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## Python Native Dependencies


### Dependencies

python3.7 or later is preferred.

You have to install Thrift (0.11.0 or later) to compile our thrift file into python code. Below is the official
tutorial of installation: 

```
http://thrift.apache.org/docs/install/
```

### Installation

* Option 1: pip install

You can find the Apache IoTDB Python Client API package on https://pypi.org/project/apache-iotdb/.

The download command is:

```
pip install apache-iotdb
```

* Option 2: basic usage of thrift

Optionally, if you know the basic usage of thrift, you can download the thrift source file in
`thrift\src\main\thrift\rpc.thrift`, and simply run `thrift -gen py -out ./target/iotdb rpc.thrift` 
to generate the Python library.

### Coding Example

We provided an example of how to use the thrift library to connect to IoTDB in `client-py/src
/SessionExample.py`, please read it carefully before you write your own code.


## C++ Native Interfaces

### Dependencies
- Java 8+
- Maven 3.5+
- Flex
- Bison 2.7+
- Boost 1.56+
- OpenSSL 1.0+
- GCC 5.5.0+


### Installation

The compilation of CPP client requires the module "compile-tools" to be built first. 
"compile-tools" is mainly responsible for building Thrift libraries locally.

#### Build Thrift on MacOS

- Bison

 Bison 2.3 is preinstalled on OSX, but this version is too low.
 When building Thrift with Bison 2.3, the following error would pop out:

 
```
invalid directive: '%code'
```
	
For such case, please update `Bison`:		
		
```		
brew install bison		
brew link bison --force		
```
		
 Then, you need to tell the OS where the new bison is.		
		
 For Bash users:		
```    		
echo 'export PATH="/usr/local/opt/bison/bin:$PATH"' >> ~/.bash_profile		
```
		
 For zsh users:		
```    		
echo 'export PATH="/usr/local/opt/bison/bin:$PATH"' >> ~/.zshrc
```

- Boost

Please make sure a relative new version of Boost is ready on your machine.
If no Boost available, install the latest version of Boost:

```
brew install boost
brew link boost
```


- OpenSSL

Make sure the Openssl libraries has been install on your Mac.
The default Openssl include file search path is "/usr/local/opt/openssl/include".
If Openssl header files can not be found when building Thrift, please add option 

```-Dopenssl.include.dir=""``` 

to specify the OpenSSL installation directory on your Mac.

#### Build Thrift on Linux

Ubuntu 20:

To install all dependencies, run:  

```
sudo apt-get install gcc-9 g++-9 libstdc++-9-dev bison flex libboost-all-dev libssl-dev zlib1g-dev
```

CentOS 7.x:  

In CentOS 7.x, Some packages can be installed using Yum:

```
sudo yum install bison flex openssl-devel
```

The version of gcc and boost installed by yum is too low, therefore you should compile or download these binary packages by yourself. 


#### Build Thrift on Windows

Make sure a complete Windows C++ building environment is prepared on your machine. 
MSVC, MinGW... are supported.

If you are using MS Visual Studio, remember to install Visual Studio C/C++ IDE and compiler(supporting CMake, Clang, MinGW).

- Flex and Bison
Windows Flex and Bison could be downloaded from SourceForge: https://sourceforge.net/projects/winflexbison/

After downloaded, please rename the executables to flex.exe and bison.exe and add them to "PATH" environment variables.

- Boost
For Boost, please download from the official website: https://www.boost.org/users/download/

Then build Boost by executing bootstrap.bat and b2.exe.
```
bootstrap.bat
.\b2.exe
```

To help CMake find your Boost libraries on windows, you should set `-Dboost.include.dir=${your boost header folder} -Dboost.library.dir=${your boost lib (stage) folder}`
to your mvn build command.

#### Cmake generator on Windows

There is a long list of supported Cmake generators on Windows environment. 


