Mercurial > public > mercurial-scm > hg
comparison rust/hg-core/src/dirstate_tree/dispatch.rs @ 47678:065e61628980
dirstate-v2: Support appending to the same data file
For now we?re still writing the entire data every time, so appending is not
useful yet. Later we?ll have new nodes pointing to some existing data for
nodes and paths that haven?t changed.
The decision whether to append is pseudo-random in order to make tests exercise
both code paths. This will be replaced by a heuristic based on the amount
of unused existing data.
Differential Revision: https://phab.mercurial-scm.org/D11094
| author | Simon Sapin <simon.sapin@octobus.net> |
|---|---|
| date | Tue, 13 Jul 2021 17:18:23 +0200 |
| parents | ff97e793ed36 |
| children | 78f7f0d490ee |
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| 47677:da1c0cd68d53 | 47678:065e61628980 |
|---|---|
| 177 now: Timestamp, | 177 now: Timestamp, |
| 178 ) -> Result<Vec<u8>, DirstateError>; | 178 ) -> Result<Vec<u8>, DirstateError>; |
| 179 | 179 |
| 180 /// Clear mtimes that are ambigous with `now` (similar to | 180 /// Clear mtimes that are ambigous with `now` (similar to |
| 181 /// `clear_ambiguous_times` but for all files in the dirstate map), and | 181 /// `clear_ambiguous_times` but for all files in the dirstate map), and |
| 182 /// serialize bytes to write the `.hg/dirstate` file to disk in dirstate-v2 | 182 /// serialize bytes to write a dirstate data file to disk in dirstate-v2 |
| 183 /// format. | 183 /// format. |
| 184 /// | 184 /// |
| 185 /// Returns new data together with whether that data should be appended to | |
| 186 /// the existing data file whose content is at `self.on_disk` (true), | |
| 187 /// instead of written to a new data file (false). | |
| 188 /// | |
| 185 /// Note: this is only supported by the tree dirstate map. | 189 /// Note: this is only supported by the tree dirstate map. |
| 186 fn pack_v2(&mut self, now: Timestamp) -> Result<Vec<u8>, DirstateError>; | 190 fn pack_v2( |
| 191 &mut self, | |
| 192 now: Timestamp, | |
| 193 can_append: bool, | |
| 194 ) -> Result<(Vec<u8>, bool), DirstateError>; | |
| 187 | 195 |
| 188 /// Run the status algorithm. | 196 /// Run the status algorithm. |
| 189 /// | 197 /// |
| 190 /// This is not sematically a method of the dirstate map, but a different | 198 /// This is not sematically a method of the dirstate map, but a different |
| 191 /// algorithm is used for the flat v.s. tree dirstate map so having it in | 199 /// algorithm is used for the flat v.s. tree dirstate map so having it in |
| 381 now: Timestamp, | 389 now: Timestamp, |
| 382 ) -> Result<Vec<u8>, DirstateError> { | 390 ) -> Result<Vec<u8>, DirstateError> { |
| 383 self.pack(parents, now) | 391 self.pack(parents, now) |
| 384 } | 392 } |
| 385 | 393 |
| 386 fn pack_v2(&mut self, _now: Timestamp) -> Result<Vec<u8>, DirstateError> { | 394 fn pack_v2( |
| 395 &mut self, | |
| 396 _now: Timestamp, | |
| 397 _can_append: bool, | |
| 398 ) -> Result<(Vec<u8>, bool), DirstateError> { | |
| 387 panic!( | 399 panic!( |
| 388 "should have used dirstate_tree::DirstateMap to use the v2 format" | 400 "should have used dirstate_tree::DirstateMap to use the v2 format" |
| 389 ) | 401 ) |
| 390 } | 402 } |
| 391 | 403 |