Initial revision of "git", the information manager from hell
diff --git a/update-cache.c b/update-cache.c
new file mode 100644
index 0000000..5085a5c
--- /dev/null
+++ b/update-cache.c
@@ -0,0 +1,248 @@
+#include "cache.h"
+
+static int cache_name_compare(const char *name1, int len1, const char *name2, int len2)
+{
+ int len = len1 < len2 ? len1 : len2;
+ int cmp;
+
+ cmp = memcmp(name1, name2, len);
+ if (cmp)
+ return cmp;
+ if (len1 < len2)
+ return -1;
+ if (len1 > len2)
+ return 1;
+ return 0;
+}
+
+static int cache_name_pos(const char *name, int namelen)
+{
+ int first, last;
+
+ first = 0;
+ last = active_nr;
+ while (last > first) {
+ int next = (last + first) >> 1;
+ struct cache_entry *ce = active_cache[next];
+ int cmp = cache_name_compare(name, namelen, ce->name, ce->namelen);
+ if (!cmp)
+ return -next-1;
+ if (cmp < 0) {
+ last = next;
+ continue;
+ }
+ first = next+1;
+ }
+ return first;
+}
+
+static int remove_file_from_cache(char *path)
+{
+ int pos = cache_name_pos(path, strlen(path));
+ if (pos < 0) {
+ pos = -pos-1;
+ active_nr--;
+ if (pos < active_nr)
+ memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos - 1) * sizeof(struct cache_entry *));
+ }
+}
+
+static int add_cache_entry(struct cache_entry *ce)
+{
+ int pos;
+
+ pos = cache_name_pos(ce->name, ce->namelen);
+
+ /* existing match? Just replace it */
+ if (pos < 0) {
+ active_cache[-pos-1] = ce;
+ return 0;
+ }
+
+ /* Make sure the array is big enough .. */
+ if (active_nr == active_alloc) {
+ active_alloc = alloc_nr(active_alloc);
+ active_cache = realloc(active_cache, active_alloc * sizeof(struct cache_entry *));
+ }
+
+ /* Add it in.. */
+ active_nr++;
+ if (active_nr > pos)
+ memmove(active_cache + pos + 1, active_cache + pos, (active_nr - pos - 1) * sizeof(ce));
+ active_cache[pos] = ce;
+ return 0;
+}
+
+static int index_fd(const char *path, int namelen, struct cache_entry *ce, int fd, struct stat *st)
+{
+ z_stream stream;
+ int max_out_bytes = namelen + st->st_size + 200;
+ void *out = malloc(max_out_bytes);
+ void *metadata = malloc(namelen + 200);
+ void *in = mmap(NULL, st->st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ SHA_CTX c;
+
+ close(fd);
+ if (!out || (int)(long)in == -1)
+ return -1;
+
+ memset(&stream, 0, sizeof(stream));
+ deflateInit(&stream, Z_BEST_COMPRESSION);
+
+ /*
+ * ASCII size + nul byte
+ */
+ stream.next_in = metadata;
+ stream.avail_in = 1+sprintf(metadata, "blob %lu", (unsigned long) st->st_size);
+ stream.next_out = out;
+ stream.avail_out = max_out_bytes;
+ while (deflate(&stream, 0) == Z_OK)
+ /* nothing */;
+
+ /*
+ * File content
+ */
+ stream.next_in = in;
+ stream.avail_in = st->st_size;
+ while (deflate(&stream, Z_FINISH) == Z_OK)
+ /*nothing */;
+
+ deflateEnd(&stream);
+
+ SHA1_Init(&c);
+ SHA1_Update(&c, out, stream.total_out);
+ SHA1_Final(ce->sha1, &c);
+
+ return write_sha1_buffer(ce->sha1, out, stream.total_out);
+}
+
+static int add_file_to_cache(char *path)
+{
+ int size, namelen;
+ struct cache_entry *ce;
+ struct stat st;
+ int fd;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0) {
+ if (errno == ENOENT)
+ return remove_file_from_cache(path);
+ return -1;
+ }
+ if (fstat(fd, &st) < 0) {
+ close(fd);
+ return -1;
+ }
+ namelen = strlen(path);
+ size = cache_entry_size(namelen);
+ ce = malloc(size);
+ memset(ce, 0, size);
+ memcpy(ce->name, path, namelen);
+ ce->ctime.sec = st.st_ctime;
+ ce->ctime.nsec = st.st_ctim.tv_nsec;
+ ce->mtime.sec = st.st_mtime;
+ ce->mtime.nsec = st.st_mtim.tv_nsec;
+ ce->st_dev = st.st_dev;
+ ce->st_ino = st.st_ino;
+ ce->st_mode = st.st_mode;
+ ce->st_uid = st.st_uid;
+ ce->st_gid = st.st_gid;
+ ce->st_size = st.st_size;
+ ce->namelen = namelen;
+
+ if (index_fd(path, namelen, ce, fd, &st) < 0)
+ return -1;
+
+ return add_cache_entry(ce);
+}
+
+static int write_cache(int newfd, struct cache_entry **cache, int entries)
+{
+ SHA_CTX c;
+ struct cache_header hdr;
+ int i;
+
+ hdr.signature = CACHE_SIGNATURE;
+ hdr.version = 1;
+ hdr.entries = entries;
+
+ SHA1_Init(&c);
+ SHA1_Update(&c, &hdr, offsetof(struct cache_header, sha1));
+ for (i = 0; i < entries; i++) {
+ struct cache_entry *ce = cache[i];
+ int size = ce_size(ce);
+ SHA1_Update(&c, ce, size);
+ }
+ SHA1_Final(hdr.sha1, &c);
+
+ if (write(newfd, &hdr, sizeof(hdr)) != sizeof(hdr))
+ return -1;
+
+ for (i = 0; i < entries; i++) {
+ struct cache_entry *ce = cache[i];
+ int size = ce_size(ce);
+ if (write(newfd, ce, size) != size)
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ * We fundamentally don't like some paths: we don't want
+ * dot or dot-dot anywhere, and in fact, we don't even want
+ * any other dot-files (.dircache or anything else). They
+ * are hidden, for chist sake.
+ *
+ * Also, we don't want double slashes or slashes at the
+ * end that can make pathnames ambiguous.
+ */
+static int verify_path(char *path)
+{
+ char c;
+
+ goto inside;
+ for (;;) {
+ if (!c)
+ return 1;
+ if (c == '/') {
+inside:
+ c = *path++;
+ if (c != '/' && c != '.' && c != '\0')
+ continue;
+ return 0;
+ }
+ c = *path++;
+ }
+}
+
+int main(int argc, char **argv)
+{
+ int i, newfd, entries;
+
+ entries = read_cache();
+ if (entries < 0) {
+ perror("cache corrupted");
+ return -1;
+ }
+
+ newfd = open(".dircache/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
+ if (newfd < 0) {
+ perror("unable to create new cachefile");
+ return -1;
+ }
+ for (i = 1 ; i < argc; i++) {
+ char *path = argv[i];
+ if (!verify_path(path)) {
+ fprintf(stderr, "Ignoring path %s\n", argv[i]);
+ continue;
+ }
+ if (add_file_to_cache(path)) {
+ fprintf(stderr, "Unable to add %s to database\n", path);
+ goto out;
+ }
+ }
+ if (!write_cache(newfd, active_cache, active_nr) && !rename(".dircache/index.lock", ".dircache/index"))
+ return 0;
+out:
+ unlink(".dircache/index.lock");
+}
