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# Building C++ Client

## Compile and Test:

### Compile

#### Unix
To compile the cpp client, use the following command:
`mvn clean package -P with-cpp -pl iotdb-client/client-cpp -am -DskipTests`

#### Windows
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}` 
```

The thrift dependency that the cpp client uses is incompatible with MinGW, please use Visual 
Studio. It is highly recommended to use Visual Studio 2022 or later.

##### Visual Studio 2022
If you are using Visual Studio 2022, you can compile the cpp client with the following command:

```
mvn clean package -P with-cpp -pl iotdb-client/client-cpp -am -DskipTest
-D"boost.include.dir"="D:\boost_1_75_0" -D"boost.library.dir"="D:\boost_1_75_0\stage\lib"
```

#### Visual Studio 2019 or older
If you are using Visual Studio 2019 or older, the pre-built Thrift library is incompatible. You 
will have to compile the thrift library manually:

1. Install the dependencies of Thrift:
* flex http://gnuwin32.sourceforge.net/packages/flex.htm
* bison http://gnuwin32.sourceforge.net/packages/bison.htm
* openssl https://slproweb.com/products/Win32OpenSSL.html

2. Clone the repository: https://github.com/apache/iotdb-bin-resources.

3. Enter the "iotdb-tools-thrift" folder in the cloned repository; use the following command to 
   compile the thrift library:

`mvn install`

4. If you encounter a problem like "cannot find 'unistd.h'", please open the file
"iotdb-bin-resources\iotdb-tools-thrift\target\build\compiler\cpp\thrift\thriftl.cc" and replace
"#include <unistd.h>" with "#include <io.h>" and "#include <process.h>"; then, rerun the command 
   in the third step;

5. Return to the cpp client repository and compile it with:

```
mvn clean package -P with-cpp -pl iotdb-client/client-cpp -am -DskipTest
-D"boost.include.dir"="D:\boost_1_75_0" -D"boost.library.dir"="D:\boost_1_75_0\stage\lib"
```


### Test
First build IoTDB server together with the cpp client.

Explicitly using "install" instead of package in order to be sure we're using libs built on this 
machine.

`mvn clean install -P with-cpp -pl distribution,iotdb-client/client-cpp -am -DskipTests`

After run verify

`mvn clean verify -P with-cpp -pl iotdb-client/client-cpp -am`

## Package Hierarchy

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

On macOS, the hierarchy of the package should look like this:
```
.
+-- client
|   +-- include
|       +-- Session.h
|       +-- IClientRPCService.h
|       +-- client_types.h
|       +-- common_types.h
|       +-- thrift
|           +-- thrift_headers...
|   +-- lib
|       +-- Release
|          +-- libiotdb_session.dylib
|          +-- parser.dylib
|          +-- thriftmd.dylib
|          +-- tutorialgencpp.dylib
```

## Using C++ Client:
```
1. Put the zip file "client-cpp-${project.version}-cpp-${os}.zip" wherever you want;

2. Unzip the archive using the following command, and then you can get the two directories 
mentioned above, the header file and the dynamic library:
    unzip client-cpp-${project.version}-cpp-${os}.zip

3. Write C++ code to call the operation interface of the cpp client to operate IoTDB,
    for detail interface information, please refer to the link: https://iotdb.apache.org/zh/UserGuide/Master/API/Programming-Cpp-Native-API.html

   E.g:
    #include "include/Session.h"
    #include <memory>
    #include <iostream>

    int main() {
        std::cout << "open session" << std::endl;
        std::shared_ptr<Session> session(new Session("127.0.0.1", 6667, "root", "root"));
        session->open(false);

        std::cout << "setStorageGroup: root.test01" << std::endl;
        session->setStorageGroup("root.test01");

        if (!session->checkTimeseriesExists("root.test01.d0.s0")) {
            session->createTimeseries("root.test01.d0.s0", TSDataType::INT64, TSEncoding::RLE, CompressionType::SNAPPY);
            std::cout << "create Timeseries: root.test01.d0.s0" << std::endl;
        }

        std::cout << "session close" << std::endl;
        session->close();
    }

4. Compile and execute
    clang++ -O2 user-cpp-code.cpp -liotdb_session -L/user-unzip-absolute-path/lib -Wl,-rpath /user-unzip-absolute-path/lib -std=c++11
    ./a.out
```