Git 2.15-rc2
[gitweb.git] / fast-import.c
index 84a13756cc6387d7546ebda8d3c92a6c49a53cf8..d5e4cf0bad411dad859dbe421ab7583cfb0f1561 100644 (file)
@@ -154,6 +154,7 @@ Format of STDIN stream:
 
 #include "builtin.h"
 #include "cache.h"
+#include "config.h"
 #include "lockfile.h"
 #include "object.h"
 #include "blob.h"
@@ -165,6 +166,8 @@ Format of STDIN stream:
 #include "csum-file.h"
 #include "quote.h"
 #include "dir.h"
+#include "run-command.h"
+#include "packfile.h"
 
 #define PACK_ID_BITS 16
 #define MAX_PACK_ID ((1<<PACK_ID_BITS)-1)
@@ -225,7 +228,7 @@ struct tree_entry {
        struct atom_str *name;
        struct tree_entry_ms {
                uint16_t mode;
-               unsigned char sha1[20];
+               struct object_id oid;
        } versions[2];
 };
 
@@ -251,19 +254,19 @@ struct branch {
        unsigned active : 1;
        unsigned delete : 1;
        unsigned pack_id : PACK_ID_BITS;
-       unsigned char sha1[20];
+       struct object_id oid;
 };
 
 struct tag {
        struct tag *next_tag;
        const char *name;
        unsigned int pack_id;
-       unsigned char sha1[20];
+       struct object_id oid;
 };
 
 struct hash_list {
        struct hash_list *next;
-       unsigned char sha1[20];
+       struct object_id oid;
 };
 
 typedef enum {
@@ -279,11 +282,10 @@ struct recent_command {
 };
 
 /* Configured limits on output */
-static unsigned long max_depth = 10;
+static unsigned long max_depth = 50;
 static off_t max_packsize;
+static int unpack_limit = 100;
 static int force_update;
-static int pack_compression_level = Z_DEFAULT_COMPRESSION;
-static int pack_compression_seen;
 
 /* Stats and misc. counters */
 static uintmax_t alloc_count;
@@ -386,13 +388,15 @@ static void write_branch_report(FILE *rpt, struct branch *b)
                fputs(" active", rpt);
        if (b->branch_tree.tree)
                fputs(" loaded", rpt);
-       if (is_null_sha1(b->branch_tree.versions[1].sha1))
+       if (is_null_oid(&b->branch_tree.versions[1].oid))
                fputs(" dirty", rpt);
        fputc('\n', rpt);
 
-       fprintf(rpt, "  tip commit  : %s\n", sha1_to_hex(b->sha1));
-       fprintf(rpt, "  old tree    : %s\n", sha1_to_hex(b->branch_tree.versions[0].sha1));
-       fprintf(rpt, "  cur tree    : %s\n", sha1_to_hex(b->branch_tree.versions[1].sha1));
+       fprintf(rpt, "  tip commit  : %s\n", oid_to_hex(&b->oid));
+       fprintf(rpt, "  old tree    : %s\n",
+               oid_to_hex(&b->branch_tree.versions[0].oid));
+       fprintf(rpt, "  cur tree    : %s\n",
+               oid_to_hex(&b->branch_tree.versions[1].oid));
        fprintf(rpt, "  commit clock: %" PRIuMAX "\n", b->last_commit);
 
        fputs("  last pack   : ", rpt);
@@ -470,7 +474,7 @@ static void write_crash_report(const char *err)
                fputs("Annotated Tags\n", rpt);
                fputs("--------------\n", rpt);
                for (tg = first_tag; tg; tg = tg->next_tag) {
-                       fputs(sha1_to_hex(tg->sha1), rpt);
+                       fputs(oid_to_hex(&tg->oid), rpt);
                        fputc(' ', rpt);
                        fputs(tg->name, rpt);
                        fputc('\n', rpt);
@@ -555,7 +559,7 @@ static void alloc_objects(unsigned int cnt)
        alloc_count += cnt;
 }
 
-static struct object_entry *new_object(unsigned char *sha1)
+static struct object_entry *new_object(struct object_id *oid)
 {
        struct object_entry *e;
 
