Commit 359240b674ad809c4986596bfe8a6837ee386e13
2022-02-11T17:56:05
diff: indicate when the file size is "valid" When we know the file size (because we're producing it from a working directory iterator, or an index with an up-to-date cache) then set a flag indicating as such. This removes the ambiguity about a 0 file size, which could indicate that a file exists and is 0 bytes, or that we haven't read it yet.
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diff --git a/include/git2/diff.h b/include/git2/diff.h
index 9424ffd..3839f00 100644
--- a/include/git2/diff.h
+++ b/include/git2/diff.h
@@ -207,7 +207,8 @@ typedef enum {
GIT_DIFF_FLAG_BINARY = (1u << 0), /**< file(s) treated as binary data */
GIT_DIFF_FLAG_NOT_BINARY = (1u << 1), /**< file(s) treated as text data */
GIT_DIFF_FLAG_VALID_ID = (1u << 2), /**< `id` value is known correct */
- GIT_DIFF_FLAG_EXISTS = (1u << 3) /**< file exists at this side of the delta */
+ GIT_DIFF_FLAG_EXISTS = (1u << 3), /**< file exists at this side of the delta */
+ GIT_DIFF_FLAG_VALID_SIZE = (1u << 4) /**< file size value is known correct */
} git_diff_flag_t;
/**
diff --git a/src/diff_generate.c b/src/diff_generate.c
index dca16d5..cfaefba 100644
--- a/src/diff_generate.c
+++ b/src/diff_generate.c
@@ -117,6 +117,26 @@ static bool diff_pathspec_match(
matched_pathspec, NULL);
}
+static void diff_delta__flag_known_size(git_diff_file *file)
+{
+ /*
+ * If we don't know the ID, that can only come from the workdir
+ * iterator, which means we *do* know the file size. This is a
+ * leaky abstraction, but alas. Otherwise, we test against the
+ * empty blob id.
+ */
+ if (file->size ||
+ !(file->flags & GIT_DIFF_FLAG_VALID_ID) ||
+ git_oid_equal(&file->id, &git_oid__empty_blob_sha1))
+ file->flags |= GIT_DIFF_FLAG_VALID_SIZE;
+}
+
+static void diff_delta__flag_known_sizes(git_diff_delta *delta)
+{
+ diff_delta__flag_known_size(&delta->old_file);
+ diff_delta__flag_known_size(&delta->new_file);
+}
+
static int diff_delta__from_one(
git_diff_generated *diff,
git_delta_t status,
@@ -182,6 +202,8 @@ static int diff_delta__from_one(
if (has_old || !git_oid_is_zero(&delta->new_file.id))
delta->new_file.flags |= GIT_DIFF_FLAG_VALID_ID;
+ diff_delta__flag_known_sizes(delta);
+
return diff_insert_delta(diff, delta, matched_pathspec);
}
@@ -244,6 +266,8 @@ static int diff_delta__from_two(
delta->new_file.flags |= GIT_DIFF_FLAG_VALID_ID;
}
+ diff_delta__flag_known_sizes(delta);
+
return diff_insert_delta(diff, delta, matched_pathspec);
}
diff --git a/src/diff_generate.h b/src/diff_generate.h
index f39bf6b..b782f29 100644
--- a/src/diff_generate.h
+++ b/src/diff_generate.h
@@ -119,8 +119,10 @@ GIT_INLINE(int) git_diff_file__resolve_zero_size(
git_odb_free(odb);
- if (!error)
+ if (!error) {
file->size = (git_object_size_t)len;
+ file->flags |= GIT_DIFF_FLAG_VALID_SIZE;
+ }
return error;
}
diff --git a/src/diff_tform.c b/src/diff_tform.c
index f9836d2..913d649 100644
--- a/src/diff_tform.c
+++ b/src/diff_tform.c
@@ -460,7 +460,8 @@ static int similarity_init(
info->blob = NULL;
git_str_init(&info->data, 0);
- if (info->file->size > 0 || info->src == GIT_ITERATOR_WORKDIR)
+ if ((info->file->flags & GIT_DIFF_FLAG_VALID_SIZE) ||
+ info->src == GIT_ITERATOR_WORKDIR)
return 0;
return git_diff_file__resolve_zero_size(
diff --git a/src/odb.c b/src/odb.c
index 3abeae2..14eff53 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -16,6 +16,7 @@
#include "filter.h"
#include "repository.h"
#include "blob.h"
+#include "oid.h"
#include "git2/odb_backend.h"
#include "git2/oid.h"
@@ -58,10 +59,7 @@ static int error_null_oid(int error, const char *message);
static git_object_t odb_hardcoded_type(const git_oid *id)
{
- static git_oid empty_tree = {{ 0x4b, 0x82, 0x5d, 0xc6, 0x42, 0xcb, 0x6e, 0xb9, 0xa0, 0x60,
- 0xe5, 0x4b, 0xf8, 0xd6, 0x92, 0x88, 0xfb, 0xee, 0x49, 0x04 }};
-
- if (!git_oid_cmp(id, &empty_tree))
+ if (!git_oid_cmp(id, &git_oid__empty_tree_sha1))
return GIT_OBJECT_TREE;
return GIT_OBJECT_INVALID;
diff --git a/src/oid.c b/src/oid.c
index 1a50d3d..19061e8 100644
--- a/src/oid.c
+++ b/src/oid.c
@@ -13,6 +13,9 @@
#include <string.h>
#include <limits.h>
+const git_oid git_oid__empty_blob_sha1 =
+ {{ 0xe6, 0x9d, 0xe2, 0x9b, 0xb2, 0xd1, 0xd6, 0x43, 0x4b, 0x8b,
+ 0x29, 0xae, 0x77, 0x5a, 0xd8, 0xc2, 0xe4, 0x8c, 0x53, 0x91 }};
const git_oid git_oid__empty_tree_sha1 =
{{ 0x4b, 0x82, 0x5d, 0xc6, 0x42, 0xcb, 0x6e, 0xb9, 0xa0, 0x60,
0xe5, 0x4b, 0xf8, 0xd6, 0x92, 0x88, 0xfb, 0xee, 0x49, 0x04 }};
diff --git a/src/oid.h b/src/oid.h
index 5c9b68f..5baec33 100644
--- a/src/oid.h
+++ b/src/oid.h
@@ -11,6 +11,7 @@
#include "git2/oid.h"
+extern const git_oid git_oid__empty_blob_sha1;
extern const git_oid git_oid__empty_tree_sha1;
/**