```
  Visual Studio 16 2019        = Generates Visual Studio 2019 project files.
                                 Use -A option to specify architecture.
  Visual Studio 15 2017 [arch] = Generates Visual Studio 2017 project files.
                                 Optional [arch] can be "Win64" or "ARM".
  Visual Studio 14 2015 [arch] = Generates Visual Studio 2015 project files.
                                 Optional [arch] can be "Win64" or "ARM".
  Visual Studio 12 2013 [arch] = Generates Visual Studio 2013 project files.
                                 Optional [arch] can be "Win64" or "ARM".
  Visual Studio 11 2012 [arch] = Generates Visual Studio 2012 project files.
                                 Optional [arch] can be "Win64" or "ARM".
  Visual Studio 10 2010 [arch] = Generates Visual Studio 2010 project files.
                                 Optional [arch] can be "Win64" or "IA64".
  Visual Studio 9 2008 [arch]  = Generates Visual Studio 2008 project files.
                                 Optional [arch] can be "Win64" or "IA64".
  Borland Makefiles            = Generates Borland makefiles.
* NMake Makefiles              = Generates NMake makefiles.
  NMake Makefiles JOM          = Generates JOM makefiles.
  MSYS Makefiles               = Generates MSYS makefiles.
  MinGW Makefiles              = Generates a make file for use with
                                 mingw32-make.
  Unix Makefiles               = Generates standard UNIX makefiles.
  Green Hills MULTI            = Generates Green Hills MULTI files
                                 (experimental, work-in-progress).
  Ninja                        = Generates build.ninja files.
  Ninja Multi-Config           = Generates build-<Config>.ninja files.
  Watcom WMake                 = Generates Watcom WMake makefiles.
  CodeBlocks - MinGW Makefiles = Generates CodeBlocks project files.
  CodeBlocks - NMake Makefiles = Generates CodeBlocks project files.
  CodeBlocks - NMake Makefiles = Generates CodeBlocks project fi

```
the list is available via command: `cmake --help`

When building client-cpp project, use -Dcmake.generator="" option to specify a Cmake generator.
E.g., `mvn package -Dcmake.generator="Visual Studio 15 2017 [arch]"`


#### Building C++ Client


To compile cpp client, add "-P compile-cpp" option to maven build command.

The compiling requires the module "compile-tools" to be built first.

#### Compile and Test:

`mvn package -P compile-cpp  -pl example/client-cpp-example -am -DskipTest`

To compile on Windows, please install Boost first and add following Maven settings:
```
-Dboost.include.dir=${your boost header folder} -Dboost.library.dir=${your boost lib (stage) folder}` 
```

e.g.,

```
mvn package -P compile-cpp -pl client-cpp,server,example/client-cpp-example -am 
-D"boost.include.dir"="D:\boost_1_75_0" -D"boost.library.dir"="D:\boost_1_75_0\stage\lib" -DskipTests
```

If the compilation finishes successfully, the packaged zip file will be placed under
"client-cpp/target/client-cpp-${project.version}-cpp-${os}.zip". 

On Mac machines, the hierarchy of the package should look like this:

```
.
+-- client
|   +-- include
|       +-- Session.h
|       +-- TSIService.h
|       +-- rpc_types.h
|       +-- rpc_constants.h
|       +-- thrift
|           +-- thrift_headers...
|   +-- lib
|       +-- libiotdb_session.dylib
```


### Q&A

#### on Mac

If errors occur when compiling thrift source code, try to downgrade your xcode-commandline from 12 to 11.5

see https://stackoverflow.com/questions/63592445/ld-unsupported-tapi-file-type-tapi-tbd-in-yaml-file/65518087#65518087

#### on Windows

When Building Thrift and downloading packages via "wget", a possible annoying issue may occur with
error message looks like:
```
Failed to delete cached file C:\Users\Administrator\.m2\repository\.cache\download-maven-plugin\index.ser
```
Possible fixes:
- Try to delete the ".m2\repository\\.cache\" directory and try again.
- Add "\<skipCache>true\</skipCache>" configuration to the download-maven-plugin maven phase that complains this error.