@@ -563,38 +567,65 @@ static struct object_entry *new_object(unsigned char *sha1)
                alloc_objects(object_entry_alloc);
 
        e = blocks->next_free++;
-       hashcpy(e->idx.sha1, sha1);
+       oidcpy(&e->idx.oid, oid);
        return e;
 }
 
-static struct object_entry *find_object(unsigned char *sha1)
+static struct object_entry *find_object(struct object_id *oid)
 {
-       unsigned int h = sha1[0] << 8 | sha1[1];
+       unsigned int h = oid->hash[0] << 8 | oid->hash[1];
        struct object_entry *e;
        for (e = object_table[h]; e; e = e->next)
-               if (!hashcmp(sha1, e->idx.sha1))
+               if (!oidcmp(oid, &e->idx.oid))
                        return e;
        return NULL;
 }
 
-static struct object_entry *insert_object(unsigned char *sha1)
+static struct object_entry *insert_object(struct object_id *oid)
 {
-       unsigned int h = sha1[0] << 8 | sha1[1];
+       unsigned int h = oid->hash[0] << 8 | oid->hash[1];
        struct object_entry *e = object_table[h];
 
        while (e) {
-               if (!hashcmp(sha1, e->idx.sha1))
+               if (!oidcmp(oid, &e->idx.oid))
                        return e;
                e = e->next;
        }
 
-       e = new_object(sha1);
+       e = new_object(oid);
        e->next = object_table[h];
        e->idx.offset = 0;
        object_table[h] = e;
        return e;
 }
 
+static void invalidate_pack_id(unsigned int id)
+{
+       unsigned int h;
+       unsigned long lu;
+       struct tag *t;
+
+       for (h = 0; h < ARRAY_SIZE(object_table); h++) {
+               struct object_entry *e;
+
+               for (e = object_table[h]; e; e = e->next)
+                       if (e->pack_id == id)
+                               e->pack_id = MAX_PACK_ID;
+       }
+
+       for (lu = 0; lu < branch_table_sz; lu++) {
+               struct branch *b;
+
+               for (b = branch_table[lu]; b; b = b->table_next_branch)
+                       if (b->pack_id == id)
+                               b->pack_id = MAX_PACK_ID;
+       }
+
+       for (t = first_tag; t; t = t->next_tag)
+               if (t->pack_id == id)
+                       t->pack_id = MAX_PACK_ID;
+}
+
 static unsigned int hc_str(const char *s, size_t len)
 {
        unsigned int r = 0;
@@ -849,7 +880,7 @@ static struct tree_content *dup_tree_content(struct tree_content *s)
                a = s->entries[i];
                b = new_tree_entry();
                memcpy(b, a, sizeof(*a));
-               if (a->tree && is_null_sha1(b->versions[1].sha1))
+               if (a->tree && is_null_oid(&b->versions[1].oid))
                        b->tree = dup_tree_content(a->tree);
                else
                        b->tree = NULL;
@@ -863,14 +894,15 @@ static struct tree_content *dup_tree_content(struct tree_content *s)
 
 static void start_packfile(void)
 {
-       static char tmp_file[PATH_MAX];
+       struct strbuf tmp_file = STRBUF_INIT;
        struct packed_git *p;
        struct pack_header hdr;
        int pack_fd;
 
-       pack_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
-                             "pack/tmp_pack_XXXXXX");
-       FLEX_ALLOC_STR(p, pack_name, tmp_file);
+       pack_fd = odb_mkstemp(&tmp_file, "pack/tmp_pack_XXXXXX");
+       FLEX_ALLOC_STR(p, pack_name, tmp_file.buf);
+       strbuf_release(&tmp_file);
+
        p->pack_fd = pack_fd;
        p->do_not_close = 1;
        pack_file = sha1fd(pack_fd, p->pack_name);
@@ -913,41 +945,57 @@ static const char *create_index(void)
 
 static char *keep_pack(const char *curr_index_name)
 {
-       static char name[PATH_MAX];
        static const char *keep_msg = "fast-import";
+       struct strbuf name = STRBUF_INIT;
        int keep_fd;
 
-       keep_fd = odb_pack_keep(name, sizeof(name), pack_data->sha1);
+       odb_pack_name(&name, pack_data->sha1, "keep");
+       keep_fd = odb_pack_keep(name.buf);
        if (keep_fd < 0)
                die_errno("cannot create keep file");
        write_or_die(keep_fd, keep_msg, strlen(keep_msg));
        if (close(keep_fd))
                die_errno("failed to write keep file");
 
