mybuffer.cpp

#include <string>
#include <string.h>
#include "datatype.h"
//#include "BufferManager.h"
using namespace std;

blockInfo *get_new_block(const std::string& table_name, int fileType, int blockNum);
blockInfo *readBlock(const std::string& table_name, int fileType, int blockNum);

blockInfo *get_my_file_block(const std::string& database, const std::string& table_name, int fileType, int blockNum) {
    blockInfo *node = readBlock(table_name, blockNum, fileType );
    if (node == NULL) {
        node = get_new_block(table_name, fileType, blockNum);
        memset(node->cBlock, 0, 4096);
        node->charNum = 0;
        return node;
    }
    int i = -1;
    while (node->cBlock[++i] != '\0');
    node->charNum = i;
    return node;
}

// blockNum == 0 --> search from beginning
// else search after the blockNum
blockInfo *get_my_new_block(const std::string& database, const std::string& table_name, int blockNum) {
    blockInfo *node;
    while (node = readBlock(table_name, ++blockNum, IndexFile)) {
        if (node->cBlock[0] == '\0')
            break;
    }
    if (node == NULL)
        node = get_new_block(table_name, IndexFile, blockNum);
    node->charNum = 0;
    memset(node->cBlock, 0, 4096);
    return node;
}