5 million UID white list PHP bit map processing

5 million UID white list of PHP Bitmap processing

Recently, some colleagues said there is a 5 million white list processing, to find similar cases on the Internet, said there is a bitmap solution,

Google again, Baidu has no relevance to the solution of PHP, so he wrote a:

?

 Handler = @fopen ($file, ' r+ ') or Die (' Open bitmap file failed '); Else$this->handler = @fopen ($file, ' w+ ') or Die (' Open Bitmap file failed '); $this->max = file_exists ($file)? (FileSize ($file) * 8-1): 0;} Public Function __destruct () {@fclose ($this->handler);} Private Function Binary_dump ($binary _data) {return sprintf ('%08d ', Decbin (Hexdec (Bin2Hex ($binary _data)));} Private Function Num_check ($num) {($num >-1) or Die (' number must is Greater than-1 ');($num < 4294967296) or Die (' Nu Mber must is less than 4294967296 '); 2^32if ($this->max < $num) {fseek ($this->handler, 0, Seek_end), fwrite ($this->handler, Str_repeat ("\x00" , Ceil (($num-$this->max)/8)); Fill with 0$this->max = Ceil ($num/8) *8-1;}} Public function set ($num) {$this->num_check ($num); Fseek ($this->handler, Floor ($num/8), seek_set); $bin = Fread ($ This->handler, 1) | Pack (' C ', 0x100 >> fmod ($num, 8) +1); Mark with 1fseek ($this->handler, Ftell ($this->handler)-1, Seek_set); //Write a new Bytefwrite ($this->handler, $bin); Fflush ($this->handler);} Public Function del ($num) {$this->num_check ($num); Fseek ($this->handler, Floor ($num/8), seek_set); $bin = Fread ($ This->handler, 1) & ~pack (' C ', 0x100 >> fmod ($num, 8) +1); Mark with 0fseek ($this->handler, Ftell ($this->handler)-1, Seek_set); Write a new Bytefwrite ($this->handler, $bin); Fflush ($this->handler);} Public function Find ($num) {if (Fseek ($this->handler, Floor ($num/8), seek_set) = = 1) return FALSE; $bin = fread ($this-& Gt;handler, 1); if ($bin = = = False | | strlen ($bin) = = 0) return FALSE; $bin = $bin & Pack (' C ', 0x100 >> fmod ($num, 8) +1); if ($bin = = = "\x00") return False;return TRUE;}} $b = new Bitmap ('/dev/shm/bitmapdata ');//Set white list $b->set (1); $b->set (3); $b->set (5); $b->set (7); $b->set (9); $b->set (501), $uid = 501;var_dump ($b->find ($uid)); Find white list $b->del ($UID); Delete Whitelist Var_dump ($b->find ($uid)); Find White List

?

where "$b = new Bitmap ('/dev/shm/bitmapdata ');"? Put the file in memory to increase read and write speed

The results of the implementation are as follows:

[Email protected]:~/web/test/shm$/bin/sh./geany_run_script.sh
BOOL (TRUE)
BOOL (FALSE)

?

The generated bitmapdata file is in the attachment:

?

?

