Add git_pathspec_match_diff API

This adds an additional pathspec API that will match a pathspec
against a diff object.  This is convenient if you want to handle
renames (so you need the whole diff and can't use the pathspec
constraint built into the diff API) but still want to tell if the
diff had any files that matched the pathspec.

When the pathspec is matched against a diff, instead of keeping
a list of filenames that matched, instead the API keeps the list
of git_diff_deltas that matched and they can be retrieved via a
new API git_pathspec_match_list_diff_entry.

There are a couple of other minor API extensions here that were
mostly for the sake of convenience and to reduce dependencies
on knowing the internal data structure between files inside the
library.

1 files changed, 239 insertions, 75 deletions

diff --git a/src/pathspec.c b/src/pathspec.c
index 021f38f1c..625726e0b 100644
--- a/src/pathspec.c
+++ b/src/pathspec.c
@@ -6,12 +6,15 @@
  */
 
 #include "git2/pathspec.h"
+#include "git2/diff.h"
 #include "pathspec.h"
 #include "buf_text.h"
 #include "attr_file.h"
 #include "iterator.h"
 #include "repository.h"
 #include "index.h"
+#include "bitvec.h"
+#include "diff.h"
 
 /* what is the common non-wildcard prefix for all items in the pathspec */
 char *git_pathspec_prefix(const git_strarray *pathspec)
@@ -162,6 +165,28 @@ static int pathspec_match_one(
 	return -1;
 }
 
+static int git_pathspec__match_at(
+	size_t *matched_at,
+	const git_vector *vspec,
+	struct pathspec_match_context *ctxt,
+	const char *path0,
+	const char *path1)
+{
+	int result = GIT_ENOTFOUND;
+	size_t i = 0;
+	const git_attr_fnmatch *match;
+
+	git_vector_foreach(vspec, i, match) {
+		if (path0 && (result = pathspec_match_one(match, ctxt, path0)) >= 0)
+			break;
+		if (path1 && (result = pathspec_match_one(match, ctxt, path1)) >= 0)
+			break;
+	}
+
+	*matched_at = i;
+	return result;
+}
+
 /* match a path against the vectorized pathspec */
 bool git_pathspec__match(
 	const git_vector *vspec,
@@ -171,8 +196,8 @@ bool git_pathspec__match(
 	const char **matched_pathspec,
 	size_t *matched_at)
 {
-	size_t i;
-	const git_attr_fnmatch *match;
+	int result;
+	size_t pos;
 	struct pathspec_match_context ctxt;
 
 	if (matched_pathspec)
@@ -185,20 +210,18 @@ bool git_pathspec__match(
 
 	pathspec_match_context_init(&ctxt, disable_fnmatch, casefold);
 
-	git_vector_foreach(vspec, i, match) {
-		int result = pathspec_match_one(match, &ctxt, path);
-
-		if (result >= 0) {
-			if (matched_pathspec)
-				*matched_pathspec = match->pattern;
-			if (matched_at)
-				*matched_at = i;
-
-			return (result != 0);
+	result = git_pathspec__match_at(&pos, vspec, &ctxt, path, NULL);
+	if (result >= 0) {
+		if (matched_pathspec) {
+			const git_attr_fnmatch *match = git_vector_get(vspec, pos);
+			*matched_pathspec = match->pattern;
 		}
+
+		if (matched_at)
+			*matched_at = pos;
 	}
 
-	return false;
+	return (result > 0);
 }
 
 
@@ -277,7 +300,8 @@ static void pathspec_match_free(git_pathspec_match_list *m)
 	git__free(m);
 }
 
-static git_pathspec_match_list *pathspec_match_alloc(git_pathspec *ps)
+static git_pathspec_match_list *pathspec_match_alloc(
+	git_pathspec *ps, int datatype)
 {
 	git_pathspec_match_list *m = git__calloc(1, sizeof(git_pathspec_match_list));
 
