o
[ 79%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmstypes.c.o
[ 80%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsvirt.c.o
[ 81%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmswtpnt.c.o
[ 81%] Building C object thirdparty/liblcms2/CMakeFiles/lcms2.dir/src/cmsxform.c.o
[ 82%] Linking C static library ../lib/liblcms2.a
[ 82%] Built target lcms2
Scanning dependencies of target opj_dump
[ 82%] Building C object src/bin/jp2/CMakeFiles/opj_dump.dir/opj_dump.c.o
[ 83%] Building C object src/bin/jp2/CMakeFiles/opj_dump.dir/convert.c.o
[ 84%] Building C object src/bin/jp2/CMakeFiles/opj_dump.dir/convertbmp.c.o
[ 84%] Building C object src/bin/jp2/CMakeFiles/opj_dump.dir/index.c.o
[ 85%] Building C object src/bin/jp2/CMakeFiles/opj_dump.dir/__/common/color.c.o
[ 86%] Building C object src/bin/jp2/CMakeFiles/opj_dump.dir/__/common/opj_getopt.c.o
[ 86%] Building C object src/bin/jp2/CMakeFiles/opj_dump.dir/converttif.c.o
[ 87%] Building C object src/bin/jp2/CMakeFiles/opj_dump.dir/convertpng.c.o
[ 88%] Linking C executable ../../../bin/opj_dump
[ 88%] Built target opj_dump
Scanning dependencies of target opj_compress
[ 89%] Building C object src/bin/jp2/CMakeFiles/opj_compress.dir/opj_compress.c.o
[ 90%] Building C object src/bin/jp2/CMakeFiles/opj_compress.dir/convert.c.o
[ 90%] Building C object src/bin/jp2/CMakeFiles/opj_compress.dir/convertbmp.c.o
[ 91%] Building C object src/bin/jp2/CMakeFiles/opj_compress.dir/index.c.o
[ 92%] Building C object src/bin/jp2/CMakeFiles/opj_compress.dir/__/common/color.c.o
[ 92%] Building C object src/bin/jp2/CMakeFiles/opj_compress.dir/__/common/opj_getopt.c.o
[ 93%] Building C object src/bin/jp2/CMakeFiles/opj_compress.dir/converttif.c.o
[ 93%] Building C object src/bin/jp2/CMakeFiles/opj_compress.dir/convertpng.c.o
[ 94%] Linking C executable ../../../bin/opj_compress
[ 94%] Built target opj_compress
Scanning dependencies of target opj_decompress
[ 95%] Building C object src/bin/jp2/CMakeFiles/opj_decompress.dir/opj_decompress.c.o
[ 95%] Building C object src/bin/jp2/CMakeFiles/opj_decompress.dir/convert.c.o
[ 96%] Building C object src/bin/jp2/CMakeFiles/opj_decompress.dir/convertbmp.c.o
[ 97%] Building C object src/bin/jp2/CMakeFiles/opj_decompress.dir/index.c.o
[ 97%] Building C object src/bin/jp2/CMakeFiles/opj_decompress.dir/__/common/color.c.o
[ 98%] Building C object src/bin/jp2/CMakeFiles/opj_decompress.dir/__/common/opj_getopt.c.o
[ 99%] Building C object src/bin/jp2/CMakeFiles/opj_decompress.dir/converttif.c.o
[ 99%] Building C object src/bin/jp2/CMakeFiles/opj_decompress.dir/convertpng.c.o
[100%] Linking C executable ../../../bin/opj_decompress
[100%] Built target opj_decompress

由上面过程可看出,每个编译目标(Built target)所依赖的文件由上一个目标(如果上一个目标由的话)生成后以及该目标生成前的文件组成,如生成libopenjp2.so(Built target openjp)的文件是Built target openjp2_static之后以及Built target openjp之前的文件:

[ 14%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/thread.c.o
[ 15%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/bio.c.o
[ 16%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/cio.c.o
[ 16%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/dwt.c.o
[ 17%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/event.c.o
[ 18%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/ht_dec.c.o
[ 18%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/image.c.o
[ 19%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/invert.c.o
[ 20%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/j2k.c.o
[ 20%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/jp2.c.o
[ 21%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/mct.c.o
[ 22%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/mqc.c.o
[ 22%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/openjpeg.c.o
[ 23%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/opj_clock.c.o
[ 23%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/pi.c.o
[ 24%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/t1.c.o
[ 25%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/t2.c.o
[ 25%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/tcd.c.o
[ 26%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/tgt.c.o
[ 27%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/function_list.c.o
[ 27%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/opj_malloc.c.o
[ 28%] Building C object src/lib/openjp2/CMakeFiles/openjp2.dir/sparse_array.c.o

