Using ZipInputStream efficiently

[Chris Berg]

Which one is best:

1:
DataInputStream dis=new DataInputStream(
new ZipInputStream(
new FileInputStream(filename));
2:
DataInputStream dis=new DataInputStream(
new ZipInputStream(
new BufferedInputStream(
new FileInputStream(filename))));
3:
DataInputStream dis=new DataInputStream(
new BufferedInputStream(
new ZipInputStream(
new FileInputStream(filename))));
4:
DataInputStream dis=new DataInputStream(
new BufferedInputStream(
new ZipInputStream(
new BufferedInputStream(
new FileInputStream(filename)))));


Chris

 

[Chris Head]

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Which one is best:

1:
DataInputStream dis=new DataInputStream(
new ZipInputStream(
new FileInputStream(filename));
2:
DataInputStream dis=new DataInputStream(
new ZipInputStream(
new BufferedInputStream(
new FileInputStream(filename))));
3:
DataInputStream dis=new DataInputStream(
new BufferedInputStream(
new ZipInputStream(
new FileInputStream(filename))));
4:
DataInputStream dis=new DataInputStream(
new BufferedInputStream(
new ZipInputStream(
new BufferedInputStream(
new FileInputStream(filename)))));


Chris

Hi,
I'm guessing either 2 or 4. I would guess that ZipInputStream might well
issue repeated small reads in the process of doing its normal operations
(though I don't know this for sure), so those should be coalesced by
using a BufferedInputStream between it and FileInputStream. However, the
fact that you're using DataInputStream tells me that you're probably
reading small amounts at a time from the resulting unzipped stream as
well, so buffering between DIS and ZIS might also be useful so that the
Zip algorithm can work on large blocks of data at a time.

I guess the real answer is: benchmark it.

Chris
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