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authorJeff King <peff@peff.net>2012-02-24 17:10:17 -0500
committerJunio C Hamano <gitster@pobox.com>2012-02-24 14:18:20 -0800
commit4f22b1015d4203ccdf2b66f27ee5946504342ace (patch)
treef9d35c08590a1cac42e16466b110acaf9d1c7dfe /sha1_file.c
parent4c3b57b98bccfdb740b8f1d0ca574dd51deacfad (diff)
downloadgit-4f22b1015d4203ccdf2b66f27ee5946504342ace.tar.gz
do not stream large files to pack when filters are in usejk/maint-avoid-streaming-filtered-contents
Because git's object format requires us to specify the number of bytes in the object in its header, we must know the size before streaming a blob into the object database. This is not a problem when adding a regular file, as we can get the size from stat(). However, when filters are in use (such as autocrlf, or the ident, filter, or eol gitattributes), we have no idea what the ultimate size will be. The current code just punts on the whole issue and ignores filter configuration entirely for files larger than core.bigfilethreshold. This can generate confusing results if you use filters for large binary files, as the filter will suddenly stop working as the file goes over a certain size. Rather than try to handle unknown input sizes with streaming, this patch just turns off the streaming optimization when filters are in use. This has a slight performance regression in a very specific case: if you have autocrlf on, but no gitattributes, a large binary file will avoid the streaming code path because we don't know beforehand whether it will need conversion or not. But if you are handling large binary files, you should be marking them as such via attributes (or at least not using autocrlf, and instead marking your text files as such). And the flip side is that if you have a large _non_-binary file, there is a correctness improvement; before we did not apply the conversion at all. The first half of the new t1051 script covers these failures on input. The second half tests the matching output code paths. These already work correctly, and do not need any adjustment. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'sha1_file.c')
-rw-r--r--sha1_file.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/sha1_file.c b/sha1_file.c
index 956422ba4a..c9ae7ec2ae 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2688,10 +2688,13 @@ static int index_core(unsigned char *sha1, int fd, size_t size,
* This also bypasses the usual "convert-to-git" dance, and that is on
* purpose. We could write a streaming version of the converting
* functions and insert that before feeding the data to fast-import
- * (or equivalent in-core API described above), but the primary
- * motivation for trying to stream from the working tree file and to
- * avoid mmaping it in core is to deal with large binary blobs, and
- * by definition they do _not_ want to get any conversion.
+ * (or equivalent in-core API described above). However, that is
+ * somewhat complicated, as we do not know the size of the filter
+ * result, which we need to know beforehand when writing a git object.
+ * Since the primary motivation for trying to stream from the working
+ * tree file and to avoid mmaping it in core is to deal with large
+ * binary blobs, they generally do not want to get any conversion, and
+ * callers should avoid this code path when filters are requested.
*/
static int index_stream(unsigned char *sha1, int fd, size_t size,
enum object_type type, const char *path,
@@ -2766,7 +2769,8 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st,
if (!S_ISREG(st->st_mode))
ret = index_pipe(sha1, fd, type, path, flags);
- else if (size <= big_file_threshold || type != OBJ_BLOB)
+ else if (size <= big_file_threshold || type != OBJ_BLOB ||
+ (path && would_convert_to_git(path, NULL, 0, 0)))
ret = index_core(sha1, fd, size, type, path, flags);
else
ret = index_stream(sha1, fd, size, type, path, flags);