Implement filters for status/diff blobs

This adds support to diff and status for running filters (a la crlf)
on blobs in the workdir before computing SHAs and before generating
text diffs.  This ended up being a bit more code change than I had
thought since I had to reorganize some of the diff logic to minimize
peak memory use when filtering blobs in a diff.

This also adds a cap on the maximum size of data that will be loaded
to diff.  I set it at 512Mb which should match core git.  Right now
it is a #define in src/diff.h but it could be moved into the public
API if desired.

1 files changed, 22 insertions, 11 deletions

diff --git a/src/diff.c b/src/diff.c
index f8a01086c..499b95b44 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -11,6 +11,7 @@
 #include "fileops.h"
 #include "config.h"
 #include "attr_file.h"
+#include "filter.h"
 
 static char *diff_prefix_from_pathspec(const git_strarray *pathspec)
 {
@@ -63,8 +64,8 @@ static bool diff_path_matches_pathspec(git_diff_list *diff, const char *path)
 
 	git_vector_foreach(&diff->pathspec, i, match) {
 		int result = strcmp(match->pattern, path) ? FNM_NOMATCH : 0;
-		
-		if (((diff->opts.flags & GIT_DIFF_DISABLE_PATHSPEC_MATCH) == 0) && 
+
+		if (((diff->opts.flags & GIT_DIFF_DISABLE_PATHSPEC_MATCH) == 0) &&
 			result == FNM_NOMATCH)
 			result = p_fnmatch(match->pattern, path, 0);
 
@@ -262,12 +263,14 @@ static int diff_delta__from_two(
 	delta = diff_delta__alloc(diff, status, old_entry->path);
 	GITERR_CHECK_ALLOC(delta);
 
-	delta->old_file.mode = old_mode;
 	git_oid_cpy(&delta->old_file.oid, &old_entry->oid);
+	delta->old_file.size = old_entry->file_size;
+	delta->old_file.mode = old_mode;
 	delta->old_file.flags |= GIT_DIFF_FILE_VALID_OID;
 
-	delta->new_file.mode = new_mode;
 	git_oid_cpy(&delta->new_file.oid, new_oid ? new_oid : &new_entry->oid);
+	delta->new_file.size = new_entry->file_size;
+	delta->new_file.mode = new_mode;
 	if (new_oid || !git_oid_iszero(&new_entry->oid))
 		delta->new_file.flags |= GIT_DIFF_FILE_VALID_OID;
 
@@ -440,14 +443,22 @@ static int oid_for_workdir_item(
 		giterr_set(GITERR_OS, "File size overflow for 32-bit systems");
 		result = -1;
 	} else {
-		int fd = git_futils_open_ro(full_path.ptr);
-		if (fd < 0)
-			result = fd;
-		else {
-			result = git_odb__hashfd(
-				oid, fd, (size_t)item->file_size, GIT_OBJ_BLOB);
-			p_close(fd);
+		git_vector filters = GIT_VECTOR_INIT;
+
+		result = git_filters_load(
+			&filters, repo, item->path, GIT_FILTER_TO_ODB);
+		if (result >= 0) {
+			int fd = git_futils_open_ro(full_path.ptr);
+			if (fd < 0)
+				result = fd;
+			else {
+				result = git_odb__hashfd_filtered(
+					oid, fd, (size_t)item->file_size, GIT_OBJ_BLOB, &filters);
+				p_close(fd);
+			}
 		}
+
+		git_filters_free(&filters);
 	}
 
 	git_buf_free(&full_path);