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-rw-r--r--cache-tree.c705
1 files changed, 705 insertions, 0 deletions
diff --git a/cache-tree.c b/cache-tree.c
new file mode 100644
index 0000000000..37e4d008b5
--- /dev/null
+++ b/cache-tree.c
@@ -0,0 +1,705 @@
+#include "cache.h"
+#include "tree.h"
+#include "tree-walk.h"
+#include "cache-tree.h"
+
+#ifndef DEBUG
+#define DEBUG 0
+#endif
+
+struct cache_tree *cache_tree(void)
+{
+ struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
+ it->entry_count = -1;
+ return it;
+}
+
+void cache_tree_free(struct cache_tree **it_p)
+{
+ int i;
+ struct cache_tree *it = *it_p;
+
+ if (!it)
+ return;
+ for (i = 0; i < it->subtree_nr; i++)
+ if (it->down[i]) {
+ cache_tree_free(&it->down[i]->cache_tree);
+ free(it->down[i]);
+ }
+ free(it->down);
+ free(it);
+ *it_p = NULL;
+}
+
+static int subtree_name_cmp(const char *one, int onelen,
+ const char *two, int twolen)
+{
+ if (onelen < twolen)
+ return -1;
+ if (twolen < onelen)
+ return 1;
+ return memcmp(one, two, onelen);
+}
+
+static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
+{
+ struct cache_tree_sub **down = it->down;
+ int lo, hi;
+ lo = 0;
+ hi = it->subtree_nr;
+ while (lo < hi) {
+ int mi = (lo + hi) / 2;
+ struct cache_tree_sub *mdl = down[mi];
+ int cmp = subtree_name_cmp(path, pathlen,
+ mdl->name, mdl->namelen);
+ if (!cmp)
+ return mi;
+ if (cmp < 0)
+ hi = mi;
+ else
+ lo = mi + 1;
+ }
+ return -lo-1;
+}
+
+static struct cache_tree_sub *find_subtree(struct cache_tree *it,
+ const char *path,
+ int pathlen,
+ int create)
+{
+ struct cache_tree_sub *down;
+ int pos = subtree_pos(it, path, pathlen);
+ if (0 <= pos)
+ return it->down[pos];
+ if (!create)
+ return NULL;
+
+ pos = -pos-1;
+ if (it->subtree_alloc <= it->subtree_nr) {
+ it->subtree_alloc = alloc_nr(it->subtree_alloc);
+ it->down = xrealloc(it->down, it->subtree_alloc *
+ sizeof(*it->down));
+ }
+ it->subtree_nr++;
+
+ down = xmalloc(sizeof(*down) + pathlen + 1);
+ down->cache_tree = NULL;
+ down->namelen = pathlen;
+ memcpy(down->name, path, pathlen);
+ down->name[pathlen] = 0;
+
+ if (pos < it->subtree_nr)
+ memmove(it->down + pos + 1,
+ it->down + pos,
+ sizeof(down) * (it->subtree_nr - pos - 1));
+ it->down[pos] = down;
+ return down;
+}
+
+struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
+{
+ int pathlen = strlen(path);
+ return find_subtree(it, path, pathlen, 1);
+}
+
+void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
+{
+ /* a/b/c
+ * ==> invalidate self
+ * ==> find "a", have it invalidate "b/c"
+ * a
+ * ==> invalidate self
+ * ==> if "a" exists as a subtree, remove it.
