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How do I efficiently iterate over each entry in a Java Map?
...r();
while (it.hasNext()) {
i += it.next() + it.getValue();
}
Using MutableMap of Eclipse (CS) collections
final long[] i = {0};
mutableMap.forEachKeyValue((key, value) -> {
i[0] += key + value;
});
Perfomance tests (mode = AverageTime, system = Windows 8.1 64-bit, Intel i7-4790 3.6...
What are some (concrete) use-cases for metaclasses?
... About the ORM case, are you talking about the class-based way of defining tables, or the metaclasses on mapped objects. Because SQLAlchemy can (rightly) map to any class (and I am assuming that it doesn't use a metaclass for that activity).
– Ali Afshar
Dec 24...
Python subprocess.Popen “OSError: [Errno 12] Cannot allocate memory”
...as originally asked here but the bounty time expired even though an acceptable answer was not actually found. I am re-asking this question including all details provided in the original question.
...
When should I use mmap for file access?
...om. (The OS can detect which pages are unmodified by initially marking writable mmap'd pages as read only and catching seg faults, similar to Copy on Write strategy).
mmap is also useful for inter process communication. You can mmap a file as read / write in the processes that need to communica...
Hidden Features of SQL Server
...T clause allows to do this very easily - it allows access to the "virtual" tables called inserted and deleted (like in triggers):
DELETE FROM (table)
OUTPUT deleted.ID, deleted.Description
WHERE (condition)
If you're inserting values into a table which has an INT IDENTITY primary key field, with ...
How can I get a specific number child using CSS?
I have a table whose td s are created dynamically. I know how to get the first and last child but my question is:
2 Answ...
Create SQLite Database and table [closed]
...Database.sqlite;Version=3;");
m_dbConnection.Open();
string sql = "create table highscores (name varchar(20), score int)";
SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection);
command.ExecuteNonQuery();
sql = "insert into highscores (name, score) values ('Me', 9001)";
command = new SQ...
There can be only one auto column
...
My MySQL says "Incorrect table definition; there can be only one auto column and it must be defined as a key" So when I added primary key as below it started working:
CREATE TABLE book (
id INT AUTO_INCREMENT NOT NULL,
accepted_terms BIT(1) NO...
The order of elements in Dictionary
...ry is non-deterministic. The notion of order simply is not defined for hashtables. So don't rely on enumerating in the same order as elements were added to the dictionary. That's not guaranteed.
Quote from the doc:
For purposes of enumeration, each item in the dictionary is treated as a KeyValu...
Best Practices: Salting & peppering passwords?
...n order for it to be considered secure. Additionally, it has to be implementable in a maintainable way. The most secure system that can't be maintained is considered insecure (because if any part of that security breaks down, the entire system falls apart).
And peppers fit neither the provable or t...