@@ -292,16 +316,73 @@ static git_pathspec_match_list *pathspec_match_alloc(git_pathspec *ps)
 	 */
 	GIT_REFCOUNT_INC(ps);
 	m->pathspec = ps;
+	m->datatype = datatype;
 
 	return m;
 }
 
-GIT_INLINE(void) pathspec_mark_pattern(uint8_t *used, size_t pos, size_t *ct)
+GIT_INLINE(size_t) pathspec_mark_pattern(git_bitvec *used, size_t pos)
+{
+	if (!git_bitvec_get(used, pos)) {
+		git_bitvec_set(used, pos, true);
+		return 1;
+	}
+
+	return 0;
+}
+
+static size_t pathspec_mark_remaining(
+	git_bitvec *used,
+	git_vector *patterns,
+	struct pathspec_match_context *ctxt,
+	size_t start,
+	const char *path0,
+	const char *path1)
+{
+	size_t count = 0;
+
+	if (path1 == path0)
+		path1 = NULL;
+
+	for (; start < patterns->length; ++start) {
+		const git_attr_fnmatch *pat = git_vector_get(patterns, start);
+
+		if (git_bitvec_get(used, start))
+			continue;
+
+		if (path0 && pathspec_match_one(pat, ctxt, path0) > 0)
+			count += pathspec_mark_pattern(used, start);
+		else if (path1 && pathspec_match_one(pat, ctxt, path1) > 0)
+			count += pathspec_mark_pattern(used, start);
+	}
+
+	return count;
+}
+
+static int pathspec_build_failure_array(
+	git_pathspec_string_array_t *failures,
+	git_vector *patterns,
+	git_bitvec *used,
+	git_pool *pool)
 {
-	if (!used[pos]) {
-		used[pos] = 1;
-		(*ct)++;
+	size_t pos;
+	char **failed;
+	const git_attr_fnmatch *pat;
+
+	for (pos = 0; pos < patterns->length; ++pos) {
+		if (git_bitvec_get(used, pos))
+			continue;
+
+		if ((failed = git_array_alloc(*failures)) == NULL)
+			return -1;
+
+		pat = git_vector_get(patterns, pos);
+
+		if ((*failed = git_pool_strdup(pool, pat->pattern)) == NULL)
+			return -1;
 	}
+
+	return 0;
 }
 
 static int pathspec_match_from_iterator(
@@ -315,47 +396,37 @@ static int pathspec_match_from_iterator(
 	const git_index_entry *entry = NULL;
 	struct pathspec_match_context ctxt;
 	git_vector *patterns = &ps->pathspec;
-	bool find_failures = (flags & GIT_PATHSPEC_FIND_FAILURES) != 0;
-	bool failures_only = (flags & GIT_PATHSPEC_FAILURES_ONLY) != 0;
+	bool find_failures = out && (flags & GIT_PATHSPEC_FIND_FAILURES) != 0;
+	bool failures_only = !out || (flags & GIT_PATHSPEC_FAILURES_ONLY) != 0;
 	size_t pos, used_ct = 0, found_files = 0;
 	git_index *index = NULL;
-	uint8_t *used_patterns = NULL;
+	git_bitvec used_patterns;
 	char **file;
 
+	if (git_bitvec_init(&used_patterns, patterns->length) < 0)
+		return -1;
+
 	if (out) {
-		*out = m = pathspec_match_alloc(ps);
+		*out = m = pathspec_match_alloc(ps, PATHSPEC_DATATYPE_STRINGS);
 		GITERR_CHECK_ALLOC(m);
-	} else {
-		failures_only = true;
-		find_failures = false;
 	}
 
 	if ((error = git_iterator_reset(iter, ps->prefix, ps->prefix)) < 0)
 		goto done;
 
-	if (patterns->length > 0) {
-		used_patterns = git__calloc(patterns->length, sizeof(uint8_t));
-		GITERR_CHECK_ALLOC(used_patterns);
-	}
-
 	if (git_iterator_type(iter) == GIT_ITERATOR_TYPE_WORKDIR &&
 		(error = git_repository_index__weakptr(
 			&index, git_iterator_owner(iter))) < 0)
 		goto done;
 
-	pathspec_match_context_init(&ctxt,
-		(flags & GIT_PATHSPEC_NO_GLOB) != 0, git_iterator_ignore_case(iter));
+	pathspec_match_context_init(
+		&ctxt, (flags & GIT_PATHSPEC_NO_GLOB) != 0,
+		git_iterator_ignore_case(iter));
 
 	while (!(error = git_iterator_advance(&entry, iter))) {
-		int result = -1;
-
-		for (pos = 0; pos < patterns->length; ++pos) {
-			const git_attr_fnmatch *pat = git_vector_get(patterns, pos);
-
-			result = pathspec_match_one(pat, &ctxt, entry->path);
-			if (result >= 0)
-				break;
-		}
+		/* search for match with entry->path */
+		int result = git_pathspec__match_at(
+			&pos, patterns, &ctxt, entry->path, NULL);
 
