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How can I tell if a DOM element is visible in the current viewport?
... old answer is very slow, not accurate and has several bugs.
The solution selected as correct is almost never precise. You can read more about its bugs.
This solution was tested on Internet Explorer 7 (and later), iOS 5 (and later) Safari, Android 2.0 (Eclair) and later, BlackBerry, Opera Mob...
How do I safely pass objects, especially STL objects, to and from a DLL?
...ply specific packing. The compiler will still apply default packing if you select a pack value bigger than the one the compiler would have chosen, so if you pick a large packing value, a class can still have different packing between compilers. The solution for this is to use #pragma pack(1), which ...
Unit Test? Integration Test? Regression Test? Acceptance Test?
...
@Honey Well, the regression test suite is mostly a selection of some or all of your unit and integration tests. It's a policy thing, how much regression testing you want to do. The main difference is that Unit tests are done in active development while regression tests is mor...
mongoDB/mongoose: unique if not null
...
Just a quick update to those researching this topic.
The selected answer will work, but you might want to consider using partial indexes instead.
Changed in version 3.2: Starting in MongoDB 3.2, MongoDB provides the
option to create partial indexes. Partial indexes offer a su...
How to convert number to words in java
...o use a built-in function of your DBMS (if available).
For Oracle
SQL> select to_char(to_date(873,'J'), 'JSP') as converted_form from dual;
CONVERTED_FORM
---------------------------
EIGHT HUNDRED SEVENTY-THREE
SQL>
'JSP' means :
J : the Julian format.
SP : spells the word for the number pa...
Android studio: new project vs new module
...d" name="Android">
<configuration>
<option name="SELECTED_BUILD_VARIANT" value="debug" />
<option name="ASSEMBLE_TASK_NAME" value="assembleDebug" />
<option name="COMPILE_JAVA_TASK_NAME" value="compileDebugSources" />
<afterSyncTask...
Ship an application with a database
...();
}
public void test(){
try{
String query ="SELECT value FROM test1";
Cursor cursor = database.rawQuery(query, null);
if (cursor.moveToFirst()){
do{
String value = cursor.getString(0);
Log....
Is there a CSS selector by class prefix?
...ble with CSS2.1, but it is possible with CSS3 attribute substring-matching selectors (which are supported in IE7+):
div[class^="status-"], div[class*=" status-"]
Notice the space character in the second attribute selector. This picks up div elements whose class attribute meets either of these con...
How to have no pagebreak after \include in LaTeX
...e!
use \include instead of \input, and use the \includeonly command to select sections to process
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TCP 的那些事儿（上） - 更多技术 - 清泛网 - 专注C/C++及内核技术
...，这是一把双刃剑。
SACK 方法
另外一种更好的方式叫：Selective Acknowledgment (SACK)（参看RFC 2018），这种方式需要在TCP头里加一个SACK的东西，ACK还是Fast Retransmit的ACK，SACK则是汇报收到的数据碎版。参看下图：
这样，在发送端...