Backend (FileCacheStore): LevelDB
Currently, the default configuration outputs Fedora data to LevelDB (a fast filesystem based key-value store). When Fedora 4 is started, Modeshape (actually Infinispan and LevelDB in the background) will create several directories on the filesystem. Currently, the directories created are:
- fcrepo.ispn.binary.CacheDirPath (binary data)
- fcrepo.ispn.CacheDirPath (metadata)
- fcrepo.ispn.repo.CacheDirPath (repository)
- fcrepo.modeshape.index.location
The layout of files in directories 1-3 is determined by LevelDB. Some of the important files are:
- File .log holds entries for recent transactions. The relevant API for representing these entries is modeshape-schematics (see, e.g., org.infinispan.schematic.SchematicEntry)
- File .sst stores these entries when the .log file reaches a size threshold. A new log file is generated.
- File MANIFEST.x records info about .sst files.
- File CURRENT specifies the current MANIFEST file.
Most of these files are binary and can be read by a LevelDB Java library.