Read and write each 1024 byte buffer, rather than trying to buffer
the entire content of the file.
Previous code would crash on all files > 2 Gib, when the offset variable
became negative (perhaps below the level of perl), resulting in a crash.
On a 32 bit system, or a system with low memory it might crash before
reaching 2 GiB due to memory exhaustion.
This code may leave a partial file behind in case of failure, where the
old code would leave a completely empty file.
Neither version verifies the correctness of the content.
Calling code must take care of verification and cleanup.
Signed-off-by: Joshua Clayton <stillcompiling@xxxxxxxxx>
Reviewed-by: Jeff King <peff@xxxxxxxx>
Reviewed-by: Junio C Hamano <gitster@xxxxxxxxx>
---
perl/Git.pm | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/perl/Git.pm b/perl/Git.pm
index 931047c..db6e0a8 100644
--- a/perl/Git.pm
+++ b/perl/Git.pm
@@ -942,20 +942,22 @@ sub cat_blob {
my $size = $1;
my $blob;
- my $bytesRead = 0;
+ my $bytesLeft = $size;
while (1) {
- my $bytesLeft = $size - $bytesRead;
last unless $bytesLeft;
my $bytesToRead = $bytesLeft < 1024 ? $bytesLeft : 1024;
- my $read = read($in, $blob, $bytesToRead, $bytesRead);
+ my $read = read($in, $blob, $bytesToRead);
unless (defined($read)) {
$self->_close_cat_blob();
throw Error::Simple("in pipe went bad");
}
-
- $bytesRead += $read;
+ unless (print $fh $blob) {
+ $self->_close_cat_blob();
+ throw Error::Simple("couldn't write to passed in filehandle");
+ }
+ $bytesLeft -= $read;
}
# Skip past the trailing newline.
@@ -970,11 +972,6 @@ sub cat_blob {
throw Error::Simple("didn't find newline after blob");
}
- unless (print $fh $blob) {
- $self->_close_cat_blob();
- throw Error::Simple("couldn't write to passed in filehandle");
- }
-
return $size;
}
--
1.7.10.4
I'm trying to send this with git-send-email this time around to beat
the linewrapping problem.
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