+ */
+ const char *slash;
+ int namelen;
+ struct cache_tree_sub *down;
+
+#if DEBUG
+ fprintf(stderr, "cache-tree invalidate <%s>\n", path);
+#endif
+
+ if (!it)
+ return;
+ slash = strchr(path, '/');
+ it->entry_count = -1;
+ if (!slash) {
+ int pos;
+ namelen = strlen(path);
+ pos = subtree_pos(it, path, namelen);
+ if (0 <= pos) {
+ cache_tree_free(&it->down[pos]->cache_tree);
+ free(it->down[pos]);
+ /* 0 1 2 3 4 5
+ * ^ ^subtree_nr = 6
+ * pos
+ * move 4 and 5 up one place (2 entries)
+ * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
+ */
+ memmove(it->down+pos, it->down+pos+1,
+ sizeof(struct cache_tree_sub *) *
+ (it->subtree_nr - pos - 1));
+ it->subtree_nr--;
+ }
+ return;
+ }
+ namelen = slash - path;
+ down = find_subtree(it, path, namelen, 0);
+ if (down)
+ cache_tree_invalidate_path(down->cache_tree, slash + 1);
+}
+
+static int verify_cache(struct cache_entry **cache,
+ int entries, int flags)
+{
+ int i, funny;
+ int silent = flags & WRITE_TREE_SILENT;
+
+ /* Verify that the tree is merged */
+ funny = 0;
+ for (i = 0; i < entries; i++) {
+ struct cache_entry *ce = cache[i];
+ if (ce_stage(ce)) {
+ if (silent)
+ return -1;
+ if (10 < ++funny) {
+ fprintf(stderr, "...\n");
+ break;
+ }
+ fprintf(stderr, "%s: unmerged (%s)\n",
+ ce->name, sha1_to_hex(ce->sha1));
+ }
+ }
+ if (funny)
+ return -1;
+
+ /* Also verify that the cache does not have path and path/file
+ * at the same time. At this point we know the cache has only
+ * stage 0 entries.
+ */
+ funny = 0;
+ for (i = 0; i < entries - 1; i++) {
+ /* path/file always comes after path because of the way
+ * the cache is sorted. Also path can appear only once,
+ * which means conflicting one would immediately follow.
+ */
+ const char *this_name = cache[i]->name;
+ const char *next_name = cache[i+1]->name;
+ int this_len = strlen(this_name);
+ if (this_len < strlen(next_name) &&
+ strncmp(this_name, next_name, this_len) == 0 &&
+ next_name[this_len] == '/') {
+ if (10 < ++funny) {
+ fprintf(stderr, "...\n");
+ break;
+ }
+ fprintf(stderr, "You have both %s and %s\n",
+ this_name, next_name);
+ }
+ }
+ if (funny)
+ return -1;
+ return 0;
+}
+
+static void discard_unused_subtrees(struct cache_tree *it)
+{
+ struct cache_tree_sub **down = it->down;
+ int nr = it->subtree_nr;
+ int dst, src;
+ for (dst = src = 0; src < nr; src++) {
+ struct cache_tree_sub *s = down[src];
+ if (s->used)
+ down[dst++] = s;
+ else {
+ cache_tree_free(&s->cache_tree);
+ free(s);
+ it->subtree_nr--;
+ }
+ }
+}
+
+int cache_tree_fully_valid(struct cache_tree *it)
+{
+ int i;
+ if (!it)
+ return 0;
+ if (it->entry_count < 0 || !has_sha1_file(it->sha1))
+ return 0;
+ for (i = 0; i < it->subtree_nr; i++) {
+ if (!cache_tree_fully_valid(it->down[i]->cache_tree))
+ return 0;
+ }
+ return 1;
+}
+
+static int update_one(struct cache_tree *it,
+ struct cache_entry **cache,
+ int entries,
+ const char *base,
+ int baselen,
+ int *skip_count,
+ int flags)
+{
+ struct strbuf buffer;
+ int missing_ok = flags & WRITE_TREE_MISSING_OK;
+ int dryrun = flags & WRITE_TREE_DRY_RUN;
+ int to_invalidate = 0;
+ int i;
+
+ *skip_count = 0;
+
+ if (0 <= it->entry_count && has_sha1_file(it->sha1))
+ return it->entry_count;
+
+ /*
+ * We first scan for subtrees and update them; we start by
+ * marking existing subtrees -- the ones that are unmarked
+ * should not be in the result.
+ */
+ for (i = 0; i < it->subtree_nr; i++)
+ it->down[i]->used = 0;
+
+ /*
+ * Find the subtrees and update them.
