(no version information, might be only in CVS)
php_stream_copy_to_mem -- Copy data from stream and into an allocated buffer
Description
size_t 
php_stream_copy_to_mem ( php_stream * src, char ** buf, size_t maxlen, int persistent)
     php_stream_copy_to_mem() allocates a buffer maxlen+1
     bytes in length using pemalloc() (passing persistent).
     It then reads maxlen bytes from src and stores
     them in the allocated buffer.
    
     The allocated buffer is returned in buf, and the number of bytes successfully
     read.  You, the caller, are responsible for freeing the buffer by passing it and persistent
     to pefree().
    
     If you want to copy all remaining data from the src stream, pass the
     constant PHP_STREAM_COPY_ALL as the value of maxlen.
    
注: 
      This function will attempt to copy the data in the most efficient manner, using memory mapped
      files when possible.