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Class Acme.Serve.ThrottledOutputStream

java.lang.Object
   |
   +----java.io.OutputStream
           |
           +----java.io.FilterOutputStream
                   |
                   +----Acme.Serve.ThrottledOutputStream

public class ThrottledOutputStream

extends FilterOutputStream

Restricts output to a specified rate. Also includes a static utility routine for parsing a file of throttle settings.

Fetch the software.
Fetch the entire Acme package.

ThrottledOutputStream(OutputStream, long)

Constructor.

parseThrottleFile(String)

Parses a standard throttle file.

write(byte[], int, int)

Writes a subarray of bytes.

write(int)

Writes a byte.

 public ThrottledOutputStream(OutputStream out,
                              long maxBps)

Constructor.

 public static WildcardDictionary parseThrottleFile(String filename) throws IOException

Parses a standard throttle file.

A throttle file lets you set maximum byte rates on filename patterns. The format of the throttle file is very simple. A # starts a comment, and the rest of the line is ignored. Blank lines are ignored. The rest of the lines should consist of a pattern, whitespace, and a number. The pattern is a simple shell-style filename pattern, using ? and *, or multiple such patterns separated by |.

The numbers in the file are byte rates, specified in units of bytes per second. For comparison, a v.32b/v.42b modem gives about 1500/2000 B/s depending on compression, a double-B-channel ISDN line about 12800 B/s, and a T1 line is about 150000 B/s.

Example:

 # throttle file for www.acme.com
 *               100000  # limit total web usage to 2/3 of our T1
 *.jpg|*.gif     50000   # limit images to 1/3 of our T1
 *.mpg           20000   # and movies to even less
 jef/*           20000   # jef's pages are too popular
 

The routine returns a WildcardDictionary. Do a lookup in this dictionary using a filename, and you'll get back a ThrottleItem containing the corresponding byte rate.

 public void write(int b) throws IOException

Writes a byte. This method will block until the byte is actually written.

Parameters:

b - the byte to be written

Throws: IOException

if an I/O error has occurred

Overrides:

write in class FilterOutputStream

 public void write(byte b[],
                   int off,
                   int len) throws IOException

Writes a subarray of bytes.

Parameters:

b - the data to be written

off - the start offset in the data

len - the number of bytes that are written

Throws: IOException

if an I/O error has occurred

Overrides:

write in class FilterOutputStream

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