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Difference between revisions of "Equinox/p2/p2 index"
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The p2.index file provides a description of the kind of repository available at a particular location; simple or composite. | The p2.index file provides a description of the kind of repository available at a particular location; simple or composite. | ||
| − | The presence of this file in a repository will cause p2 to replace its default lookup order for repository to match the one | + | The presence of this file in a repository will cause p2 to replace its default lookup order for repository to match the one advised in the file. This only happens the first time a repository is accessed, as p2 then caches "what worked before" and uses that on subsequent accesses. See {{bug|347448}} for more detail, links, and history behind this advisory file. The latest version of the [[Eclipse_b3/aggregator/manual| b3 aggregator]] adds an appropriate p2.index file as it publishes its p2 repository (not sure about other p2 repository publishers). |
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| + | For example the example below will cause p2 to look for content.jar, and then content.xml and if it does not find those, it would fail, rather than look for compositeContent.jar and compositeContent.xml. | ||
version = 1 | version = 1 | ||
Revision as of 11:35, 1 March 2012
Contents
What is the p2.index file?
The p2.index file provides a description of the kind of repository available at a particular location; simple or composite.
The presence of this file in a repository will cause p2 to replace its default lookup order for repository to match the one advised in the file. This only happens the first time a repository is accessed, as p2 then caches "what worked before" and uses that on subsequent accesses. See bug 347448 for more detail, links, and history behind this advisory file. The latest version of the b3 aggregator adds an appropriate p2.index file as it publishes its p2 repository (not sure about other p2 repository publishers).
For example the example below will cause p2 to look for content.jar, and then content.xml and if it does not find those, it would fail, rather than look for compositeContent.jar and compositeContent.xml.
version = 1 metadata.repository.factory.order = content.xml,\! artifact.repository.factory.order = artifacts.xml,\!
How does it help me?
As a provider of a repository, it does not help you directly, but it helps your users to get a better experience and also slightly reduce the number of hits your server will be subject to.
What happens if I get it wrong ?
Should you get the content of this file wrong, the repository will fail loading. For example specifying compositeContent.xml where the repository is a content.xml will cause p2 to only look for compositeContent.xml and never look at the content.xml.
How many files for composite repositories
Given that a composite repository is just a repository that refers to other repositories, the full benefit of p2.index can only be achieved if every child repo has the file.
Jar vs XML extension
The content of p2.index does not reflect whether the files are zipped or not.
To quote the output of the b3 aggregator:
- Please note that the values in this file denotes repository factories and
- not files. The factory '<name>.xml' will look for both the <name>.jar
- and the <name>.xml file, in that order
For example for a simple repository that contains artifacts.jar and content.jar, the p2.index would still name: "artifacts.xml" and "content.xml".
Example for composite repository
version = 1 metadata.repository.factory.order = compositeContent.xml,\! artifact.repository.factory.order = compositeArtifacts.xml,\!
Example for simple repository
version = 1 metadata.repository.factory.order = content.xml,\! artifact.repository.factory.order = artifacts.xml,\!