From: Jonathan Nieder <jrnieder@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Brian Gernhardt <brian@gernhardtsoftware.com>,
"git@vger.kernel.org List" <git@vger.kernel.org>,
David Barr <david.barr@cordelta.com>
Subject: [PATCH jn/fast-import-blob-access] t9300: use perl "head -c" clone in place of "dd bs=1 count=16000" kluge
Date: Mon, 13 Dec 2010 03:28:05 -0600 [thread overview]
Message-ID: <20101213092805.GB23443@burratino> (raw)
In-Reply-To: <7vfwu25e9q.fsf@alter.siamese.dyndns.org>
It is unfortunate to have to issue thousands of one-byte read calls to
work around dd's refusal to buffer input that would fill a block after
a short read (a3a6f4, 2010-12-13). We could do better by using
"head -c", if it were available on all platforms we cared about.
Replace it with some simple perl.
While doing so, restructure 9300.114 to use a subshell instead of a
script. Subshells can inherit functions (like the new head_c) from
the parent shell while external scripts cannot.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Junio C Hamano wrote:
> It is unfortunate and feels
> yucky that we have to issue 8k+ read(2) of one byte
How about this?
t/t9300-fast-import.sh | 84 ++++++++++++++++++++++++++++--------------------
1 files changed, 49 insertions(+), 35 deletions(-)
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index ed28d3c..924a833 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -7,6 +7,23 @@ test_description='test git fast-import utility'
. ./test-lib.sh
. "$TEST_DIRECTORY"/diff-lib.sh ;# test-lib chdir's into trash
+# Print $1 bytes from stdin to stdout.
+#
+# This could be written as "head -c $1", but IRIX "head" does not
+# support the -c option.
+head_c () {
+ perl -e '
+ my $len = $ARGV[1];
+ while ($len > 0) {
+ my $s;
+ my $nread = sysread(STDIN, $s, $len);
+ die "cannot read: $!" unless defined($nread);
+ print $s;
+ $len -= $nread;
+ }
+ ' - "$1"
+}
+
file2_data='file2
second line of EOF'
@@ -1780,44 +1797,41 @@ test_expect_success PIPE 'R: copy using cat-file' '
rm -f blobs &&
cat >frontend <<-\FRONTEND_END &&
#!/bin/sh
- cat <<EOF &&
- feature cat-blob
- blob
- mark :1
- data <<BLOB
- EOF
- cat big
- cat <<EOF
- BLOB
- cat-blob :1
- EOF
-
- read blob_id type size <&3 &&
- echo "$blob_id $type $size" >response &&
- dd of=blob bs=1 count=$size <&3 &&
- read newline <&3 &&
-
- cat <<EOF &&
- commit refs/heads/copied
- committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
- data <<COMMIT
- copy big file as file3
- COMMIT
- M 644 inline file3
- data <<BLOB
- EOF
- cat blob &&
- cat <<EOF
- BLOB
- EOF
FRONTEND_END
mkfifo blobs &&
(
export GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL GIT_COMMITTER_DATE &&
- sh frontend 3<blobs |
- git fast-import --cat-blob-fd=3 3>blobs
- ) &&
+ cat <<-\EOF &&
+ feature cat-blob
+ blob
+ mark :1
+ data <<BLOB
+ EOF
+ cat big &&
+ cat <<-\EOF &&
+ BLOB
+ cat-blob :1
+ EOF
+
+ read blob_id type size <&3 &&
+ echo "$blob_id $type $size" >response &&
+ head_c $size >blob <&3 &&
+ read newline <&3 &&
+
+ cat <<-EOF &&
+ commit refs/heads/copied
+ committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+ data <<COMMIT
+ copy big file as file3
+ COMMIT
+ M 644 inline file3
+ data <<BLOB
+ EOF
+ cat blob &&
+ echo BLOB
+ ) 3<blobs |
+ git fast-import --cat-blob-fd=3 3>blobs &&
git show copied:file3 >actual &&
test_cmp expect.response response &&
test_cmp big actual
@@ -1845,7 +1859,7 @@ test_expect_success PIPE 'R: print blob mid-commit' '
EOF
read blob_id type size <&3 &&
- dd of=actual bs=1 count=$size <&3 &&
+ head_c $size >actual <&3 &&
read newline <&3 &&
echo
@@ -1880,7 +1894,7 @@ test_expect_success PIPE 'R: print staged blob within commit' '
echo "cat-blob $to_get" &&
read blob_id type size <&3 &&
- dd of=actual bs=1 count=$size <&3 &&
+ head_c $size >actual <&3 &&
read newline <&3 &&
echo deleteall
--
1.7.2.4.568.g3733c.dirty
prev parent reply other threads:[~2010-12-13 9:28 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-12 20:49 SIGPIPE in t9300-fast-import Brian Gernhardt
2010-12-12 21:49 ` Jonathan Nieder
2010-12-12 22:04 ` Brian Gernhardt
2010-12-13 6:31 ` [PATCH jn/fast-import-blob-access] t9300: avoid short reads from dd Jonathan Nieder
2010-12-13 7:21 ` Junio C Hamano
2010-12-13 9:28 ` Jonathan Nieder [this message]
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