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use std::fmt;
macro_rules! dbg_log {
($($arg:tt)*) => (#[cfg(debug_assertions)] println!($($arg)*));
}
pub const ERR_STR_INVALID_LEN: &str = "invalid length";
pub const ERR_STR_BUFFER_FULL: &str = "buffer is full";
pub struct BrBuffer {
buffer: Vec<u8>,
buffer_len: usize,
rpos: usize,
wpos: usize,
cumulated_len: usize,
contiguous: Vec<u8>,
}
impl fmt::Debug for BrBuffer {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("[BrBuffer] => ")
.field("buffer", &self.buffer)
.field("buffer len", &self.buffer_len)
.field("rpos", &self.rpos)
.field("wpos", &self.wpos)
.field("cumulated_len", &self.cumulated_len)
.field("contiguous", &self.contiguous)
.finish()
}
}
impl BrBuffer {
pub fn new(len: usize) -> Self {
BrBuffer {
buffer: vec![0; len],
buffer_len: len,
rpos: 0,
wpos: 0,
cumulated_len: 0,
contiguous: vec![],
}
}
pub fn append(&mut self, len: usize, data: &[u8]) -> Result<bool, (i32, &str)> {
self.debug_me(Some(data), len, "append before", line!());
if self.buffer_len < len {
eprintln!("error ({}) -> {}", line!(), ERR_STR_INVALID_LEN);
return Err((-10001, ERR_STR_INVALID_LEN));
} else if self.buffer_len == self.cumulated_len {
eprintln!("error ({}) -> {}", line!(), ERR_STR_BUFFER_FULL);
return Err((-10002, ERR_STR_BUFFER_FULL));
}
if self.rpos > self.wpos {
if self.rpos - self.wpos >= len {
dbg_log!("append : rpos > wpos (reversed and free space exists)");
self.buffer[self.wpos..(self.wpos + len)].copy_from_slice(data);
self.wpos += len;
self.cumulated_len += len;
self.debug_me(Some(data), len, "append after", line!());
Ok(true)
} else {
eprintln!("error ({}) -> {}", line!(), ERR_STR_BUFFER_FULL);
Err((-10003, ERR_STR_BUFFER_FULL))
}
} else {
dbg_log!("append : wpos >= rpos (not reversed)");
if self.buffer_len < self.wpos + len {
dbg_log!("append : wpos 이후 버퍼로 모자라는 경우");
if (self.wpos > 0) && (len - (self.buffer_len - self.wpos) <= self.rpos) {
dbg_log!("append : 2번 나누어서 들어갈 공간이 있는 경우");
let first_block_len = self.buffer_len - self.wpos;
let second_block_len = len - first_block_len;
dbg_log!("first {},second {}", first_block_len, second_block_len);
if first_block_len > 0 {
self.buffer[self.wpos..self.wpos + first_block_len]
.copy_from_slice(&data[..first_block_len]);
}
self.buffer[..second_block_len].copy_from_slice(
&data[first_block_len..first_block_len + second_block_len],
);
self.wpos = second_block_len;
self.cumulated_len += len;
self.debug_me(Some(data), len, "append after", line!());
Ok(true)
} else {
dbg_log!("append : 2번 나누어서 들어갈 공간 없는 경우");
eprintln!("error ({}) -> {}", line!(), ERR_STR_BUFFER_FULL);
Err((-10004, ERR_STR_BUFFER_FULL))
}
} else {
dbg_log!("append : most general case");
self.buffer[self.wpos..(self.wpos + len)].copy_from_slice(data);
self.wpos += len;
self.cumulated_len += len;
self.debug_me(Some(data), len, "append after", line!());
Ok(true)
}
}
}
pub fn get(&mut self, len: usize) -> Result<&[u8], (i32, &str)> {
self.debug_me(None, len, "get before", line!());
if self.wpos > self.rpos {
if self.wpos < self.rpos + len {
eprintln!("error ({}) -> {}", line!(), ERR_STR_INVALID_LEN);
Err((-20001, ERR_STR_INVALID_LEN))
} else {
dbg_log!("get : general case");
let rslt_slice = &self.buffer[self.rpos..(self.rpos + len)];
self.rpos += len;
self.cumulated_len -= len;
self.debug_me(None, len, "get after", line!());
Ok(rslt_slice)
}
} else {
dbg_log!("get : reversed : rpos >= wpos ");
if self.buffer_len < self.rpos + len {
let first_block_len = self.buffer_len - self.rpos;
let second_block_len = len - first_block_len;
dbg_log!("{},{}", first_block_len, second_block_len);
if self.wpos > 0 && self.wpos >= second_block_len {
dbg_log!("get : reversed (need to combine 2 parts)");
let slice1 = &self.buffer[self.rpos..self.rpos + first_block_len];
let slice2 = &self.buffer[..second_block_len];
self.rpos = second_block_len;
self.cumulated_len -= len;
self.contiguous = [slice1, slice2].concat();
self.debug_me(None, len, "get after", line!());
Ok(self.contiguous.as_slice())
} else {
eprintln!("error ({}) -> {}", line!(), ERR_STR_INVALID_LEN);
Err((-20002, ERR_STR_INVALID_LEN))
}
} else {
dbg_log!("get : reversed (no need to combine)");
let rslt_slice = &self.buffer[self.rpos..(self.rpos + len)];
self.rpos += len;
self.cumulated_len -= len;
self.debug_me(None, len, "get after", line!());
Ok(rslt_slice)
}
}
}
pub fn capacity(&self) -> usize {
self.buffer.capacity()
}
pub fn cumulated_len(&self) -> usize {
self.cumulated_len
}
pub fn rpos(&self) -> usize {
self.rpos
}
pub fn wpos(&self) -> usize {
self.wpos
}
#[cfg(debug_assertions)]
fn debug_me(&self, _data: Option<&[u8]>, _data_len: usize, _msg: &str, _fline: u32) {
println!(
"{} ({}) : {:?}, buffer_len={}, len={}, rpos={}, wpos={}, cumulated={}",
_msg,
_fline,
_data,
self.buffer_len,
_data_len,
self.rpos,
self.wpos,
self.cumulated_len
);
}
#[cfg(not(debug_assertions))]
fn debug_me(&self, _data: Option<&[u8]>, _data_len: usize, _msg: &str, _fline: u32) {}
}