因此生成libopenjpeg.so的源文件我们就可以这样写:

set(SHARED_LIB_SRC "${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/thread.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/bio.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/cio.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/dwt.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/event.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/ht_dec.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/image.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/invert.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/j2k.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/jp2.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/mct.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/mqc.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/openjpeg.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_clock.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/pi.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/t1.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/t2.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/tcd.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/tgt.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/function_list.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_malloc.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/sparse_array.c")

其中CMAKE_CURRENT_SOURCE_DIR是代表当前CMakeLists.txt文件所在的路径。

  • 目标文件生成 这里我们调用add_library生成一个目标文件libopenjpeg_shared.so,其依赖上面分析的源码share_lib_src:
add_library(openjp2 SHARED ${SHARED_LIB_SRC})
  • 添加其他四方库依赖 如果三方库有对其他四方库依赖的话,需要通过target_link_libraries()方法添加对应的依赖。如在工程CPP目录下的CMakeLists.txt文件中的:
target_link_libraries(entry PUBLIC libace_napi.z.so openjg2)      # libace_napi.z.so-系统napi库, openjg2-依赖的openjpeg库
  • 完整的CMakeLists.txt
# the minimum version of CMake.
cmake_minimum_required(VERSION 3.4.1)
set(CMAKE_CXX_STANDARD 17)
project(openjpeg)set(OPJ_HAVE_STDINT_H TRUE)
set(OPJ_HAVE_INTTYPES_H TRUE)
set(OPENJPEG_VERSION_MAJOR 2)
set(OPENJPEG_VERSION_MINOR 5)
set(OPENJPEG_VERSION_BUILD 0)
set(OPENJPEG_VERSION"${OPENJPEG_VERSION_MAJOR}.${OPENJPEG_VERSION_MINOR}.${OPENJPEG_VERSION_BUILD}")
set(PACKAGE_VERSION"${OPENJPEG_VERSION_MAJOR}.${OPENJPEG_VERSION_MINOR}.${OPENJPEG_VERSION_BUILD}")configure_file(${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_config.h.cmake.in${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_config.h@ONLY)configure_file(${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_config_private.h.cmake.in${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_config_private.h@ONLY)add_definitions(-DOPJ_HAVE_PNG_H=0 -DOPJ_HAVE_TIFF_H=1 -DOPJ_HAVE_LCMS2_H=1)
set(INCLUDE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2")
set(SHARED_LIB_SRC "${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/thread.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/bio.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/cio.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/dwt.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/event.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/ht_dec.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/image.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/invert.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/j2k.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/jp2.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/mct.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/mqc.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/openjpeg.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_clock.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/pi.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/t1.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/t2.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/tcd.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/tgt.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/function_list.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/opj_malloc.c""${CMAKE_CURRENT_SOURCE_DIR}/src/lib/openjp2/sparse_array.c")add_library(openjp2 SHARED ${SHARED_LIB_SRC})
target_include_directories(openjp2 PRIVATE ${INCLUDE_DIR})

加入编译构建

原生库源码准备完后,我们需要将库加入到工程的编译构建中。在工程目录CPP下的CMakeLists.txt文件中,通过add_subdirectory将openjpeg加入到编译中,并通过target_link_libraries添加对openjpeg的链接,如下图:

特别说明:
如果使用原生库的CMakeLists文件,编译时会提示添加目标时需要重新更改目标路径:

此时我们就需要在顶层目录的CMakeLists.txt文件中添加

set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE)

到此,我们的三方库适配已经完成并可以正常编译成功。

三方库napi接口开发

三方库napi的接口一般是由需求方提供的,对于无需求或需要自己定义接口的,我们可以根据三方库对外导出的API接口进行封装或是根据原生库的测试用例对外封装测试接口。本文中我们已封装2个openjpeg测试接口为例详细说明napi接口开发的具体流程。