-       snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
-                get_object_directory(), sha1_to_hex(pack_data->sha1));
-       if (finalize_object_file(pack_data->pack_name, name))
+       odb_pack_name(&name, pack_data->sha1, "pack");
+       if (finalize_object_file(pack_data->pack_name, name.buf))
                die("cannot store pack file");
 
-       snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
-                get_object_directory(), sha1_to_hex(pack_data->sha1));
-       if (finalize_object_file(curr_index_name, name))
+       odb_pack_name(&name, pack_data->sha1, "idx");
+       if (finalize_object_file(curr_index_name, name.buf))
                die("cannot store index file");
        free((void *)curr_index_name);
-       return name;
+       return strbuf_detach(&name, NULL);
 }
 
 static void unkeep_all_packs(void)
 {
-       static char name[PATH_MAX];
+       struct strbuf name = STRBUF_INIT;
        int k;
 
        for (k = 0; k < pack_id; k++) {
                struct packed_git *p = all_packs[k];
-               snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
-                        get_object_directory(), sha1_to_hex(p->sha1));
-               unlink_or_warn(name);
+               odb_pack_name(&name, p->sha1, "keep");
+               unlink_or_warn(name.buf);
        }
+       strbuf_release(&name);
+}
+
+static int loosen_small_pack(const struct packed_git *p)
+{
+       struct child_process unpack = CHILD_PROCESS_INIT;
+
+       if (lseek(p->pack_fd, 0, SEEK_SET) < 0)
+               die_errno("Failed seeking to start of '%s'", p->pack_name);
+
+       unpack.in = p->pack_fd;
+       unpack.git_cmd = 1;
+       unpack.stdout_to_stderr = 1;
+       argv_array_push(&unpack.args, "unpack-objects");
+       if (!show_stats)
+               argv_array_push(&unpack.args, "-q");
+
+       return run_command(&unpack);
 }
 
 static void end_packfile(void)
@@ -961,17 +1009,25 @@ static void end_packfile(void)
        clear_delta_base_cache();
        if (object_count) {
                struct packed_git *new_p;
-               unsigned char cur_pack_sha1[20];
+               struct object_id cur_pack_oid;
                char *idx_name;
                int i;
                struct branch *b;
                struct tag *t;
 
                close_pack_windows(pack_data);
-               sha1close(pack_file, cur_pack_sha1, 0);
+               sha1close(pack_file, cur_pack_oid.hash, 0);
                fixup_pack_header_footer(pack_data->pack_fd, pack_data->sha1,
                                    pack_data->pack_name, object_count,
-                                   cur_pack_sha1, pack_size);
+                                   cur_pack_oid.hash, pack_size);
+
+               if (object_count <= unpack_limit) {
+                       if (!loosen_small_pack(pack_data)) {
+                               invalidate_pack_id(pack_id);
+                               goto discard_pack;
+                       }
+               }
+
                close(pack_data->pack_fd);
                idx_name = keep_pack(create_index());
 
@@ -981,6 +1037,7 @@ static void end_packfile(void)
                        die("core git rejected index %s", idx_name);
                all_packs[pack_id] = new_p;
                install_packed_git(new_p);
+               free(idx_name);
 
                /* Print the boundary */
                if (pack_edges) {
@@ -988,12 +1045,14 @@ static void end_packfile(void)
                        for (i = 0; i < branch_table_sz; i++) {
                                for (b = branch_table[i]; b; b = b->table_next_branch) {
                                        if (b->pack_id == pack_id)
-                                               fprintf(pack_edges, " %s", sha1_to_hex(b->sha1));
+                                               fprintf(pack_edges, " %s",
+                                                       oid_to_hex(&b->oid));
                                }
                        }
                        for (t = first_tag; t; t = t->next_tag) {
                                if (t->pack_id == pack_id)
-                                       fprintf(pack_edges, " %s", sha1_to_hex(t->sha1));
+                                       fprintf(pack_edges, " %s",
+                                               oid_to_hex(&t->oid));
                        }
                        fputc('\n', pack_edges);
                        fflush(pack_edges);
@@ -1002,11 +1061,11 @@ static void end_packfile(void)
                pack_id++;
        }
        else {
+discard_pack:
                close(pack_data->pack_fd);
                unlink_or_warn(pack_data->pack_name);
        }
-       free(pack_data);
-       pack_data = NULL;
+       FREE_AND_NULL(pack_data);
        running = 0;
 
