[Need Help] How to access a structure array, returned from C as pointer?

[engrvivs-neosoft]

Hi

Through list_buckets() C function, I am retrieving a C structure, BucketList, through ref-struct, defined as follows:

const BucketList = struct({
    more  : ref.types.bool,
    items : ref.refType(BucketInfo),
    length: "int32"
});

Here, I mainly need to access the "array" of BucketInfo, which I have declared as follows:

const BucketInfo = struct({
    name                 : ref.refType(ref.types.CString),
    created              : "int64",
    path_cipher          : "uint32",
    segment_size         : "uint64",
    encryption_parameters: EncryptionParameters,
    redundancy_scheme    : RedundancyScheme
});

const EncryptionParameters = struct({
    cipher_suite: "uint32",
    block_size  : "int32"
});

const RedundancyScheme = struct({
    algorithm      : "uint32",
    share_size     : "int32",
    required_shares: "int16",
    repair_shares  : "int16",
    optimal_shares : "int16",
    total_shares   : "int16"
});

Although, I am able to access the first bucket's information, through BucketList.items. But, I am not able to "point" to the next bucket's information.

May someone hint, as to how I may access the next information?

Thank in Advance Vivs

[pierre-arlaud]

@engrvivs-neosoft have you managed to do this in the end? I tried using readPointer and get with an offset to get the next element but this results in "Buffer instance must be at least 32 bytes to back this struct type"

[pierre-arlaud]

Oh I have finally found it. It was difficult because the full api doc of ref is missing but for anyone who falls onto this:

The buffer is allocated for only one structure by default (as it is a pointer) so you need to use the reinterpret function:

    // const structType = new StructType({…});
    const myStructType = ref.refType(structType);
    const result = myLibraryStruct.reinterpret(n * myStructType.size); // with n being the number of elements in the array
    let el = ref.get(result, i * myStructType.size, structType); // retrieves the element in the array at rank i