[
https://issues.apache.org/jira/browse/IMAGING-356?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17739170#comment-17739170
]
Gary Lucas commented on IMAGING-356:
------------------------------------
Looking at the code history in github, I may have found one issue, though I am
not sure that it is the major issue. In the ByteSource class, there is a call
to a function called size with the following logic
{code:java}
public long size() throws IOException {
return origin.getByteArray().length;
}
{code}
So the question comes up, how much work is involved in a call to getByteArray?
It looks like "origin" is an object of type AbstractOrigin.FileOrigin() and the
call it makes to getByteArray is
{code:java}
@Override
public byte[] getByteArray() throws IOException {
return Files.readAllBytes(getPath());
}{code}
Which, of course, is a pretty expensive call. On the other hand, the size()
method is only called 12 times when loading the PICT2883.TIF image. But each
call does pull back 14788608 bytes.
I think that this my be a case where there's an impedance mismatch between the
ideas from commons.io and the assumptions in the commons.imaging classes.
> TIFF reading extremely slow in version 1.0-SNAPSHOT
> ---------------------------------------------------
>
> Key: IMAGING-356
> URL: https://issues.apache.org/jira/browse/IMAGING-356
> Project: Commons Imaging
> Issue Type: Bug
> Components: Format: TIFF
> Affects Versions: 1.0
> Reporter: Gary Lucas
> Priority: Major
>
> I am using the latest code from github (1.0-SNAPSHOT downloaded from github
> of June 2023) to read a 300 megabyte TIFF file. Version 1.0-alpha3 required
> 673 milliseconds to read that file. The new code requires upward of 15
> minutes. Clearly something got broken since the last release.
> The TIFF file is a 10000x10000 pixel 4 byte image format organized in strips.
> The bottleneck appears to occur in the TiffReader getTiffRawImageData method
> which reads raw data from the file in preparation of creating a BufferedImage
> object.
> I suspect that there may be a general slowness of file access. In debugging,
> even reading the initial metadata (22 TIFF tags) took a couple of seconds.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
