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;
}
static struct cache_entry *dup_entry(const struct cache_entry *ce)
{
unsigned int size = ce_size(ce);
struct cache_entry *new = xmalloc(size);
memcpy(new, ce, size);
return new;
}
int read_cache(void)
{
int fd, i;
struct stat st;
unsigned long size, offset;
void *map;
struct cache_header *hdr;
errno = EBUSY;
if (active_cache)
return error("more than one cachefile");
errno = ENOENT;
sha1_file_directory = getenv(DB_ENVIRONMENT);
if (!sha1_file_directory)
sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
if (access(sha1_file_directory, X_OK) < 0)
return error("no access to SHA1 file directory");
fd = open(get_index_file(), O_RDONLY);
if (fd < 0)
return (errno == ENOENT) ? 0 : error("open failed");
size = 0; // avoid gcc warning
map = (void *)-1;
if (!fstat(fd, &st)) {
size = st.st_size;
errno = EINVAL;
if (size >= sizeof(struct cache_header) + 20)
map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
}
close(fd);
if (-1 == (int)(long)map)
return error("mmap failed");
hdr = map;
if (verify_hdr(hdr, size) < 0)
goto unmap;
active_nr = ntohl(hdr->hdr_entries);
active_alloc = alloc_nr(active_nr);
active_cache = calloc(active_alloc, sizeof(struct cache_entry *));
offset = sizeof(*hdr);
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = map + offset;
offset = offset + ce_size(ce);
active_cache[i] = ce;
}
return active_nr;
unmap:
munmap(map, size);
errno = EINVAL;
return error("verify header failed");
}
int write_cache(int newfd, struct cache_entry **cache, int entries)
{
SHA_CTX c;
struct cache_header hdr;
int i;
hdr.hdr_signature = htonl(CACHE_SIGNATURE);
hdr.hdr_version = htonl(2);
hdr.hdr_entries = htonl(entries);
SHA1_Init(&c);
if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
return -1;
for (i = 0; i < entries; i++) {
struct cache_entry *ce = cache[i];
if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
return -1;
}
return ce_flush(&c, newfd);
}
