org.icatproject.ids.plugin

Interface MainStorageInterface

All Known Implementing Classes:

MainStorageReadOnly, MainStorageWithoutArchive, MainStorageWithoutArchiveReadOnly

public interface MainStorageInterface

An IDS interface which for which an implementation must be provided for any IDS deployment.

Method Summary

Modifier and Type	Method and Description
void	delete(DsInfo dsInfo) Deletes the files of the specified data set.
void	delete(String location, String createId, String modId) Deletes the specified file A dummy may be provided if the readOnly flag is set and no archive storage has been configured with storageUnit = DATAFILE
boolean	exists(DsInfo dsInfo) See if the data set exists.
boolean	exists(String location) See if the data file exists.
InputStream	get(String location, String createId, String modId) Return a stream of data from the specified data file
List<DfInfo>	getDatafilesToArchive(long lowArchivingLevel, long highArchivingLevel) Return the list of DfInfos which should be archived to reduce the used storage to between lowArchivingLevel and highArchivingLevel.
List<DsInfo>	getDatasetsToArchive(long lowArchivingLevel, long highArchivingLevel) Return the list of DsInfos which should be archived to reduce the used storage to between lowArchivingLevel and highArchivingLevel.
Path	getPath(String location, String createId, String modId) Return the physical path corresponding to a location for a datafile.
String	put(DsInfo dsInfo, String name, InputStream inputStream) Store the specified data file and return the chosen location of the file to allow it to be retrieved.
void	put(InputStream inputStream, String location) Store the data file at the specified location.

Method Detail

delete

void delete(DsInfo dsInfo)
     throws IOException

Deletes the files of the specified data set. A dummy implementation can be provided if no archive storage is configured with storageUnit = DATASET

Parameters:

dsInfo - describes the data set with the files to be deleted

Throws:

IOException - to indicate failure

delete

void delete(String location,
            String createId,
            String modId)
     throws IOException

Deletes the specified file A dummy may be provided if the readOnly flag is set and no archive storage has been configured with storageUnit = DATAFILE

Parameters:

location - location of the data file to be deleted

createId - the icat user name of the creator of this datafile. This is provided so that the implementation can choose whether or not to trust the ICAT datafile object which holds this location field.

modId - the icat user name of the modifier of this datafile. This is provided so that the implementation can choose whether or not to trust the ICAT datafile object which holds this location field.

Throws:

IOException - to indicate failure

exists

boolean exists(DsInfo dsInfo)
        throws IOException

See if the data set exists. A dummy implementation can be provided if no archive storage is configured with storageUnit set to dataset

Parameters:

dsInfo - describes the data set being queried

Returns:

true if the data set exists

Throws:

IOException - to indicate failure

exists

boolean exists(String location)
        throws IOException

See if the data file exists. A dummy may be provided if the readOnly flag is set and no archive storage has been configured with storageUnit = DATAFILE

Parameters:

location - the value from datafile.location

Returns:

true if the data file exists

Throws:

IOException - to indicate failure

get

InputStream get(String location,
                String createId,
                String modId)
         throws IOException

Return a stream of data from the specified data file

Parameters:

location - the value from datafile.location

createId - the icat user name of the creator of this datafile. This is provided so that the implementation can choose whether or not to trust the ICAT datafile object which holds this location field.

modId - the icat user name of the modifier of this datafile. This is provided so that the implementation can choose whether or not to trust the ICAT datafile object which holds this location field.

Returns:

input stream of data

Throws:

IOException - to indicate failure

getDatafilesToArchive

List<DfInfo> getDatafilesToArchive(long lowArchivingLevel,
                                   long highArchivingLevel)
                            throws IOException

Return the list of DfInfos which should be archived to reduce the used storage to between lowArchivingLevel and highArchivingLevel. A dummy implementation can be provided if no archive storage is configured with storageUnit set to datafile The implementaion is free to do this however it chooses. Use might be made of the information available from the java.nio.file.FileStore (obtainable by Files.getFileStore(path) for any file to see whether or not any action is required. For each DfInfo returned the IDS will find all datafiles which match all the fields that are not null in the DfInfo.

Parameters:

lowArchivingLevel - don't try to reduce space below this level

highArchivingLevel - if storage used is less than this return an empty list. Otherwise identify the list of DsInfos to get the space down to lowArchivingLevel

Returns:

list of DfInfos

Throws:

IOException - to indicate failure

getDatasetsToArchive

List<DsInfo> getDatasetsToArchive(long lowArchivingLevel,
                                  long highArchivingLevel)
                           throws IOException

Return the list of DsInfos which should be archived to reduce the used storage to between lowArchivingLevel and highArchivingLevel. A dummy implementation can be provided if no archive storage is configured with storageUnit set to dataset The implementaion is free to do this however it chooses. Use might be made of the information available from the java.nio.file.FileStore (obtainable by Files.getFileStore(path) for any file to see whether or not any action is required. For each DsInfo returned the IDS will find all datasets which match all the fields that are not null in the DsInfo.

Parameters:

lowArchivingLevel - don't try to reduce space below this level

highArchivingLevel - if storage used is less than this return an empty list. Otherwise identify the list of DsInfos to get the space down to lowArchivingLevel

Returns:

list of DsInfos

Throws:

IOException - to indicate failure

getPath

Path getPath(String location,
             String createId,
             String modId)
      throws IOException

Return the physical path corresponding to a location for a datafile. This is only useful if the file system is available to the user. In this case all files on the file system should only be readable by the user running the ids server. If the file system is not available to the user a dummy implementation may be provided.

Parameters:

location - the value from datafile.location

createId - the icat user name of the creator of this datafile. This is provided so that the implementation can choose whether or not to trust the ICAT datafile object which holds this location field.

modId - the icat user name of the modifier of this datafile. This is provided so that the implementation can choose whether or not to trust the ICAT datafile object which holds this location field.

Returns:

physical path

Throws:

IOException - to indicate failure

put

String put(DsInfo dsInfo,
           String name,
           InputStream inputStream)
    throws IOException

Store the specified data file and return the chosen location of the file to allow it to be retrieved.

Parameters:

dsInfo - describes the data set to which the data file should be added

name - name of file within data set

inputStream - stream of data to store

Returns:

the location of the stored data file

Throws:

IOException - to indicate failure

put

void put(InputStream inputStream,
         String location)
  throws IOException

Store the data file at the specified location. If no archive storage is in use a dummy may be provided.

Parameters:

inputStream - stream of data to store

location - where to store the file

Throws:

IOException - to indicate failure