1 files changed, 426 insertions, 45 deletions

diff --git a/tree-walk.c b/tree-walk.c
index 02e2aed773..33f749e1e7 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -1,5 +1,7 @@
 #include "cache.h"
 #include "tree-walk.h"
+#include "unpack-trees.h"
+#include "dir.h"
 #include "tree.h"
 
 static const char *get_mode(const char *str, unsigned int *modep)
@@ -60,13 +62,6 @@ void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
 	return buf;
 }
 
-static int entry_compare(struct name_entry *a, struct name_entry *b)
-{
-	return df_name_compare(
-			a->path, tree_entry_len(a->path, a->sha1), a->mode,
-			b->path, tree_entry_len(b->path, b->sha1), b->mode);
-}
-
 static void entry_clear(struct name_entry *a)
 {
 	memset(a, 0, sizeof(*a));
@@ -138,67 +133,269 @@ char *make_traverse_path(char *path, const struct traverse_info *info, const str
 	return path;
 }
 
+struct tree_desc_skip {
+	struct tree_desc_skip *prev;
+	const void *ptr;
+};
+
+struct tree_desc_x {
+	struct tree_desc d;
+	struct tree_desc_skip *skip;
+};
+
+static int name_compare(const char *a, int a_len,
+			const char *b, int b_len)
+{
+	int len = (a_len < b_len) ? a_len : b_len;
+	int cmp = memcmp(a, b, len);
+	if (cmp)
+		return cmp;
+	return (a_len - b_len);
+}
+
+static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
+{
+	/*
+	 * The caller wants to pick *a* from a tree or nothing.
+	 * We are looking at *b* in a tree.
+	 *
+	 * (0) If a and b are the same name, we are trivially happy.
+	 *
+	 * There are three possibilities where *a* could be hiding
+	 * behind *b*.
+	 *
+	 * (1) *a* == "t",   *b* == "ab"  i.e. *b* sorts earlier than *a* no
+	 *                                matter what.
+	 * (2) *a* == "t",   *b* == "t-2" and "t" is a subtree in the tree;
+	 * (3) *a* == "t-2", *b* == "t"   and "t-2" is a blob in the tree.
+	 *
+	 * Otherwise we know *a* won't appear in the tree without
+	 * scanning further.
+	 */
+
+	int cmp = name_compare(a, a_len, b, b_len);
+
+	/* Most common case first -- reading sync'd trees */
+	if (!cmp)
+		return cmp;
+
+	if (0 < cmp) {
+		/* a comes after b; it does not matter if it is case (3)
+		if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
+			return 1;
+		*/
+		return 1; /* keep looking */
+	}
+
+	/* b comes after a; are we looking at case (2)? */
+	if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
+		return 1; /* keep looking */
+
+	return -1; /* a cannot appear in the tree */
+}
+
+/*
+ * From the extended tree_desc, extract the first name entry, while
+ * paying attention to the candidate "first" name.  Most importantly,
+ * when looking for an entry, if there are entries that sorts earlier
+ * in the tree object representation than that name, skip them and
+ * process the named entry first.  We will remember that we haven't
+ * processed the first entry yet, and in the later call skip the
+ * entry we processed early when update_extended_entry() is called.
+ *
+ * E.g. if the underlying tree object has these entries:
+ *
+ *    blob    "t-1"
+ *    blob    "t-2"
+ *    tree    "t"
+ *    blob    "t=1"
+ *
+ * and the "first" asks for "t", remember that we still need to
+ * process "t-1" and "t-2" but extract "t".  After processing the
+ * entry "t" from this call, the caller will let us know by calling
+ * update_extended_entry() that we can remember "t" has been processed
+ * already.
+ */
+
+static void extended_entry_extract(struct tree_desc_x *t,
+				   struct name_entry *a,
+				   const char *first,
+				   int first_len)
+{
+	const char *path;
+	int len;
+	struct tree_desc probe;
+	struct tree_desc_skip *skip;
+
+	/*
+	 * Extract the first entry from the tree_desc, but skip the
+	 * ones that we already returned in earlier rounds.
+	 */
+	while (1) {
+		if (!t->d.size) {
+			entry_clear(a);
+			break; /* not found */
+		}
+		entry_extract(&t->d, a);
+		for (skip = t->skip; skip; skip = skip->prev)
+			if (a->path == skip->ptr)
+				break; /* found */
+		if (!skip)
+			break;
+		/* We have processed this entry already. */
+		update_tree_entry(&t->d);
+	}
+
+	if (!first || !a->path)
+		return;
+
+	/*
+	 * The caller wants "first" from this tree, or nothing.
+	 */
+	path = a->path;
+	len = tree_entry_len(a->path, a->sha1);
+	switch (check_entry_match(first, first_len, path, len)) {
+	case -1:
+		entry_clear(a);
+	case 0:
+		return;
+	default:
+		break;
+	}
+
+	/*
+	 * We need to look-ahead -- we suspect that a subtree whose
+	 * name is "first" may be hiding behind the current entry "path".
+	 */
+	probe = t->d;
+	while (probe.size) {
+		entry_extract(&probe, a);
+		path = a->path;
+		len = tree_entry_len(a->path, a->sha1);
+		switch (check_entry_match(first, first_len, path, len)) {
+		case -1:
+			entry_clear(a);
+		case 0:
+			return;
+		default:
+			update_tree_entry(&probe);
+			break;
+		}
+		/* keep looking */
+	}
+	entry_clear(a);
+}
+
+static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
+{
+	if (t->d.entry.path == a->path) {
+		update_tree_entry(&t->d);
+	} else {
+		/* we have returned this entry early */
+		struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
+		skip->ptr = a->path;
+		skip->prev = t->skip;
+		t->skip = skip;
+	}
+}
+
+static void free_extended_entry(struct tree_desc_x *t)
+{
+	struct tree_desc_skip *p, *s;
+
+	for (s = t->skip; s; s = p) {
+		p = s->prev;
+		free(s);
+	}
+}
+
 int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
 {
 	int ret = 0;
+	int error = 0;
 	struct name_entry *entry = xmalloc(n*sizeof(*entry));
+	int i;
+	struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
+
+	for (i = 0; i < n; i++)
+		tx[i].d = t[i];
 
