Documentation: clarify information about 'ident' attribute
[gitweb.git] / index-pack.c
index 85e20cd04bb2b1db19aa2a256557caabd0ed5651..c99a1a152c7ddbb63073461b86179f2be5bf9640 100644 (file)
@@ -10,7 +10,7 @@
 #include "fsck.h"
 
 static const char index_pack_usage[] =
-"git-index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] [--strict] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
+"git index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] [--strict] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
 
 struct object_entry
 {
@@ -29,6 +29,7 @@ union delta_base {
 struct base_data {
        struct base_data *base;
        struct base_data *child;
+       struct object_entry *obj;
        void *data;
        unsigned long size;
 };
@@ -51,6 +52,7 @@ struct delta_entry
 static struct object_entry *objects;
 static struct delta_entry *deltas;
 static struct base_data *base_cache;
+static size_t base_cache_used;
 static int nr_objects;
 static int nr_deltas;
 static int nr_resolved_deltas;
@@ -170,7 +172,7 @@ static char *open_pack_file(char *pack_name)
                if (!pack_name) {
                        static char tmpfile[PATH_MAX];
                        snprintf(tmpfile, sizeof(tmpfile),
-                                "%s/tmp_pack_XXXXXX", get_object_directory());
+                                "%s/pack/tmp_pack_XXXXXX", get_object_directory());
                        output_fd = xmkstemp(tmpfile);
                        pack_name = xstrdup(tmpfile);
                } else
@@ -198,7 +200,8 @@ static void parse_pack_header(void)
        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
                die("pack signature mismatch");
        if (!pack_version_ok(hdr->hdr_version))
-               die("pack version %d unsupported", ntohl(hdr->hdr_version));
+               die("pack version %"PRIu32" unsupported",
+                       ntohl(hdr->hdr_version));
 
        nr_objects = ntohl(hdr->hdr_entries);
        use(sizeof(struct pack_header));
@@ -218,6 +221,20 @@ static void bad_object(unsigned long offset, const char *format, ...)
        die("pack has bad object at offset %lu: %s", offset, buf);
 }
 
+static void prune_base_data(struct base_data *retain)
+{
+       struct base_data *b = base_cache;
+       for (b = base_cache;
+            base_cache_used > delta_base_cache_limit && b;
+            b = b->child) {
+               if (b->data && b != retain) {
+                       free(b->data);
+                       b->data = NULL;
+                       base_cache_used -= b->size;
+               }
+       }
+}
+
 static void link_base_data(struct base_data *base, struct base_data *c)
 {
        if (base)
@@ -227,6 +244,8 @@ static void link_base_data(struct base_data *base, struct base_data *c)
 
        c->base = base;
        c->child = NULL;
+       base_cache_used += c->size;
+       prune_base_data(c);
 }
 
 static void unlink_base_data(struct base_data *c)
@@ -236,7 +255,10 @@ static void unlink_base_data(struct base_data *c)
                base->child = NULL;
        else
                base_cache = NULL;
-       free(c->data);
+       if (c->data) {
+               free(c->data);
+               base_cache_used -= c->size;
+       }
 }
 
 static void *unpack_entry_data(unsigned long offset, unsigned long size)
@@ -343,8 +365,11 @@ static void *get_data_from_pack(struct object_entry *obj)
        data = src;
        do {
                ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
-               if (n <= 0)
+               if (n < 0)
                        die("cannot pread pack file: %s", strerror(errno));
+               if (!n)
+                       die("premature end of pack file, %lu bytes missing",
+                           len - rdy);
                rdy += n;
        } while (rdy < len);
        data = xmalloc(obj->size);
@@ -454,6 +479,30 @@ static void sha1_object(const void *data, unsigned long size,
        }
 }
 
