SCHEMA :
CREATE TABLE checksums
(i INTEGER,c VARCHAR(20) PRIMARY KEY) ;
CODE :
// Generates a Random string
QByteArray Randstr_B(int len) {
char chars[36] = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y',
'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};
QByteArray str;
for (int i = 0; i < len; i++) {
str.append(chars[qrand() % 35]);
}
return str;
}
// Converts quint64 to Little Endian bytes
QByteArray toLE(quint64 num){
unsigned char bytes[8];
bytes[0] = (unsigned char)num;
bytes[1] = (unsigned char)(num >> 8);
bytes[2] = (unsigned char)(num >> 16);
bytes[3] = (unsigned char)(num >> 24);
bytes[4] = (unsigned char)(num >> 32);
bytes[5] = (unsigned char)(num >> 40);
bytes[6] = (unsigned char)(num >> 48);
bytes[7] = (unsigned char)(num >> 56);
return QByteArray((const char *)bytes, 8);
}
insQ->prepare("INSERT INTO checksums (i, c) VALUES (?, ?)");
I then do inserts in the loop (I am using QT) :
for(quint64 i = 1; i <= 10000000; i++){
// Create the data RANDOMLY
QByteArray block = Randstr_B(4088).append(toLE(i)); // "toLE" is a
function which converts quint64 to Little Endian Bytes i.e. 8 bytes. I used
this to make each block unique
QByteArray csum = QCryptographicHash::hash(block,
QCryptographicHash::Sha1);
unsigned char C = (unsigned char)csum.at(0);
// Insert into the MAP
insQ->bindValue(0, i); // insQ is a QSqlQuery *
insQ->bindValue(1, csum);
if(!insQ->exec()){
qDebug() << "Error Inserting :" << i << csum.toHex().toUpper()
<< insQ->lastError().text();
//exit(0);
}
if((i % 10000) == 0){
mapconn.commit(); // Database Connection "mapconn"
Q.exec("PRAGMA wal_checkpoint;"); // Checkpointing the WAL and
"Q" is also another QSqlQuery.
mapconn.transaction(); // Restarting Transaction
qDebug() "Committed :" << i << csum.toHex() << time();
}
}
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