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# Third-party dependency cache (`client-cpp/third-party`)

CMake downloads (or reuses) build-time tarballs and archives here. The
directory ships with the source tree so you can **stage dependencies on a
networked machine, copy the whole IoTDB checkout to an offline host, and
build `client-cpp` with `-DIOTDB_OFFLINE=ON`**.

Tarballs themselves are **not** committed to Git (see per-platform
`.gitignore` files). Only this README and the empty platform folders are
tracked. Each `linux/`, `mac/`, and `windows/` sub-folder ships a minimal
`.gitignore` (`*` with `!.gitignore`) so Git keeps the directory in the
tree while ignoring downloaded archives.

## Layout

```
third-party/
├── linux/     # tarballs for Linux offline builds
├── mac/       # tarballs for macOS offline builds
└── windows/   # tarballs / zips for Windows offline builds
```

Override the root with `-DIOTDB_DEPS_DIR=<path>` (Maven: `-Diotdb.deps.dir=...`).
The platform sub-folder (`linux/`, `mac/`, `windows/`) is selected automatically.

## Staging dependencies (online machine)

Run a normal **online** configure once; CMake caches everything under the
matching `<os>/` folder:

```bash
cmake -S iotdb-client/client-cpp -B build
# or: mvn -P with-cpp -pl iotdb-client/client-cpp -am -DskipTests package
```

Alternatively copy files manually from the URLs listed in
[`README.md`](../README.md) (*Offline build* section).

## Offline machine (copy whole IoTDB tree)

1. Copy the entire IoTDB repository (including `iotdb-client/client-cpp/third-party/<os>/`).
2. Configure with offline mode:

   ```bash
   cmake -S iotdb-client/client-cpp -B build -DIOTDB_OFFLINE=ON
   cmake --build build --config Release --target install
   ```

## Per-platform files (offline minimum)

| Platform   | Typical files |
|------------|---------------|
| `linux/`   | `thrift-0.23.0.tar.gz`, `boost_1_60_0.tar.gz`, `m4-1.4.19.tar.gz`, `flex-2.6.4.tar.gz`, `bison-3.8.tar.gz` (+ `openssl-3.5.0.tar.gz` only when `WITH_SSL=ON` and no system OpenSSL is present) |
| `mac/`     | `thrift-0.23.0.tar.gz`, `boost_1_60_0.tar.gz` (Xcode CLT usually provides m4/flex/bison) |
| `windows/` | `thrift-0.23.0.tar.gz`, `boost_1_60_0.tar.gz`, `win_flex_bison-2.5.25.zip` (or any `win_flex_bison*.zip`; skip if flex/bison already on `PATH`) |

Download URLs: see the *Offline build* table in [`README.md`](../README.md).