--- /dev/null
+#include "cache.h"
+#include "tree.h"
+#include "cache-tree.h"
+
+#define DEBUG 0
+
+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)
+{
+ int i;
+
+ if (!it)
+ return;
+ for (i = 0; i < it->subtree_nr; i++)
+ cache_tree_free(it->down[i]->cache_tree);
+ free(it->down);
+ free(it);
+}
+
+static struct cache_tree_sub *find_subtree(struct cache_tree *it,
+ const char *path,
+ int pathlen,
+ int create)
+{
+ int i;
+ struct cache_tree_sub *down;
+ for (i = 0; i < it->subtree_nr; i++) {
+ down = it->down[i];
+ if (down->namelen == pathlen &&
+ !memcmp(down->name, path, pathlen))
+ return down;
+ }
+ if (!create)
+ return NULL;
+ 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));
+ }
+ down = xmalloc(sizeof(*down) + pathlen + 1);
+ down->cache_tree = NULL; /* cache_tree(); */
+ down->namelen = pathlen;
+ memcpy(down->name, path, pathlen);
+ down->name[pathlen] = 0; /* not strictly needed */
+ it->down[it->subtree_nr++] = down;
+ return down;
+}
+
+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 (!it)
+ return;
+ slash = strchr(path, '/');
+ it->entry_count = -1;
+ if (!slash) {
+ int i;
+ namelen = strlen(path);
+ for (i = 0; i < it->subtree_nr; i++) {
+ if (it->down[i]->namelen == namelen &&
+ !memcmp(it->down[i]->name, path, namelen))
+ break;
+ }
+ if (i < it->subtree_nr) {
+ cache_tree_free(it->down[i]->cache_tree);
+ free(it->down[i]);
+ /* 0 1 2 3 4 5
+ * ^ ^subtree_nr = 6
+ * i
+ * move 4 and 5 up one place (2 entries)
+ * 2 = 6 - 3 - 1 = subtree_nr - i - 1
+ */
+ memmove(it->down+i, it->down+i+1,
+ sizeof(struct cache_tree_sub *) *
+ (it->subtree_nr - i - 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 i, funny;
+
+ /* 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 (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--;
+ }
+ }
+}
+
+static int update_one(struct cache_tree *it,
+ struct cache_entry **cache,
+ int entries,
+ const char *base,
+ int baselen,
+ int missing_ok)
+{
+ unsigned long size, offset;
+ char *buffer;
+ int i;
+
+ if (0 <= it->entry_count)
+ 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.
+ */
+ for (i = 0; i < entries; i++) {
+ struct cache_entry *ce = cache[i];
+ struct cache_tree_sub *sub;
+ const char *path, *slash;
+ int pathlen, sublen, subcnt;
+
+ 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)
+ 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,
+ missing_ok);
+ i += subcnt - 1;
+ sub->used = 1;
+ }
+
+ discard_unused_subtrees(it);
+
+ /*
+ * Then write out the tree object for this level.
+ */
+ size = 8192;
+ buffer = xmalloc(size);
+ offset = 0;
+
+ for (i = 0; i < entries; i++) {
+ 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->cache_tree->entry_count - 1;
+ sha1 = sub->cache_tree->sha1;
+ mode = S_IFDIR;
+ }
+ else {
+ sha1 = ce->sha1;
+ mode = ntohl(ce->ce_mode);
+ entlen = pathlen - baselen;
+ }
+ if (!missing_ok && !has_sha1_file(sha1))
+ return error("invalid object %s", sha1_to_hex(sha1));
+
+ if (!ce->ce_mode)
+ continue; /* entry being removed */
+
+ if (size < offset + entlen + 100) {
+ size = alloc_nr(offset + entlen + 100);
+ buffer = xrealloc(buffer, size);
+ }
+ offset += sprintf(buffer + offset,
+ "%o %.*s", mode, entlen, path + baselen);
+ buffer[offset++] = 0;
+ memcpy(buffer + offset, sha1, 20);
+ offset += 20;
+
+#if DEBUG
+ fprintf(stderr, "cache-tree %o %.*s\n",
+ mode, entlen, path + baselen);
+#endif
+ }
+
+ write_sha1_file(buffer, offset, tree_type, it->sha1);
+ free(buffer);
+ it->entry_count = i;
+#if DEBUG
+ fprintf(stderr, "cache-tree (%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 missing_ok)
+{
+ int i;
+ i = verify_cache(cache, entries);
+ if (i)
+ return i;
+ i = update_one(it, cache, entries, "", 0, missing_ok);
+ if (i < 0)
+ return i;
+ return 0;
+}
+
+static void *write_one(struct cache_tree *it,
+ char *path,
+ int pathlen,
+ char *buffer,
+ unsigned long *size,
+ unsigned long *offset)
+{
+ 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.
