| 1 | use crate::encoding::read::{Error, Read}; |
| 2 | use crate::encoding::write::Write; |
| 3 | use std::convert::TryInto; |
| 4 | |
| 5 | pub trait VarInt: Sized + Copy { |
| 6 | fn write<W: Write>(&self, w: &mut W); |
| 7 | fn read<R: Read>(r: &mut R) -> Result<Self, Error>; |
| 8 | } |
| 9 | |
| 10 | impl VarInt for usize { |
| 11 | #[inline] |
| 12 | fn write<W: Write>(&self, w: &mut W) { |
| 13 | write_var_u64(*self as u64, w) |
| 14 | } |
| 15 | |
| 16 | #[inline] |
| 17 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 18 | Ok(read_var_u64(r)? as Self) |
| 19 | } |
| 20 | } |
| 21 | |
| 22 | impl VarInt for u128 { |
| 23 | fn write<W: Write>(&self, w: &mut W) { |
| 24 | let mut value = *self; |
| 25 | while value >= 0b10000000 { |
| 26 | let b = ((value & 0b01111111) as u8) | 0b10000000; |
| 27 | w.write_u8(b); |
| 28 | value = value >> 7; |
| 29 | } |
| 30 | |
| 31 | w.write_u8((value & 0b01111111) as u8) |
| 32 | } |
| 33 | |
| 34 | #[inline] |
| 35 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 36 | let mut num = 0u128; |
| 37 | let mut len: usize = 0; |
| 38 | loop { |
| 39 | let r = r.read_u8()?; |
| 40 | num |= u128::wrapping_shl((r & 0b01111111) as u128, len as u32); |
| 41 | len += 7; |
| 42 | if r < 0b10000000 { |
| 43 | return Ok(num); |
| 44 | } |
| 45 | if len > 180 { |
| 46 | return Err(Error::InvalidVarInt); |
| 47 | } |
| 48 | } |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | impl VarInt for u64 { |
| 53 | #[inline] |
| 54 | fn write<W: Write>(&self, w: &mut W) { |
| 55 | write_var_u64(*self, w) |
| 56 | } |
| 57 | |
| 58 | #[inline] |
| 59 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 60 | read_var_u64(r) |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | impl VarInt for u32 { |
| 65 | #[inline] |
| 66 | fn write<W: Write>(&self, w: &mut W) { |
| 67 | write_var_u32(*self, w) |
| 68 | } |
| 69 | |
| 70 | #[inline] |
| 71 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 72 | read_var_u32(r) |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | impl VarInt for u16 { |
| 77 | #[inline] |
| 78 | fn write<W: Write>(&self, w: &mut W) { |
| 79 | write_var_u32(*self as u32, w) |
| 80 | } |
| 81 | |
| 82 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 83 | let value = read_var_u32(r)?; |
| 84 | if let Ok(value) = value.try_into() { |
| 85 | Ok(value) |
| 86 | } else { |
| 87 | Err(Error::InvalidVarInt) |
| 88 | } |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | impl VarInt for u8 { |
| 93 | #[inline] |
| 94 | fn write<W: Write>(&self, w: &mut W) { |
| 95 | write_var_u32(*self as u32, w) |
| 96 | } |
| 97 | |
| 98 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 99 | let value = read_var_u32(r)?; |
| 100 | if let Ok(value) = value.try_into() { |
| 101 | Ok(value) |
| 102 | } else { |
| 103 | Err(Error::InvalidVarInt) |
| 104 | } |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | impl VarInt for isize { |
| 109 | #[inline] |
| 110 | fn write<W: Write>(&self, w: &mut W) { |
| 111 | write_var_i64(*self as i64, w) |
| 112 | } |
| 113 | |
| 114 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 115 | let value = read_var_i64(r)?; |
| 116 | if let Ok(value) = value.try_into() { |
| 117 | Ok(value) |
| 118 | } else { |
| 119 | Err(Error::InvalidVarInt) |
| 120 | } |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | impl VarInt for i64 { |
| 125 | #[inline] |
| 126 | fn write<W: Write>(&self, w: &mut W) { |