        /* We can't carry a delta across packfiles. */
@@ -1025,13 +1084,13 @@ static int store_object(
        enum object_type type,
        struct strbuf *dat,
        struct last_object *last,
-       unsigned char *sha1out,
+       struct object_id *oidout,
        uintmax_t mark)
 {
        void *out, *delta;
        struct object_entry *e;
        unsigned char hdr[96];
-       unsigned char sha1[20];
+       struct object_id oid;
        unsigned long hdrlen, deltalen;
        git_SHA_CTX c;
        git_zstream s;
@@ -1041,17 +1100,17 @@ static int store_object(
        git_SHA1_Init(&c);
        git_SHA1_Update(&c, hdr, hdrlen);
        git_SHA1_Update(&c, dat->buf, dat->len);
-       git_SHA1_Final(sha1, &c);
-       if (sha1out)
-               hashcpy(sha1out, sha1);
+       git_SHA1_Final(oid.hash, &c);
+       if (oidout)
+               oidcpy(oidout, &oid);
 
-       e = insert_object(sha1);
+       e = insert_object(&oid);
        if (mark)
                insert_mark(mark, e);
        if (e->idx.offset) {
                duplicate_count_by_type[type]++;
                return 1;
-       } else if (find_sha1_pack(sha1, packed_git)) {
+       } else if (find_sha1_pack(oid.hash, packed_git)) {
                e->type = type;
                e->pack_id = MAX_PACK_ID;
                e->idx.offset = 1; /* just not zero! */
@@ -1091,8 +1150,7 @@ static int store_object(
 
                /* We cannot carry a delta into the new pack. */
                if (delta) {
-                       free(delta);
-                       delta = NULL;
+                       FREE_AND_NULL(delta);
 
                        git_deflate_init(&s, pack_compression_level);
                        s.next_in = (void *)dat->buf;
@@ -1120,7 +1178,8 @@ static int store_object(
                delta_count_by_type[type]++;
                e->depth = last->depth + 1;
 
-               hdrlen = encode_in_pack_object_header(OBJ_OFS_DELTA, deltalen, hdr);
+               hdrlen = encode_in_pack_object_header(hdr, sizeof(hdr),
+                                                     OBJ_OFS_DELTA, deltalen);
                sha1write(pack_file, hdr, hdrlen);
                pack_size += hdrlen;
 
@@ -1131,7 +1190,8 @@ static int store_object(
                pack_size += sizeof(hdr) - pos;
        } else {
                e->depth = 0;
-               hdrlen = encode_in_pack_object_header(type, dat->len, hdr);
+               hdrlen = encode_in_pack_object_header(hdr, sizeof(hdr),
+                                                     type, dat->len);
                sha1write(pack_file, hdr, hdrlen);
                pack_size += hdrlen;
        }
@@ -1162,13 +1222,13 @@ static void truncate_pack(struct sha1file_checkpoint *checkpoint)
        pack_size = checkpoint->offset;
 }
 
-static void stream_blob(uintmax_t len, unsigned char *sha1out, uintmax_t mark)
+static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 {
        size_t in_sz = 64 * 1024, out_sz = 64 * 1024;
        unsigned char *in_buf = xmalloc(in_sz);
        unsigned char *out_buf = xmalloc(out_sz);
        struct object_entry *e;
-       unsigned char sha1[20];
+       struct object_id oid;
        unsigned long hdrlen;
        off_t offset;
        git_SHA_CTX c;
@@ -1184,9 +1244,7 @@ static void stream_blob(uintmax_t len, unsigned char *sha1out, uintmax_t mark)
        sha1file_checkpoint(pack_file, &checkpoint);
        offset = checkpoint.offset;
 
