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
boolean	blobExists(java.lang.String blobName)	Tests whether a blob with the given blob name exists in the container.
void	deleteBlob(java.lang.String blobName)	Deletes a blob with giving name, if the blob exists.
default void	deleteBlobIgnoringIfNotExists(java.lang.String blobName)	Deletes a blob with giving name, ignoring if the blob does not exist.
java.util.Map<java.lang.String,BlobMetaData>	listBlobs()	Lists all blobs in the container.
java.util.Map<java.lang.String,BlobMetaData>	listBlobsByPrefix(java.lang.String blobNamePrefix)	Lists all blobs in the container that match the specified prefix.
void	move(java.lang.String sourceBlobName, java.lang.String targetBlobName)	Renames the source blob into the target blob.
BlobPath	path()	Gets the BlobPath that defines the implementation specific paths to where the blobs are contained.
java.io.InputStream	readBlob(java.lang.String blobName)	Creates a new InputStream for the given blob name.
void	writeBlob(java.lang.String blobName, java.io.InputStream inputStream, long blobSize)	Reads blob content from the input stream and writes it to the container in a new blob with the given name.

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

blobExists

boolean blobExists(java.lang.String blobName)

Tests whether a blob with the given blob name exists in the container.

Parameters:

blobName - The name of the blob whose existence is to be determined.

Returns:

true if a blob exists in the BlobContainer with the given name, and false otherwise.

readBlob

java.io.InputStream readBlob(java.lang.String blobName)
                      throws java.io.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:

java.nio.file.NoSuchFileException - if the blob does not exist

java.io.IOException - if the blob can not be read.

writeBlob

void writeBlob(java.lang.String blobName,
               java.io.InputStream inputStream,
               long blobSize)
        throws java.io.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.

Throws:

java.nio.file.FileAlreadyExistsException - if a blob by the same name already exists

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

deleteBlob

void deleteBlob(java.lang.String blobName)
         throws java.io.IOException

Deletes a blob with giving name, if the blob exists. If the blob does not exist, this method throws a NoSuchFileException.

Parameters:

blobName - The name of the blob to delete.

Throws:

java.nio.file.NoSuchFileException - if the blob does not exist

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

deleteBlobIgnoringIfNotExists

default void deleteBlobIgnoringIfNotExists(java.lang.String blobName)
                                    throws java.io.IOException

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

Parameters:

blobName - The name of the blob to delete.

Throws:

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

listBlobs

java.util.Map<java.lang.String,BlobMetaData> listBlobs()
                                                throws java.io.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:

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

listBlobsByPrefix

java.util.Map<java.lang.String,BlobMetaData> listBlobsByPrefix(java.lang.String blobNamePrefix)
                                                        throws java.io.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:

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

move

void move(java.lang.String sourceBlobName,
          java.lang.String targetBlobName)
   throws java.io.IOException

Renames the source blob into the target blob. If the source blob does not exist or the target blob already exists, an exception is thrown. Atomicity of the move operation can only be guaranteed on an implementation-by-implementation basis. The only current implementation of BlobContainer for which atomicity can be guaranteed is the FsBlobContainer.

Parameters:

sourceBlobName - The blob to rename.

targetBlobName - The name of the blob after the renaming.

Throws:

java.io.IOException - if the source blob does not exist, the target blob already exists, or there were any failures in reading from the blob container.