1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396
#![forbid(missing_docs)] //! A utility for recursively measuring the size of an object //! //! This contains the [`DeepSizeOf`](DeepSizeOf) trait, and re-exports //! the `DeepSizeOf` derive macro from [`deepsize_derive`](https://docs.rs/deepsize_derive) //! //! ```rust //! use deepsize::DeepSizeOf; //! //! #[derive(DeepSizeOf)] //! struct Test { //! a: u32, //! b: Box<u8>, //! } //! //! fn main() { //! let object = Test { //! a: 15, //! b: Box::new(255), //! }; //! //! assert_eq!(object.deep_size_of(), 17); //! } //! ``` //! pub use deepsize_derive::*; use std::collections::HashSet; mod default_impls; #[cfg(test)] mod test; /// A trait for measuring the size of an object and its children /// /// In many cases this is just `std::mem::size_of::<T>()`, but if /// the struct contains a `Vec`, `String`, `Box`, or other allocated object or /// reference, then it is the size of the struct, plus the size of the contents /// of the object. pub trait DeepSizeOf { /// Returns an estimation of a total size of memory owned by the /// object, including heap-managed storage. /// /// This is an estimation and not a precise result, because it /// doesn't account for allocator's overhead. /// /// ```rust /// use deepsize::DeepSizeOf; /// use std::collections::HashMap; /// /// let mut map: HashMap<Box<u32>, Vec<String>> = HashMap::new(); /// /// map.insert(Box::new(42u32), vec![String::from("Hello World")]); /// map.insert(Box::new(20u32), vec![String::from("Something")]); /// map.insert(Box::new(0u32), vec![String::from("A string")]); /// map.insert(Box::new(255u32), vec![String::from("Dynamically Allocated!")]); /// /// assert_eq!(map.deep_size_of(), 1312); /// ``` fn deep_size_of(&self) -> usize { self.recurse_deep_size_of(&mut Context::new()) } /// Returns an estimation of a total size of memory owned by the /// object, including heap-managed storage. /// /// This is an estimation and not a precise result, because it /// doesn't account for allocator's overhead. /// /// This is an internal function, and requires a [`Context`](Context) /// to track visited references. fn recurse_deep_size_of(&self, context: &mut Context) -> usize { self.stack_size() + self.deep_size_of_children(context) } /// Returns an estimation of a total size of memory owned by the /// object, including heap-managed storage. /// /// This is an estimation and not a precise result, because it /// doesn't account for allocator's overhead. /// /// This is an internal function, and requires a [`Context`](Context) /// to track visited references. fn deep_size_of_children(&self, context: &mut Context) -> usize; /// Returns the size of the memory the object uses itself /// /// This method is generally equivalent to [`size_of_val`](std::mem::size_of_val) fn stack_size(&self) -> usize { std::mem::size_of_val(self) } } /// The context of which references have already been seen /// /// Keeps track of the [`Arc`](std::sync::Arc)s, [`Rc`](std::rc::Rc)s, and references /// that have been visited, so that [`Arc`](std::sync::Arc)s and other references /// aren't double counted. /// /// Currently this counts each reference once, although there are arguments for /// only counting owned data, and ignoring partial ownership, or for counting /// partial refernces like Arc as its size divided by the strong reference count. /// [Github Issue discussion here](https://github.com/dtolnay/request-for-implementation/issues/22) #[derive(Debug)] pub struct Context { /// A set of all [`Arcs`](std::sync::Arc) that have already been counted arcs: HashSet<usize>, /// A set of all [`Rcs`](std::sync::Arc) that have already been counted rcs: HashSet<usize>, /// A set of all normal references that have already been counted refs: HashSet<usize>, } impl Context { /// Creates a new empty context for use in the deep_size