定义napi接口

根据原生库的测试用例,我们封装2个测试用例接口

typedef struct {int comps_num;           // the number of components of the image.int comps_prec;         // number of bits per component per pixelint img_width;          // the image widthint img_height;         // the image heightint title_width;        // width of tileint title_height;       // height of titleint irreversible;       // 1 : use the irreversible DWT 9-7// 0 : use lossless compression (default)int cblockw_init;       // initial code block width, default to 64int cblockh_init;       // initial code block height, default to 64int numresolution;      // number of resolutionsint offsetx;            // x component offset compared to the whole imageint offsety;            // y component offset compared to the whole imageint is_rand;            // Whether to generate data randomlychar file[256];         // output filename
} J2K_Info;int OpenjpegCompress(const char *input_file, char *output_file)   # 图片压缩成J2K格式
int openjpeg_create_j2k(J2K_Info *info)                # 创建一张J2K格式图片

注册接口

napi_property_descriptor desc[] = {{"openjpeg_compress", nullptr, OpenjpegCompress, nullptr, nullptr,nullptr, napi_default, nullptr},{"openjpeg_create_j2k", nullptr, OpenjpegCreateJ2K , nullptr, nullptr,nullptr, napi_default, nullptr}};

接口实现

  • openjpeg_compress接口的实现
static napi_value OpenjpegCompressMethod(napi_env env, napi_callback_info info)
{napi_value result = nullptr;napi_get_undefined(env, &result);napi_value value;size_t argc = 2;napi_value args[2];size_t size;char input_file[256] = {0};char output_file[256] = {0};// 获取参数if (napi_get_cb_info(env, info, &argc, args, nullptr, nullptr) != napi_ok) {return result;}// js类型转换成C/C++类型if (napi_get_value_string_utf8(env, args[0], input_file, sizeof(input_file),&size) != napi_ok) {return result;}// js类型转换成C/C++类型if (napi_get_value_string_utf8(env, args[1], output_file, sizeof(output_file),&size) != napi_ok) {return result;}// 封装一个通过调用openjpeg接口实现编码的接口// 三方库实现调用的业务逻辑接口if (OpenjpegCompress(input_file, output_file) != 0) {return result;}// 创建返回的js类型参数if (napi_create_int64(env, 0, &result) != napi_ok) {std::cout << "napi_create_int64" << std::endl;}// 返回最终结果。return result;
}
  • openjpeg_create_j2k接口的实现
static napi_value OpenjpegCreateJ2K(napi_env env, napi_callback_info info)
{napi_value result = nullptr;napi_get_undefined(env, &result);napi_value value;size_t argc = 1;J2K_Info j2kInfo;// 获取参数if (napi_get_cb_info(env, info, &argc, &value, nullptr, nullptr) != napi_ok) {return result;}// 解析参数if (OpenjpegGetJ2kInfo(env, value, &j2kInfo) < 0) {return result;}// 封装一个通过调用openjpeg接口实现创建J2K文件的接口// 三方库实现调用的业务逻辑接口if (OpenjpegCreateJ2K(&j2kInfo) < 0) {return result;}if (napi_create_int64(env, 0, &result) != napi_ok) {std::cout << "napi_create_int64" << std::endl;}return result;
}

解析参数接口的实现:

static int OpenjpegGetJ2kInfo(napi_env env, napi_value value, J2K_Info *info)
{if (info == nullptr) {return -1;}if(GetObjectPropetry(env, value,"output_file", STRING, info->file) != napi_ok) {return -1;}if (GetObjectPropetry(env, value,"comps_prec", NUMBER, &info->comps_prec) !=napi_ok) {return -1;}if (GetObjectPropetry(env, value,"img_width", NUMBER, &info->img_width) !=napi_ok) {return -1;}if (GetObjectPropetry(env, value,"img_height", NUMBER, &info->img_height) !=napi_ok) {return -1;}if (GetObjectPropetry(env, value,"title_width", NUMBER, &info->title_width) !=napi_ok) {return -1;}if (GetObjectPropetry(env, value,"title_height", NUMBER, &info->title_height) !=napi_ok) {return -1;}if (GetObjectPropetry(env, value,"irreversible", NUMBER, &info->irreversible) !=napi_ok) {return -1;}GetObjectPropetry(env, value,"cblockw_init", NUMBER, &info->cblockw_init);GetObjectPropetry(env, value,"cblockh_init", NUMBER, &info->cblockh_init);GetObjectPropetry(env, value,"numresolution", NUMBER, &info->numresolution);GetObjectPropetry(env, value,"offsetx", NUMBER, &info->offsetx);GetObjectPropetry(env, value,"offsety", NUMBER, &info->offsety);GetObjectPropetry(env, value,"is_rand", BOOLEAN, &info->is_rand);return 0;
}

