We were discussing document libraries and file synchronization service. This service provide incremental synchronization between two file system locations based on change detection which is a process that evaluates changes from last synchronization.
It stores metadata about the synchronization which describes where and when the item was changed, giving a snapshot of every file and folder in the replica. Changes are detected by comparing the current file metadata with the version last saved in the snapshot. For files, the comparison is done on the file size, file times, file attributes, file name and optionally a hash of the file contents. For folders, the comparison is done on folder attributes and folder names.
When a file is renamed or moved, just that operation will be performed on the replica avoiding a copy operation. If a folder is renamed or moved, it is deleted and created on other replicas. Files within the folders are processed as renames.
Since change detection evaluates all files, a large number of files in the replica may degrade performance. Therefore, this expensive operation should be done as often as required by the applications using the sync framework.
The file synchronization provider supports extensive progress reporting during the synchronization operation. This can be visualized through the User Interface as a progress bar. This information is reported to the application via events in the managed code or callbacks in the unmanaged code. These event handlers and callbacks enable an application to even skip a change.
The preview mode displays what changes would happen during synchronization. The changes are not committed but the progress notifications are still sent out. It can be used by the application to present the verification UI to the user with all the changes that will be made if synchronization is executed.
The file synchronization provider does not provide an upfront estimate of the total number of files to be synchronized before the synchronization starts because this can be expensive to perform. However, some statistics can be collected using a two pass approach where a preview mode is run before the real synchronization session.
Files can be filtered out of synchronization based on filename-based exclusion, filename based inclusion, subdirectory exclude and file attribute based exclusion. Certain files may always be excluded if they are marked with both SYSTEM and HIDDEN attributes.
It stores metadata about the synchronization which describes where and when the item was changed, giving a snapshot of every file and folder in the replica. Changes are detected by comparing the current file metadata with the version last saved in the snapshot. For files, the comparison is done on the file size, file times, file attributes, file name and optionally a hash of the file contents. For folders, the comparison is done on folder attributes and folder names.
When a file is renamed or moved, just that operation will be performed on the replica avoiding a copy operation. If a folder is renamed or moved, it is deleted and created on other replicas. Files within the folders are processed as renames.
Since change detection evaluates all files, a large number of files in the replica may degrade performance. Therefore, this expensive operation should be done as often as required by the applications using the sync framework.
The file synchronization provider supports extensive progress reporting during the synchronization operation. This can be visualized through the User Interface as a progress bar. This information is reported to the application via events in the managed code or callbacks in the unmanaged code. These event handlers and callbacks enable an application to even skip a change.
The preview mode displays what changes would happen during synchronization. The changes are not committed but the progress notifications are still sent out. It can be used by the application to present the verification UI to the user with all the changes that will be made if synchronization is executed.
The file synchronization provider does not provide an upfront estimate of the total number of files to be synchronized before the synchronization starts because this can be expensive to perform. However, some statistics can be collected using a two pass approach where a preview mode is run before the real synchronization session.
Files can be filtered out of synchronization based on filename-based exclusion, filename based inclusion, subdirectory exclude and file attribute based exclusion. Certain files may always be excluded if they are marked with both SYSTEM and HIDDEN attributes.
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