Function s3_import

gpcontrib/gpcloud/src/gpcloud.cpp:265–316

* Import data into GPDB. * invoked by GPDB, be careful with C++ exceptions. */

 * invoked by GPDB, be careful with C++ exceptions.
 */
Datum s3_import(PG_FUNCTION_ARGS) {
    /* Must be called via the external table format manager */
    if (!CALLED_AS_EXTPROTOCOL(fcinfo))
        elog(ERROR, "extprotocol_import: not called by external protocol manager");

    /* Get our internal description of the protocol */
    gpcloudResHandle *resHandle = (gpcloudResHandle *)EXTPROTOCOL_GET_USER_CTX(fcinfo);

    /* last call. destroy reader */
    if (EXTPROTOCOL_IS_LAST_CALL(fcinfo)) {
        destroyGpcloudResHandle(resHandle);

        EXTPROTOCOL_SET_USER_CTX(fcinfo, NULL);
        PG_RETURN_INT32(0);
    }

    /* first call. do any desired init */
    if (resHandle == NULL) {
        if (!isGpcloudResReleaseCallbackRegistered) {
            RegisterResourceReleaseCallback(gpcloudAbortCallback, NULL);
            isGpcloudResReleaseCallbackRegistered = true;
        }
        resHandle = createGpcloudResHandle();

        queryCancelFlag = false;
        const char *url_with_options = EXTPROTOCOL_GET_URL(fcinfo);

        // has HEADER? and newline EOL?
        parseFormatOpts(fcinfo);

        thread_setup();

        resHandle->gpreader = reader_init(url_with_options);
        if (!resHandle->gpreader) {
            ereport(ERROR, errmsg("Failed to init gpcloud extension (segid = %d, "
				  "segnum = %d), please check your "
				  "configurations and network connection: %s",
				  s3ext_segid, s3ext_segnum, s3extErrorMessage.c_str()));
        }

        EXTPROTOCOL_SET_USER_CTX(fcinfo, resHandle);
    }

    char *data_buf = EXTPROTOCOL_GET_DATABUF(fcinfo);
    int32 data_len = EXTPROTOCOL_GET_DATALEN(fcinfo);

    if (!reader_transfer_data(resHandle->gpreader, data_buf, data_len)) {
        ereport(ERROR,
                errmsg("s3_import: could not read data: %s", s3extErrorMessage.c_str()));
    }
    PG_RETURN_INT32(data_len);
}

/*
 * Export data out of GPDB.