#include "commit.h"
#include "blob.h"
#include "resolve-undo.h"
+#include "strbuf.h"
+#include "varint.h"
static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
return refresh_cache_ent(&the_index, ce, really, NULL, NULL);
}
+
+/*****************************************************************
+ * Index File I/O
+ *****************************************************************/
+
+/*
+ * dev/ino/uid/gid/size are also just tracked to the low 32 bits
+ * Again - this is just a (very strong in practice) heuristic that
+ * the inode hasn't changed.
+ *
+ * We save the fields in big-endian order to allow using the
+ * index file over NFS transparently.
+ */
+struct ondisk_cache_entry {
+ struct cache_time ctime;
+ struct cache_time mtime;
+ unsigned int dev;
+ unsigned int ino;
+ unsigned int mode;
+ unsigned int uid;
+ unsigned int gid;
+ unsigned int size;
+ unsigned char sha1[20];
+ unsigned short flags;
+ char name[FLEX_ARRAY]; /* more */
+};
+
+/*
+ * This struct is used when CE_EXTENDED bit is 1
+ * The struct must match ondisk_cache_entry exactly from
+ * ctime till flags
+ */
+struct ondisk_cache_entry_extended {
+ struct cache_time ctime;
+ struct cache_time mtime;
+ unsigned int dev;
+ unsigned int ino;
+ unsigned int mode;
+ unsigned int uid;
+ unsigned int gid;
+ unsigned int size;
+ unsigned char sha1[20];
+ unsigned short flags;
+ unsigned short flags2;
+ char name[FLEX_ARRAY]; /* more */
+};
+
+/* These are only used for v3 or lower */
+#define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7)
+#define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len)
+#define ondisk_cache_entry_extended_size(len) align_flex_name(ondisk_cache_entry_extended,len)
+#define ondisk_ce_size(ce) (((ce)->ce_flags & CE_EXTENDED) ? \
+ ondisk_cache_entry_extended_size(ce_namelen(ce)) : \
+ ondisk_cache_entry_size(ce_namelen(ce)))
+
static int verify_hdr(struct cache_header *hdr, unsigned long size)
{
git_SHA_CTX c;
unsigned char sha1[20];
+ int hdr_version;
if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
return error("bad signature");
- if (hdr->hdr_version != htonl(2) && hdr->hdr_version != htonl(3))
- return error("bad index version");
+ hdr_version = ntohl(hdr->hdr_version);
+ if (hdr_version < 2 || 4 < hdr_version)
+ return error("bad index version %d", hdr_version);
git_SHA1_Init(&c);
git_SHA1_Update(&c, hdr, size - 20);
git_SHA1_Final(sha1, &c);
return read_index_from(istate, get_index_file());
}
-static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk)
+#ifndef NEEDS_ALIGNED_ACCESS
+#define ntoh_s(var) ntohs(var)
+#define ntoh_l(var) ntohl(var)
+#else
+static inline uint16_t ntoh_s_force_align(void *p)
+{
+ uint16_t x;
+ memcpy(&x, p, sizeof(x));
+ return ntohs(x);
+}
+static inline uint32_t ntoh_l_force_align(void *p)
+{
+ uint32_t x;
+ memcpy(&x, p, sizeof(x));
+ return ntohl(x);
+}
+#define ntoh_s(var) ntoh_s_force_align(&(var))
+#define ntoh_l(var) ntoh_l_force_align(&(var))
+#endif
+
+static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk,
+ unsigned int flags,
+ const char *name,
+ size_t len)
+{
+ struct cache_entry *ce = xmalloc(cache_entry_size(len));
+
+ ce->ce_ctime.sec = ntoh_l(ondisk->ctime.sec);
+ ce->ce_mtime.sec = ntoh_l(ondisk->mtime.sec);
+ ce->ce_ctime.nsec = ntoh_l(ondisk->ctime.nsec);
+ ce->ce_mtime.nsec = ntoh_l(ondisk->mtime.nsec);
+ ce->ce_dev = ntoh_l(ondisk->dev);
+ ce->ce_ino = ntoh_l(ondisk->ino);
+ ce->ce_mode = ntoh_l(ondisk->mode);
+ ce->ce_uid = ntoh_l(ondisk->uid);
+ ce->ce_gid = ntoh_l(ondisk->gid);
+ ce->ce_size = ntoh_l(ondisk->size);
+ ce->ce_flags = flags;
+ hashcpy(ce->sha1, ondisk->sha1);
+ memcpy(ce->name, name, len);
+ ce->name[len] = '\0';
+ return ce;
+}
+
+/*
+ * Adjacent cache entries tend to share the leading paths, so it makes
+ * sense to only store the differences in later entries. In the v4
+ * on-disk format of the index, each on-disk cache entry stores the
+ * number of bytes to be stripped from the end of the previous name,
+ * and the bytes to append to the result, to come up with its name.
