| /* |
| * Sample Buffer - Allows reading and writing of timed samples |
| * |
| * Copyright 2010,2011 Free Software Foundation, Inc. |
| * Copyright (C) 2015 Ettus Research LLC |
| * Copyright 2019 sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * |
| * Author: Tom Tsou <tom.tsou@ettus.com> |
| * |
| * This program is free software: you can redistribute it and/or modify |
| * it under the terms of the GNU Affero General Public License as published by |
| * the Free Software Foundation, either version 3 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * See the COPYING file in the main directory for details. |
| */ |
| |
| #include "smpl_buf.h" |
| #include <inttypes.h> |
| |
| smpl_buf::smpl_buf(size_t len) |
| : buf_len(len), time_start(0), time_end(0), |
| data_start(0), data_end(0) |
| { |
| data = new uint32_t[len]; |
| } |
| |
| smpl_buf::~smpl_buf() |
| { |
| delete[] data; |
| } |
| |
| ssize_t smpl_buf::avail_smpls(TIMESTAMP timestamp) const |
| { |
| if (timestamp < time_start) |
| return ERROR_TIMESTAMP; |
| else if (timestamp >= time_end) |
| return 0; |
| else |
| return time_end - timestamp; |
| } |
| |
| ssize_t smpl_buf::read(void *buf, size_t len, TIMESTAMP timestamp) |
| { |
| int type_sz = 2 * sizeof(short); |
| |
| // Check for valid read |
| if (timestamp < time_start) |
| return ERROR_TIMESTAMP; |
| if (timestamp >= time_end) |
| return 0; |
| if (len >= buf_len) |
| return ERROR_READ; |
| |
| // How many samples should be copied |
| size_t num_smpls = time_end - timestamp; |
| if (num_smpls > len) |
| num_smpls = len; |
| |
| // Starting index |
| size_t read_start = (data_start + (timestamp - time_start)) % buf_len; |
| |
| // Read it |
| if (read_start + num_smpls < buf_len) { |
| size_t numBytes = len * type_sz; |
| memcpy(buf, data + read_start, numBytes); |
| } else { |
| size_t first_cp = (buf_len - read_start) * type_sz; |
| size_t second_cp = len * type_sz - first_cp; |
| |
| memcpy(buf, data + read_start, first_cp); |
| memcpy((char*) buf + first_cp, data, second_cp); |
| } |
| |
| data_start = (read_start + len) % buf_len; |
| time_start = timestamp + len; |
| |
| if (time_start > time_end) |
| return ERROR_READ; |
| else |
| return num_smpls; |
| } |
| |
| ssize_t smpl_buf::write(void *buf, size_t len, TIMESTAMP timestamp) |
| { |
| int type_sz = 2 * sizeof(short); |
| |
| // Check for valid write |
| if ((len == 0) || (len >= buf_len)) |
| return ERROR_WRITE; |
| if ((timestamp + len) <= time_end) |
| return ERROR_TIMESTAMP; |
| |
| if (timestamp < time_end) { |
| LOGC(DDEV, ERR) << "Overwriting old buffer data: timestamp=" |
| << timestamp << " time_end=" << time_end; |
| // Do not return error here, because it's a rounding error and is not fatal |
| } |
| if (timestamp > time_end && time_end != 0) { |
| LOGC(DDEV, ERR) << "Skipping buffer data: timestamp=" |
| << timestamp << " time_end=" << time_end; |
| // Do not return error here, because it's a rounding error and is not fatal |
| } |
| |
| // Starting index |
| size_t write_start = (data_start + (timestamp - time_start)) % buf_len; |
| |
| // Write it |
| if ((write_start + len) < buf_len) { |
| size_t numBytes = len * type_sz; |
| memcpy(data + write_start, buf, numBytes); |
| } else { |
| size_t first_cp = (buf_len - write_start) * type_sz; |
| size_t second_cp = len * type_sz - first_cp; |
| |
| memcpy(data + write_start, buf, first_cp); |
| memcpy(data, (char*) buf + first_cp, second_cp); |
| } |
| |
| data_end = (write_start + len) % buf_len; |
| time_end = timestamp + len; |
| |
| if (!data_start) |
| data_start = write_start; |
| |
| if (((write_start + len) > buf_len) && (data_end > data_start)) |
| return ERROR_OVERFLOW; |
| else if (time_end <= time_start) |
| return ERROR_WRITE; |
| else |
| return len; |
| } |
| |
| std::string smpl_buf::str_status(TIMESTAMP timestamp) const |
| { |
| std::ostringstream ost("Sample buffer: "); |
| |
| ost << "timestamp = " << timestamp; |
| ost << ", length = " << buf_len; |
| ost << ", time_start = " << time_start; |
| ost << ", time_end = " << time_end; |
| ost << ", data_start = " << data_start; |
| ost << ", data_end = " << data_end; |
| |
| return ost.str(); |
| } |
| |
| std::string smpl_buf::str_code(ssize_t code) |
| { |
| switch (code) { |
| case ERROR_TIMESTAMP: |
| return "Sample buffer: Requested timestamp is not valid"; |
| case ERROR_READ: |
| return "Sample buffer: Read error"; |
| case ERROR_WRITE: |
| return "Sample buffer: Write error"; |
| case ERROR_OVERFLOW: |
| return "Sample buffer: Overrun"; |
| default: |
| return "Sample buffer: Unknown error"; |
| } |
| } |