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Diffstat (limited to 'docs/pageupdater.md')
| -rw-r--r-- | docs/pageupdater.md | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/docs/pageupdater.md b/docs/pageupdater.md index 2b26a3ec580f..71df9a75ff64 100644 --- a/docs/pageupdater.md +++ b/docs/pageupdater.md @@ -125,11 +125,11 @@ The primary reason for `DerivedPageDataUpdater` to be stateful is internal cachi - `getSecondaryDataUpdates()` returns `DataUpdates` that represent derived data for the revision. These may be used to update such data, e.g. in `ApiPurge`, `RefreshLinksJob`, and the `refreshLinks` script. -- `doUpdates()` triggers the updates defined by `getSecondaryDataUpdates()`, and also causes updates to cached artifacts in the `ParserCache`, the CDN layer, etc. This is primarily used by PageUpdater, but also by `PageArchive` during undeletion, and when importing revisions from XML. `doUpdates()` can only be called after `prepareUpdate()` was used to initialize the `DerivedPageDataUpdater` instance for a specific revision. Calling it before `prepareUpdate()` is called raises a `LogicException`. +- `doUpdates()` triggers the updates defined by `getSecondaryDataUpdates()`, and also causes updates to cached artifacts in the `ParserCache`, the CDN layer, etc. This is primarily used by PageUpdater, but also by `UndeletePage` during undeletion, and when importing revisions from XML. `doUpdates()` can only be called after `prepareUpdate()` was used to initialize the `DerivedPageDataUpdater` instance for a specific revision. Calling it before `prepareUpdate()` is called raises a `LogicException`. A `DerivedPageDataUpdater` instance is intended to be re-used during different stages of complex update operations that often involve callbacks to extension code via MediaWiki's hook mechanism, or deferred or even asynchronous execution of Jobs and `DeferredUpdates`. Since these mechanisms typically do not provide a way to pass a -`DerivedPageDataUpdater` directly, `WikiPage::getDerivedPageDataUpdater()` has to be used to obtain a `DerivedPageDataUpdater` for the update currently in progress - re-using the same `DerivedPageDataUpdater` if possible avoids re-generation of `ParserOutput` objects +`DerivedPageDataUpdater` directly, `WikiPage::getDerivedDataUpdater()` has to be used to obtain a `DerivedPageDataUpdater` for the update currently in progress - re-using the same `DerivedPageDataUpdater` if possible avoids re-generation of `ParserOutput` objects and other expensively derived artifacts. -This mechanism for re-using a `DerivedPageDataUpdater` instance without passing it directly requires a way to ensure that a given `DerivedPageDataUpdater` instance can actually be used in the calling code's context. For this purpose, `WikiPage::getDerivedPageDataUpdater()` calls the `isReusableFor()` method on `DerivedPageDataUpdater`, which ensures that the given instance is applicable to the given parameters. In other words, `isReusableFor()` predicts whether calling `prepareContent()` or `prepareUpdate()` with a given set of parameters will trigger a `LogicException.` In that case, `WikiPage::getDerivedPageDataUpdater()` creates a fresh `DerivedPageDataUpdater` instance. +This mechanism for re-using a `DerivedPageDataUpdater` instance without passing it directly requires a way to ensure that a given `DerivedPageDataUpdater` instance can actually be used in the calling code's context. For this purpose, `WikiPage::getDerivedDataUpdater()` calls the `isReusableFor()` method on `DerivedPageDataUpdater`, which ensures that the given instance is applicable to the given parameters. In other words, `isReusableFor()` predicts whether calling `prepareContent()` or `prepareUpdate()` with a given set of parameters will trigger a `LogicException`. In that case, `WikiPage::getDerivedDataUpdater()` creates a fresh `DerivedPageDataUpdater` instance. |