For some reason, I recently started using FilterInputStream and FilterOutputStream as a convenient basis for subclasses of InputStream and OutputStream. Narrowing down a brand new serious performance issue in my code, I found that while FilterInputStream redirected read(byte[], int, int) to an identical invocation on its backing InputStream, FilterOutputStream redirected write(byte[], int, int) to a loop of calls to write(int), which is, depending on the OutputStream backing it (sockets/files), extremely inefficient.
Don't let it
byte you!
Code snippets from java.io.*
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| public class FilterInputStream extends InputStream {
public int read(byte b[], int off, int len) throws IOException {
return in.read(b, off, len);
}
} |
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| public class FilterOutputStream extends OutputStream {
public void write(byte b[], int off, int len) throws IOException {
if ((off | len | (b.length - (len + off)) | (off + len)) < 0)
throw new IndexOutOfBoundsException();
for (int i = 0 ; i < len ; i++) {
write(b[off + i]);
}
}
} |
