Multiple contract or single contract for record keeping

Question

I have to store the file hash of all the files stored on our server. Can I use single contract with fields like:

contract FileDetail {
    string fileName;
    string fileHash;

.................
}

Whenever I will call set method will it overwrite the field values of fileName and fileHash or it will create new values/copies of fileName or fileHash ? Or do I need to use a list/map if I use single contract approach.

Is it feasible to create new contract for each file. ? Can creation of a contract get automated ?

Answer 1

Just to add to Shawn's answer, here's a bit more complete example:

pragma solidity ^0.4.24;

contract Test {
    struct File {
        string fileName;
        string fileHash;
    }

    File[] files;

    function addFile(string fileName, string fileHash) public {
        File memory f = File(fileName, fileHash);
        files.push(f);
    }

    // a test function for getting data at certain index
    function getFiles(uint256 index) public view returns (string, string) {
        return (files[index].fileName, files[index].fileHash);
    }
}

Answer 2

It is possible to automate contract creation, however, it is not likely that creating a new contract for every file would be correct here. It would be extremely expensive and likely not very scalable or manageable.

It seems like you want to use a struct here to define a File object which contains the properties fileName and fileHash. And then you would make an array or mapping of these objects so that you can manage and track multiple files.

struct File
{
    string fileName;
    string fileHash;
}

File[] files;
files.push(File(fileName, fileHash));