Always ensure the pack.keep file is removed by git-fetch
[gitweb.git] / pack-write.c
index de72f44dc8ea5098b5824eb30b119a8508293226..979bdfff7c516ada7fb36281a22b41d303d1b99c 100644 (file)
@@ -1,5 +1,147 @@
 #include "cache.h"
 #include "pack.h"
+#include "csum-file.h"
+
+uint32_t pack_idx_default_version = 1;
+uint32_t pack_idx_off32_limit = 0x7fffffff;
+
+static int sha1_compare(const void *_a, const void *_b)
+{
+       struct pack_idx_entry *a = *(struct pack_idx_entry **)_a;
+       struct pack_idx_entry *b = *(struct pack_idx_entry **)_b;
+       return hashcmp(a->sha1, b->sha1);
+}
+
+/*
+ * On entry *sha1 contains the pack content SHA1 hash, on exit it is
+ * the SHA1 hash of sorted object names. The objects array passed in
+ * will be sorted by SHA1 on exit.
+ */
+const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, unsigned char *sha1)
+{
+       struct sha1file *f;
+       struct pack_idx_entry **sorted_by_sha, **list, **last;
+       off_t last_obj_offset = 0;
+       uint32_t array[256];
+       int i, fd;
+       SHA_CTX ctx;
+       uint32_t index_version;
+
+       if (nr_objects) {
+               sorted_by_sha = objects;
+               list = sorted_by_sha;
+               last = sorted_by_sha + nr_objects;
+               for (i = 0; i < nr_objects; ++i) {
+                       if (objects[i]->offset > last_obj_offset)
+                               last_obj_offset = objects[i]->offset;
+               }
+               qsort(sorted_by_sha, nr_objects, sizeof(sorted_by_sha[0]),
+                     sha1_compare);
+       }
+       else
+               sorted_by_sha = list = last = NULL;
+
+       if (!index_name) {
+               static char tmpfile[PATH_MAX];
+               snprintf(tmpfile, sizeof(tmpfile),
+                        "%s/tmp_idx_XXXXXX", get_object_directory());
+               fd = xmkstemp(tmpfile);
+               index_name = xstrdup(tmpfile);
+       } else {
+               unlink(index_name);
+               fd = open(index_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
+       }
+       if (fd < 0)
+               die("unable to create %s: %s", index_name, strerror(errno));
+       f = sha1fd(fd, index_name);
+
+       /* if last object's offset is >= 2^31 we should use index V2 */
+       index_version = (last_obj_offset >> 31) ? 2 : pack_idx_default_version;
+
+       /* index versions 2 and above need a header */
+       if (index_version >= 2) {
+               struct pack_idx_header hdr;
+               hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
+               hdr.idx_version = htonl(index_version);
+               sha1write(f, &hdr, sizeof(hdr));
+       }
+
+       /*
+        * Write the first-level table (the list is sorted,
+        * but we use a 256-entry lookup to be able to avoid
+        * having to do eight extra binary search iterations).
+        */
+       for (i = 0; i < 256; i++) {
+               struct pack_idx_entry **next = list;
+               while (next < last) {
+                       struct pack_idx_entry *obj = *next;
+                       if (obj->sha1[0] != i)
+                               break;
+                       next++;
+               }
+               array[i] = htonl(next - sorted_by_sha);
+               list = next;
+       }
+       sha1write(f, array, 256 * 4);
+
+       /* compute the SHA1 hash of sorted object names. */
+       SHA1_Init(&ctx);
+
+       /*
+        * Write the actual SHA1 entries..
+        */
+       list = sorted_by_sha;
+       for (i = 0; i < nr_objects; i++) {
+               struct pack_idx_entry *obj = *list++;
+               if (index_version < 2) {
+                       uint32_t offset = htonl(obj->offset);
+                       sha1write(f, &offset, 4);
+               }
+               sha1write(f, obj->sha1, 20);
+               SHA1_Update(&ctx, obj->sha1, 20);
+       }
+
+       if (index_version >= 2) {
+               unsigned int nr_large_offset = 0;
+
+               /* write the crc32 table */
+               list = sorted_by_sha;
+               for (i = 0; i < nr_objects; i++) {
+                       struct pack_idx_entry *obj = *list++;
+                       uint32_t crc32_val = htonl(obj->crc32);
+                       sha1write(f, &crc32_val, 4);
+               }
+
+               /* write the 32-bit offset table */
+               list = sorted_by_sha;
+               for (i = 0; i < nr_objects; i++) {
+                       struct pack_idx_entry *obj = *list++;
+                       uint32_t offset = (obj->offset <= pack_idx_off32_limit) ?
+                               obj->offset : (0x80000000 | nr_large_offset++);
+                       offset = htonl(offset);
+                       sha1write(f, &offset, 4);
+               }
+
+               /* write the large offset table */
+               list = sorted_by_sha;
+               while (nr_large_offset) {
+                       struct pack_idx_entry *obj = *list++;
+                       uint64_t offset = obj->offset;
+                       if (offset > pack_idx_off32_limit) {
+                               uint32_t split[2];
+                               split[0] = htonl(offset >> 32);
+                               split[1] = htonl(offset & 0xffffffff);
+                               sha1write(f, split, 8);
+                               nr_large_offset--;
+                       }
+               }
+       }
+
+       sha1write(f, sha1, 20);
+       sha1close(f, NULL, 1);
+       SHA1_Final(sha1, &ctx);
+       return index_name;
+}
 
 void fixup_pack_header_footer(int pack_fd,
                         unsigned char *pack_file_sha1,
@@ -25,7 +167,7 @@ void fixup_pack_header_footer(int pack_fd,
 
        buf = xmalloc(buf_sz);
        for (;;) {
-               size_t n = xread(pack_fd, buf, buf_sz);
+               ssize_t n = xread(pack_fd, buf, buf_sz);
                if (!n)
                        break;
                if (n < 0)
@@ -37,3 +179,29 @@ void fixup_pack_header_footer(int pack_fd,
        SHA1_Final(pack_file_sha1, &c);
        write_or_die(pack_fd, pack_file_sha1, 20);
 }
+
+char *index_pack_lockfile(int ip_out)
+{
+       int len, s;
+       char packname[46];
+
+       /*
+        * The first thing we expects from index-pack's output
+        * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
+        * %40s is the newly created pack SHA1 name.  In the "keep"
+        * case, we need it to remove the corresponding .keep file
+        * later on.  If we don't get that then tough luck with it.
+        */
+       for (len = 0;
+                len < 46 && (s = xread(ip_out, packname+len, 46-len)) > 0;
+                len += s);
+       if (len == 46 && packname[45] == '\n' &&
+               memcmp(packname, "keep\t", 5) == 0) {
+               char path[PATH_MAX];
+               packname[45] = 0;
+               snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
+                        get_object_directory(), packname + 5);
+               return xstrdup(path);
+       }
+       return NULL;
+}