+static void *get_base_data(struct base_data *c)
+{
+       if (!c->data) {
+               struct object_entry *obj = c->obj;
+
+               if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
+                       void *base = get_base_data(c->base);
+                       void *raw = get_data_from_pack(obj);
+                       c->data = patch_delta(
+                               base, c->base->size,
+                               raw, obj->size,
+                               &c->size);
+                       free(raw);
+                       if (!c->data)
+                               bad_object(obj->idx.offset, "failed to apply delta");
+               } else
+                       c->data = get_data_from_pack(obj);
+
+               base_cache_used += c->size;
+               prune_base_data(c);
+       }
+       return c->data;
+}
+
 static void resolve_delta(struct object_entry *delta_obj,
                          struct base_data *base_obj, enum object_type type)
 {
@@ -466,7 +515,7 @@ static void resolve_delta(struct object_entry *delta_obj,
        delta_obj->real_type = type;
        delta_data = get_data_from_pack(delta_obj);
        delta_size = delta_obj->size;
-       result.data = patch_delta(base_obj->data, base_obj->size,
+       result.data = patch_delta(get_base_data(base_obj), base_obj->size,
                             delta_data, delta_size,
                             &result.size);
        free(delta_data);
@@ -475,6 +524,7 @@ static void resolve_delta(struct object_entry *delta_obj,
        sha1_object(result.data, result.size, type, delta_obj->idx.sha1);
        nr_resolved_deltas++;
 
+       result.obj = delta_obj;
        link_base_data(base_obj, &result);
 
        hashcpy(delta_base.sha1, delta_obj->idx.sha1);
@@ -587,6 +637,7 @@ static void parse_pack_objects(unsigned char *sha1)
                        continue;
                base_obj.data = get_data_from_pack(obj);
                base_obj.size = obj->size;
+               base_obj.obj = obj;
                link_base_data(NULL, &base_obj);
 
                if (ref)
@@ -606,7 +657,7 @@ static void parse_pack_objects(unsigned char *sha1)
        }
 }
 
-static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_crc)
+static int write_compressed(struct sha1file *f, void *in, unsigned int size)
 {
        z_stream stream;
        unsigned long maxsize;
@@ -626,13 +677,13 @@ static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_c
        deflateEnd(&stream);
 
        size = stream.total_out;
-       write_or_die(fd, out, size);
-       *obj_crc = crc32(*obj_crc, out, size);
+       sha1write(f, out, size);
        free(out);
        return size;
 }
 
-static void append_obj_to_pack(const unsigned char *sha1, void *buf,
+static struct object_entry *append_obj_to_pack(struct sha1file *f,
+                              const unsigned char *sha1, void *buf,
                               unsigned long size, enum object_type type)
 {
        struct object_entry *obj = &objects[nr_objects++];
@@ -647,12 +698,18 @@ static void append_obj_to_pack(const unsigned char *sha1, void *buf,
                s >>= 7;
        }
        header[n++] = c;
-       write_or_die(output_fd, header, n);
-       obj[0].idx.crc32 = crc32(0, Z_NULL, 0);
-       obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n);
+       crc32_begin(f);
+       sha1write(f, header, n);
+       obj[0].size = size;
+       obj[0].hdr_size = n;
+       obj[0].type = type;
+       obj[0].real_type = type;
        obj[1].idx.offset = obj[0].idx.offset + n;
-       obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
+       obj[1].idx.offset += write_compressed(f, buf, size);
+       obj[0].idx.crc32 = crc32_end(f);
+       sha1flush(f);
        hashcpy(obj->idx.sha1, sha1);
+       return obj;
 }
 
 static int delta_pos_compare(const void *_a, const void *_b)
@@ -662,7 +719,7 @@ static int delta_pos_compare(const void *_a, const void *_b)
        return a->obj_no - b->obj_no;
 }
 
-static void fix_unresolved_deltas(int nr_unresolved)
+static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
 {
        struct delta_entry **sorted_by_pos;
        int i, n = 0;
@@ -696,6 +753,12 @@ static void fix_unresolved_deltas(int nr_unresolved)
                base_obj.data = read_sha1_file(d->base.sha1, &type, &base_obj.size);
                if (!base_obj.data)
                        continue;
+
+               if (check_sha1_signature(d->base.sha1, base_obj.data,
+                               base_obj.size, typename(type)))
+                       die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
+               base_obj.obj = append_obj_to_pack(f, d->base.sha1,
+                                       base_obj.data, base_obj.size, type);
                link_base_data(NULL, &base_obj);
 
                find_delta_children(&d->base, &first, &last);
@@ -705,11 +768,6 @@ static void fix_unresolved_deltas(int nr_unresolved)
                                resolve_delta(child, &base_obj, type);
                }
 
