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Diffstat (limited to 'core/ring_buffer.h')
| -rw-r--r-- | core/ring_buffer.h | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/core/ring_buffer.h b/core/ring_buffer.h new file mode 100644 index 0000000000..71105e7bf1 --- /dev/null +++ b/core/ring_buffer.h @@ -0,0 +1,185 @@ +/*************************************************************************/ +/* ring_buffer.h */ +/*************************************************************************/ +/* This file is part of: */ +/* GODOT ENGINE */ +/* http://www.godotengine.org */ +/*************************************************************************/ +/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */ +/* */ +/* Permission is hereby granted, free of charge, to any person obtaining */ +/* a copy of this software and associated documentation files (the */ +/* "Software"), to deal in the Software without restriction, including */ +/* without limitation the rights to use, copy, modify, merge, publish, */ +/* distribute, sublicense, and/or sell copies of the Software, and to */ +/* permit persons to whom the Software is furnished to do so, subject to */ +/* the following conditions: */ +/* */ +/* The above copyright notice and this permission notice shall be */ +/* included in all copies or substantial portions of the Software. */ +/* */ +/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ +/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ +/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/ +/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ +/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ +/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ +/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ +/*************************************************************************/ +#ifndef RINGBUFFER_H +#define RINGBUFFER_H + +#include "vector.h" + +template <typename T> +class RingBuffer { + + Vector<T> data; + int read_pos; + int write_pos; + int size_mask; + + inline int inc(int& p_var, int p_size) { + int ret = p_var; + p_var += p_size; + p_var = p_var&size_mask; + return ret; + }; + +public: + + T read() { + ERR_FAIL_COND_V(space_left() < 1, T()); + return data[inc(read_pos, 1)]; + }; + + int read(T* p_buf, int p_size, bool p_advance=true) { + int left = data_left(); + p_size = MIN(left, p_size); + int pos = read_pos; + int to_read = p_size; + int dst = 0; + while(to_read) { + int end = pos + to_read; + end = MIN(end, size()); + int total = end - pos; + for (int i=0; i<total; i++) { + p_buf[dst++] = data[pos + i]; + }; + to_read -= total; + pos = 0; + }; + if (p_advance) { + inc(read_pos, p_size); + }; + return p_size; + }; + + int copy(T* p_buf, int p_offset, int p_size) { + + int left = data_left(); + if ((p_offset+p_size)>left) { + p_size-=left-p_offset; + if (p_size<=0) + return 0; + } + p_size = MIN(left, p_size); + int pos = read_pos; + inc(pos,p_offset); + int to_read = p_size; + int dst = 0; + while(to_read) { + int end = pos + to_read; + end = MIN(end, size()); + int total = end - pos; + for (int i=0; i<total; i++) { + p_buf[dst++] = data[pos + i]; + }; + to_read -= total; + pos = 0; + }; + return p_size; + }; + + inline int advance_read(int p_n) { + p_n = MIN(p_n, data_left()); + inc(read_pos, p_n); + return p_n; + }; + + Error write(const T& p_v) { + ERR_FAIL_COND_V( space_left() < 1, FAILED); + data[inc(write_pos, 1)] = p_v; + return OK; + }; + + int write(const T* p_buf, int p_size) { + + int left = space_left(); + p_size = MIN(left, p_size); + + int pos = write_pos; + int to_write = p_size; + int src = 0; + while (to_write) { + + int end = pos + to_write; + end = MIN(end, size()); + int total = end - pos; + + for (int i=0; i<total; i++) { + data[pos+i] = p_buf[src++]; + }; + to_write -= total; + pos = 0; + }; + + inc(write_pos, p_size); + return p_size; + }; + + inline int space_left() { + int left = read_pos - write_pos; + if (left < 0) { + return size() + left; + }; + if (left == 0) { + return size(); + }; + return left; + }; + inline int data_left() { + return size() - space_left(); + }; + + inline int size() { + return data.size(); + }; + + void resize(int p_power) { + int old_size = size(); + int new_size = 1<<p_power; + int mask = new_size - 1; + data.resize(1<<p_power); + if (old_size < new_size && read_pos > write_pos) { + for (int i=0; i<write_pos; i++) { + data[(old_size + i)&mask] = data[i]; + }; + write_pos = (old_size + write_pos) & mask; + } else { + read_pos = read_pos & mask; + write_pos = write_pos & mask; + }; + + size_mask = mask; + }; + + RingBuffer<T>(int p_power=0) { + read_pos = 0; + write_pos = 0; + resize(p_power); + }; + ~RingBuffer<T>() {}; +}; + +#endif |