 	for (;;) {
-		unsigned long mask = 0;
-		unsigned long dirmask = 0;
-		int i, last;
+		unsigned long mask, dirmask;
+		const char *first = NULL;
+		int first_len = 0;
+		struct name_entry *e;
+		int len;
+
+		for (i = 0; i < n; i++) {
+			e = entry + i;
+			extended_entry_extract(tx + i, e, NULL, 0);
+		}
 
-		last = -1;
+		/*
+		 * A tree may have "t-2" at the current location even
+		 * though it may have "t" that is a subtree behind it,
+		 * and another tree may return "t".  We want to grab
+		 * all "t" from all trees to match in such a case.
+		 */
 		for (i = 0; i < n; i++) {
-			if (!t[i].size)
+			e = entry + i;
+			if (!e->path)
 				continue;
-			entry_extract(t+i, entry+i);
-			if (last >= 0) {
-				int cmp = entry_compare(entry+i, entry+last);
+			len = tree_entry_len(e->path, e->sha1);
+			if (!first) {
+				first = e->path;
+				first_len = len;
+				continue;
+			}
+			if (name_compare(e->path, len, first, first_len) < 0) {
+				first = e->path;
+				first_len = len;
+			}
+		}
 
-				/*
-				 * Is the new name bigger than the old one?
-				 * Ignore it
-				 */
-				if (cmp > 0)
+		if (first) {
+			for (i = 0; i < n; i++) {
+				e = entry + i;
+				extended_entry_extract(tx + i, e, first, first_len);
+				/* Cull the ones that are not the earliest */
+				if (!e->path)
 					continue;
-				/*
-				 * Is the new name smaller than the old one?
-				 * Ignore all old ones
-				 */
-				if (cmp < 0)
-					mask = 0;
+				len = tree_entry_len(e->path, e->sha1);
+				if (name_compare(e->path, len, first, first_len))
+					entry_clear(e);
 			}
+		}
+
+		/* Now we have in entry[i] the earliest name from the trees */
+		mask = 0;
+		dirmask = 0;
+		for (i = 0; i < n; i++) {
+			if (!entry[i].path)
+				continue;
 			mask |= 1ul << i;
 			if (S_ISDIR(entry[i].mode))
 				dirmask |= 1ul << i;
-			last = i;
 		}
 		if (!mask)
 			break;
-		dirmask &= mask;
-
-		/*
-		 * Clear all the unused name-entries.
-		 */
-		for (i = 0; i < n; i++) {
-			if (mask & (1ul << i))
-				continue;
-			entry_clear(entry + i);
-		}
 		ret = info->fn(n, mask, dirmask, entry, info);
-		if (ret < 0)
-			break;
-		if (ret)
-			mask &= ret;
+		if (ret < 0) {
+			error = ret;
+			if (!info->show_all_errors)
+				break;
+		}
+		mask &= ret;
 		ret = 0;
-		for (i = 0; i < n; i++) {
+		for (i = 0; i < n; i++)
 			if (mask & (1ul << i))
-				update_tree_entry(t + i);
-		}
+				update_extended_entry(tx + i, entry + i);
 	}
 	free(entry);
-	return ret;
+	for (i = 0; i < n; i++)
+		free_extended_entry(tx + i);
+	free(tx);
+	return error;
 }
 
 static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
@@ -250,6 +447,7 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
 
