Merge branch 'jk/doc-fsck' into maint
[gitweb.git] / tree-walk.c
index 02e2aed7737207225f1b96eed774a1b75dd6d8d9..f82dba6a1f43bf2a259952a4fd6db94d6335deb7 100644 (file)
@@ -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));
@@ -121,7 +116,7 @@ void setup_traverse_info(struct traverse_info *info, const char *base)
 
 char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n)
 {
-       int len = tree_entry_len(n->path, n->sha1);
+       int len = tree_entry_len(n);
        int pathlen = info->pathlen;
 
        path[pathlen + len] = 0;
@@ -131,74 +126,303 @@ char *make_traverse_path(char *path, const struct traverse_info *info, const str
                        break;
                path[--pathlen] = '/';
                n = &info->name;
-               len = tree_entry_len(n->path, n->sha1);
+               len = tree_entry_len(n);
                info = info->prev;
                pathlen -= len;
        }
        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);
+       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);
+               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);
+       }
+}
+
+static inline int prune_traversal(struct name_entry *e,
+                                 struct traverse_info *info,
+                                 struct strbuf *base,
+                                 int still_interesting)
+{
+       if (!info->pathspec || still_interesting == 2)
+               return 2;
+       if (still_interesting < 0)
+               return still_interesting;
+       return tree_entry_interesting(e, base, 0, info->pathspec);
+}
+
 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));
+       struct strbuf base = STRBUF_INIT;
+       int interesting = 1;
+
+       for (i = 0; i < n; i++)
+               tx[i].d = t[i];
+
+       if (info->prev) {
+               strbuf_grow(&base, info->pathlen);
+               make_traverse_path(base.buf, info->prev, &info->name);
+               base.buf[info->pathlen-1] = '/';
+               strbuf_setlen(&base, info->pathlen);
+       }
        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 = NULL;
+               int len;
 
-               last = -1;
                for (i = 0; i < n; i++) {
-                       if (!t[i].size)
+                       e = entry + i;
+                       extended_entry_extract(tx + i, e, NULL, 0);
+               }
+
+               /*
+                * 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++) {
+                       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);
+                       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);
+                               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;
+                       e = &entry[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)
+               interesting = prune_traversal(e, info, &base, interesting);
+               if (interesting < 0)
                        break;
-               if (ret)
+               if (interesting) {
+                       ret = info->fn(n, mask, dirmask, entry, info);
+                       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);
+       strbuf_release(&base);
+       return error;
 }
 
 static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
@@ -210,8 +434,8 @@ static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char
                int entrylen, cmp;
 
                sha1 = tree_entry_extract(t, &entry, mode);
+               entrylen = tree_entry_len(&t->entry);
                update_tree_entry(t);
-               entrylen = tree_entry_len(entry, sha1);
                if (entrylen > namelen)
                        continue;
                cmp = memcmp(name, entry, entrylen);
@@ -241,7 +465,6 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
        int retval;
        void *tree;
        unsigned long size;
-       struct tree_desc t;
        unsigned char root[20];
 
        tree = read_object_with_reference(tree_sha1, tree_type, &size, root);
@@ -250,11 +473,197 @@ 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;
        }
 
-       init_tree_desc(&t, tree, size);
-       retval = find_tree_entry(&t, name, sha1, mode);
+       if (!size) {
+               retval = -1;
+       } else {
+               struct tree_desc t;
+               init_tree_desc(&t, tree, size);
+               retval = find_tree_entry(&t, name, sha1, mode);
+       }
        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,
+                           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).
+ */
+enum interesting 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 ?
+               entry_not_interesting : all_entries_not_interesting;
+
+       if (!ps->nr) {
+               if (!ps->recursive || ps->max_depth == -1)
+                       return all_entries_interesting;
+               return within_depth(base->buf + base_offset, baselen,
+                                   !!S_ISDIR(entry->mode),
+                                   ps->max_depth) ?
+                       entry_interesting : entry_not_interesting;
+       }
+
+       pathlen = tree_entry_len(entry);
+
+       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, match, matchlen))
+                               goto match_wildcards;
+
+                       if (!ps->recursive || ps->max_depth == -1)
+                               return all_entries_interesting;
+
+                       return within_depth(base_str + matchlen + 1,
+                                           baselen - matchlen - 1,
+                                           !!S_ISDIR(entry->mode),
+                                           ps->max_depth) ?
+                               entry_interesting : entry_not_interesting;
+               }
+
+               /* Either there must be no base, or the base must match. */
+               if (baselen == 0 || !strncmp(base_str, match, baselen)) {
+                       if (match_entry(entry, pathlen,
+                                       match + baselen, matchlen - baselen,
+                                       &never_interesting))
+                               return entry_interesting;
+
+                       if (item->use_wildcard) {
+                               if (!fnmatch(match + baselen, entry->path, 0))
+                                       return entry_interesting;
+
+                               /*
+                                * Match all directories. We'll try to
+                                * match files later on.
+                                */
+                               if (ps->recursive && S_ISDIR(entry->mode))
+                                       return entry_interesting;
+                       }
+
+                       continue;
+               }
+
+match_wildcards:
+               if (!item->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 entry_interesting;
+               }
+               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 entry_interesting;
+       }
+       return never_interesting; /* No matches */
+}