Methods and devices for data traversal

1. A computer-implemented method for data traversal, the method comprising:

parsing a smart contract provided for execution on a blockchain to obtain one or more key-value pairs specified in the smart contract; and

facilitating traversal of the one or more key-value pairs obtained from the smart contract, wherein the facilitating comprises:

indexing one or more original keys specified in the one or more key-value pairs obtained from the smart contract to generate an index, the index associating the one or more original keys specified in the one or more key-value pairs obtained from the smart contract with an identifier of the smart contract to enable retrieval of the one or more original keys specified in the one or more key-value pairs obtained from the smart contract using the identifier of the smart contract;

recording one or more characteristics of the index on the blockchain, the one or more characteristics of the index comprise a hash value of the index; and

retrieving at least one value specified in the one or more key-value pairs based on the index.

2. The method of claim 1 , further comprising:

recording the index locally on a computer implementing the method.

3. The method of claim 1 , wherein the identifier of the smart contract comprises an address assigned to the smart contract when the smart contract is incorporated into the blockchain.

4. The method of claim 1 , wherein the one or more characteristics of the index comprise a number of data records recorded in the index.

5. The method of claim 1 , further comprising:

determining whether a plurality of nodes maintaining the blockchain are in an agreement with respect to the one or more characteristics of the index.

6. The method of claim 5 , further comprising:

in response to a determination that the plurality of nodes are not in an agreement with respect to the one or more characteristics of the index, updating the index.

7. The method of claim 1 , wherein the index associates an original key specified in each of the one or more key-value pairs with the identifier of the smart contract.

8. The method of claim 7 , further comprising:

receiving a traversal request, the traversal request including information corresponding to the identifier of the smart contract; and

retrieving, from the index, a key list containing the one or more original keys specified in the one or more key-value pairs based on the traversal request.

9. The method of claim 8 , further comprising:

retrieving a value corresponding to each key contained in the key list.

10. The method of claim 1 , wherein the one or more key-value pairs include a group of key-value pairs as corresponding to a map, and the index associates an original key specified in each key-value pair in the group of key-value pairs with the identifier of the smart contract and an identifier of the map.

11. The method of claim 10 , further comprising:

receiving a traversal request, the traversal request including information corresponding to the identifier of the smart contract and the identifier of the map; and

retrieving, from the index, a key list containing the original key specified in each key-value pair in the group of key value pairs based on the traversal request.

12. A device for data traversal, comprising:

one or more processors; and

one or more computer-readable memories coupled to the one or more processors and having instructions stored thereon that are executable by the one or more processors, wherein the one or more processors are configured to:

parse a smart contract provided for execution on a blockchain to obtain one or more key-value pairs specified in the smart contract; and

facilitate traversal of the one or more key-value pairs obtained from the smart contract, wherein in facilitating the traversal, the one or more processors are further configured to:

index one or more original keys specified in the one or more key-value pairs obtained from the smart contract to generate an index, the index associating the one or more original keys specified in the one or more key-value pairs obtained from the smart contract with an identifier of the smart contract to enable retrieval of the one or more original keys specified in the one or more key-value pairs obtained from the smart contract using the identifier of the smart contract;

record one or more characteristics of the index on the blockchain, the one or more characteristics of the index comprise a hash value of the index; and

retrieve at least one value specified in the one or more key-value pairs based on the index.

13. The device of claim 12 , wherein the one or more processors are further configured to:

record the index locally on the device.

14. The device of claim 12 , wherein the identifier of the smart contract comprises an address assigned to the smart contract when the smart contract is incorporated into the blockchain.

15. A non-transitory computer-readable medium having stored therein instructions that, when executed by a processor of a device, cause the device to perform a method for data traversal, the method comprising:

parsing a smart contract provided for execution on a blockchain to obtain one or more key-value pairs specified in the smart contract; and

facilitating traversal of the one or more key-value pairs obtained from the smart contract, wherein the facilitating comprises:

indexing one or more original keys specified in the one or more key-value pairs obtained from the smart contract to generate an index, the index associating the one or more original keys specified in the one or more key-value pairs obtained from the smart contract with an identifier of the smart contract to enable retrieval of the one or more original keys specified in the one or more key-value pairs obtained from the smart contract using the identifier of the smart contract;

recording one or more characteristics of the index on the blockchain, the one or more characteristics of the index comprise a hash value of the index; and

retrieving at least one value specified in the one or more key-value pairs based on the index.