update.cpp

//
// Created by Yuchen Zhang on 2/22/23.
//

#include "library.h"
bool update(RecordID* recordId, Heapfile *heapfile, int attribute_id, char* newValue){
    Record record;
    Page* page = new Page;
    init_fixed_len_page(page, heapfile->page_size, SLOT_SIZE);
    if(recordId->page_id > maxPid(heapfile)){
        return false;
    }
    read_page(heapfile, recordId->page_id, page);
    if(recordId->slot > fixed_len_page_capacity(page)){
        return false;
    }
    read_fixed_len_page(page, recordId->slot, &record);

    if(attribute_id >= record.size()){
        return false;
    }
    record[attribute_id] = newValue;

    write_fixed_len_page(page, recordId->slot, &record);

    write_page(page, heapfile, recordId->page_id);

    return true;
}

//<heapfile> <record_id> <attribute_id> <new_value> <page_size>
int main(int argc, char* argv[]){
    auto startTime = system_clock::now();
    FILE* heapFile = fopen(argv[1], "r+");
    string record_id = argv[2];
    auto* recordId = new RecordID;
    for(int i = 0; i < record_id.size(); ++i){
        if(record_id[i] == '-'){
            recordId->page_id = stoi(record_id.substr(0, i+1));
            recordId->slot = stoi(record_id.substr(i+1, record_id.size()-i-1));
        }
    }
    int attribute_id = atoi(argv[3]);
    char* newValue = new char[ATTRIBUTE_SIZE];
    newValue = argv[4];
    int page_size = atoi(argv[5]);

    // Initialize heapfile
    auto* heapfile = new Heapfile;
    init_heapfile(heapfile, page_size, heapFile);

    if(!update(recordId, heapfile, attribute_id, newValue)){
        cerr << "ERROR";
    }
    auto endTime = system_clock::now();
    auto duration = duration_cast<microseconds>(endTime - startTime);
    std::cout << "TIME: " << double(duration.count()) * microseconds::period::num / microseconds::period::den << "s" << endl;

}