+ */
+ i = 0;
+ while (i < entries) {
+ struct cache_entry *ce = cache[i];
+ struct cache_tree_sub *sub;
+ const char *path, *slash;
+ int pathlen, sublen, subcnt, subskip;
+
+ path = ce->name;
+ pathlen = ce_namelen(ce);
+ if (pathlen <= baselen || memcmp(base, path, baselen))
+ break; /* at the end of this level */
+
+ slash = strchr(path + baselen, '/');
+ if (!slash) {
+ i++;
+ continue;
+ }
+ /*
+ * a/bbb/c (base = a/, slash = /c)
+ * ==>
+ * path+baselen = bbb/c, sublen = 3
+ */
+ sublen = slash - (path + baselen);
+ sub = find_subtree(it, path + baselen, sublen, 1);
+ if (!sub->cache_tree)
+ sub->cache_tree = cache_tree();
+ subcnt = update_one(sub->cache_tree,
+ cache + i, entries - i,
+ path,
+ baselen + sublen + 1,
+ &subskip,
+ flags);
+ if (subcnt < 0)
+ return subcnt;
+ i += subcnt;
+ sub->count = subcnt; /* to be used in the next loop */
+ *skip_count += subskip;
+ sub->used = 1;
+ }
+
+ discard_unused_subtrees(it);
+
+ /*
+ * Then write out the tree object for this level.
+ */
+ strbuf_init(&buffer, 8192);
+
+ i = 0;
+ while (i < entries) {
+ struct cache_entry *ce = cache[i];
+ struct cache_tree_sub *sub;
+ const char *path, *slash;
+ int pathlen, entlen;
+ const unsigned char *sha1;
+ unsigned mode;
+
+ path = ce->name;
+ pathlen = ce_namelen(ce);
+ if (pathlen <= baselen || memcmp(base, path, baselen))
+ break; /* at the end of this level */
+
+ slash = strchr(path + baselen, '/');
+ if (slash) {
+ entlen = slash - (path + baselen);
+ sub = find_subtree(it, path + baselen, entlen, 0);
+ if (!sub)
+ die("cache-tree.c: '%.*s' in '%s' not found",
+ entlen, path + baselen, path);
+ i += sub->count;
+ sha1 = sub->cache_tree->sha1;
+ mode = S_IFDIR;
+ if (sub->cache_tree->entry_count < 0)
+ to_invalidate = 1;
+ }
+ else {
+ sha1 = ce->sha1;
+ mode = ce->ce_mode;
+ entlen = pathlen - baselen;
+ i++;
+ }
+ if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1)) {
+ strbuf_release(&buffer);
+ return error("invalid object %06o %s for '%.*s'",
+ mode, sha1_to_hex(sha1), entlen+baselen, path);
+ }
+
+ /*
+ * CE_REMOVE entries are removed before the index is
+ * written to disk. Skip them to remain consistent
+ * with the future on-disk index.
+ */
+ if (ce->ce_flags & CE_REMOVE) {
+ *skip_count = *skip_count + 1;
+ continue;
+ }
+
+ /*
+ * CE_INTENT_TO_ADD entries exist on on-disk index but
+ * they are not part of generated trees. Invalidate up
+ * to root to force cache-tree users to read elsewhere.
+ */
+ if (ce->ce_flags & CE_INTENT_TO_ADD) {
+ to_invalidate = 1;
+ continue;
+ }
+
+ strbuf_grow(&buffer, entlen + 100);
+ strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
+ strbuf_add(&buffer, sha1, 20);
+
+#if DEBUG
+ fprintf(stderr, "cache-tree update-one %o %.*s\n",
+ mode, entlen, path + baselen);
+#endif
+ }
+
+ if (dryrun)
+ hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
+ else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
+ strbuf_release(&buffer);
+ return -1;
+ }
+
+ strbuf_release(&buffer);
+ it->entry_count = to_invalidate ? -1 : i - *skip_count;
+#if DEBUG
+ fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
+ it->entry_count, it->subtree_nr,
+ sha1_to_hex(it->sha1));
+#endif
+ return i;
+}
+
+int cache_tree_update(struct cache_tree *it,
+ struct cache_entry **cache,
+ int entries,
+ int flags)
+{
+ int i, skip;
+ i = verify_cache(cache, entries, flags);
+ if (i)
+ return i;
+ i = update_one(it, cache, entries, "", 0, &skip, flags);
+ if (i < 0)
+ return i;
+ return 0;
+}
+
+static void write_one(struct strbuf *buffer, struct cache_tree *it,
+ const char *path, int pathlen)
+{
+ int i;
+
+ /* One "cache-tree" entry consists of the following:
+ * path (NUL terminated)
+ * entry_count, subtree_nr ("%d %d\n")
+ * tree-sha1 (missing if invalid)
+ * subtree_nr "cache-tree" entries for subtrees.
