Hi,
when writing large chunks of data over UNC paths (SMB shares) on Windows
it may happen that an errnous exception ("insufficient system
ressources") is thrown. Actually, the problem seems to be that the
underlying Windows subsystem fails when one uses OutputStream#write() on
buffers larger than 64 MB when the stream points to a file on the
network on Windows. See for example this forum thread for more info:
http://forums.sun.com/thread.jspa?threadID=5270971
For us, this happened when embedding large PDFs into even larger PDFs on
a network drive with iText. The patch below was developed as a
"quick-and-dirty" solution to the problem. In theory, writing data in 1
MB chunks may lead to slightly degraded performance, however, in the
real world this effect should be neglectible for such large blocks.
I am posting this here for discussion. We do know that a more complete
and elegant solution may exist and would be grateful for suggestions. In
the end, we would welcome when a fix for this issue would find the way
into the main iText distribution so we do not have to maintain separate
patches.
Markus
---
itext_orig\src\core\com\itextpdf\text\pdf\OutputStreamCounter.java
2010-01-27 22:24:09.974291300 +0100
+++ itext\src\core\com\itextpdf\text\pdf\OutputStreamCounter.java
2010-01-28 19:34:08.583642600 +0100
@@ -100,8 +100,7 @@
*
*/
public void write(byte[] b) throws IOException {
- counter += b.length;
- out.write(b);
+ write(b, 0, b.length);
}
/** Writes the specified byte to this output stream. The general
@@ -154,7 +153,17 @@
*/
public void write(byte[] b, int off, int len) throws IOException {
counter += len;
- out.write(b, off, len);
+
+ // On some Windows systems, writing large amounts of bytes at once
+ // using os.write() fails when using UNC paths, so we write data in
+ // 1 MB chunks instead. Actually, we could go as high as about
64 MB
+ // until Windows fails. See for example this page for information:
+ // http://forums.sun.com/thread.jspa?threadID=5270971
+ final int BUFSIZE = 1024 * 1024;
+ for (int cur = off; cur < off + len; cur += BUFSIZE) {
+ out.write(b, cur, Math.min(BUFSIZE, off + len - cur));
+ out.flush();
+ }
}
public int getCounter() {
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