 		/* no matches for this path */
 		if (result < 0)
@@ -363,31 +434,24 @@ static int pathspec_match_from_iterator(
 
 		/* if result was a negative pattern match, then don't list file */
 		if (!result) {
-			pathspec_mark_pattern(used_patterns, pos, &used_ct);
+			used_ct += pathspec_mark_pattern(&used_patterns, pos);
 			continue;
 		}
 
-		/* check if path is untracked and ignored */
+		/* check if path is ignored and untracked */
 		if (index != NULL &&
 			git_iterator_current_is_ignored(iter) &&
 			git_index__find(NULL, index, entry->path, GIT_INDEX_STAGE_ANY) < 0)
 			continue;
 
 		/* mark the matched pattern as used */
-		pathspec_mark_pattern(used_patterns, pos, &used_ct);
+		used_ct += pathspec_mark_pattern(&used_patterns, pos);
 		++found_files;
 
 		/* if find_failures is on, check if any later patterns also match */
-		if (find_failures && used_ct < patterns->length) {
-			for (++pos; pos < patterns->length; ++pos) {
-				const git_attr_fnmatch *pat = git_vector_get(patterns, pos);
-				if (used_patterns[pos])
-					continue;
-
-				if (pathspec_match_one(pat, &ctxt, entry->path) > 0)
-					pathspec_mark_pattern(used_patterns, pos, &used_ct);
-			}
-		}
+		if (find_failures && used_ct < patterns->length)
+			used_ct += pathspec_mark_remaining(
+				&used_patterns, patterns, &ctxt, pos + 1, entry->path, NULL);
 
 		/* if only looking at failures, exit early or just continue */
 		if (failures_only || !out) {
@@ -397,7 +461,7 @@ static int pathspec_match_from_iterator(
 		}
 
 		/* insert matched path into matches array */
-		if ((file = git_array_alloc(m->matches)) == NULL ||
+		if ((file = (char **)git_array_alloc(m->matches)) == NULL ||
 			(*file = git_pool_strdup(&m->pool, entry->path)) == NULL) {
 			error = -1;
 			goto done;
@@ -409,19 +473,10 @@ static int pathspec_match_from_iterator(
 	error = 0;
 
 	/* insert patterns that had no matches into failures array */
-	if (find_failures && used_ct < patterns->length) {
-		for (pos = 0; pos < patterns->length; ++pos) {
-			const git_attr_fnmatch *pat = git_vector_get(patterns, pos);
-			if (used_patterns[pos])
-				continue;
-
-			if ((file = git_array_alloc(m->failures)) == NULL ||
-				(*file = git_pool_strdup(&m->pool, pat->pattern)) == NULL) {
-				error = -1;
-				goto done;
-			}
-		}
-	}
+	if (find_failures && used_ct < patterns->length &&
+		(error = pathspec_build_failure_array(
+			&m->failures, patterns, &used_patterns, &m->pool)) < 0)
+		goto done;
 
 	/* if every pattern failed to match, then we have failed */
 	if ((flags & GIT_PATHSPEC_NO_MATCH_ERROR) != 0 && !found_files) {
@@ -430,7 +485,7 @@ static int pathspec_match_from_iterator(
 	}
 
 done:
-	git__free(used_patterns);
+	git_bitvec_free(&used_patterns);
 
 	if (error < 0) {
 		pathspec_match_free(m);
@@ -518,33 +573,142 @@ int git_pathspec_match_tree(
 	return error;
 }
 