functions pub fn new() -> Context { Context { arcs: HashSet::new(), rcs: HashSet::new(), refs: HashSet::new(), } } /// Adds an [`Arc`](std::sync::Arc) to the list of visited [`Arc`](std::sync::Arc)s fn add_arc<T>(&mut self, arc: &std::sync::Arc<T>) { // Somewhat unsafe way of getting a pointer to the inner `ArcInner` // object without changing the count let pointer: usize = *unsafe { std::mem::transmute::<&std::sync::Arc<T>, &usize>(arc) }; self.arcs.insert(pointer); } /// Checks if an [`Arc`](std::sync::Arc) is in the list visited [`Arc`](std::sync::Arc)s fn contains_arc<T>(&self, arc: &std::sync::Arc<T>) -> bool { let pointer: usize = *unsafe { std::mem::transmute::<&std::sync::Arc<T>, &usize>(arc) }; self.arcs.contains(&pointer) } /// Adds an [`Rc`](std::rc::Rc) to the list of visited [`Rc`](std::rc::Rc)s fn add_rc<T>(&mut self, rc: &std::rc::Rc<T>) { // Somewhat unsafe way of getting a pointer to the inner `RcBox` // object without changing the count let pointer: usize = *unsafe { std::mem::transmute::<&std::rc::Rc<T>, &usize>(rc) }; self.rcs.insert(pointer); } /// Checks if an [`Rc`](std::rc::Rc) is in the list visited [`Rc`](std::rc::Rc)s /// Adds an [`Rc`](std::rc::Rc) to the list of visited [`Rc`](std::rc::Rc)s fn contains_rc<T>(&self, rc: &std::rc::Rc<T>) -> bool { let pointer: usize = *unsafe { std::mem::transmute::<&std::rc::Rc<T>, &usize>(rc) }; self.rcs.contains(&pointer) } /// Adds a [`reference`](std::reference) to the list of visited [`reference`](std::reference)s /// Adds an [`Rc`](std::rc::Rc) to the list of visited [`Rc`](std::rc::Rc)s fn add_ref<T>(&mut self, reference: &T) { let pointer: usize = reference as *const _ as usize; self.refs.insert(pointer); } /// Checks if a [`reference`](std::reference) is in the list of visited [`reference`](std::reference)s fn contains_ref<T>(&self, reference: &T) -> bool { let pointer: usize = reference as *const _ as usize; self.refs.contains(&pointer) } } impl<T> DeepSizeOf for std::vec::Vec<T> where T: DeepSizeOf, { /// Sums the size of each child object, and then adds the size of /// the unused capacity. /// /// ```rust /// use deepsize::DeepSizeOf; /// /// let mut vec: Vec<u8> = vec![]; /// for i in 0..13 { /// vec.push(i); /// } /// /// // The capacity (16) plus three usizes (len, cap, pointer) /// assert_eq!(vec.deep_size_of(), 16 + 24); /// ``` /// With allocated objects: /// ```rust /// use deepsize::DeepSizeOf; /// /// let mut vec: Vec<Box<u64>> = vec![]; /// for i in 0..13 { /// vec.push(Box::new(i)); /// } /// /// // The capacity (16?) * size (8) plus three usizes (len, cap, pointer) /// // and length (13) * the allocated size of each object /// assert_eq!(vec.deep_size_of(), 24 + vec.capacity() * 8 + 13 * 8); /// ``` fn deep_size_of_children(&self, context: &mut Context) -> usize { self.iter() .fold(0, |sum, child| sum + child.recurse_deep_size_of(context)) + (self.capacity() - self.len()) * std::mem::size_of::<T>() // Size of unused capacity } } impl<T> DeepSizeOf for std::collections::VecDeque<T> where T: DeepSizeOf, { /// Sums the size of each child object, and then adds the size of /// the unused capacity. /// /// ```rust /// use deepsize::DeepSizeOf; /// use std::collections::VecDeque; /// /// let mut vec: VecDeque<u8> = VecDeque::new(); /// for i in 0..12 { /// vec.push_back(i); /// } /// vec.push_front(13); /// /// // The capacity (15?) plus four usizes (start, end, cap, pointer) /// assert_eq!(vec.deep_size_of(), vec.capacity() * 1 + 32); /// ``` /// With allocated objects: /// ```rust /// use deepsize::DeepSizeOf; /// use std::collections::VecDeque; /// /// let mut vec: VecDeque<Box<u64>> = VecDeque::new(); /// for i in 0..12 { /// vec.push_back(Box::new(i)); /// } /// vec.push_front(Box::new(13)); /// /// // The capacity (15?) * size (8) plus four usizes (start, end, cap, pointer) /// // and length (13) * the allocated size of each object /// assert_eq!