-       hdrlen = snprintf((char *)out_buf, out_sz, "blob %" PRIuMAX, len) + 1;
-       if (out_sz <= hdrlen)
-               die("impossibly large object header");
+       hdrlen = xsnprintf((char *)out_buf, out_sz, "blob %" PRIuMAX, len) + 1;
 
        git_SHA1_Init(&c);
        git_SHA1_Update(&c, out_buf, hdrlen);
@@ -1195,9 +1253,7 @@ static void stream_blob(uintmax_t len, unsigned char *sha1out, uintmax_t mark)
 
        git_deflate_init(&s, pack_compression_level);
 
-       hdrlen = encode_in_pack_object_header(OBJ_BLOB, len, out_buf);
-       if (out_sz <= hdrlen)
-               die("impossibly large object header");
+       hdrlen = encode_in_pack_object_header(out_buf, out_sz, OBJ_BLOB, len);
 
        s.next_out = out_buf + hdrlen;
        s.avail_out = out_sz - hdrlen;
@@ -1235,12 +1291,12 @@ static void stream_blob(uintmax_t len, unsigned char *sha1out, uintmax_t mark)
                }
        }
        git_deflate_end(&s);
-       git_SHA1_Final(sha1, &c);
+       git_SHA1_Final(oid.hash, &c);
 
-       if (sha1out)
-               hashcpy(sha1out, sha1);
+       if (oidout)
+               oidcpy(oidout, &oid);
 
-       e = insert_object(sha1);
+       e = insert_object(&oid);
 
        if (mark)
                insert_mark(mark, e);
@@ -1249,7 +1305,7 @@ static void stream_blob(uintmax_t len, unsigned char *sha1out, uintmax_t mark)
                duplicate_count_by_type[OBJ_BLOB]++;
                truncate_pack(&checkpoint);
 
-       } else if (find_sha1_pack(sha1, packed_git)) {
+       } else if (find_sha1_pack(oid.hash, packed_git)) {
                e->type = OBJ_BLOB;
                e->pack_id = MAX_PACK_ID;
                e->idx.offset = 1; /* just not zero! */
@@ -1333,7 +1389,7 @@ static const char *get_mode(const char *str, uint16_t *modep)
 
 static void load_tree(struct tree_entry *root)
 {
-       unsigned char *sha1 = root->versions[1].sha1;
+       struct object_id *oid = &root->versions[1].oid;
        struct object_entry *myoe;
        struct tree_content *t;
        unsigned long size;
@@ -1341,22 +1397,22 @@ static void load_tree(struct tree_entry *root)
        const char *c;
 
        root->tree = t = new_tree_content(8);
-       if (is_null_sha1(sha1))
+       if (is_null_oid(oid))
                return;
 
-       myoe = find_object(sha1);
+       myoe = find_object(oid);
        if (myoe && myoe->pack_id != MAX_PACK_ID) {
                if (myoe->type != OBJ_TREE)
-                       die("Not a tree: %s", sha1_to_hex(sha1));
+                       die("Not a tree: %s", oid_to_hex(oid));
                t->delta_depth = myoe->depth;
                buf = gfi_unpack_entry(myoe, &size);
                if (!buf)
-                       die("Can't load tree %s", sha1_to_hex(sha1));
+                       die("Can't load tree %s", oid_to_hex(oid));
        } else {
                enum object_type type;
-               buf = read_sha1_file(sha1, &type, &size);
+               buf = read_sha1_file(oid->hash, &type, &size);
                if (!buf || type != OBJ_TREE)
-                       die("Can't load tree %s", sha1_to_hex(sha1));
+                       die("Can't load tree %s", oid_to_hex(oid));
        }
 
        c = buf;
@@ -1370,13 +1426,13 @@ static void load_tree(struct tree_entry *root)
                e->tree = NULL;
                c = get_mode(c, &e->versions[1].mode);
                if (!c)
-                       die("Corrupt mode in %s", sha1_to_hex(sha1));
+                       die("Corrupt mode in %s", oid_to_hex(oid));
                e->versions[0].mode = e->versions[1].mode;
                e->name = to_atom(c, strlen(c));
                c += e->name->str_len + 1;
-               hashcpy(e->versions[0].sha1, (unsigned char *)c);
-               hashcpy(e->versions[1].sha1, (unsigned char *)c);
-               c += 20;
+               hashcpy(e->versions[0].oid.hash, (unsigned char *)c);
+               hashcpy(e->versions[1].oid.hash, (unsigned char *)c);
+               c += GIT_SHA1_RAWSZ;
        }
        free(buf);
 }
@@ -1405,9 +1461,9 @@ static void mktree(struct tree_content *t, int v, struct strbuf *b)
        unsigned int i;
 