| 127 | write_var_i64(*self, w) |
| 128 | } |
| 129 | |
| 130 | #[inline] |
| 131 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 132 | read_var_i64(r) |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | impl VarInt for i32 { |
| 137 | #[inline] |
| 138 | fn write<W: Write>(&self, w: &mut W) { |
| 139 | write_var_i64(*self as i64, w) |
| 140 | } |
| 141 | |
| 142 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 143 | let value = read_var_i64(r)?; |
| 144 | if let Ok(value) = value.try_into() { |
| 145 | Ok(value) |
| 146 | } else { |
| 147 | Err(Error::InvalidVarInt) |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | impl VarInt for i16 { |
| 153 | #[inline] |
| 154 | fn write<W: Write>(&self, w: &mut W) { |
| 155 | write_var_i64(*self as i64, w) |
| 156 | } |
| 157 | |
| 158 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 159 | let value = read_var_i64(r)?; |
| 160 | if let Ok(value) = value.try_into() { |
| 161 | Ok(value) |
| 162 | } else { |
| 163 | Err(Error::InvalidVarInt) |
| 164 | } |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | impl VarInt for i8 { |
| 169 | #[inline] |
| 170 | fn write<W: Write>(&self, w: &mut W) { |
| 171 | write_var_i64(*self as i64, w) |
| 172 | } |
| 173 | |
| 174 | fn read<R: Read>(r: &mut R) -> Result<Self, Error> { |
| 175 | let value = read_var_i64(r)?; |
| 176 | if let Ok(value) = value.try_into() { |
| 177 | Ok(value) |
| 178 | } else { |
| 179 | Err(Error::InvalidVarInt) |
| 180 | } |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | fn write_var_u32<W: Write>(mut value: u32, w: &mut W) { |
| 185 | while value >= 0b10000000 { |
| 186 | let b = ((value & 0b01111111) as u8) | 0b10000000; |
| 187 | w.write_u8(b); |
| 188 | value = value >> 7; |
| 189 | } |
| 190 | |
| 191 | w.write_u8((value & 0b01111111) as u8) |
| 192 | } |
| 193 | |
| 194 | fn write_var_u64<W: Write>(mut value: u64, w: &mut W) { |
| 195 | while value >= 0b10000000 { |
| 196 | let b = ((value & 0b01111111) as u8) | 0b10000000; |
| 197 | w.write_u8(b); |
| 198 | value = value >> 7; |
| 199 | } |
| 200 | |
| 201 | w.write_u8((value & 0b01111111) as u8) |
| 202 | } |
| 203 | |
| 204 | fn write_var_i64<W: Write>(mut value: i64, w: &mut W) { |
| 205 | let is_negative = value < 0; |
| 206 | value = if is_negative { -value } else { value }; |
| 207 | w.write_u8( |
| 208 | // whether to continue reading |
| 209 | (if value > 0b00111111 as i64 { 0b10000000 as u8 } else { 0 }) |
| 210 | // whether number is negative |
| 211 | | (if is_negative { 0b01000000 as u8 } else { 0 }) |
| 212 | // number |
| 213 | | (0b00111111 as i64 & value) as u8, |
| 214 | ); |
| 215 | value >>= 6; |
| 216 | while value > 0 { |
| 217 | w.write_u8( |
| 218 | if value > 0b01111111 as i64 { |
| 219 | 0b10000000 as u8 |
| 220 | } else { |
| 221 | 0 |
| 222 | } | (0b01111111 as i64 & value) as u8, |
| 223 | ); |
| 224 | value >>= 7; |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | fn read_var_u64<R: Read>(r: &mut R) -> Result<u64, Error> { |
| 229 | let mut num = 0; |
| 230 | let mut len: usize = 0; |
| 231 | loop { |
| 232 | let r = r.read_u8()?; |
| 233 | num |= u64::wrapping_shl((r & 0b01111111) as u64, len as u32); |
| 234 | len += 7; |
| 235 | if r < 0b10000000 { |
| 236 | return Ok(num); |
| 237 | } |
| 238 | if len > 70 { |
| 239 | return Err(Error::InvalidVarInt); |
| 240 | } |
| 241 | } |
| 242 | } |
| 243 | |
