diff options
Diffstat (limited to 'tree-walk.c')
-rw-r--r-- | tree-walk.c | 859 |
1 files changed, 859 insertions, 0 deletions
diff --git a/tree-walk.c b/tree-walk.c new file mode 100644 index 0000000000..4dc86c7fe5 --- /dev/null +++ b/tree-walk.c @@ -0,0 +1,859 @@ +#include "cache.h" +#include "tree-walk.h" +#include "unpack-trees.h" +#include "dir.h" +#include "tree.h" +#include "pathspec.h" + +static const char *get_mode(const char *str, unsigned int *modep) +{ + unsigned char c; + unsigned int mode = 0; + + if (*str == ' ') + return NULL; + + while ((c = *str++) != ' ') { + if (c < '0' || c > '7') + return NULL; + mode = (mode << 3) + (c - '0'); + } + *modep = mode; + return str; +} + +static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size) +{ + const char *path; + unsigned int mode, len; + + if (size < 24 || buf[size - 21]) + die("corrupt tree file"); + + path = get_mode(buf, &mode); + if (!path || !*path) + die("corrupt tree file"); + len = strlen(path) + 1; + + /* Initialize the descriptor entry */ + desc->entry.path = path; + desc->entry.mode = canon_mode(mode); + desc->entry.sha1 = (const unsigned char *)(path + len); +} + +void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size) +{ + desc->buffer = buffer; + desc->size = size; + if (size) + decode_tree_entry(desc, buffer, size); +} + +void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1) +{ + unsigned long size = 0; + void *buf = NULL; + + if (sha1) { + buf = read_object_with_reference(sha1, tree_type, &size, NULL); + if (!buf) + die("unable to read tree %s", sha1_to_hex(sha1)); + } + init_tree_desc(desc, buf, size); + return buf; +} + +static void entry_clear(struct name_entry *a) +{ + memset(a, 0, sizeof(*a)); +} + +static void entry_extract(struct tree_desc *t, struct name_entry *a) +{ + *a = t->entry; +} + +void update_tree_entry(struct tree_desc *desc) +{ + const void *buf = desc->buffer; + const unsigned char *end = desc->entry.sha1 + 20; + unsigned long size = desc->size; + unsigned long len = end - (const unsigned char *)buf; + + if (size < len) + die("corrupt tree file"); + buf = end; + size -= len; + desc->buffer = buf; + desc->size = size; + if (size) + decode_tree_entry(desc, buf, size); +} + +int tree_entry(struct tree_desc *desc, struct name_entry *entry) +{ + if (!desc->size) + return 0; + + *entry = desc->entry; + update_tree_entry(desc); + return 1; +} + +void setup_traverse_info(struct traverse_info *info, const char *base) +{ + int pathlen = strlen(base); + static struct traverse_info dummy; + + memset(info, 0, sizeof(*info)); + if (pathlen && base[pathlen-1] == '/') + pathlen--; + info->pathlen = pathlen ? pathlen + 1 : 0; + info->name.path = base; + info->name.sha1 = (void *)(base + pathlen + 1); + if (pathlen) + info->prev = &dummy; +} + +char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n) +{ + int len = tree_entry_len(n); + int pathlen = info->pathlen; + + path[pathlen + len] = 0; + for (;;) { + memcpy(path + pathlen, n->path, len); + if (!pathlen) + break; + path[--pathlen] = '/'; + n = &info->name; + 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 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 (;;) { + int trees_used; + unsigned long mask, dirmask; + const char *first = NULL; + int first_len = 0; + struct name_entry *e = NULL; + int len; + + for (i = 0; i < n; i++) { + 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; + 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; + } + } + + 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; + 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; + e = &entry[i]; + } + if (!mask) + break; + interesting = prune_traversal(e, info, &base, interesting); + if (interesting < 0) + break; + if (interesting) { + trees_used = info->fn(n, mask, dirmask, entry, info); + if (trees_used < 0) { + error = trees_used; + if (!info->show_all_errors) + break; + } + mask &= trees_used; + } + for (i = 0; i < n; i++) + if (mask & (1ul << i)) + update_extended_entry(tx + i, entry + i); + } + free(entry); + 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) +{ + int namelen = strlen(name); + while (t->size) { + const char *entry; + const unsigned char *sha1; + int entrylen, cmp; + + sha1 = tree_entry_extract(t, &entry, mode); + entrylen = tree_entry_len(&t->entry); + update_tree_entry(t); + if (entrylen > namelen) + continue; + cmp = memcmp(name, entry, entrylen); + if (cmp > 0) + continue; + if (cmp < 0) + break; + if (entrylen == namelen) { + hashcpy(result, sha1); + return 0; + } + if (name[entrylen] != '/') + continue; + if (!S_ISDIR(*mode)) + break; + if (++entrylen == namelen) { + hashcpy(result, sha1); + return 0; + } + return get_tree_entry(sha1, name + entrylen, result, mode); + } + return -1; +} + +int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode) +{ + int retval; + void *tree; + unsigned long size; + unsigned char root[20]; + + tree = read_object_with_reference(tree_sha1, tree_type, &size, root); + if (!tree) + return -1; + + if (name[0] == '\0') { + hashcpy(sha1, root); + free(tree); + return 0; + } + + 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 pathspec_item *item, + const struct name_entry *entry, int pathlen, + const char *match, int matchlen, + enum interesting *never_interesting) +{ + int m = -1; /* signals that we haven't called strncmp() */ + + if (item->magic & PATHSPEC_ICASE) + /* + * "Never interesting" trick requires exact + * matching. We could do something clever with inexact + * matching, but it's trickier (and not to forget that + * strcasecmp is locale-dependent, at least in + * glibc). Just disable it for now. It can't be worse + * than the wildcard's codepath of '[Tt][Hi][Is][Ss]' + * pattern. + */ + *never_interesting = entry_not_interesting; + else if (*never_interesting != entry_not_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 = entry_not_interesting; + } + + if (pathlen > matchlen) + return 0; + + if (matchlen > pathlen) { + if (match[pathlen] != '/') + return 0; + if (!S_ISDIR(entry->mode) && !S_ISGITLINK(entry->mode)) + return 0; + } + + if (m == -1) + /* + * we cheated and did not do strncmp(), so we do + * that here. + */ + m = ps_strncmp(item, 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) + /* + * match_entry does not check if the prefix part is + * matched case-sensitively. If the entry is a + * directory and part of prefix, it'll be rematched + * eventually by basecmp with special treatment for + * the prefix. + */ + return 1; + + return 0; +} + +/* :(icase)-aware string compare */ +static int basecmp(const struct pathspec_item *item, + const char *base, const char *match, int len) +{ + if (item->magic & PATHSPEC_ICASE) { + int ret, n = len > item->prefix ? item->prefix : len; + ret = strncmp(base, match, n); + if (ret) + return ret; + base += n; + match += n; + len -= n; + } + return ps_strncmp(item, base, match, len); +} + +static int match_dir_prefix(const struct pathspec_item *item, + const char *base, + const char *match, int matchlen) +{ + if (basecmp(item, 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; +} + +/* + * Perform matching on the leading non-wildcard part of + * pathspec. item->nowildcard_len must be greater than zero. Return + * non-zero if base is matched. + */ +static int match_wildcard_base(const struct pathspec_item *item, + const char *base, int baselen, + int *matched) +{ + const char *match = item->match; + /* the wildcard part is not considered in this function */ + int matchlen = item->nowildcard_len; + + if (baselen) { + int dirlen; + /* + * Return early if base is longer than the + * non-wildcard part but it does not match. + */ + if (baselen >= matchlen) { + *matched = matchlen; + return !basecmp(item, base, match, matchlen); + } + + dirlen = matchlen; + while (dirlen && match[dirlen - 1] != '/') + dirlen--; + + /* + * Return early if base is shorter than the + * non-wildcard part but it does not match. Note that + * base ends with '/' so we are sure it really matches + * directory + */ + if (basecmp(item, base, match, baselen)) + return 0; + *matched = baselen; + } else + *matched = 0; + /* + * we could have checked entry against the non-wildcard part + * that is not in base and does similar never_interesting + * optimization as in match_entry. For now just be happy with + * base comparison. + */ + return entry_interesting; +} + +/* + * 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). + */ +static enum interesting do_match(const struct name_entry *entry, + struct strbuf *base, int base_offset, + const struct pathspec *ps, + int exclude) +{ + int i; + int pathlen, baselen = base->len - base_offset; + enum interesting never_interesting = ps->has_wildcard ? + entry_not_interesting : all_entries_not_interesting; + + GUARD_PATHSPEC(ps, + PATHSPEC_FROMTOP | + PATHSPEC_MAXDEPTH | + PATHSPEC_LITERAL | + PATHSPEC_GLOB | + PATHSPEC_ICASE | + PATHSPEC_EXCLUDE); + + if (!ps->nr) { + if (!ps->recursive || + !