buffer_test.md

#Buffer test set buffer size= 3 blocks ##text1:write_data

insert five blocks continously with 4 different address. the input list is [8,9,10.8,11].

address.database_name="zyh";
address.file_name="friend";
address.file_offset=8;
Buffer buffer;
unsigned char newdata[BLOCK_SIZE];
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='s';
}
Block newblock1(newdata);
buffer.write_data(address,&newblock1);
address.database_name="zyh";
address.file_name="friend";
address.file_offset=9;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='s';
}
Block newblock2(newdata);
buffer.write_data(address,&newblock2);
address.database_name="zyh";
address.file_name="friend";
address.file_offset=10;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='s';
}
Block newblock3(newdata);
buffer.write_data(address,&newblock3);
address.database_name="zyh";
address.file_name="friend";
address.file_offset=8;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='s';
}
Block newblock4(newdata);
buffer.write_data(address,&newblock4);
address.database_name="zyh";
address.file_name="friend";
address.file_offset=11;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='s';
}
Block newblock5(newdata);
buffer.write_data(address,&newblock1);
address.database_name="zyh";
address.file_name="friend";
address.file_offset=11;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='s';
}
buffer.write_data(address,&newblock3);

###test result ####the change of buffer list 8 8,9 8,9 8,9,10 9,10,8 10,8,11 ##test2:read and write test read and write together and check whether the data is write back to the disk.

Block* data=new Block();
Address address;
address.database_name="zyh";
address.file_name="friend";
address.file_offset=8;
Buffer buffer;
unsigned char newdata[BLOCK_SIZE];
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='e';
}
Block newblock1(newdata);
buffer.write_data(address,&newblock1);
address.database_name="zyh";
address.file_name="friend";
address.file_offset=9;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='9';
}
Block newblock2(newdata);
buffer.write_data(address,&newblock2);
address.database_name="zyh";
address.file_name="friend";
address.file_offset=10;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='X';
}
Block newblock3(newdata);
buffer.write_data(address,&newblock3);
address.database_name="zyh";
address.file_name="friend";
address.file_offset=8;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='8';
}
Block newblock4(newdata);
buffer.write_data(address,&newblock4);
Block readblock;
buffer.read_data(address,&readblock);
std::cout<<readblock[0]<<std::endl;
address.database_name="zyh";
address.file_name="friend";
address.file_offset=11;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='L';
}
Block newblock5(newdata);
buffer.write_data(address,&newblock1);
address.file_offset=9;
buffer.read_data(address,&readblock);
std::cout<<readblock[0]<<std::endl;

###test result

the change of the buffer list

8
8,9
8,9,10
9,10,8
9,10,8
10,8,11
8,11,9

output

8
9

##test3:write back test if the data in the buffer will be written back to the disk when the close the database.add one write near the end of the program.

address.database_name="zyh";
address.file_name="friend";
address.file_offset=8;
for (int i=0;i<BLOCK_SIZE;i++)
{
    newdata[i]='p';
}
Block newblocknew(newdata);
buffer.write_data(address,&newblocknew);

###test result the 8th block of the file is all of 'p'.