由上代码可以看出,OpenjpegGetJ2kInfo接扣调用了一个封装的接口GetObjectPropetry,该接口实现了通过调用napi的接口获取对应的数据:

static int GetObjectPropetry(napi_env env, napi_value object, std::string key, int keyType, void *retValue) {napi_value property = nullptr;napi_value result = nullptr;bool flag = false;int ret = -1;// 通过字符串获取napi_value对象if (napi_create_string_utf8(env, key.c_str(), strlen(key.c_str()), &property)!= napi_ok) {return ret;}// 判断该字符串是否对应由属性值if (napi_has_property(env, object, property, &flag) != napi_ok && flag == true) {return ret;}// 获取字符串对应的属性值if (napi_get_property(env, object, property, &result) != napi_ok) {return ret;}if (keyType == NUMBER) {int64_t value = 0;// JS数据类型转换成C/C++的int数据类型if (napi_get_value_int64(env, result, &value) != napi_ok) {return ret;}*(int *)retValue = value;ret = 0;} else if (keyType == BOOLEAN) {bool value = false;// JS数据类型转换成C/C++ 的bool数据类型if (napi_get_value_bool(env, result, &value) != napi_ok) {return ret;}*(int *)retValue = (value == true ? 1 : 0);}else if (keyType == STRING) {size_t s = 0;char buf[256] = {0};// JS数据类型转换成C/C++的string数据类型if (napi_get_value_string_utf8(env, result, buf, sizeof(buf), &s) !=napi_ok) {return ret;}strncpy((char *)retValue, buf, strlen(buf));ret = 0;}return 0;
}

应用调用napi接口

  • 应用申明接口 在确定需要封装的接口后,我们需要将这些接口定义在index.d.ts文件中(路径entry/src/main/cpp/types/libentry/index.d.ts)
export const openjpeg_compress: (srcName:string, desName:string) =>number;
interface openjpegOption{comps_num:number                // the number of components of the image.comps_prec:number               // number of bits per component per pixelimg_width:number                // the image widthimg_height:number               // the image heighttitle_width:number              // width of tiletitle_height:number             // height of titleirreversible:number             // 1 : use the irreversible DWT 9-7, // 0 : use lossless compression (default)output_file:string              // output filenamecblockw_init?:number            // initial code block width, default to 64cblockh_init?:number            // initial code block height, default to 64numresolution?:number           // number of resolutionsoffsetx?:number                 // x component offset compared to the whole imageoffsety?:number                 // y component offset compared to the whole imageis_rand?:boolean                // Whether to generate data randomly
}
export const openjpeg_create_j2k: (option:openjpegOption) => number
  • 应用调用接口 在ets工程中创建2个按钮,并通过按钮调用相关的接口,具体代码如下:
Button(this.buttonTxt0)
.fontSize(50)
.margin({top:30})
.fontWeight(FontWeight.Normal)
.onClick(() => {testNapi.openjpeg_compress(this.dir + "test_pic.bmp", this.dir + "result.j2k")
})
Button(this.buttonTxt1)
.fontSize(50)
.margin({top:30})
.fontWeight(FontWeight.Normal)
.onClick(() => {testNapi.openjpeg_create_j2k({comps_num:3,comps_prec:8,img_width:2000,img_height:2000,title_width:1000,title_height:1000,irreversible:1, output_file:this.dir +"newImage.j2k"})
})

为了能让大家更好的学习鸿蒙(HarmonyOS NEXT)开发技术,这边特意整理了《鸿蒙开发学习手册》(共计890页),希望对大家有所帮助:https://qr21.cn/FV7h05

《鸿蒙开发学习手册》:

如何快速入门:https://qr21.cn/FV7h05

  1. 基本概念
  2. 构建第一个ArkTS应用
  3. ……

开发基础知识:https://qr21.cn/FV7h05

  1. 应用基础知识
  2. 配置文件
  3. 应用数据管理
  4. 应用安全管理
  5. 应用隐私保护
  6. 三方应用调用管控机制
  7. 资源分类与访问
  8. 学习ArkTS语言
  9. ……

基于ArkTS 开发:https://qr21.cn/FV7h05

  1. Ability开发
  2. UI开发
  3. 公共事件与通知
  4. 窗口管理
  5. 媒体
  6. 安全
  7. 网络与链接
  8. 电话服务
  9. 数据管理
  10. 后台任务(Background Task)管理
  11. 设备管理
  12. 设备使用信息统计
  13. DFX
  14. 国际化开发
  15. 折叠屏系列
  16. ……

