C, C++, R, Rust (ADBC)

Hardcharger™’s ADBC driver is one C shared library, libadbc_driver_hardcharger, built from the same Go code for every platform. Any ADBC driver manager (C/C++, R’s adbcdrivermanager, Rust’s adbc_driver_manager, Python’s, …) loads it by name once its driver manifest, hardcharger.toml, is installed.

Install the manifest

With the Python package installed, it writes the manifest for you, pointing at the library inside the wheel:

$ python3 -m adbc_driver_hardcharger.manifest --print | grep -E '^(name|entrypoint) ='
name = 'Hardcharger'
entrypoint = 'AdbcDriverHardchargerInit'
$ python3 -m adbc_driver_hardcharger.manifest --dir drivers > /dev/null
$ ls drivers
hardcharger.toml

Without --dir it goes to your user’s driver directory:

Platform	Directory
Linux	`~/.config/adbc/drivers/`
macOS	`~/Library/Application Support/ADBC/Drivers/`
Windows	`%LOCALAPPDATA%\ADBC\Drivers\`
Any	a directory on `ADBC_DRIVER_PATH`

Without Python, take the library from a release and fill in the template packaging/hardcharger.toml.in.

Load it by name

Every driver manager then finds it as hardcharger, with the same options in every language. Through Python’s driver manager:

import adbc_driver_manager.dbapi
import subprocess

subprocess.run(args=["python3", "-m", "adbc_driver_hardcharger.manifest", "--dir", "drivers"], check=True,
               capture_output=True)
with adbc_driver_manager.dbapi.connect(driver="drivers/hardcharger.toml", db_kwargs={
        "uri": "hardcharger://localhost?tls=false", "username": "hardcharger", "password": "change-me",
        "adbc.hardcharger.query_tag": '{"app": "driver-manager"}'}) as conn:
    with conn.cursor() as cur:
        cur.execute(operation="SELECT 42 AS answer")
        print(cur.fetchone())

(42,)

Here driver names the manifest file; with the manifest in a search directory, driver="hardcharger" is enough.

In C, the same takes AdbcDatabaseSetOption(&database, "driver", "hardcharger", &error) after AdbcDriverManagerDatabaseSetLoadFlags(&database, ADBC_LOAD_FLAG_DEFAULT, &error), then the uri, username and password options. examples/c/hello.c is a complete program, and hardcharger-adbc’s CI builds and runs it against a real server. R and Rust load it the same way, by the name hardcharger.

The options are listed on the Go page: they are the same everywhere, since every language runs the same driver.