| 244 | fn read_var_u32<R: Read>(r: &mut R) -> Result<u32, Error> { |
| 245 | let mut num = 0; |
| 246 | let mut len: usize = 0; |
| 247 | loop { |
| 248 | let r = r.read_u8()?; |
| 249 | num |= u32::wrapping_shl((r & 0b01111111) as u32, len as u32); |
| 250 | len += 7; |
| 251 | if r < 0b10000000 { |
| 252 | return Ok(num); |
| 253 | } |
| 254 | if len > 70 { |
| 255 | // a proper setting for 32bit int would be 35 bits, however for Yjs compatibility |
| 256 | // we allow wrap up up to 64bit ints (with int overflow wrap) |
| 257 | return Err(Error::InvalidVarInt); |
| 258 | } |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | fn read_var_i64<R: Read>(reader: &mut R) -> Result<i64, Error> { |
| 263 | let mut r = reader.read_u8()?; |
| 264 | let mut num = (r & 0b00111111 as u8) as i64; |
| 265 | let mut len: u32 = 6; |
| 266 | let is_negative = r & 0b01000000 as u8 > 0; |
| 267 | if r & 0b10000000 as u8 == 0 { |
| 268 | return Ok(if is_negative { -num } else { num }); |
| 269 | } |
| 270 | loop { |
| 271 | r = reader.read_u8()?; |
| 272 | num |= (r as i64 & 0b01111111 as i64) << len; |
| 273 | len += 7; |
| 274 | if r < 0b10000000 as u8 { |
| 275 | return Ok(if is_negative { -num } else { num }); |
| 276 | } |
| 277 | if len > 70 { |
| 278 | return Err(Error::InvalidVarInt); |
| 279 | } |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | pub trait SignedVarInt: Sized + Copy { |
| 284 | fn write_signed<W: Write>(value: &Signed<Self>, w: &mut W); |
| 285 | fn read_signed<R: Read>(r: &mut R) -> Result<Signed<Self>, Error>; |
| 286 | } |
| 287 | |
| 288 | /// Struct which recognizes signed integer values. This special case has been build for Yjs encoding |
| 289 | /// compatibility, which recognizes differences between `0` and `-0`, which is used in some |
| 290 | /// cases (eg. `UIntOptRleDecoder`). |
| 291 | #[derive(Debug, Clone, Eq, PartialEq)] |
| 292 | pub struct Signed<T: Sized + Copy> { |
| 293 | value: T, |
| 294 | is_negative: bool, |
| 295 | } |
| 296 | |
| 297 | impl<T: Sized + Copy> Signed<T> { |
| 298 | pub fn new(value: T, is_negative: bool) -> Self { |
| 299 | Signed { value, is_negative } |
| 300 | } |
| 301 | |
| 302 | /// Returns true is stored number is a positive value. |
| 303 | pub fn is_positive(&self) -> bool { |
| 304 | !self.is_negative |
| 305 | } |
| 306 | |
| 307 | /// Returns true is stored number is a negative value (including `-0` as a special case). |
| 308 | pub fn is_negative(&self) -> bool { |
| 309 | self.is_negative |
| 310 | } |
| 311 | |
| 312 | /// Returns a stored value. |
| 313 | pub fn value(&self) -> T { |
| 314 | self.value |
| 315 | } |
| 316 | |
| 317 | /// Maps contents of a [Signed] value container to a new data type, retaining the sign |
| 318 | /// information. |
| 319 | pub fn map<F, U>(&self, f: F) -> Signed<U> |
| 320 | where |
| 321 | F: FnOnce(T) -> U, |
| 322 | U: Sized + Copy, |
| 323 | { |
| 324 | let mapped = f(self.value); |
| 325 | Signed::new(mapped, self.is_negative) |
| 326 | } |
| 327 | } |
| 328 | |
| 329 | impl SignedVarInt for i64 { |
| 330 | fn write_signed<W: Write>(s: &Signed<Self>, w: &mut W) { |
| 331 | let mut value = s.value; |
| 332 | let is_negative = s.is_negative; |
| 333 | value = if is_negative { -value } else { value }; |
| 334 | w.write_u8( |
| 335 | // whether to continue reading |
| 336 | (if value > 0b00111111 as i64 { 0b10000000 as u8 } else { 0 }) |
| 337 | // whether number is negative |