鸿蒙开发面试真题(含参考答案):https://qr18.cn/F781PH

鸿蒙开发面试大盘集篇(共计319页):https://qr18.cn/F781PH

1.项目开发必备面试题
2.性能优化方向
3.架构方向
4.鸿蒙开发系统底层方向
5.鸿蒙音视频开发方向
6.鸿蒙车载开发方向
7.鸿蒙南向开发方向

本文来自互联网用户投稿,该文观点仅代表作者本人,不代表本站立场。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如若转载,请注明出处:http://www.mzph.cn/news/814140.shtml

如若内容造成侵权/违法违规/事实不符,请联系多彩编程网进行投诉反馈email:809451989@qq.com,一经查实,立即删除!

相关文章

mp3怎样才能转换成wav格式?音频互相转换的方法

一&#xff0c;什么是WAV WAV&#xff0c;全称为波形音频文件&#xff08;Waveform Audio File Format&#xff09;&#xff0c;是一种由微软公司和IBM公司联合开发的音频文件格式。自1991年问世以来&#xff0c;WAV格式因其无损的音频质量和广泛的兼容性&#xff0c;成为了多…

【opencv】示例-morphology2.cpp 形态学操作:膨胀、腐蚀、开运算、闭运算

element_shape MORPH_ELLIPSE; element_shape MORPH_RECT element_shape MORPH_CROSS; // 包含必要的OpenCV头文件 #include "opencv2/imgproc.hpp" // 图像处理 #include "opencv2/imgcodecs.hpp" // 图像编码解码 #include "opencv2/highgui.hpp…

Zynq学习笔记--AXI 总线概述

目录 1. AXI总线概述 1.1 主要特点 1.2 通道功能 1.3 信号概览 2. AXI Interconnect 2.1 信号说明 2.2 内部结构 3. PS-PL AXI Interface 3.1 AXI FPD/LFP/ACP 3.2 Address Editor 3.3 地址空间 3.4 AXI-DDR 4. 通过ILA观察AXI信号 4.1 AXI 读通道 1. AXI总线概述…

Linux高级IO——多路转接之poll

本章代码Gitee地址&#xff1a;PollServer 文章目录 1. poll2. poll_server 1. poll poll的作用和select一模一样&#xff0c;只负责等待 poll在select的基础之上解决了select的两个硬伤&#xff1a; select等待的fd有上限select输入输出参数较多 #include <poll.h> …

【软件设计师知识点】八、数据库技术基础

文章目录 数据库基本术语关系型数据库基本术语数据库模型三级模式二级映射数据的独立性数据模型常用数据模型E-R 图(概念设计)数据库操作完整性规则关系代数运算集合运算符关系运算符数据库语言 SQL数据定义语言(DDL)

uniapp开发小程序手写板、签名、签字

可以使用这个插件进行操作 手写板-签名签字-lime-signature - DCloud 插件市场 但是目前这个插件没有vue3 setup Composition API的写法。所以对于此文档提供的可以直接使用,需要使用Composition API方式实现的,可以继续看。 因为Composition API方式,更加的简单、灵活,…

Java编程题目 | 四个数的三三组合

大家可以关注一下专栏&#xff0c;方便大家需要的时候直接查找&#xff0c;专栏将持续更新~ 题目描述 使用数字1、2、3、4&#xff0c;编写一个Java程序&#xff0c;找出所有互不相同且每个三位数中不含有重复数字的组合&#xff0c;并输出这些组合。 解题思路 使…

记录一个腾讯云上kafka不能正常启动问题

问题描述&#xff1a;刚在新的腾讯云三台节点上安了Zookeeper和kafka&#xff0c;改好对应配置文件后&#xff0c;启动zk和kafka。 启动zk后&#xff0c;启动kafka jpsall以后 发现两个进程都启了&#xff08;这里有猫腻&#xff0c;kafka其实没起来&#xff0c;过几秒就自动掉…

在Windows中用命令行编译C项目

在Windows中可以用命令行编译C项目 官方指导文档&#xff1a; 演练&#xff1a;在命令行上编译 C 程序 | Microsoft Learn 在官方文档中可以看到&#xff0c;可以只安装VS的命令行工具集&#xff0c;如下图所示