+ */
+ strbuf_grow(buffer, pathlen + 100);
+ strbuf_add(buffer, path, pathlen);
+ strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
+
+#if DEBUG
+ if (0 <= it->entry_count)
+ fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
+ pathlen, path, it->entry_count, it->subtree_nr,
+ sha1_to_hex(it->sha1));
+ else
+ fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
+ pathlen, path, it->subtree_nr);
+#endif
+
+ if (0 <= it->entry_count) {
+ strbuf_add(buffer, it->sha1, 20);
+ }
+ for (i = 0; i < it->subtree_nr; i++) {
+ struct cache_tree_sub *down = it->down[i];
+ if (i) {
+ struct cache_tree_sub *prev = it->down[i-1];
+ if (subtree_name_cmp(down->name, down->namelen,
+ prev->name, prev->namelen) <= 0)
+ die("fatal - unsorted cache subtree");
+ }
+ write_one(buffer, down->cache_tree, down->name, down->namelen);
+ }
+}
+
+void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
+{
+ write_one(sb, root, "", 0);
+}
+
+static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
+{
+ const char *buf = *buffer;
+ unsigned long size = *size_p;
+ const char *cp;
+ char *ep;
+ struct cache_tree *it;
+ int i, subtree_nr;
+
+ it = NULL;
+ /* skip name, but make sure name exists */
+ while (size && *buf) {
+ size--;
+ buf++;
+ }
+ if (!size)
+ goto free_return;
+ buf++; size--;
+ it = cache_tree();
+
+ cp = buf;
+ it->entry_count = strtol(cp, &ep, 10);
+ if (cp == ep)
+ goto free_return;
+ cp = ep;
+ subtree_nr = strtol(cp, &ep, 10);
+ if (cp == ep)
+ goto free_return;
+ while (size && *buf && *buf != '\n') {
+ size--;
+ buf++;
+ }
+ if (!size)
+ goto free_return;
+ buf++; size--;
+ if (0 <= it->entry_count) {
+ if (size < 20)
+ goto free_return;
+ hashcpy(it->sha1, (const unsigned char*)buf);
+ buf += 20;
+ size -= 20;
+ }
+
+#if DEBUG
+ if (0 <= it->entry_count)
+ fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
+ *buffer, it->entry_count, subtree_nr,
+ sha1_to_hex(it->sha1));
+ else
+ fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
+ *buffer, subtree_nr);
+#endif
+
+ /*
+ * Just a heuristic -- we do not add directories that often but
+ * we do not want to have to extend it immediately when we do,
+ * hence +2.
+ */
+ it->subtree_alloc = subtree_nr + 2;
+ it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
+ for (i = 0; i < subtree_nr; i++) {
+ /* read each subtree */
+ struct cache_tree *sub;
+ struct cache_tree_sub *subtree;
+ const char *name = buf;
+
+ sub = read_one(&buf, &size);
+ if (!sub)
+ goto free_return;
+ subtree = cache_tree_sub(it, name);
+ subtree->cache_tree = sub;
+ }
+ if (subtree_nr != it->subtree_nr)
+ die("cache-tree: internal error");
+ *buffer = buf;
+ *size_p = size;
+ return it;
+
+ free_return:
+ cache_tree_free(&it);
+ return NULL;
+}
+
+struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
+{
+ if (buffer[0])
+ return NULL; /* not the whole tree */
+ return read_one(&buffer, &size);
+}
+
+static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
+{
+ if (!it)
+ return NULL;
+ while (*path) {
+ const char *slash;
+ struct cache_tree_sub *sub;
+
+ slash = strchr(path, '/');
+ if (!slash)
+ slash = path + strlen(path);
+ /* between path and slash is the name of the
+ * subtree to look for.
