From: Jeff King <peff@xxxxxxxx>
When you are doing a tree-diff, there are basically two options: do not
recurse into subtrees at all, or recurse indefinitely. While most
callers would want to always recurse and see full pathnames, some may
want the efficiency of looking only at a particular level of the tree.
This is currently easy to do for the top-level (just turn off
recursion), but you cannot say "show me what changed in subdir/, but do
not recurse".
This patch adds a max-depth parameter which is measured from the closest
pathspec match, so that you can do:
git log --raw --max-depth=1 -- a/b/c
and see the raw output for a/b/c/, but not those of a/b/c/d/
(instead of the raw output you would see for a/b/c/d).
Signed-off-by: Jeff King <peff@xxxxxxxx>
Signed-off-by: Toon Claes <toon@xxxxxxxxx>
---
Documentation/diff-options.adoc | 28 +++++++++++
diff-lib.c | 5 ++
diff.c | 19 +++++++
diff.h | 9 ++++
t/meson.build | 1 +
t/t4072-diff-max-depth.sh | 109 ++++++++++++++++++++++++++++++++++++++++
tree-diff.c | 78 ++++++++++++++++++++++++++--
7 files changed, 246 insertions(+), 3 deletions(-)
diff --git a/Documentation/diff-options.adoc b/Documentation/diff-options.adoc
index f3a35d8141..46e6ed2d67 100644
--- a/Documentation/diff-options.adoc
+++ b/Documentation/diff-options.adoc
@@ -893,5 +893,33 @@ endif::git-format-patch[]
reverted with `--ita-visible-in-index`. Both options are
experimental and could be removed in future.
+--max-depth=<n>::
+
+ Limit diff recursion to `<n>` levels (implies `-r`). The depth
+ is measured from the closest pathspec. Given a tree containing
+ `foo/bar/baz`, the following list shows the matches generated by
+ each set of options:
++
+--
+ - `--max-depth=0 -- foo`: `foo`
+
+ - `--max-depth=1 -- foo`: `foo/bar`
+
+ - `--max-depth=1 -- foo/bar`: `foo/bar/baz`
+
+ - `--max-depth=1 -- foo foo/bar`: `foo/bar/baz`
+
+ - `--max-depth=2 -- foo`: `foo/bar/baz`
+--
++
+If no pathspec is given, the depth is measured as if all
+top-level entries were specified. Note that this is different
+than measuring from the root, in that `--max-depth=0` would
+still return `foo`. This allows you to still limit depth while
+asking for a subset of the top-level entries.
++
+Note that this option is only supported for diffs between tree objects,
+not against the index or working tree.
+
For more detailed explanation on these common options, see also
linkgit:gitdiffcore[7].
diff --git a/diff-lib.c b/diff-lib.c
index 244468dd1a..fa7c24c267 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -115,6 +115,9 @@ void run_diff_files(struct rev_info *revs, unsigned int option)
uint64_t start = getnanotime();
struct index_state *istate = revs->diffopt.repo->index;
+ if (revs->diffopt.max_depth_valid)
+ die("max-depth is not supported for worktree diffs");
+
diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
refresh_fsmonitor(istate);
@@ -560,6 +563,8 @@ static int diff_cache(struct rev_info *revs,
opts.dst_index = NULL;
opts.pathspec = &revs->diffopt.pathspec;
opts.pathspec->recursive = 1;
+ if (revs->diffopt.max_depth_valid)
+ die("max-depth is not supported for index diffs");
init_tree_desc(&t, &tree->object.oid, tree->buffer, tree->size);
return unpack_trees(1, &t, &opts);
diff --git a/diff.c b/diff.c
index dca87e164f..c03a59ac3b 100644
--- a/diff.c
+++ b/diff.c
@@ -4988,6 +4988,9 @@ void diff_setup_done(struct diff_options *options)
options->filter = ~filter_bit[DIFF_STATUS_FILTER_AON];
options->filter &= ~options->filter_not;
}
+
+ if (options->pathspec.has_wildcard && options->max_depth_valid)
+ die("max-depth cannot be used with wildcard pathspecs");
}
int parse_long_opt(const char *opt, const char **argv,
@@ -5622,6 +5625,18 @@ static int diff_opt_rotate_to(const struct option *opt, const char *arg, int uns
return 0;
}
+static int diff_opt_max_depth(const struct option *opt,
+ const char *arg, int unset)
+{
+ struct diff_options *options = opt->value;
+
+ BUG_ON_OPT_NEG(unset);
+ options->flags.recursive = 1;
+ options->max_depth = strtol(arg, NULL, 10);
+ options->max_depth_valid = 1;
+ return 0;
+}
+
/*
* Consider adding new flags to __git_diff_common_options
* in contrib/completion/git-completion.bash
@@ -5894,6 +5909,10 @@ struct option *add_diff_options(const struct option *opts,
OPT_CALLBACK_F(0, "diff-filter", options, N_("[(A|C|D|M|R|T|U|X|B)...[*]]"),
N_("select files by diff type"),
PARSE_OPT_NONEG, diff_opt_diff_filter),
+ OPT_CALLBACK_F(0, "max-depth", options, N_("<depth>"),
+ N_("maximum tree depth to recurse"),
+ PARSE_OPT_NONEG, diff_opt_max_depth),
+
{
.type = OPTION_CALLBACK,
.long_name = "output",
diff --git a/diff.h b/diff.h
index 62e5768a9a..e3767df237 100644
--- a/diff.h
+++ b/diff.h
@@ -404,6 +404,15 @@ struct diff_options {
struct strmap *additional_path_headers;
int no_free;
+
+ /*
+ * The extra "valid" flag is a slight hack. The value "0" is perfectly
+ * valid for max-depth. We would normally use -1 to indicate "not set",
+ * but there are many code paths which assume that assume that just
+ * zero-ing out a diff_options is enough to initialize it.