+ */
+ if (*size < *offset + pathlen + 100) {
+ *size = alloc_nr(*offset + pathlen + 100);
+ buffer = xrealloc(buffer, *size);
+ }
+ *offset += sprintf(buffer + *offset, "%.*s%c%d %d\n",
+ pathlen, path, 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) {
+ memcpy(buffer + *offset, it->sha1, 20);
+ *offset += 20;
+ }
+ for (i = 0; i < it->subtree_nr; i++) {
+ struct cache_tree_sub *down = it->down[i];
+ buffer = write_one(down->cache_tree, down->name, down->namelen,
+ buffer, size, offset);
+ }
+ return buffer;
+}
+
+static void *cache_tree_write(const unsigned char *cache_sha1,
+ struct cache_tree *root,
+ unsigned long *offset_p)
+{
+ char path[PATH_MAX];
+ unsigned long size = 8192;
+ char *buffer = xmalloc(size);
+
+ /* the cache checksum of the corresponding index file. */
+ memcpy(buffer, cache_sha1, 20);
+ *offset_p = 20;
+ path[0] = 0;
+ return write_one(root, path, 0, buffer, &size, offset_p);
+}
+
+static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
+{
+ const char *buf = *buffer;
+ unsigned long size = *size_p;
+ 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();
+ if (sscanf(buf, "%d %d\n", &it->entry_count, &subtree_nr) != 2)
+ 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;
+ memcpy(it->sha1, buf, 20);
+ 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;
+ const char *name = buf;
+ int namelen;
+ sub = read_one(&buf, &size);
+ if (!sub)
+ goto free_return;
+ namelen = strlen(name);
+ it->down[i] = find_subtree(it, name, namelen, 1);
+ it->down[i]->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;
+}
+
+static struct cache_tree *cache_tree_read(unsigned char *sha1,
+ const char *buffer,
+ unsigned long size)
+{
+ /* check the cache-tree matches the index */
+ if (memcmp(buffer, sha1, 20))
+ return NULL; /* checksum mismatch */
+ if (buffer[20])
+ return NULL; /* not the whole tree */
+ buffer += 20;
+ size -= 20;
+ return read_one(&buffer, &size);
+}
+
+struct cache_tree *read_cache_tree(unsigned char *sha1)
+{
+ int fd;
+ struct stat st;
+ char path[PATH_MAX];
+ unsigned long size = 0;
+ void *map;
+ struct cache_tree *it;
+
+ sprintf(path, "%s.aux", get_index_file());
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return cache_tree();
+
+ if (fstat(fd, &st))
+ return cache_tree();
+ size = st.st_size;
+ map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+ if (map == MAP_FAILED)
+ return cache_tree();
+ it = cache_tree_read(sha1, map, size);
+ munmap(map, size);
+ if (!it)
+ return cache_tree();
+ return it;
+}
+
+int write_cache_tree(const unsigned char *sha1, struct cache_tree *root)
+{
+ char path[PATH_MAX];
+ unsigned long size = 0;
+ void *buf, *buffer;
+ int fd, ret = -1;
+
+ sprintf(path, "%s.aux", get_index_file());
+ if (!root) {
+ unlink(path);
+ return -1;
+ }
+ fd = open(path, O_WRONLY|O_CREAT, 0666);
+ if (fd < 0)
+ return -1;
+ buffer = buf = cache_tree_write(sha1, root, &size);
+ while (size) {
+ int written = xwrite(fd, buf, size);
+ if (written <= 0)
+ goto fail;
+ buf += written;
+ size -= written;
+ }
+ ret = 0;
+
+ fail:
+ close(fd);
+ free(buffer);
+ if (ret)
+ unlink(path);
+ return ret;
+}
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