-               if (check_sha1_signature(d->base.sha1, base_obj.data,
-                               base_obj.size, typename(type)))
-                       die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
-               append_obj_to_pack(d->base.sha1, base_obj.data,
-                       base_obj.size, type);
                unlink_base_data(&base_obj);
                display_progress(progress, nr_resolved_deltas);
        }
@@ -805,7 +863,8 @@ static int git_index_pack_config(const char *k, const char *v, void *cb)
        if (!strcmp(k, "pack.indexversion")) {
                pack_idx_default_version = git_config_int(k, v);
                if (pack_idx_default_version > 2)
-                       die("bad pack.indexversion=%d", pack_idx_default_version);
+                       die("bad pack.indexversion=%"PRIu32,
+                               pack_idx_default_version);
                return 0;
        }
        return git_default_config(k, v, cb);
@@ -819,9 +878,27 @@ int main(int argc, char **argv)
        const char *keep_name = NULL, *keep_msg = NULL;
        char *index_name_buf = NULL, *keep_name_buf = NULL;
        struct pack_idx_entry **idx_objects;
-       unsigned char sha1[20];
+       unsigned char pack_sha1[20];
 
-       git_config(git_index_pack_config, NULL);
+       /*
+        * We wish to read the repository's config file if any, and
+        * for that it is necessary to call setup_git_directory_gently().
+        * However if the cwd was inside .git/objects/pack/ then we need
+        * to go back there or all the pack name arguments will be wrong.
+        * And in that case we cannot rely on any prefix returned by
+        * setup_git_directory_gently() either.
+        */
+       {
+               char cwd[PATH_MAX+1];
+               int nongit;
+
+               if (!getcwd(cwd, sizeof(cwd)-1))
+                       die("Unable to get current working directory");
+               setup_git_directory_gently(&nongit);
+               git_config(git_index_pack_config, NULL);
+               if (chdir(cwd))
+                       die("Cannot come back to cwd");
+       }
 
        for (i = 1; i < argc; i++) {
                char *arg = argv[i];
@@ -904,13 +981,15 @@ int main(int argc, char **argv)
        parse_pack_header();
        objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
        deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
-       parse_pack_objects(sha1);
+       parse_pack_objects(pack_sha1);
        if (nr_deltas == nr_resolved_deltas) {
                stop_progress(&progress);
                /* Flush remaining pack final 20-byte SHA1. */
                flush();
        } else {
                if (fix_thin_pack) {
+                       struct sha1file *f;
+                       unsigned char read_sha1[20], tail_sha1[20];
                        char msg[48];
                        int nr_unresolved = nr_deltas - nr_resolved_deltas;
                        int nr_objects_initial = nr_objects;
@@ -919,12 +998,19 @@ int main(int argc, char **argv)
                        objects = xrealloc(objects,
                                           (nr_objects + nr_unresolved + 1)
                                           * sizeof(*objects));
-                       fix_unresolved_deltas(nr_unresolved);
+                       f = sha1fd(output_fd, curr_pack);
+                       fix_unresolved_deltas(f, nr_unresolved);
                        sprintf(msg, "completed with %d local objects",
                                nr_objects - nr_objects_initial);
                        stop_progress_msg(&progress, msg);
-                       fixup_pack_header_footer(output_fd, sha1,
-                                                curr_pack, nr_objects);
+                       sha1close(f, tail_sha1, 0);
+                       hashcpy(read_sha1, pack_sha1);
+                       fixup_pack_header_footer(output_fd, pack_sha1,
+                                                curr_pack, nr_objects,
+                                                read_sha1, consumed_bytes-20);
+                       if (hashcmp(read_sha1, tail_sha1) != 0)
+                               die("Unexpected tail checksum for %s "
+                                   "(disk corruption?)", curr_pack);
                }
                if (nr_deltas != nr_resolved_deltas)
                        die("pack has %d unresolved deltas",
@@ -937,13 +1023,13 @@ int main(int argc, char **argv)
        idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
        for (i = 0; i < nr_objects; i++)
                idx_objects[i] = &objects[i].idx;
-       curr_index = write_idx_file(index_name, idx_objects, nr_objects, sha1);
+       curr_index = write_idx_file(index_name, idx_objects, nr_objects, pack_sha1);
        free(idx_objects);
 
        final(pack_name, curr_pack,
                index_name, curr_index,
                keep_name, keep_msg,
-               sha1);
+               pack_sha1);
        free(objects);
        free(index_name_buf);
        free(keep_name_buf);