Instead, we will most likely copy a version resource out of the appropriate baseline. Or, more precisely, how we synthesize the value from information stored in the repository. This is still under investigation. The final action of the commit process is to issue a MERGE request to the Subversion server, specifying that the activity created earlier be checked in and the corresponding version-controlled resources be updated to refer to the new version resources.
The version-controlled resources are also baseline-controlled, which means that updates to them will automatically create a new baseline. In essence, the commit will create a new baseline corresponding to the new Subversion revision.
Consider it out of date until this warning is removed. Consider the following set of operations and its corresponding tree delta taken from the SVN design document :. Walking through this delta, we map out the WebDAV requests listed below. The numbers in the above delta roughly correspond to the numbered entries below. The correspondence is not exact because a specific, resulting behavior is typically based on a combination of a few elements in the delta.
The Subversion server exposes repositories at user-defined URLs. However, the server also requires a number of other resources to be exposed for proper operation.
These additional resources will be associated with each repository in a location under the main repository URL. Only a subset of methods are allowed on the activities within the collection. This collection contains the version history resources for files and directories in a project.
Its internal layout is completely server-defined. Clients will receive URLs into this collection or a subcollection from various responses. The node-id is an internal value that Subversion uses to reference individual files and directories. This node-id is a single integer defined by the Subversion repository. Note that this is an undotted node id, which is the base for the entire history of a given node in the repository.
Note: the above information is probably not quite correct. The issue of linking one version history to another is still open. Further, I think that node 73 and node The layout of this collection is internal to the server.
For reference purposes here and to describe the implementation , it is laid out as:. Only read-only methods are allowed against these resources e. The DAV:resourcetype of a version resource is simply the value of the resource at checkin time e. Any method is allowed on the working resources, but no methods are allowed on any of its parents.
Since these resources are all version resources, the properties below are read-only. Based on the client design, it may be important to specify other read-only live properties for information about versions. Creating these live properties will be quite straight-forward, and driven by the client design over time. Note: if we do this, however, then we'd end up tying the client to the server. Of course, if the client were run against another DeltaV server which didn't report these properties, then we'd simply not display them in the UI.
After the initial checkout, the client can request a status report what has been changed on the client, pending a commit; what has been changed on the server, pending an update. The update process is similar, except that we also fetch the changes from the server. The local changes can be handled entirely on the client side. The Working Copy library can easily handle the detection and reporting of these changes. We're concerned with efficiently detecting what has changed on the server.
While it would be possible to traverse the repository, fetching the current state, and comparing that to the client state, it would not be efficient. The Subversion design enables the server to easily compute what has changed relative to the client , if it is given a description of the client state.
This custom report will transmit the state of the working copy to the server, and the server response will specify which resources will need to be updated fetched. The body will use the standard Subversion technique of reporting a top-level revision number, and then only reporting children that have different revisions.
The result of the report will use the same technique of reporting only the resources where a change is found. If a change is found, the server will provide a URL to the version resource to fetch for the changed resource.
The server will also report the current revision number. The custom report will tie the client to only those servers which support the report, but a future version of the software will contain a fallback codepath, a graceful degradation, to support other DeltaV servers. When an updated is performed, the client will fetch each of the URLs using GET requests provided in the server response. Etags are required to be unique across all versions of a resource. Luckily, this is very easy for a version control system.
Each etag will be simply be the repository's node-id for the resource. The problem then becomes how to get the etag for each file stored on the client we don't need etags for directories since we never fetch them. Lastly, overwrite protection handles aspects related to locking of files.
In fact, Berners-Lee's first web browser, called WorldWideWeb, could both view and edit web pages; but, as the Web grew, it became a read-only medium for most users.
Whitehead and other like-minded people wanted to transcend that limitation. As work began on the protocol, it became clear that handling both distributed authoring and versioning together would involve too much work and that the tasks would have to be separated. The WebDAV group focused on distributed authoring, and left versioning for the future.
The Delta-V extension added versioning later — see the Extensions section below. Other extensions left unfinished at that time, such as the BIND method, have been finished by their individual authors, independent of the formal working group. Add a comment. Active Oldest Votes. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password.
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