Php reads memcache binary data

As a data middle layer, memcache is often used for data exchange.

For example, in a system, we define the following user status information. Each user only needs to exist in 52 bytes.
Key state # ID, for example, "state #10888"
Value: (binary data)
User ID Uint32
Type User Type Uint8:
State user status Uint8:
Server IP Uint32
Last online time Uint64
Session ID length Uint16

Session ID char [32]

A total of 52 bytes

So how can we get the above data through memcache in php?

The stored data contains binary 0. Will the string be truncated?

Actually, no!

Perform the following tests:

$ Mem = new Memcache ();

$ Mem-> connect ('192. 168.0.69 ', 192 );

$ Memstr = $ mem-> get ('State #105709 ');

Var_dump ($ memstr );
The following output is displayed. We can see that memstr is exactly 53 bytes. SessionId has an Terminator.
String (53) "contains F> * R! 8w.fmsik41kbdkmlqc7m7qowicq8nzz7"

Furthermore, we output the data to a file and use winhex to view the data status.

File_put_contents ('./dd.txt', $ memstr );

Use winhex dd.txt to view hexadecimal data.

Bytes

 

Next I can retrieve data by byte, mainly using the ord function to obtain the byte ASCII code.

$ Type = ord ($ memstr {4 });

$ State = ord ($ memstr {5 });

$ Ip = ord ($ memstr {6 }). '. '. ord ($ memstr {7 }). '. '. ord ($ memstr {8 }). '. '. ord ($ memstr {9 });

$ Ses_long = ord ($ memstr {19}) * 16 + ord ($ memstr {18 });

// The timestamp only needs 4 bytes and is allocated with 8 bytes.
$ Lastactive = ord ($ memstr {13}) * 16777216 + ord ($ memstr {12}) * 65536 + ord ($ memstr {11 }) * 256 + ord ($ memstr {10 });

$ Sessionid = substr ($ memstr, 20, $ ses_long );