diff options
Diffstat (limited to 'cache-tree.c')
| -rw-r--r-- | cache-tree.c | 508 |
1 files changed, 508 insertions, 0 deletions
diff --git a/cache-tree.c b/cache-tree.c new file mode 100644 index 0000000000..35740b3647 --- /dev/null +++ b/cache-tree.c @@ -0,0 +1,508 @@ +#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_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); + 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 (!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 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--; + } + } +} + +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 missing_ok) +{ + unsigned long size, offset; + char *buffer; + int i; + + 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. + */ + 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]; + 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"); + } + buffer = write_one(down->cache_tree, down->name, down->namelen, + buffer, size, offset); + } + return buffer; +} + +void *cache_tree_write(struct cache_tree *root, unsigned long *size_p) +{ + char path[PATH_MAX]; + unsigned long size = 8192; + char *buffer = xmalloc(size); + + *size_p = 0; + path[0] = 0; + return write_one(root, path, 0, buffer, &size, size_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; + 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); +} |