Package org.nuxeo.ecm.core.blob

Interface BlobStore

All Known Implementing Classes:
AbstractBlobStore, AESBlobStore, AzureBlobStore, CachingBlobStore, EmptyBlobStore, GoogleStorageBlobStore, GridFSBlobStore, InMemoryBlobStore, LocalBlobStore, S3BlobStore, TransactionalBlobStore
public interface BlobStore
Interface for basic access to storage of a Blob (read/write/copy/delete).

A blob is identified by a key, and holds a stream of bytes. It may have some associated metadata (filename, content type).

A blob store may have versioning. When this is the case, the write method will return a key that includes a version number. This same complete key must subsequently be provided to the read or delete methods. With versioning, two writes may be requested with the same key in the blob context, and both will succeed because they return keys that include a version number to distinguish them.

Since:
11.1

  • Method Details

    • getName

      String getName()
      Name used for debugging / tracing.

    • hasVersioning

      boolean hasVersioning()
      Whether this blob store has versioning.

      With versioning, two writes may use the same key. The returned keys will include a different version number to distinguish the writes.

    • getKeyStrategy

      KeyStrategy getKeyStrategy()
      Gets the key strategy used by the store.

    • writeBlob

      String writeBlob(BlobContext blobContext) throws IOException
      Writes a blob.
      Parameters:
      blobContext - the blob context
      Returns:
      the blob key
      Throws:
      IOException

    • writeBlob

      String writeBlob(BlobWriteContext blobWriteContext) throws IOException
      Writes a blob.

      Note that the returned key may be different than the one requested by the BlobWriteContext, if the blob store needs additional version info to retrieve it.

      Parameters:
      blobWriteContext - the context of the blob write, including the blob
      Returns:
      the key to use to read this blob in the future
      Throws:
      IOException

    • copyBlobIsOptimized

      boolean copyBlobIsOptimized(BlobStore sourceStore)
      Checks if blob copy/move from another blob store to this one can be done efficiently.
      Parameters:
      sourceStore - the source store
      Returns:
      true if the copy/move can be done efficiently

    • copyBlob

      @Deprecated default boolean copyBlob(String key, BlobStore sourceStore, String sourceKey, boolean atomicMove) throws IOException
      Deprecated.
      since 11.5, use copyOrMoveBlob(java.lang.String, org.nuxeo.ecm.core.blob.BlobStore, java.lang.String, boolean) instead
      Writes a file based on a key, as a copy/move from a source in another blob store.

      If the copy/move is requested to be atomic, then the destination file is created atomically. In case of atomic move, in some stores the destination will be created atomically but the source will only be deleted afterwards.

      Parameters:
      key - the key
      sourceStore - the source store
      sourceKey - the source key
      atomicMove - true for an atomic move, false for a regular copy
      Returns:
      true if the file was found in the source store, false if it was not found
      Throws:
      IOException

    • copyOrMoveBlob

      String copyOrMoveBlob(String key, BlobStore sourceStore, String sourceKey, boolean atomicMove) throws IOException
      Writes a file based on a key, as an optimized copy/move from a source in another compatible blob store.

      The target key may be null, which is a signal from the caller that it has determined that deduplication is enabled and async digest computation is enabled, but the needed digest hasn't been computed, so this method should either find the digest in an efficient way if it can, or otherwise trigger an async digest computation.

      If the copy/move is requested to be atomic, then the destination file is created atomically. In case of atomic move, in some stores the destination will be created atomically but the source will only be deleted afterwards.

      The returned key may be different than the passed one when versioning is used.

      Parameters:
      key - the key; or null if the store should choose it or trigger async digest computation
      sourceStore - the source store
      sourceKey - the source key
      atomicMove - true for an atomic move, false for a regular copy
      Returns:
      the key of the copied/moved file, or null if copy/move failed
      Throws:
      IOException
      Since:
      11.5

    • getFile

      @NotNull BlobStore.OptionalOrUnknown<Path> getFile(String key)
      Gets an already-existing file containing the blob for the given key, if present.

      Note that this method is best-effort, it may return unknown even though the blob exists in the store, it's just that it's not handily available locally in a file.

      Parameters:
      key - the blob key
      Returns:
      the file containing the blob, or empty if the blob cannot be found, or unknown if no file is available locally

    • getStream

      @NotNull BlobStore.OptionalOrUnknown<InputStream> getStream(String key) throws IOException
      Gets the stream of the blob for the given key, if present.

      Note that this method is best-effort, it may return unknown even though the blob exists in the store, it's just that it's not efficient to return it as a stream.

      Parameters:
      key - the blob key
      Returns:
      the blob stream, or empty if the blob cannot be found, or unknown if no stream is efficiently available
      Throws:
      IOException

    • readBlob

      boolean readBlob(String key, Path dest) throws IOException
      Reads a blob based on its key into the given file.
      Parameters:
      key - the blob key
      dest - the file to use to store the fetched data
      Returns:
      true if the file was fetched, false if the file was not found
      Throws:
      IOException

    • writeBlobProperties

      void writeBlobProperties(BlobUpdateContext blobUpdateContext) throws IOException
      Sets properties on a blob.
      Parameters:
      blobUpdateContext - the blob update context
      Throws:
      IOException

    • deleteBlob

      void deleteBlob(BlobContext blobContext)
      Deletes a blob.
      Parameters:
      blobContext - the blob context

    • deleteBlob

      void deleteBlob(String key)
      Deletes a blob based on a key. No error occurs if the blob does not exist.

      This method does not throw IOException, but may log an error message.

      Parameters:
      key - the blob key

    • exists

      default boolean exists(String key)
      Does a blob with the given key exist in the blob store.

      The existence of the blob is checked in the store where the blob is effectively stored. Intermediate cache is ignored.

      Parameters:
      key - the blob key
      Returns:
      true if it exists in the blob store
      Since:
      2023

    • hasDefaultStorageClass

      default boolean hasDefaultStorageClass(String key)
      Does a blob with the given key exist in the blob store with the default storage class.

      The existence of the blob is checked in the store where the blob is effectively stored. Intermediate cache is ignored. A blob with a cold storage storage class is not in default storage class and this method will return false for such a blob.

      Parameters:
      key - the blob key
      Returns:
      true if it exists in the blob store and has the default storage class
      Since:
      2023.5

    • getBinaryGarbageCollector

      BinaryGarbageCollector getBinaryGarbageCollector()
      Returns the binary garbage collector (GC).

      Several calls to this method will return the same GC, so that its status can be monitored using BinaryGarbageCollector.isInProgress().

      Returns:
      the binary GC

    • unwrap

      BlobStore unwrap()
      If this blob store wraps another one, returns it, otherwise returns this.
      Returns:
      the lowest-level blob store

    • clear

      void clear()
      INTERNAL (TESTS). Clears the blob store of all its data.
      Since:
      11.5