base: Rewrite the CircleBuf to fix bugs and add serialization

The CircleBuf class has at least one bug causing it to overwrite the
wrong elements when wrapping. The current code has a lot of unused
functionality and duplicated code. This changeset replaces the old
implementation with a new version that supports serialization and
arbitrary types in the buffer (not just char).

1 files changed, 0 insertions, 215 deletions

diff --git a/src/base/circlebuf.cc b/src/base/circlebuf.cc
deleted file mode 100644
index 2f04bc16e..000000000
--- a/src/base/circlebuf.cc
+++ /dev/null
@@ -1,215 +0,0 @@
-/*
- * Copyright (c) 2002-2005 The Regents of The University of Michigan
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met: redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer;
- * redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution;
- * neither the name of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * Authors: Nathan Binkert
- */
-
-#include <algorithm>
-#include <cstdio>
-#include <cstring>
-#include <string>
-
-#include "base/atomicio.hh"
-#include "base/circlebuf.hh"
-#include "base/cprintf.hh"
-#include "base/intmath.hh"
-
-using namespace std;
-
-CircleBuf::CircleBuf(int l)
-    : _rollover(false), _buflen(l), _size(0), _start(0), _stop(0)
-{
-    _buf = new char[_buflen];
-}
-
-CircleBuf::~CircleBuf()
-{
-    if (_buf)
-        delete [] _buf;
-}
-
-void
-CircleBuf::dump()
-{
-    cprintf("start = %10d, stop = %10d, buflen = %10d\n",
-            _start, _stop, _buflen);
-    fflush(stdout);
-    atomic_write(STDOUT_FILENO, _buf, _buflen);
-    atomic_write(STDOUT_FILENO, "<\n", 2);
-}
-
-void
-CircleBuf::flush()
-{
-    _start = 0;
-    _stop = 0;
-    _size = 0;
-    _rollover = false;
-}
-
-void
-CircleBuf::read(char *b, int len)
-{
-    _size -= len;
-    if (_size < 0)
-        _size = 0;
-
-    if (_stop > _start) {
-        len = min(len, _stop - _start);
-        memcpy(b, _buf + _start, len);
-        _start += len;
-    }
-    else {
-        int endlen = _buflen - _start;
-        if (endlen > len) {
-            memcpy(b, _buf + _start, len);
-            _start += len;
-        }
-        else {
-            memcpy(b, _buf + _start, endlen);
-            _start = min(len - endlen, _stop);
-            memcpy(b + endlen, _buf, _start);
-        }
-    }
-}
-
-void
-CircleBuf::read(int fd, int len)
-{
-    _size -= len;
-    if (_size < 0)
-        _size = 0;
-
-    if (_stop > _start) {
-        len = min(len, _stop - _start);
-        atomic_write(fd, _buf + _start, len);
-        _start += len;
-    }
-    else {
-        int endlen = _buflen - _start;
-        if (endlen > len) {
-            atomic_write(fd, _buf + _start, len);
-            _start += len;
-        }
-        else {
-            atomic_write(fd, _buf + _start, endlen);
-            _start = min(len - endlen, _stop);
-            atomic_write(fd, _buf, _start);
-        }
-    }
-}
-
-void
-CircleBuf::read(int fd)
-{
-    _size = 0;
-
-    if (_stop > _start) {
-        atomic_write(fd, _buf + _start, _stop - _start);
-    }
-    else {
-        atomic_write(fd, _buf + _start, _buflen - _start);
-        atomic_write(fd, _buf, _stop);
-    }
-
-    _start = _stop;
-}
-
-void
-CircleBuf::read(ostream &out)
-{
-    _size = 0;
-
-    if (_stop > _start) {
-        out.write(_buf + _start, _stop - _start);
-    }
-    else {
-        out.write(_buf + _start, _buflen - _start);
-        out.write(_buf, _stop);
-    }
-
-    _start = _stop;
-}
-
-void
-CircleBuf::readall(int fd)
-{
-    if (_rollover)
-        atomic_write(fd, _buf + _stop, _buflen - _stop);
-
-    atomic_write(fd, _buf, _stop);
-    _start = _stop;
-}
-
-void
-CircleBuf::write(char b)
-{
-    write(&b, 1);
-}
-
-void
-CircleBuf::write(const char *b)
-{
-    write(b, strlen(b));
-}
-
-void
-CircleBuf::write(const char *b, int len)
-{
-    if (len <= 0)
-        return;
-
-    _size += len;
-    if (_size > _buflen)
-        _size = _buflen;
-
-    int old_start = _start;
-    int old_stop = _stop;
-
-    if (len >= _buflen) {
-        _start = 0;
-        _stop = _buflen;
-        _rollover = true;
-        memcpy(_buf, b + (len - _buflen), _buflen);
-        return;
-    }
-
-    if (_stop + len <= _buflen) {
-        memcpy(_buf + _stop, b, len);
-        _stop += len;
-    } else {
-        int end_len = _buflen - old_stop;
-        _stop = len - end_len;
-        memcpy(_buf + old_stop, b, end_len);
-        memcpy(_buf, b + end_len, _stop);
-        _rollover = true;
-    }
-
-    if ((old_start > old_stop && old_start < _stop) ||
-        (old_start < old_stop && _stop < old_stop))
-        _start = _stop + 1;
-}