Package org.elasticsearch.common.blobstore

Interface BlobContainer

All Known Implementing Classes:

AbstractBlobContainer, FsBlobContainer

public interface BlobContainer

An interface for managing a repository of blob entries, where each blob entry is just a named group of bytes.

Method Summary

Modifier and Type	Method	Description
Map<String,BlobContainer>	children()	Lists all child containers under this container.
DeleteResult	delete()	Deletes this container and all its contents from the repository.
void	deleteBlob(String blobName)	Deletes the blob with the given name, if the blob exists.
default void	deleteBlobIgnoringIfNotExists(String blobName)	Deletes a blob with giving name, ignoring if the blob does not exist.
default void	deleteBlobsIgnoringIfNotExists(List<String> blobNames)	Deletes the blobs with given names.
Map<String,BlobMetaData>	listBlobs()	Lists all blobs in the container.
Map<String,BlobMetaData>	listBlobsByPrefix(String blobNamePrefix)	Lists all blobs in the container that match the specified prefix.
BlobPath	path()	Gets the BlobPath that defines the implementation specific paths to where the blobs are contained.
InputStream	readBlob(String blobName)	Creates a new InputStream for the given blob name.
void	writeBlob(String blobName, InputStream inputStream, long blobSize, boolean failIfAlreadyExists)	Reads blob content from the input stream and writes it to the container in a new blob with the given name.
void	writeBlobAtomic(String blobName, InputStream inputStream, long blobSize, boolean failIfAlreadyExists)	Reads blob content from the input stream and writes it to the container in a new blob with the given name, using an atomic write operation if the implementation supports it.

Method Detail

path

BlobPath path()

Gets the BlobPath that defines the implementation specific paths to where the blobs are contained.

Returns:

the BlobPath where the blobs are contained

readBlob

InputStream readBlob(String blobName)
              throws IOException

Creates a new InputStream for the given blob name.

Parameters:

blobName - The name of the blob to get an InputStream for.

Returns:

The InputStream to read the blob.

Throws:

NoSuchFileException - if the blob does not exist

IOException - if the blob can not be read.

writeBlob

void writeBlob(String blobName,
               InputStream inputStream,
               long blobSize,
               boolean failIfAlreadyExists)
        throws IOException

Reads blob content from the input stream and writes it to the container in a new blob with the given name. This method assumes the container does not already contain a blob of the same blobName. If a blob by the same name already exists, the operation will fail and an IOException will be thrown.

Parameters:

blobName - The name of the blob to write the contents of the input stream to.

inputStream - The input stream from which to retrieve the bytes to write to the blob.

blobSize - The size of the blob to be written, in bytes. It is implementation dependent whether this value is used in writing the blob to the repository.

failIfAlreadyExists - whether to throw a FileAlreadyExistsException if the given blob already exists

Throws:

FileAlreadyExistsException - if failIfAlreadyExists is true and a blob by the same name already exists

IOException - if the input stream could not be read, or the target blob could not be written to.

writeBlobAtomic

void writeBlobAtomic(String blobName,
                     InputStream inputStream,
                     long blobSize,
                     boolean failIfAlreadyExists)
              throws IOException

Reads blob content from the input stream and writes it to the container in a new blob with the given name, using an atomic write operation if the implementation supports it. This method assumes the container does not already contain a blob of the same blobName. If a blob by the same name already exists, the operation will fail and an IOException will be thrown.

Parameters:

blobName - The name of the blob to write the contents of the input stream to.

inputStream - The input stream from which to retrieve the bytes to write to the blob.

blobSize - The size of the blob to be written, in bytes. It is implementation dependent whether this value is used in writing the blob to the repository.

failIfAlreadyExists - whether to throw a FileAlreadyExistsException if the given blob already exists

Throws:

FileAlreadyExistsException - if failIfAlreadyExists is true and a blob by the same name already exists

IOException - if the input stream could not be read, or the target blob could not be written to.

deleteBlob

void deleteBlob(String blobName)
         throws IOException

Deletes the blob with the given name, if the blob exists. If the blob does not exist, this method may throw a NoSuchFileException if the underlying implementation supports an existence check before delete.

Parameters:

blobName - The name of the blob to delete.

Throws:

NoSuchFileException - if the blob does not exist

IOException - if the blob exists but could not be deleted.

delete

DeleteResult delete()
             throws IOException

Deletes this container and all its contents from the repository.

Returns:

delete result

Throws:

IOException - on failure

deleteBlobsIgnoringIfNotExists

default void deleteBlobsIgnoringIfNotExists(List<String> blobNames)
                                     throws IOException

Deletes the blobs with given names. Unlike deleteBlob(String) this method will not throw an exception when one or multiple of the given blobs don't exist and simply ignore this case.

Parameters:

blobNames - The names of the blob to delete.

Throws:

IOException - if a subset of blob exists but could not be deleted.

deleteBlobIgnoringIfNotExists

default void deleteBlobIgnoringIfNotExists(String blobName)
                                    throws IOException

Deletes a blob with giving name, ignoring if the blob does not exist.

Parameters:

blobName - The name of the blob to delete.

Throws:

IOException - if the blob exists but could not be deleted.

listBlobs

Map<String,BlobMetaData> listBlobs()
                                  throws IOException

Lists all blobs in the container.

Returns:

A map of all the blobs in the container. The keys in the map are the names of the blobs and the values are BlobMetaData, containing basic information about each blob.

Throws:

IOException - if there were any failures in reading from the blob container.

children

Map<String,BlobContainer> children()
                                  throws IOException

Lists all child containers under this container. A child container is defined as a container whose path() method returns a path that has this containers path() return as its prefix and has one more path element than the current container's path.

Returns:

Map of name of the child container to child container

Throws:

IOException - on failure to list child containers

listBlobsByPrefix

Map<String,BlobMetaData> listBlobsByPrefix(String blobNamePrefix)
                                          throws IOException

Lists all blobs in the container that match the specified prefix.

Parameters:

blobNamePrefix - The prefix to match against blob names in the container.

Returns:

A map of the matching blobs in the container. The keys in the map are the names of the blobs and the values are BlobMetaData, containing basic information about each blob.

Throws:

IOException - if there were any failures in reading from the blob container.