(ps->magic & PATHSPEC_MAXDEPTH) || + 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, matched = 0; + + if ((!exclude && item->magic & PATHSPEC_EXCLUDE) || + ( exclude && !(item->magic & PATHSPEC_EXCLUDE))) + continue; + + if (baselen >= matchlen) { + /* If it doesn't match, move along... */ + if (!match_dir_prefix(item, base_str, match, matchlen)) + goto match_wildcards; + + if (!ps->recursive || + !(ps->magic & PATHSPEC_MAXDEPTH) || + 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 || !basecmp(item, base_str, match, baselen)) { + if (match_entry(item, entry, pathlen, + match + baselen, matchlen - baselen, + &never_interesting)) + return entry_interesting; + + if (item->nowildcard_len < item->len) { + if (!git_fnmatch(item, match + baselen, entry->path, + item->nowildcard_len - baselen)) + 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->nowildcard_len == item->len) + continue; + + if (item->nowildcard_len && + !match_wildcard_base(item, base_str, baselen, &matched)) + continue; + + /* + * Concatenate base and entry->path into one and do + * fnmatch() on it. + * + * While we could avoid concatenation in certain cases + * [1], which saves a memcpy and potentially a + * realloc, it turns out not worth it. Measurement on + * linux-2.6 does not show any clear improvements, + * partly because of the nowildcard_len optimization + * in git_fnmatch(). Avoid micro-optimizations here. + * + * [1] if match_wildcard_base() says the base + * directory is already matched, we only need to match + * the rest, which is shorter so _in theory_ faster. + */ + + strbuf_add(base, entry->path, pathlen); + + if (!git_fnmatch(item, match, base->buf + base_offset, + item->nowildcard_len)) { + 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. + * max_depth is ignored but we may consider support it + * in future, see + * http://thread.gmane.org/gmane.comp.version-control.git/163757/focus=163840 + */ + if (ps->recursive && S_ISDIR(entry->mode)) + return entry_interesting; + } + return never_interesting; /* No matches */ +} + +/* + * 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) +{ + enum interesting positive, negative; + positive = do_match(entry, base, base_offset, ps, 0); + + /* + * case | entry | positive | negative | result + * -----+-------+----------+----------+------- + * 1 | file | -1 | -1..2 | -1 + * 2 | file | 0 | -1..2 | 0 + * 3 | file | 1 | -1 | 1 + * 4 | file | 1 | 0 | 1 + * 5 | file | 1 | 1 | 0 + * 6 | file | 1 | 2 | 0 + * 7 | file | 2 | -1 | 2 + * 8 | file | 2 | 0 | 2 + * 9 | file | 2 | 1 | 0 + * 10 | file | 2 | 2 | -1 + * -----+-------+----------+----------+------- + * 11 | dir | -1 | -1..2 | -1 + * 12 | dir | 0 | -1..2 | 0 + * 13 | dir | 1 | -1 | 1 + * 14 | dir | 1 | 0 | 1 + * 15 | dir | 1 | 1 | 1 (*) + * 16 | dir | 1 | 2 | 0 + * 17 | dir | 2 | -1 | 2 + * 18 | dir | 2 | 0 | 2 + * 19 | dir | 2 | 1 | 1 (*) + * 20 | dir | 2 | 2 | -1 + * + * (*) An exclude pattern interested in a directory does not + * necessarily mean it will exclude all of the directory. In + * wildcard case, it can't decide until looking at individual + * files inside. So don't write such directories off yet. + */ + + if (!(ps->magic & PATHSPEC_EXCLUDE) || + positive <= entry_not_interesting) /* #1, #2, #11, #12 */ + return positive; + + negative = do_match(entry, base, base_offset, ps, 1); + + /* #3, #4, #7, #8, #13, #14, #17, #18 */ + if (negative <= entry_not_interesting) + return positive; + + /* #15, #19 */ + if (S_ISDIR(entry->mode) && + positive >= entry_interesting && + negative == entry_interesting) + return entry_interesting; + + if ((positive == entry_interesting && + negative >= entry_interesting) || /* #5, #6, #16 */ + (positive == all_entries_interesting && + negative == entry_interesting)) /* #9 */ + return entry_not_interesting; + + return all_entries_not_interesting; /* #10, #20 */ +} |