(vec.deep_size_of(), 32 + vec.capacity() * 8 + 13 * 8); /// ``` fn deep_size_of_children(&self, context: &mut Context) -> usize { self.iter() .fold(0, |sum, child| sum + child.recurse_deep_size_of(context)) + (self.capacity() - self.len()) * std::mem::size_of::<T>() // Size of unused capacity } } impl<T> DeepSizeOf for std::collections::LinkedList<T> where T: DeepSizeOf, { /// Sums the size of each child object, assuming the overhead of /// each node is 2 usize (next, prev) /// /// ```rust /// use deepsize::DeepSizeOf; /// use std::collections::LinkedList; /// /// let mut list: LinkedList<u8> = LinkedList::new(); /// for i in 0..12 { /// list.push_back(i); /// } /// list.push_front(13); /// /// assert_eq!(list.deep_size_of(), std::mem::size_of::<LinkedList<u8>>() /// + 13 * 1 + 13 * 2 * 8); /// ``` fn deep_size_of_children(&self, context: &mut Context) -> usize { self.iter().fold(0, |sum, child| { sum + child.recurse_deep_size_of(context) + std::mem::size_of::<usize>() * 2 // overhead of each node }) } } impl<K, V, S> DeepSizeOf for std::collections::HashMap<K, V, S> where K: DeepSizeOf + Eq + std::hash::Hash, V: DeepSizeOf, S: std::hash::BuildHasher { // FIXME // How much more overhead is there to a hashmap? The docs say it is // essensially just a Vec<Option<(u64, K, V)>> fn deep_size_of_children(&self, context: &mut Context) -> usize { self.iter() .fold(0, |sum, (key, val)| { sum + key.deep_size_of_children(context) + val.deep_size_of_children(context) + std::mem::size_of::<Option<(u64, K, V)>>() }) + (self.capacity() - self.len()) * (std::mem::size_of::<Option<(u64, K, V)>>()) // Size of unused capacity } } impl<T, S> DeepSizeOf for std::collections::HashSet<T, S> where T: DeepSizeOf + Eq + std::hash::Hash, S: std::hash::BuildHasher { fn deep_size_of_children(&self, context: &mut Context) -> usize { self.iter() .fold(0, |sum, item| { sum + item.deep_size_of_children(context) + std::mem::size_of::<Option<(u64, T, ())>>() }) + (self.capacity() - self.len()) * (std::mem::size_of::<Option<(u64, T, ())>>()) // Size of unused capacity } } impl<T> DeepSizeOf for std::boxed::Box<T> where T: DeepSizeOf, { fn deep_size_of_children(&self, context: &mut Context) -> usize { // May cause inacuracies, measures size of the value, but not the allocation size let val: &T = &*self; val.recurse_deep_size_of(context) } } impl<T> DeepSizeOf for std::sync::Arc<T> where T: DeepSizeOf, { fn deep_size_of_children(&self, context: &mut Context) -> usize { let val: &T = &*self; val.recurse_deep_size_of(context) } fn recurse_deep_size_of(&self, context: &mut Context) -> usize { if context.contains_arc(self) { self.stack_size() } else { context.add_arc(self); self.stack_size() + self.deep_size_of_children(context) } } } impl<T> DeepSizeOf for std::rc::Rc<T> where T: DeepSizeOf, { fn deep_size_of_children(&self, context: &mut Context) -> usize { let val: &T = &*self; val.recurse_deep_size_of(context) } fn recurse_deep_size_of(&self, context: &mut Context) -> usize { if context.contains_rc(self) { self.stack_size() } else { context.add_rc(self); self.stack_size() + self.deep_size_of_children(context) } } } impl<T: ?Sized> DeepSizeOf for &T where T: DeepSizeOf, { fn deep_size_of_children(&self, context: &mut Context) -> usize { if context.contains_ref(&self) { 0 } else { context.add_ref(&self); (*self).recurse_deep_size_of(context) } } fn recurse_deep_size_of(&self, context: &mut Context) -> usize { if context.contains_ref(&self) { self.stack_size() } else { context.add_ref(&self); self.stack_size() + self.deep_size_of_children(context) } } } impl<T> DeepSizeOf for [T] where T: DeepSizeOf, { fn deep_size_of_children(&self, context: &mut Context) -> usize { self.iter() .fold(0, |sum, child| sum + child.recurse_deep_size_of(context)) } fn stack_size(&self) -> usize { 0 } }