initial import

cores/esp32/cbuf.cpp

@@ -0,0 +1,196 @@
+/*
+ cbuf.cpp - Circular buffer implementation
+ Copyright (c) 2014 Ivan Grokhotkov. All rights reserved.
+ This file is part of the esp8266 core for Arduino environment.
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include "cbuf.h"
+
+cbuf::cbuf(size_t size) :
+    next(NULL), _size(size), _buf(new char[size]), _bufend(_buf + size), _begin(_buf), _end(_begin)
+{
+}
+
+cbuf::~cbuf()
+{
+    delete[] _buf;
+}
+
+size_t cbuf::resizeAdd(size_t addSize)
+{
+    return resize(_size + addSize);
+}
+
+size_t cbuf::resize(size_t newSize)
+{
+
+    size_t bytes_available = available();
+
+    // not lose any data
+    // if data can be lost use remove or flush before resize
+    if((newSize < bytes_available) || (newSize == _size)) {
+        return _size;
+    }
+
+    char *newbuf = new char[newSize];
+    char *oldbuf = _buf;
+
+    if(!newbuf) {
+        return _size;
+    }
+
+    if(_buf) {
+        read(newbuf, bytes_available);
+        memset((newbuf + bytes_available), 0x00, (newSize - bytes_available));
+    }
+
+    _begin = newbuf;
+    _end = newbuf + bytes_available;
+    _bufend = newbuf + newSize;
+    _size = newSize;
+
+    _buf = newbuf;
+    delete[] oldbuf;
+
+    return _size;
+}
+
+size_t cbuf::available() const
+{
+    if(_end >= _begin) {
+        return _end - _begin;
+    }
+    return _size - (_begin - _end);
+}
+
+size_t cbuf::size()
+{
+    return _size;
+}
+
+size_t cbuf::room() const
+{
+    if(_end >= _begin) {
+        return _size - (_end - _begin) - 1;
+    }
+    return _begin - _end - 1;
+}
+
+int cbuf::peek()
+{
+    if(empty()) {
+        return -1;
+    }
+
+    return static_cast<int>(*_begin);
+}
+
+size_t cbuf::peek(char *dst, size_t size)
+{
+    size_t bytes_available = available();
+    size_t size_to_read = (size < bytes_available) ? size : bytes_available;
+    size_t size_read = size_to_read;
+    char * begin = _begin;
+    if(_end < _begin && size_to_read > (size_t) (_bufend - _begin)) {
+        size_t top_size = _bufend - _begin;
+        memcpy(dst, _begin, top_size);
+        begin = _buf;
+        size_to_read -= top_size;
+        dst += top_size;
+    }
+    memcpy(dst, begin, size_to_read);
+    return size_read;
+}
+
+int cbuf::read()
+{
+    if(empty()) {
+        return -1;
+    }
+
+    char result = *_begin;
+    _begin = wrap_if_bufend(_begin + 1);
+    return static_cast<int>(result);
+}
+
+size_t cbuf::read(char* dst, size_t size)
+{
+    size_t bytes_available = available();
+    size_t size_to_read = (size < bytes_available) ? size : bytes_available;
+    size_t size_read = size_to_read;
+    if(_end < _begin && size_to_read > (size_t) (_bufend - _begin)) {
+        size_t top_size = _bufend - _begin;
+        memcpy(dst, _begin, top_size);
+        _begin = _buf;
+        size_to_read -= top_size;
+        dst += top_size;
+    }
+    memcpy(dst, _begin, size_to_read);
+    _begin = wrap_if_bufend(_begin + size_to_read);
+    return size_read;
+}
+
+size_t cbuf::write(char c)
+{
+    if(full()) {
+        return 0;
+    }
+
+    *_end = c;
+    _end = wrap_if_bufend(_end + 1);
+    return 1;
+}
+
+size_t cbuf::write(const char* src, size_t size)
+{
+    size_t bytes_available = room();
+    size_t size_to_write = (size < bytes_available) ? size : bytes_available;
+    size_t size_written = size_to_write;
+    if(_end >= _begin && size_to_write > (size_t) (_bufend - _end)) {
+        size_t top_size = _bufend - _end;
+        memcpy(_end, src, top_size);
+        _end = _buf;
+        size_to_write -= top_size;
+        src += top_size;
+    }
+    memcpy(_end, src, size_to_write);
+    _end = wrap_if_bufend(_end + size_to_write);
+    return size_written;
+}
+
+void cbuf::flush()
+{
+    _begin = _buf;
+    _end = _buf;
+}
+
+size_t cbuf::remove(size_t size)
+{
+    size_t bytes_available = available();
+    if(size >= bytes_available) {
+        flush();
+        return 0;
+    }
+    size_t size_to_remove = (size < bytes_available) ? size : bytes_available;
+    if(_end < _begin && size_to_remove > (size_t) (_bufend - _begin)) {
+        size_t top_size = _bufend - _begin;
+        _begin = _buf;
+        size_to_remove -= top_size;
+    }
+    _begin = wrap_if_bufend(_begin + size_to_remove);
+    return available();
+}