Solution of file_put_contents concurrency problem

Solution One , file_put_contents high concurrency and exclusive locking

Data is empty when high concurrent access is found using File_put_contents to write files.

View Official documents:

int file_put_contents (string $filename, String $data [, int $flags [, Resource $context]])
Parameters:

FileName to be written to the data file name. Data to write to. Types can be String,array or stream resources (as described above). Flags flags can be file_use_include_path,file_append and/or LOCK_EX (get an exclusive lock), but use File_use_include_path with special care. Context a context resource.
Direct until the flags parameter is LOCK_EX to obtain an exclusive lock at high concurrency.

In addition, the Flock function also provides a file locking method:

$fp = fopen ("/tmp/lock.txt", "w+");
if (Flock ($FP, LOCK_EX)) {//For exclusive locking of
fwrite ($fp, "Write something here\n");
Flock ($FP, lock_un); Release Lock
} else {
echo ' couldn ' t lock the file!
}
Fclose ($FP);

Note that flock () requires a file pointer.

method Two , file_put_contents () has a high concurrency problem, and the Smarty processing method is as follows.

<?php   Define ("File_put_contents_atomic_temp",  dirname (__file__).

/cache ");

Define ("File_put_contents_atomic_mode",  0777);   Function file_put_contents_atomic ($filename,  $content)  {      $

Temp = tempnam (file_put_contents_atomic_temp,  ' TEMP ');     if  (!) ( $f  =  @fopen ($temp,  ' WB '))  {         $temp  =

 file_put_contents_atomic_temp . directory_separator . uniqid (' TEMP ');         if  (!) ( $f  =  @fopen ($temp,  ' WB '))  {             trigger_error ("File_put_contents_atomic ()  : error writing temporary file

  ' $temp ',  e_user_warning);

            return false;    &NBSP;&NBSP;&NBSP;&NBSP;&NBSP}    &nbsp}       fwrite ($f,  $content

);

    fclose ($f);       if  (! @rename ($temp,  $filename))  {     

    @unlink ($filename);

         @rename ($temp,  $filename);

&NBSP;&NBSP;&NBSP;&NBSP}        @chmod ($filename,  file_put_contents_atomic_mode);

      return true;  }  ?>