Build Flavor 作用
- 在一个分支上，编译不同的版本（包名/应用图标/debug/release）
- 多个分支代码片段/so库，合并到同一分支进行维护，并且可以根据不同的Build Variant 进行选择性编译；
使用方法
比如现在有如下需求：
- 第一维度是高通835/845平台（不同平台可能使用不同的DSP相关的so）
- 第二维度是算法提供商，以人脸检测为例提供商有SenseTime和Face++;
- 第三维度是Debug/Release版本
那么结果是在Android Studio中生成8种Build Variant供编译选择。
步骤
- Step - 1
在app的build.gradle的android节点中添加dimension：
android {
//......
flavorDimensions "pipeline", "platform"
}
其中:
pipeline 可取 : face++ / sensetime ;
platform 可取 ： 835 / 845
- Step - 2
在productFlavors节点中添加新的flavor并指定dimension:
productFlavors {
flavor845 {
dimension "platform"
applicationId 'com.test.845'
externalNativeBuild {
cmake {
arguments "-DFLAVOR=845"
cppFlags "-frtti -fexceptions -std=c++14 -llog -fpermissive -Wno-deprecated"
}
ndk {
abiFilters "armeabi-v7a"
}
}
}
flavor835 {
dimension "platform"
applicationId 'com.test.835'
externalNativeBuild {
cmake {
arguments "-DFLAVOR=835"
cppFlags "-frtti -fexceptions -std=c++14 -llog -fpermissive -Wno-deprecated"
}
ndk {
abiFilters "armeabi-v7a"
}
}
}
flavor_SenseTime {
dimension "pipeline"
externalNativeBuild {
cmake {
arguments "-DFLAVOR=senseTime"
cppFlags "-frtti -fexceptions -std=c++14 -llog -fpermissive -Wno-deprecated"
}
ndk {
abiFilters "armeabi-v7a"
}
}
}
flavor_Face++ {
dimension "pipeline"
externalNativeBuild {
cmake {
arguments "-DFLAVOR=face++"
cppFlags "-frtti -fexceptions -std=c++14 -llog -fpermissive -Wno-deprecated"
}
ndk {
abiFilters "armeabi-v7a"
}
}
}
如上所示，在各个flavor中添加了dimension，按照需要添加cmake的一些编译条件，其中注意cmake中的 arguments属性，是用于CMakeLists中可以用于条件分支判断使用的值域（注意不是前面flavor_name）
-
Step - 3 (optional)
如果需要根据不同的build variant 选择不同的代码段/so库进行编译，可以继续往下看：
sourceSets {
main {
jniLibs.srcDirs = ['src/main/cpp/testJNI',
'src/main/cpp/libs_for_android_n',]
}
flavor835 {
//other source sets will overlay main
jniLibs.srcDirs = ['src/main/cpp/dsp_libs_835']
}
flavor845 {
jniLibs.srcDirs = ['src/main/cpp/dsp_libs_845']
}
flavor_Face++ {
if (getBuildTypes().getNames().contains("debug")){
jniLibs.srcDirs = ['src/main/cpp/face++_libs_debug']
}else{
jniLibs.srcDirs = ['src/main/cpp/face++_libs_release']
}
}
flavor_SenseTime {
if (getBuildTypes().getNames().contains("debug")){
jniLibs.srcDirs = ['src/main/cpp/senseTime_libs_debug']
}else{
jniLibs.srcDirs = ['src/main/cpp/senseTime_libs_release']
}
}
}
如上所示，可以根据所选的Build Variant选择对应的代码/so库文件进行编译。需要注意的是,在main节点中所指定的srcDirs只会作为基准被其他不同的flavor所append，并不会被覆盖，而在同一节点内会被覆盖。
- Step - 4 (optional)
如果有JNI代码需要选择不同代码/so库文件编译新的so，那么需要在CMakeLists.txt中访问以上Gradle中定义的部分变量进行条件分支选择：
if (${FLAVOR} STREQUAL "face++")
# load face++ related libs
add_library(lib_face++ SHARED IMPORTED)
set_target_properties( lib_face++
PROPERTIES IMPORTED_LOCATION
${CMAKE_CURRENT_SOURCE_DIR}/armeabi-v7a/libface++.so )
if (CMAKE_BUILD_TYPE MATCHES Debug)
message("building - debug version...")