+ */
+ int max_depth;
+ int max_depth_valid;
};
unsigned diff_filter_bit(char status);
diff --git a/t/meson.build b/t/meson.build
index 660d780dcc..11908dad6f 100644
--- a/t/meson.build
+++ b/t/meson.build
@@ -501,6 +501,7 @@ integration_tests = [
't4069-remerge-diff.sh',
't4070-diff-pairs.sh',
't4071-diff-minimal.sh',
+ 't4072-diff-max-depth.sh',
't4100-apply-stat.sh',
't4101-apply-nonl.sh',
't4102-apply-rename.sh',
diff --git a/t/t4072-diff-max-depth.sh b/t/t4072-diff-max-depth.sh
new file mode 100755
index 0000000000..1545ebb869
--- /dev/null
+++ b/t/t4072-diff-max-depth.sh
@@ -0,0 +1,109 @@
+#!/bin/sh
+
+test_description='check that diff --max-depth will limit recursion'
+. ./test-lib.sh
+
+make_dir() {
+ mkdir -p "$1" &&
+ echo "$2" >"$1/file"
+}
+
+make_files() {
+ echo "$1" >file &&
+ make_dir one "$1" &&
+ make_dir one/two "$1" &&
+ make_dir one/two/three "$1"
+}
+
+test_expect_success 'setup' '
+ git commit --allow-empty -m empty &&
+ git tag empty &&
+ make_files added &&
+ git add . &&
+ git commit -m added &&
+ make_files modified &&
+ git add . &&
+ git commit -m modified &&
+ make_files index &&
+ git add . &&
+ make_files worktree
+'
+
+test_expect_success '--max-depth is disallowed with wildcard pathspecs' '
+ test_must_fail git diff-tree --max-depth=0 HEAD^ HEAD -- "f*"
+'
+
+check_one() {
+ type=$1; shift
+ args=$1; shift
+ path=$1; shift
+ depth=$1; shift
+ test_expect_${expect:-success} "diff-$type $args, path=$path, depth=$depth" "
+ for i in $*; do echo \$i; done >expect &&
+ git diff-$type --max-depth=$depth --name-only $args -- $path >actual &&
+ test_cmp expect actual
+ "
+}
+
+# For tree comparisons, we expect to see subtrees at the boundary
+# get their own entry.
+check_trees() {
+ check_one tree "$*" '' 0 file one
+ check_one tree "$*" '' 1 file one/file one/two
+ check_one tree "$*" '' 2 file one/file one/two/file one/two/three
+ check_one tree "$*" '' 3 file one/file one/two/file one/two/three/file
+ check_one tree "$*" one 0 one
+ check_one tree "$*" one 1 one/file one/two
+ check_one tree "$*" one 2 one/file one/two/file one/two/three
+ check_one tree "$*" one 3 one/file one/two/file one/two/three/file
+ check_one tree "$*" one/two 0 one/two
+ check_one tree "$*" one/two 1 one/two/file one/two/three
+ check_one tree "$*" one/two 2 one/two/file one/two/three/file
+ check_one tree "$*" one/two/three 0 one/two/three
+ check_one tree "$*" one/two/three 1 one/two/three/file
+}
+
+# But for index comparisons, we do not store subtrees at all, so we do not
+# expect them.