+ */
+ sub = find_subtree(it, path, slash - path, 0);
+ if (!sub)
+ return NULL;
+ it = sub->cache_tree;
+ if (slash)
+ while (*slash && *slash == '/')
+ slash++;
+ if (!slash || !*slash)
+ return it; /* prefix ended with slashes */
+ path = slash;
+ }
+ return it;
+}
+
+int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
+{
+ int entries, was_valid, newfd;
+ struct lock_file *lock_file;
+
+ /*
+ * We can't free this memory, it becomes part of a linked list
+ * parsed atexit()
+ */
+ lock_file = xcalloc(1, sizeof(struct lock_file));
+
+ newfd = hold_locked_index(lock_file, 1);
+
+ entries = read_cache();
+ if (entries < 0)
+ return WRITE_TREE_UNREADABLE_INDEX;
+ if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
+ cache_tree_free(&(active_cache_tree));
+
+ if (!active_cache_tree)
+ active_cache_tree = cache_tree();
+
+ was_valid = cache_tree_fully_valid(active_cache_tree);
+ if (!was_valid) {
+ if (cache_tree_update(active_cache_tree,
+ active_cache, active_nr,
+ flags) < 0)
+ return WRITE_TREE_UNMERGED_INDEX;
+ if (0 <= newfd) {
+ if (!write_cache(newfd, active_cache, active_nr) &&
+ !commit_lock_file(lock_file))
+ newfd = -1;
+ }
+ /* Not being able to write is fine -- we are only interested
+ * in updating the cache-tree part, and if the next caller
+ * ends up using the old index with unupdated cache-tree part
+ * it misses the work we did here, but that is just a
+ * performance penalty and not a big deal.
+ */
+ }
+
+ if (prefix) {
+ struct cache_tree *subtree =
+ cache_tree_find(active_cache_tree, prefix);
+ if (!subtree)
+ return WRITE_TREE_PREFIX_ERROR;
+ hashcpy(sha1, subtree->sha1);
+ }
+ else
+ hashcpy(sha1, active_cache_tree->sha1);
+
+ if (0 <= newfd)
+ rollback_lock_file(lock_file);
+
+ return 0;
+}
+
+static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
+{
+ struct tree_desc desc;
+ struct name_entry entry;
+ int cnt;
+
+ hashcpy(it->sha1, tree->object.sha1);
+ init_tree_desc(&desc, tree->buffer, tree->size);
+ cnt = 0;
+ while (tree_entry(&desc, &entry)) {
+ if (!S_ISDIR(entry.mode))
+ cnt++;
+ else {
+ struct cache_tree_sub *sub;
+ struct tree *subtree = lookup_tree(entry.sha1);
+ if (!subtree->object.parsed)
+ parse_tree(subtree);
+ sub = cache_tree_sub(it, entry.path);
+ sub->cache_tree = cache_tree();
+ prime_cache_tree_rec(sub->cache_tree, subtree);
+ cnt += sub->cache_tree->entry_count;
+ }
+ }
+ it->entry_count = cnt;
+}
+
+void prime_cache_tree(struct cache_tree **it, struct tree *tree)
+{
+ cache_tree_free(it);
+ *it = cache_tree();
+ prime_cache_tree_rec(*it, tree);
+}
+
+/*
+ * find the cache_tree that corresponds to the current level without
+ * exploding the full path into textual form. The root of the
+ * cache tree is given as "root", and our current level is "info".
+ * (1) When at root level, info->prev is NULL, so it is "root" itself.
+ * (2) Otherwise, find the cache_tree that corresponds to one level
+ * above us, and find ourselves in there.
+ */
+static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
+ struct traverse_info *info)
+{
+ struct cache_tree *our_parent;
+
+ if (!info->prev)
+ return root;
+ our_parent = find_cache_tree_from_traversal(root, info->prev);
+ return cache_tree_find(our_parent, info->name.path);
+}
+
+int cache_tree_matches_traversal(struct cache_tree *root,
+ struct name_entry *ent,
+ struct traverse_info *info)
+{
+ struct cache_tree *it;
+
+ it = find_cache_tree_from_traversal(root, info);
+ it = cache_tree_find(it, ent->path);
+ if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))
+ return it->entry_count;
+ return 0;
+}
+
+int update_main_cache_tree(int flags)
+{
+ if (!the_index.cache_tree)
+ the_index.cache_tree = cache_tree();
+ return cache_tree_update(the_index.cache_tree,
+ the_index.cache, the_index.cache_nr, flags);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-01 10:26:30 +0000