# add the debug flag if necessary
add_definitions("-DMSFR_ENABLE_DEBUG")
add_library(lib_msfr SHARED IMPORTED)
set_target_properties( lib_face++_so
PROPERTIES IMPORTED_LOCATION
${CMAKE_CURRENT_SOURCE_DIR}/../face_libs_debug/armeabi-v7a/lib_face++_so.so )
else(CMAKE_BUILD_TYPE MATCHES Debug)
message("building - release version...")
add_library(lib_msfr SHARED IMPORTED)
set_target_properties( lib_your_so
PROPERTIES IMPORTED_LOCATION
${CMAKE_CURRENT_SOURCE_DIR}/../face_libs_release/armeabi-v7a/lib_face++_so.so )
endif(CMAKE_BUILD_TYPE MATCHES Debug)
endif(${FLAVOR} STREQUAL "face++")
if (${FLAVOR} STREQUAL "senseTime")
# load face++ related libs
add_library(lib_face++ SHARED IMPORTED)
set_target_properties( lib_face++
PROPERTIES IMPORTED_LOCATION
${CMAKE_CURRENT_SOURCE_DIR}/armeabi-v7a/libface++.so )
if (CMAKE_BUILD_TYPE MATCHES Debug)
message("building - debug version...")
# add the debug flag if necessary
add_definitions("-DMSFR_ENABLE_DEBUG")
add_library(lib_msfr SHARED IMPORTED)
set_target_properties( lib_sensetime_so
PROPERTIES IMPORTED_LOCATION
${CMAKE_CURRENT_SOURCE_DIR}/../face_libs_debug/armeabi-v7a/lib_sensetime_so.so )
else(CMAKE_BUILD_TYPE MATCHES Debug)
message("building - release version...")
add_library(lib_msfr SHARED IMPORTED)
set_target_properties( lib_sensetime_so
PROPERTIES IMPORTED_LOCATION
${CMAKE_CURRENT_SOURCE_DIR}/../face_libs_release/armeabi-v7a/lib_sensetime_so.so )
endif(CMAKE_BUILD_TYPE MATCHES Debug)
endif(${FLAVOR} STREQUAL "senseTime")
if (${FLAVOR} STREQUAL "835")
add_library(lib_cnnARM SHARED IMPORTED)
set_target_properties( lib_cdsp
PROPERTIES IMPORTED_LOCATION
${CMAKE_CURRENT_SOURCE_DIR}/../dsp_libs_835/armeabi-v7a/libcdsp.so )
else(${FLAVOR} STREQUAL "835")
add_library(lib_cnnARM SHARED IMPORTED)
set_target_properties( lib_cdsp
PROPERTIES IMPORTED_LOCATION
${CMAKE_CURRENT_SOURCE_DIR}/../dsp_libs_845/armeabi-v7a/libcdsp.so )
endif(${FLAVOR} STREQUAL "835")
message("CMAKE_BUILD_TYPE = ${CMAKE_BUILD_TYPE}")
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log)
#---------------------------------------------------------------------------------------------------
if(${FLAVOR} STREQUAL "senseTime")
message("adding the source code for SenseTime...")
include_directories(${CMAKE_CURRENT_SOURCE_DIR}/inc_senseTime)
add_library( # Sets the name of the library.
your_built_lib
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
# Associated headers in the same location as their source
# file are automatically included.
${CMAKE_CURRENT_SOURCE_DIR}/SourceCodeJNI_SenseTime.cpp)
target_link_libraries(your_built_lib lib_sensetime_so ${log-lib})
else(${FLAVOR} STREQUAL "senseTime")
message("adding the source code for Face++...")
include_directories(${CMAKE_CURRENT_SOURCE_DIR}/inc_Face++)
add_library( # Sets the name of the library.
your_built_lib
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
# Associated headers in the same location as their source
# file are automatically included.
${CMAKE_CURRENT_SOURCE_DIR}/SourceCodeJNI_Face++.cpp)
target_link_libraries(your_built_lib lib_face++_so ${log-lib})
endif(${FLAVOR} STREQUAL "senseTime")
如上代码则是在CMakeLists.txt中根据不同的Build Flavor选择不同代码/头文件/so库文件进行编译生成 'your_built_lib'.
- Step - 5 (optional)
以上说明共有8种build variant组合供选择，但是如果告知SenseTime目前不支持835及以下平台，那则需要在build Variant中有选择性的过滤掉某些Flavor的组合：
android {
// ......
variantFilter { variant ->
//since we only have the MTCNN libs for 845+
if (variant.getName().toLowerCase().contains("senseTime") && variant.getName().toLowerCase().contains("835")){
setIgnore(true)
}
}
}
通过variantFilter获取当前build flavor的字段进行条件判断，针对特定组合进行过滤即可。完成Gradle Sync之后，在Android Studio的Build Variant中仅会存在6种供选择编译。
