+/**
+ * Send a SCPI command, read the reply, parse it as binary data with a
+ * "definite length block" header and store the as an result in scpi_response.
+ *
+ * @param scpi Previously initialised SCPI device structure.
+ * @param command The SCPI command to send to the device (can be NULL).
+ * @param scpi_response Pointer where to store the parsed result.
+ *
+ * @return SR_OK upon successfully parsing all values, SR_ERR* upon a parsing
+ * error or upon no response. The allocated response must be freed by
+ * the caller in the case of an SR_OK as well as in the case of
+ * parsing error.
+ */
+SR_PRIV int sr_scpi_get_block(struct sr_scpi_dev_inst *scpi,
+ const char *command, GByteArray **scpi_response)
+{
+ int ret;
+ GString* response;
+ char buf[10];
+ long llen;
+ long datalen;
+ gint64 timeout;
+
+ if (command)
+ if (sr_scpi_send(scpi, command) != SR_OK)
+ return SR_ERR;
+
+ if (sr_scpi_read_begin(scpi) != SR_OK)
+ return SR_ERR;
+
+ /*
+ * Assume an initial maximum length, optionally gets adjusted below.
+ * Prepare a NULL return value for when error paths will be taken.
+ */
+ response = g_string_sized_new(1024);
+
+ timeout = g_get_monotonic_time() + scpi->read_timeout_us;
+
+ *scpi_response = NULL;
+
+ /* Get (the first chunk of) the response. */
+ while (response->len < 2) {
+ ret = sr_scpi_read_response(scpi, response, timeout);
+ if (ret < 0) {
+ g_string_free(response, TRUE);
+ return ret;
+ }
+ }
+
+ /*
+ * SCPI protocol data blocks are preceeded with a length spec.
+ * The length spec consists of a '#' marker, one digit which
+ * specifies the character count of the length spec, and the
+ * respective number of characters which specify the data block's
+ * length. Raw data bytes follow (thus one must no longer assume
+ * that the received input stream would be an ASCIIZ string).
+ *
+ * Get the data block length, and strip off the length spec from
+ * the input buffer, leaving just the data bytes.
+ */
+ if (response->str[0] != '#') {
+ g_string_free(response, TRUE);
+ return SR_ERR_DATA;
+ }
+ buf[0] = response->str[1];
+ buf[1] = '\0';
+ ret = sr_atol(buf, &llen);
+ if ((ret != SR_OK) || (llen == 0)) {
+ g_string_free(response, TRUE);
+ return ret;
+ }
+
+ while (response->len < (unsigned long)(2 + llen)) {
+ ret = sr_scpi_read_response(scpi, response, timeout);
+ if (ret < 0) {
+ g_string_free(response, TRUE);
+ return ret;
+ }
+ }
+
+ memcpy(buf, &response->str[2], llen);
+ buf[llen] = '\0';
+ ret = sr_atol(buf, &datalen);
+ if ((ret != SR_OK) || (datalen == 0)) {
+ g_string_free(response, TRUE);
+ return ret;
+ }
+ g_string_erase(response, 0, 2 + llen);
+
+ /*
+ * If the initially assumed length does not cover the data block
+ * length, then re-allocate the buffer size to the now known
+ * length, and keep reading more chunks of response data.
+ */
+ if (response->len < (unsigned long)(datalen)) {
+ int oldlen = response->len;
+ g_string_set_size(response, datalen);
+ g_string_set_size(response, oldlen);
+ }
+
+ while (response->len < (unsigned long)(datalen)) {
+ ret = sr_scpi_read_response(scpi, response, timeout);
+ if (ret < 0) {
+ g_string_free(response, TRUE);
+ return ret;
+ }
+ if (ret > 0)
+ timeout = g_get_monotonic_time() + scpi->read_timeout_us;
+ }
+
+ /* Convert received data to byte array. */
+ *scpi_response = g_byte_array_new_take(
+ (guint8*)g_string_free(response, FALSE), datalen);
+
+ return SR_OK;
+}
+