Documentation: pack-refs --all vs default behaviour
[gitweb.git] / pack-check.c
index eca32b6cabeaf8881abb9c93d9ca89fc556a937c..08a9fd8dc09056c1b21cb7414f2467cffcdef077 100644 (file)
@@ -1,57 +1,57 @@
 #include "cache.h"
 #include "pack.h"
 
-static int verify_packfile(struct packed_git *p)
+static int verify_packfile(struct packed_git *p,
+               struct pack_window **w_curs)
 {
        unsigned long index_size = p->index_size;
        void *index_base = p->index_base;
        SHA_CTX ctx;
        unsigned char sha1[20];
-       unsigned long pack_size = p->pack_size;
-       void *pack_base;
-       struct pack_header *hdr;
+       unsigned long offset = 0, pack_sig = p->pack_size - 20;
        int nr_objects, err, i;
 
-       /* Header consistency check */
-       hdr = p->pack_base;
-       if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
-               return error("Packfile %s signature mismatch", p->pack_name);
-       if (!pack_version_ok(hdr->hdr_version))
-               return error("Packfile version %d unsupported",
-                            ntohl(hdr->hdr_version));
-       nr_objects = ntohl(hdr->hdr_entries);
-       if (num_packed_objects(p) != nr_objects)
-               return error("Packfile claims to have %d objects, "
-                            "while idx size expects %d", nr_objects,
-                            num_packed_objects(p));
+       /* Note that the pack header checks are actually performed by
+        * use_pack when it first opens the pack file.  If anything
+        * goes wrong during those checks then the call will die out
+        * immediately.
+        */
 
        SHA1_Init(&ctx);
-       pack_base = p->pack_base;
-       SHA1_Update(&ctx, pack_base, pack_size - 20);
+       while (offset < pack_sig) {
+               unsigned int remaining;
+               unsigned char *in = use_pack(p, w_curs, offset, &remaining);
+               offset += remaining;
+               if (offset > pack_sig)
+                       remaining -= offset - pack_sig;
+               SHA1_Update(&ctx, in, remaining);
+       }
        SHA1_Final(sha1, &ctx);
-       if (memcmp(sha1, index_base + index_size - 40, 20))
-               return error("Packfile %s SHA1 mismatch with idx",
-                            p->pack_name);
-       if (memcmp(sha1, pack_base + pack_size - 20, 20))
+       if (hashcmp(sha1, use_pack(p, w_curs, pack_sig, NULL)))
                return error("Packfile %s SHA1 mismatch with itself",
                             p->pack_name);
+       if (hashcmp(sha1, (unsigned char *)index_base + index_size - 40))
+               return error("Packfile %s SHA1 mismatch with idx",
+                            p->pack_name);
+       unuse_pack(w_curs);
 
        /* Make sure everything reachable from idx is valid.  Since we
         * have verified that nr_objects matches between idx and pack,
         * we do not do scan-streaming check on the pack file.
         */
+       nr_objects = num_packed_objects(p);
        for (i = err = 0; i < nr_objects; i++) {
                unsigned char sha1[20];
-               struct pack_entry e;
                void *data;
                char type[20];
-               unsigned long size;
+               unsigned long size, offset;
 
                if (nth_packed_object_sha1(p, i, sha1))
                        die("internal error pack-check nth-packed-object");
-               if (!find_pack_entry_one(sha1, &e, p))
+               offset = find_pack_entry_one(sha1, p);
+               if (!offset)
                        die("internal error pack-check find-pack-entry-one");
-               data = unpack_entry_gently(&e, type, &size);
+               data = unpack_entry(p, offset, type, &size);
                if (!data) {
                        err = error("cannot unpack %s from %s",
                                    sha1_to_hex(sha1), p->pack_name);
@@ -70,38 +70,55 @@ static int verify_packfile(struct packed_git *p)
 }
 
 
+#define MAX_CHAIN 40
+
 static void show_pack_info(struct packed_git *p)
 {
-       struct pack_header *hdr;
        int nr_objects, i;
+       unsigned int chain_histogram[MAX_CHAIN];
 
-       hdr = p->pack_base;
-       nr_objects = ntohl(hdr->hdr_entries);
+       nr_objects = num_packed_objects(p);
+       memset(chain_histogram, 0, sizeof(chain_histogram));
 
        for (i = 0; i < nr_objects; i++) {
                unsigned char sha1[20], base_sha1[20];
-               struct pack_entry e;
                char type[20];
                unsigned long size;
                unsigned long store_size;
+               unsigned long offset;
                unsigned int delta_chain_length;
 
                if (nth_packed_object_sha1(p, i, sha1))
                        die("internal error pack-check nth-packed-object");
-               if (!find_pack_entry_one(sha1, &e, p))
+               offset = find_pack_entry_one(sha1, p);
+               if (!offset)
                        die("internal error pack-check find-pack-entry-one");
 
-               packed_object_info_detail(&e, type, &size, &store_size,
+               packed_object_info_detail(p, offset, type, &size, &store_size,
                                          &delta_chain_length,
                                          base_sha1);
                printf("%s ", sha1_to_hex(sha1));
                if (!delta_chain_length)
-                       printf("%-6s %lu %u\n", type, size, e.offset);
-               else
-                       printf("%-6s %lu %u %u %s\n", type, size, e.offset,
+                       printf("%-6s %lu %lu\n", type, size, offset);
+               else {
+                       printf("%-6s %lu %lu %u %s\n", type, size, offset,
                               delta_chain_length, sha1_to_hex(base_sha1));
+                       if (delta_chain_length < MAX_CHAIN)
+                               chain_histogram[delta_chain_length]++;
+                       else
+                               chain_histogram[0]++;
+               }
        }
 
+       for (i = 0; i < MAX_CHAIN; i++) {
+               if (!chain_histogram[i])
+                       continue;
+               printf("chain length %s %d: %d object%s\n",
+                      i ? "=" : ">=",
+                      i ? i : MAX_CHAIN,
+                      chain_histogram[i],
+                      1 < chain_histogram[i] ? "s" : "");
+       }
 }
 
 int verify_pack(struct packed_git *p, int verbose)
@@ -117,24 +134,22 @@ int verify_pack(struct packed_git *p, int verbose)
        SHA1_Init(&ctx);
        SHA1_Update(&ctx, index_base, index_size - 20);
        SHA1_Final(sha1, &ctx);
-       if (memcmp(sha1, index_base + index_size - 20, 20))
+       if (hashcmp(sha1, (unsigned char *)index_base + index_size - 20))
                ret = error("Packfile index for %s SHA1 mismatch",
                            p->pack_name);
 
        if (!ret) {
                /* Verify pack file */
-               use_packed_git(p);
-               ret = verify_packfile(p);
-               unuse_packed_git(p);
+               struct pack_window *w_curs = NULL;
+               ret = verify_packfile(p, &w_curs);
+               unuse_pack(&w_curs);
        }
 
        if (verbose) {
                if (ret)
                        printf("%s: bad\n", p->pack_name);
                else {
-                       use_packed_git(p);
                        show_pack_info(p);
-                       unuse_packed_git(p);
                        printf("%s: ok\n", p->pack_name);
                }
        }