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初窥InnoDB的Memcached插件 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...插件目录我们能看到innodb_engine.so和libmemcached.so：
mysql> SELECT @@plugin_dir;
+------------------------------+
| @@plugin_dir |
+------------------------------+
| /usr/local/mysql/lib/plugin/ |
+------------------------------+
此外还需要导入Memcached插...
Does the C++ standard mandate poor performance for iostreams, or am I just dealing with a poor imple
...ith GCC gives the following breakdown:
44.23% in std::basic_streambuf<char>::xsputn(char const*, int)
34.62% in std::ostream::write(char const*, int)
12.50% in main
6.73% in std::ostream::sentry::sentry(std::ostream&)
0.96% in std::string::_M_replace_safe(unsigned int, unsigned int, char...
Matplotlib - Move X-Axis label downwards, but not X-Axis Ticks
...self._get_tick_bboxes(ticks_to_draw, renderer)
bbox = mtransforms.Bbox.union(bboxes)
bottom = bbox.y0
x, y = self.label.get_position()
self.label.set_position((x, bottom - self.labelpad * self.figure.dpi / 72.0))
You can set the label position independently of the ticks by using:
...
How to find out what type of a Mat object is with Mat::type() in OpenCV
...n" functionality like Visual Studio you can type cv::CV_8U right-click and select Go to Definition to open the file where cv::CV_8U is defined which is types_c.h.
– user3731622
Aug 29 '16 at 17:53
...
What column type/length should I use for storing a Bcrypt hashed password in a Database?
...d format
a two digit value denoting the cost parameter, followed by $
a 53 characters long base-64-encoded value (they use the alphabet ., /, 0–9, A–Z, a–z that is different to the standard Base 64 Encoding alphabet) consisting of:
22 characters of salt (effectively only 128 bits of the 132 d...
How to delete duplicate lines in a file without sorting it in Unix?
... <sniff> makes me sad. ;) Anyways, [ -~] represents a range of ASCII characters from 0x20 (space) to 0x7E (tilde). These are considered the printable ASCII characters (linked page also has 0x7F/delete but that doesn't seem right). That makes the solution broken for anyone not using ASCII or an...
How do you count the number of occurrences of a certain substring in a SQL varchar?
...mparing the lengths
Declare @string varchar(1000)
Set @string = 'a,b,c,d'
select len(@string) - len(replace(@string, ',', ''))
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Base64 length calculation?
...
Each character is used to represent 6 bits (log2(64) = 6).
Therefore 4 chars are used to represent 4 * 6 = 24 bits = 3 bytes.
So you need 4*(n/3) chars to represent n bytes, and this needs to be rounded up to a multiple of 4.
...
Convert seconds to Hour:Minute:Second
...ed to that of the TIME data type, which is from -838:59:59 to 838:59:59 :
SELECT SEC_TO_TIME(8525);
# 02:22:05
See: SEC_TO_TIME
Run the Demo
PostgreSQL example:
SELECT TO_CHAR('8525 second'::interval, 'HH24:MI:SS');
# 02:22:05
Run the Demo
...
UTF-8 byte[] to String
...Look at the constructor for String
String str = new String(bytes, StandardCharsets.UTF_8);
And if you're feeling lazy, you can use the Apache Commons IO library to convert the InputStream to a String directly:
String str = IOUtils.toString(inputStream, StandardCharsets.UTF_8);
...