+ */
+static unsigned long expand_name_field(struct strbuf *name, const char *cp_)
+{
+ const unsigned char *ep, *cp = (const unsigned char *)cp_;
+ size_t len = decode_varint(&cp);
+
+ if (name->len < len)
+ die("malformed name field in the index");
+ strbuf_remove(name, name->len - len, len);
+ for (ep = cp; *ep; ep++)
+ ; /* find the end */
+ strbuf_add(name, cp, ep - cp);
+ return (const char *)ep + 1 - cp_;
+}
+
+static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk,
+ unsigned long *ent_size,
+ struct strbuf *previous_name)
{
struct cache_entry *ce;
size_t len;
unsigned int flags;
/* On-disk flags are just 16 bits */
- flags = ntohs(ondisk->flags);
+ flags = ntoh_s(ondisk->flags);
len = flags & CE_NAMEMASK;
if (flags & CE_EXTENDED) {
struct ondisk_cache_entry_extended *ondisk2;
int extended_flags;
ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
- extended_flags = ntohs(ondisk2->flags2) << 16;
+ extended_flags = ntoh_s(ondisk2->flags2) << 16;
/* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
if (extended_flags & ~CE_EXTENDED_FLAGS)
die("Unknown index entry format %08x", extended_flags);
else
name = ondisk->name;
- if (len == CE_NAMEMASK)
- len = strlen(name);
-
- ce = xmalloc(cache_entry_size(len));
-
- ce->ce_ctime.sec = ntohl(ondisk->ctime.sec);
- ce->ce_mtime.sec = ntohl(ondisk->mtime.sec);
- ce->ce_ctime.nsec = ntohl(ondisk->ctime.nsec);
- ce->ce_mtime.nsec = ntohl(ondisk->mtime.nsec);
- ce->ce_dev = ntohl(ondisk->dev);
- ce->ce_ino = ntohl(ondisk->ino);
- ce->ce_mode = ntohl(ondisk->mode);
- ce->ce_uid = ntohl(ondisk->uid);
- ce->ce_gid = ntohl(ondisk->gid);
- ce->ce_size = ntohl(ondisk->size);
- ce->ce_flags = flags;
-
- hashcpy(ce->sha1, ondisk->sha1);
-
- memcpy(ce->name, name, len);
- ce->name[len] = '\0';
+ if (!previous_name) {
+ /* v3 and earlier */
+ if (len == CE_NAMEMASK)
+ len = strlen(name);
+ ce = cache_entry_from_ondisk(ondisk, flags, name, len);
+
+ *ent_size = ondisk_ce_size(ce);
+ } else {
+ unsigned long consumed;
+ consumed = expand_name_field(previous_name, name);
+ ce = cache_entry_from_ondisk(ondisk, flags,
+ previous_name->buf,
+ previous_name->len);
+
+ *ent_size = (name - ((char *)ondisk)) + consumed;
+ }
return ce;
}
struct cache_header *hdr;
void *mmap;
size_t mmap_size;
+ struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
errno = EBUSY;
if (istate->initialized)
istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
istate->initialized = 1;
+ if (hdr->hdr_version == htonl(4))
+ previous_name = &previous_name_buf;
+ else
+ previous_name = NULL;
+
src_offset = sizeof(*hdr);
for (i = 0; i < istate->cache_nr; i++) {
struct ondisk_cache_entry *disk_ce;
struct cache_entry *ce;
+ unsigned long consumed;
disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
- ce = create_from_disk(disk_ce);
+ ce = create_from_disk(disk_ce, &consumed, previous_name);
set_index_entry(istate, i, ce);
- src_offset += ondisk_ce_size(ce);
+ src_offset += consumed;
}
+ strbuf_release(&previous_name_buf);
istate->timestamp.sec = st.st_mtime;
istate->timestamp.nsec = ST_MTIME_NSEC(st);
}
}
-static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce)
+/* Copy miscellaneous fields but not the name */
+static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
+ struct cache_entry *ce)
{
- int size = ondisk_ce_size(ce);
- struct ondisk_cache_entry *ondisk = xcalloc(1, size);
- char *name;
- int result;
-
ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
struct ondisk_cache_entry_extended *ondisk2;
ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
- name = ondisk2->name;
+ return ondisk2->name;
}
- else
- name = ondisk->name;
+ else {
+ return ondisk->name;
+ }
+}
+
+static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce)
+{
+ int size = ondisk_ce_size(ce);
+ struct ondisk_cache_entry *ondisk = xcalloc(1, size);
+ char *name;
+ int result;
+
+ name = copy_cache_entry_to_ondisk(ondisk, ce);
memcpy(name, ce->name, ce_namelen(ce));
result = ce_write(c, fd, ondisk, size);