2.0 Hadoop 运行环境

2.0 Hadoop 运行环境 分类 Hadoop 教程 由于 Hadoop 是为集群设计的软件&#xff0c;所以我们在学习它的使用时难免会遇到在多台计算机上配置 Hadoop 的情况&#xff0c;这对于学习者来说会制造诸多障碍&#xff0c;主要有两个&#xff1a; 昂贵的计算机集群。多计算机构成的…

JVM性能调优——GC日志分析

文章目录 1、概述2、生成GC日志3、Parallel垃圾收集器日志解析3.1、Minor GC3.2、FULL GC 4、G1垃圾收集器日志解析4.1、Minor GC4.2、并发收集4.3、混合收集4.4、Full GC 5、CMS垃圾收集器日志解析5.1、Minor GC5.2、Major GC5.3、浮动垃圾 6、日志解析工具6.1、GCeasy6.2、GC…

SpringBoot项目 jar包方式打包部署

SpringBoot项目 jar包方式打包部署 传统的Web应用进行打包部署&#xff0c;通常会打成war包形式&#xff0c;然后将War包部署到Tomcat等服务器中。 在Spring Boot项目在开发完成后&#xff0c;确实既支持打包成JAR文件也支持打包成WAR文件。然而&#xff0c;官方通常推荐将Sp…

【Godot4.2】CanvasItem绘图函数全解析 - 8.绘制点索引

概述 在示意图绘制过程中或者测试过程中&#xff0c;可能需要标记点的索引。 最常见的形式就是用一个圆圈作为背景&#xff0c;用阿拉伯数字作为索引。 实现的重点是动态计算背景圆的半径。原理是&#xff0c;获取字符串的矩形&#xff0c;取对角线长度的一半作为外接圆的半…

AI PC元年,华为的一张航海图、一艘渡轮和一张船票

今天&#xff0c;从学术研究者到产业投资者&#xff0c;无不认为大模型掀起了一场人工智能的完美风暴。 所谓“完美风暴”&#xff0c;指的是一项新技术的各个要素&#xff0c;以新的方式互相影响、彼此加强&#xff0c;组合在一起形成了摧枯拉朽般的力量。 而我们每个人&#…

【运维笔记】深入理解反向代理的原理及应用

一、引言 在现代网络架构中&#xff0c;反向代理是一个核心组件&#xff0c;它在提升网站性能、增加安全性和简化网络流量管理方面发挥着至关重要的作用。本文将深入探讨反向代理的原理&#xff0c;展示其在不同场景下的应用&#xff0c;并通过具体案例来说明如何实现和优化反…

【opencv】示例-phase_corr.cpp 捕获视频流并通过计算相位相关性来检测画面中的移动...

// 包含OpenCV库的头文件 #include "opencv2/core.hpp" // 包含OpenCV核心功能 #include "opencv2/videoio.hpp" // 包含视频IO功能 #include "opencv2/highgui.hpp" // 包含高级GUI功能&#xff0c;显示图像 #include "opencv2/imgproc.hp…

机器视觉系列之【硬件知识】-工业相机(三)

目录 几个高频面试题目 如何解决工业相机的丢帧现象 工业相机是怎么实现触发的?

SpringCloud 2021.0.9 OpenFeign 与 circuitbreaker-resilience4j 使用示例

背景 OpenFeign是微服务中服务远程调用组件。 circuitbreaker 是断路器的抽象接口。 resilience4j是断路器的一种实现。 在服务间远程调用过程中&#xff0c;为了避免服务雪崩&#xff0c;需要设置失败保护机制&#xff0c;当下游服务超时或者不可用时&#xff0c;上游服务可…

Eureka-搭建Eureka步骤

简介&#xff1a; Eureka是Netflix开发的服务发现框架&#xff0c;本身是一个基于REST的服务&#xff0c;主要用于定位运行在AWS域中的中间层服务&#xff0c;以达到负载均衡和中间层服务故障转移的目的。SpringCloud将它集成在其子项目spring-cloud-netflix中&#xff0c;以实…

【OTA】STM32新能源汽车OTA技术ymodem协议PC串口升级过程

【OTA】STM32新能源汽车OTA技术ymodem协议PC串口升级过程 文章目录 前言一、实验工具1.串口USB线——烧录APP2生成的BIN文件2.STLINK——烧录BOOT代码和APP1代码3.烧录工具——将BIN文件烧录到单片机中4.FLYMCU——清除芯片FLASH 二、硬件绘制1.原理图2.PCB 三、软件配置1.BOOT…