| 338 | | (if is_negative { 0b01000000 as u8 } else { 0 }) |
| 339 | // number |
| 340 | | (0b00111111 as i64 & value) as u8, |
| 341 | ); |
| 342 | value >>= 6; |
| 343 | while value > 0 { |
| 344 | w.write_u8( |
| 345 | if value > 0b01111111 as i64 { |
| 346 | 0b10000000 as u8 |
| 347 | } else { |
| 348 | 0 |
| 349 | } | (0b01111111 as i64 & value) as u8, |
| 350 | ); |
| 351 | value >>= 7; |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | fn read_signed<R: Read>(reader: &mut R) -> Result<Signed<Self>, Error> { |
| 356 | let mut r = reader.read_u8()?; |
| 357 | let mut num = (r & 0b00111111 as u8) as i64; |
| 358 | let mut len: u32 = 6; |
| 359 | let is_negative = r & 0b01000000 as u8 > 0; |
| 360 | if r & 0b10000000 as u8 == 0 { |
| 361 | let num = if is_negative { -num } else { num }; |
| 362 | return Ok(Signed::new(num, is_negative)); |
| 363 | } |
| 364 | loop { |
| 365 | r = reader.read_u8()?; |
| 366 | num |= (r as i64 & 0b01111111 as i64) << len; |
| 367 | len += 7; |
| 368 | if r < 0b10000000 as u8 { |
| 369 | let num = if is_negative { -num } else { num }; |
| 370 | return Ok(Signed::new(num, is_negative)); |
| 371 | } |
| 372 | if len > 70 { |
| 373 | return Err(Error::InvalidVarInt); |
| 374 | } |
| 375 | } |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | impl SignedVarInt for isize { |
| 380 | fn write_signed<W: Write>(value: &Signed<Self>, w: &mut W) { |
| 381 | let value = value.map(|v| v as i64); |
| 382 | i64::write_signed(&value, w) |
| 383 | } |
| 384 | |
| 385 | fn read_signed<R: Read>(r: &mut R) -> Result<Signed<Self>, Error> { |
| 386 | let result = i64::read_signed(r)?; |
| 387 | match result.value.try_into() { |
| 388 | Ok(i) => Ok(Signed::new(i, result.is_negative)), |
| 389 | Err(_) => Err(Error::InvalidVarInt), |
| 390 | } |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | impl SignedVarInt for i32 { |
| 395 | fn write_signed<W: Write>(value: &Signed<Self>, w: &mut W) { |
| 396 | let value = value.map(|v| v as i64); |
| 397 | i64::write_signed(&value, w) |
| 398 | } |
| 399 | |
| 400 | fn read_signed<R: Read>(r: &mut R) -> Result<Signed<Self>, Error> { |
| 401 | let result = i64::read_signed(r)?; |
| 402 | match result.value.try_into() { |
| 403 | Ok(i) => Ok(Signed::new(i, result.is_negative)), |
| 404 | Err(_) => Err(Error::InvalidVarInt), |
| 405 | } |
| 406 | } |
| 407 | } |
| 408 | |
| 409 | impl SignedVarInt for i16 { |
| 410 | fn write_signed<W: Write>(value: &Signed<Self>, w: &mut W) { |
| 411 | let value = value.map(|v| v as i64); |
| 412 | i64::write_signed(&value, w) |
| 413 | } |
| 414 | |
| 415 | fn read_signed<R: Read>(r: &mut R) -> Result<Signed<Self>, Error> { |
| 416 | let result = i64::read_signed(r)?; |
| 417 | match result.value.try_into() { |
| 418 | Ok(i) => Ok(Signed::new(i, result.is_negative)), |
| 419 | Err(_) => Err(Error::InvalidVarInt), |
| 420 | } |
| 421 | } |
| 422 | } |
| 423 | |
| 424 | impl SignedVarInt for i8 { |
| 425 | fn write_signed<W: Write>(value: &Signed<Self>, w: &mut W) { |
| 426 | let value = value.map(|v| v as i64); |
| 427 | i64::write_signed(&value, w) |
| 428 | } |
| 429 | |
| 430 | fn read_signed<R: Read>(r: &mut R) -> Result<Signed<Self>, Error> { |
| 431 | let result = i64::read_signed(r)?; |
| 432 | match result.value.try_into() { |
| 433 | Ok(i) => Ok(Signed::new(i, result.is_negative)), |
| 434 | Err(_) => Err(Error::InvalidVarInt), |
| 435 | } |
| 436 | } |
| 437 | } |
| 438 | |
amadan