Trait spacetimedb_table::blob_store::BlobStore

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pub trait BlobStore: Sync {
    // Required methods
    fn clone_blob(&mut self, hash: &BlobHash) -> Result<(), NoSuchBlobError>;
    fn insert_blob(&mut self, bytes: &[u8]) -> BlobHash;
    fn insert_with_uses(
        &mut self,
        hash: &BlobHash,
        uses: usize,
        bytes: Box<[u8]>,
    );
    fn retrieve_blob(&self, hash: &BlobHash) -> Result<&[u8], NoSuchBlobError>;
    fn free_blob(&mut self, hash: &BlobHash) -> Result<(), NoSuchBlobError>;
    fn iter_blobs(&self) -> BlobsIter<'_>;
}
Expand description

The interface that tables use to talk to the blob store engine for large var-len objects.

These blob objects are referred to by their BlobHash, which is currently defined through BLAKE3 on the bytes of the blob object.

Required Methods§

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fn clone_blob(&mut self, hash: &BlobHash) -> Result<(), NoSuchBlobError>

Mark the hash as used.

This is a more efficient way of doing:

ⓘ
let bytes = self.retrieve_blob(&hash);
let _ = self.insert_blob(&bytes);
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fn insert_blob(&mut self, bytes: &[u8]) -> BlobHash

Insert bytes into the blob store.

Returns the content address of bytes a BlobHash which can be used in [retrieve_blob] to fetch it.

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fn insert_with_uses(&mut self, hash: &BlobHash, uses: usize, bytes: Box<[u8]>)

Insert hash referring to bytes and mark its refcount as uses.

Used when restoring from a snapshot.

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fn retrieve_blob(&self, hash: &BlobHash) -> Result<&[u8], NoSuchBlobError>

Returns the bytes stored at the content address hash.

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fn free_blob(&mut self, hash: &BlobHash) -> Result<(), NoSuchBlobError>

Marks the hash as unused.

Depending on the strategy employed by the blob store, this might not actually free the data, but rather just decrement a reference count.

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fn iter_blobs(&self) -> BlobsIter<'_>

Iterate over all blobs present in the blob store.

Each element is a tuple (hash, uses, data), where hash is a blob’s content-addressed BlobHash, uses is the number of references to that blob, and data is the data itself.

Used when capturing a snapshot.

Implementors§