+check_index() {
+ check_one "$@" '' 0 file
+ check_one "$@" '' 1 file one/file
+ check_one "$@" '' 2 file one/file one/two/file
+ check_one "$@" '' 3 file one/file one/two/file one/two/three/file
+ check_one "$@" one 0
+ check_one "$@" one 1 one/file
+ check_one "$@" one 2 one/file one/two/file
+ check_one "$@" one 3 one/file one/two/file one/two/three/file
+ check_one "$@" one/two 0
+ check_one "$@" one/two 1 one/two/file
+ check_one "$@" one/two 2 one/two/file one/two/three/file
+ check_one "$@" one/two/three 0
+ check_one "$@" one/two/three 1 one/two/three/file
+}
+
+# Check as a modification...
+check_trees HEAD^ HEAD
+# ...and as an addition...
+check_trees empty HEAD
+# ...and as a deletion.
+check_trees HEAD empty
+
+# We currently only implement max-depth for trees.
+expect=failure
+# Check index against a tree
+check_index index "--cached HEAD"
+# and index against the worktree
+check_index files ""
+expect=
+
+test_expect_success 'find shortest path within embedded pathspecs' '
+ cat >expect <<-\EOF &&
+ one/file
+ one/two/file
+ one/two/three/file
+ EOF
+ git diff-tree --max-depth=2 --name-only HEAD^ HEAD -- one one/two >actual &&
+ test_cmp expect actual
+'
+
+test_done
diff --git a/tree-diff.c b/tree-diff.c
index e00fc2f450..acd302500f 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -13,6 +13,7 @@
#include "tree-walk.h"
#include "environment.h"
#include "repository.h"
+#include "dir.h"
/*
* Some mode bits are also used internally for computations.
@@ -48,6 +49,73 @@
free((x)); \
} while(0)
+/* Returns true if and only if "dir" is a leading directory of "path" */
+static int is_dir_prefix(const char *path, const char *dir, int dirlen)
+{
+ return !strncmp(path, dir, dirlen) &&
+ (!path[dirlen] || path[dirlen] == '/');
+}
+
+static int check_recursion_depth(struct strbuf *name,
+ const struct pathspec *ps,
+ int max_depth)
+{
+ int i;
+
+ if (!ps->nr)
+ return within_depth(name->buf, name->len, 1, max_depth);
+
+ /*
+ * We look through the pathspecs in reverse-sorted order, because we
+ * want to find the longest match first (e.g., "a/b" is better for
+ * checking depth than "a/b/c").
+ */
+ for (i = ps->nr - 1; i >= 0; i--) {
+ const struct pathspec_item *item = ps->items+i;
+
+ /*
+ * If the name to match is longer than the pathspec, then we
+ * are only interested if the pathspec matches and we are
+ * within the allowed depth.
+ */
+ if (name->len >= item->len) {
+ if (!is_dir_prefix(name->buf, item->match, item->len))
+ continue;
+ return within_depth(name->buf + item->len,
+ name->len - item->len,
+ 1, max_depth);
+ }
+
+ /*
+ * Otherwise, our name is shorter than the pathspec. We need to
+ * check if it is a prefix of the pathspec; if so, we must
+ * always recurse in order to process further (the resulting
+ * paths we find might or might not match our pathspec, but we
+ * cannot know until we recurse).
+ */
+ if (is_dir_prefix(item->match, name->buf, name->len))
+ return 1;
+ }
+ return 0;
+}
+
+static int should_recurse(struct strbuf *name, struct diff_options *opt)
+{
+ if (!opt->flags.recursive)
+ return 0;
+ if (!opt->max_depth_valid)
+ return 1;
+
+ /*
+ * We catch this during diff_setup_done, but let's double-check
+ * against any internal munging.
+ */
+ if (opt->pathspec.has_wildcard)
+ die("BUG: wildcard pathspecs are incompatible with max-depth");
+
+ return check_recursion_depth(name, &opt->pathspec, opt->max_depth);
+}
+
static void ll_diff_tree_paths(
struct combine_diff_path ***tail, const struct object_id *oid,
const struct object_id **parents_oid, int nparent,
@@ -170,9 +238,13 @@ static void emit_path(struct combine_diff_path ***tail,
mode = 0;
}
- if (opt->flags.recursive && isdir) {
- recurse = 1;
- emitthis = opt->flags.tree_in_recursive;
+ if (isdir) {
+ strbuf_add(base, path, pathlen);
+ if (should_recurse(base, opt)) {
+ recurse = 1;
+ emitthis = opt->flags.tree_in_recursive;
+ }
+ strbuf_setlen(base, old_baselen);
}
if (emitthis) {
--
2.50.1.327.g047016eb4a