 	if (name[0] == '\0') {
 		hashcpy(sha1, root);
+		free(tree);
 		return 0;
 	}
 
@@ -258,3 +456,186 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
 	free(tree);
 	return retval;
 }
+
+static int match_entry(const struct name_entry *entry, int pathlen,
+		       const char *match, int matchlen,
+		       int *never_interesting)
+{
+	int m = -1; /* signals that we haven't called strncmp() */
+
+	if (*never_interesting) {
+		/*
+		 * We have not seen any match that sorts later
+		 * than the current path.
+		 */
+
+		/*
+		 * Does match sort strictly earlier than path
+		 * with their common parts?
+		 */
+		m = strncmp(match, entry->path,
+			    (matchlen < pathlen) ? matchlen : pathlen);
+		if (m < 0)
+			return 0;
+
+		/*
+		 * If we come here even once, that means there is at
+		 * least one pathspec that would sort equal to or
+		 * later than the path we are currently looking at.
+		 * In other words, if we have never reached this point
+		 * after iterating all pathspecs, it means all
+		 * pathspecs are either outside of base, or inside the
+		 * base but sorts strictly earlier than the current
+		 * one.  In either case, they will never match the
+		 * subsequent entries.  In such a case, we initialized
+		 * the variable to -1 and that is what will be
+		 * returned, allowing the caller to terminate early.
+		 */
+		*never_interesting = 0;
+	}
+
+	if (pathlen > matchlen)
+		return 0;
+
+	if (matchlen > pathlen) {
+		if (match[pathlen] != '/')
+			return 0;
+		if (!S_ISDIR(entry->mode))
+			return 0;
+	}
+
+	if (m == -1)
+		/*
+		 * we cheated and did not do strncmp(), so we do
+		 * that here.
+		 */
+		m = strncmp(match, entry->path, pathlen);
+
+	/*
+	 * If common part matched earlier then it is a hit,
+	 * because we rejected the case where path is not a
+	 * leading directory and is shorter than match.
+	 */
+	if (!m)
+		return 1;
+
+	return 0;
+}
+
+static int match_dir_prefix(const char *base, int baselen,
+			    const char *match, int matchlen)
+{
+	if (strncmp(base, match, matchlen))
+		return 0;
+
+	/*
+	 * If the base is a subdirectory of a path which
+	 * was specified, all of them are interesting.
+	 */
+	if (!matchlen ||
+	    base[matchlen] == '/' ||
+	    match[matchlen - 1] == '/')
+		return 1;
+
+	/* Just a random prefix match */
+	return 0;
+}
+
+/*
+ * Is a tree entry interesting given the pathspec we have?
+ *
+ * Pre-condition: either baselen == base_offset (i.e. empty path)
+ * or base[baselen-1] == '/' (i.e. with trailing slash).
+ *
+ * Return:
+ *  - 2 for "yes, and all subsequent entries will be"
+ *  - 1 for yes
+ *  - zero for no
+ *  - negative for "no, and no subsequent entries will be either"
+ */
+int tree_entry_interesting(const struct name_entry *entry,
+			   struct strbuf *base, int base_offset,
+			   const struct pathspec *ps)
+{
+	int i;
+	int pathlen, baselen = base->len - base_offset;
+	int never_interesting = ps->has_wildcard ? 0 : -1;
+
+	if (!ps->nr) {
+		if (!ps->recursive || ps->max_depth == -1)
+			return 2;
+		return !!within_depth(base->buf + base_offset, baselen,
+				      !!S_ISDIR(entry->mode),
+				      ps->max_depth);
+	}
+
+	pathlen = tree_entry_len(entry->path, entry->sha1);
+
+	for (i = ps->nr - 1; i >= 0; i--) {
+		const struct pathspec_item *item = ps->items+i;
+		const char *match = item->match;
+		const char *base_str = base->buf + base_offset;
+		int matchlen = item->len;
+
+		if (baselen >= matchlen) {
+			/* If it doesn't match, move along... */
+			if (!match_dir_prefix(base_str, baselen, match, matchlen))
+				goto match_wildcards;
+
+			if (!ps->recursive || ps->max_depth == -1)
+				return 2;
+
+			return !!within_depth(base_str + matchlen + 1,
+					      baselen - matchlen - 1,
+					      !!S_ISDIR(entry->mode),
+					      ps->max_depth);
+		}
+
+		/* Does the base match? */
+		if (!strncmp(base_str, match, baselen)) {
+			if (match_entry(entry, pathlen,
+					match + baselen, matchlen - baselen,
+					&never_interesting))
+				return 1;
+
+			if (ps->items[i].use_wildcard) {
+				if (!fnmatch(match + baselen, entry->path, 0))
+					return 1;
+
+				/*
+				 * Match all directories. We'll try to
+				 * match files later on.
+				 */
+				if (ps->recursive && S_ISDIR(entry->mode))
+					return 1;
+			}
+
+			continue;
+		}
+
+match_wildcards:
+		if (!ps->items[i].use_wildcard)
+			continue;
+
+		/*
+		 * Concatenate base and entry->path into one and do
+		 * fnmatch() on it.
+		 */
+
+		strbuf_add(base, entry->path, pathlen);
+
+		if (!fnmatch(match, base->buf + base_offset, 0)) {
+			strbuf_setlen(base, base_offset + baselen);
+			return 1;
+		}
+		strbuf_setlen(base, base_offset + baselen);
+
+		/*
+		 * Match all directories. We'll try to match files
+		 * later on.
+		 */
+		if (ps->recursive && S_ISDIR(entry->mode))
+			return 1;
+	}
+	return never_interesting; /* No matches */
+}