+int git_pathspec_match_diff(
+	git_pathspec_match_list **out,
+	git_diff_list *diff,
+	uint32_t flags,
+	git_pathspec *ps)
+{
+	int error = 0;
+	git_pathspec_match_list *m = NULL;
+	struct pathspec_match_context ctxt;
+	git_vector *patterns = &ps->pathspec;
+	bool find_failures = out && (flags & GIT_PATHSPEC_FIND_FAILURES) != 0;
+	bool failures_only = !out || (flags & GIT_PATHSPEC_FAILURES_ONLY) != 0;
+	size_t i, pos, used_ct = 0, found_deltas = 0;
+	const git_diff_delta *delta, **match;
+	git_bitvec used_patterns;
+
+	assert(diff);
+
+	if (git_bitvec_init(&used_patterns, patterns->length) < 0)
+		return -1;
+
+	if (out) {
+		*out = m = pathspec_match_alloc(ps, PATHSPEC_DATATYPE_DIFF);
+		GITERR_CHECK_ALLOC(m);
+	}
+
+	pathspec_match_context_init(
+		&ctxt, (flags & GIT_PATHSPEC_NO_GLOB) != 0,
+		git_diff_is_sorted_icase(diff));
+
+	git_vector_foreach(&diff->deltas, i, delta) {
+		/* search for match with delta */
+		int result = git_pathspec__match_at(
+			&pos, patterns, &ctxt, delta->old_file.path, delta->new_file.path);
+
+		/* no matches for this path */
+		if (result < 0)
+			continue;
+
+		/* mark the matched pattern as used */
+		used_ct += pathspec_mark_pattern(&used_patterns, pos);
+
+		/* if result was a negative pattern match, then don't list file */
+		if (!result)
+			continue;
+
+		++found_deltas;
+
+		/* if find_failures is on, check if any later patterns also match */
+		if (find_failures && used_ct < patterns->length)
+			used_ct += pathspec_mark_remaining(
+				&used_patterns, patterns, &ctxt, pos + 1,
+				delta->old_file.path, delta->new_file.path);
+
+		/* if only looking at failures, exit early or just continue */
+		if (failures_only || !out) {
+			if (used_ct == patterns->length)
+				break;
+			continue;
+		}
+
+		/* insert matched delta into matches array */
+		if (!(match = (const git_diff_delta **)git_array_alloc(m->matches))) {
+			error = -1;
+			goto done;
+		} else {
+			*match = delta;
+		}
+	}
+
+	/* insert patterns that had no matches into failures array */
+	if (find_failures && used_ct < patterns->length &&
+		(error = pathspec_build_failure_array(
+			&m->failures, patterns, &used_patterns, &m->pool)) < 0)
+		goto done;
+
+	/* if every pattern failed to match, then we have failed */
+	if ((flags & GIT_PATHSPEC_NO_MATCH_ERROR) != 0 && !found_deltas) {
+		giterr_set(GITERR_INVALID, "No matching deltas were found");
+		error = GIT_ENOTFOUND;
+	}
+
+done:
+	git_bitvec_free(&used_patterns);
+
+	if (error < 0) {
+		pathspec_match_free(m);
+		if (out) *out = NULL;
+	}
+
+	return error;
+}
+
 void git_pathspec_match_list_free(git_pathspec_match_list *m)
 {
-	pathspec_match_free(m);
+	if (m)
+		pathspec_match_free(m);
 }
 
 size_t git_pathspec_match_list_entrycount(
 	const git_pathspec_match_list *m)
 {
-	return git_array_size(m->matches);
+	return m ? git_array_size(m->matches) : 0;
 }
 
 const char *git_pathspec_match_list_entry(
 	const git_pathspec_match_list *m, size_t pos)
 {
-	char **entry = git_array_get(m->matches, pos);
-	return entry ? *entry : NULL;
+	if (!m || m->datatype != PATHSPEC_DATATYPE_STRINGS ||
+		!git_array_valid_index(m->matches, pos))
+		return NULL;
+
+	return *((const char **)git_array_get(m->matches, pos));
+}
+
+const git_diff_delta *git_pathspec_match_list_diff_entry(
+	const git_pathspec_match_list *m, size_t pos)
+{
+	if (!m || m->datatype != PATHSPEC_DATATYPE_DIFF ||
+		!git_array_valid_index(m->matches, pos))
+		return NULL;
+
+	return *((const git_diff_delta **)git_array_get(m->matches, pos));
 }
 
 size_t git_pathspec_match_list_failed_entrycount(
 	const git_pathspec_match_list *m)
 {
-	return git_array_size(m->failures);
+	return m ? git_array_size(m->failures) : 0;
 }
 
 const char * git_pathspec_match_list_failed_entry(
 	const git_pathspec_match_list *m, size_t pos)
 {
-	char **entry = git_array_get(m->failures, pos);
+	char **entry = m ? git_array_get(m->failures, pos) : NULL;
+
 	return entry ? *entry : NULL;
 }
+