QLDB / Client / get_revision

get_revision

QLDB.Client.get_revision(**kwargs)

Returns a revision data object for a specified document ID and block address. Also returns a proof of the specified revision for verification if DigestTipAddress is provided.

See also: AWS API Documentation

Request Syntax

response = client.get_revision(
    Name='string',
    BlockAddress={
        'IonText': 'string'
    },
    DocumentId='string',
    DigestTipAddress={
        'IonText': 'string'
    }
)

Parameters:

• Name (string) –

  [REQUIRED]

  The name of the ledger.

• BlockAddress (dict) –

  [REQUIRED]

  The block location of the document revision to be verified. An address is an Amazon Ion structure that has two fields: strandId and sequenceNo .

  For example: {strandId:"BlFTjlSXze9BIh1KOszcE3",sequenceNo:14} .

  • IonText (string) –

    An Amazon Ion plaintext value contained in a ValueHolder structure.

• DocumentId (string) –

  [REQUIRED]

  The UUID (represented in Base62-encoded text) of the document to be verified.

• DigestTipAddress (dict) –

  The latest block location covered by the digest for which to request a proof. An address is an Amazon Ion structure that has two fields: strandId and sequenceNo .

  For example: {strandId:"BlFTjlSXze9BIh1KOszcE3",sequenceNo:49} .

  • IonText (string) –

    An Amazon Ion plaintext value contained in a ValueHolder structure.

Return type:

dict

Returns:

Response Syntax

{
    'Proof': {
        'IonText': 'string'
    },
    'Revision': {
        'IonText': 'string'
    }
}

Response Structure

• (dict) –

  • Proof (dict) –

    The proof object in Amazon Ion format returned by a GetRevision request. A proof contains the list of hash values that are required to recalculate the specified digest using a Merkle tree, starting with the specified document revision.

    • IonText (string) –

      An Amazon Ion plaintext value contained in a ValueHolder structure.

  • Revision (dict) –

    The document revision data object in Amazon Ion format.

    • IonText (string) –

      An Amazon Ion plaintext value contained in a ValueHolder structure.

Exceptions

• QLDB.Client.exceptions.InvalidParameterException

• QLDB.Client.exceptions.ResourceNotFoundException

• QLDB.Client.exceptions.ResourcePreconditionNotMetException