        if (!v)
-               qsort(t->entries,t->entry_count,sizeof(t->entries[0]),tecmp0);
+               QSORT(t->entries, t->entry_count, tecmp0);
        else
-               qsort(t->entries,t->entry_count,sizeof(t->entries[0]),tecmp1);
+               QSORT(t->entries, t->entry_count, tecmp1);
 
        for (i = 0; i < t->entry_count; i++) {
                if (t->entries[i]->versions[v].mode)
@@ -1423,7 +1479,7 @@ static void mktree(struct tree_content *t, int v, struct strbuf *b)
                strbuf_addf(b, "%o %s%c",
                        (unsigned int)(e->versions[v].mode & ~NO_DELTA),
                        e->name->str_dat, '\0');
-               strbuf_add(b, e->versions[v].sha1, 20);
+               strbuf_add(b, e->versions[v].oid.hash, GIT_SHA1_RAWSZ);
        }
 }
 
@@ -1434,7 +1490,7 @@ static void store_tree(struct tree_entry *root)
        struct last_object lo = { STRBUF_INIT, 0, 0, /* no_swap */ 1 };
        struct object_entry *le = NULL;
 
-       if (!is_null_sha1(root->versions[1].sha1))
+       if (!is_null_oid(&root->versions[1].oid))
                return;
 
        if (!root->tree)
@@ -1447,7 +1503,7 @@ static void store_tree(struct tree_entry *root)
        }
 
        if (!(root->versions[0].mode & NO_DELTA))
-               le = find_object(root->versions[0].sha1);
+               le = find_object(&root->versions[0].oid);
        if (S_ISDIR(root->versions[0].mode) && le && le->pack_id == pack_id) {
                mktree(t, 0, &old_tree);
                lo.data = old_tree;
@@ -1456,14 +1512,14 @@ static void store_tree(struct tree_entry *root)
        }
 
        mktree(t, 1, &new_tree);
-       store_object(OBJ_TREE, &new_tree, &lo, root->versions[1].sha1, 0);
+       store_object(OBJ_TREE, &new_tree, &lo, &root->versions[1].oid, 0);
 
        t->delta_depth = lo.depth;
        for (i = 0, j = 0, del = 0; i < t->entry_count; i++) {
                struct tree_entry *e = t->entries[i];
                if (e->versions[1].mode) {
                        e->versions[0].mode = e->versions[1].mode;
-                       hashcpy(e->versions[0].sha1, e->versions[1].sha1);
+                       oidcpy(&e->versions[0].oid, &e->versions[1].oid);
                        t->entries[j++] = e;
                } else {
                        release_tree_entry(e);
@@ -1475,14 +1531,14 @@ static void store_tree(struct tree_entry *root)
 
 static void tree_content_replace(
        struct tree_entry *root,
-       const unsigned char *sha1,
+       const struct object_id *oid,
        const uint16_t mode,
        struct tree_content *newtree)
 {
        if (!S_ISDIR(mode))
                die("Root cannot be a non-directory");
-       hashclr(root->versions[0].sha1);
-       hashcpy(root->versions[1].sha1, sha1);
+       oidclr(&root->versions[0].oid);
+       oidcpy(&root->versions[1].oid, oid);
        if (root->tree)
                release_tree_content_recursive(root->tree);
        root->tree = newtree;
@@ -1491,7 +1547,7 @@ static void tree_content_replace(
 static int tree_content_set(
        struct tree_entry *root,
        const char *p,
-       const unsigned char *sha1,
+       const struct object_id *oid,
        const uint16_t mode,
        struct tree_content *subtree)
 {
@@ -1516,10 +1572,10 @@ static int tree_content_set(
                        if (!*slash1) {
                                if (!S_ISDIR(mode)
                                                && e->versions[1].mode == mode
-                                               && !hashcmp(e->versions[1].sha1, sha1))
+                                               && !oidcmp(&e->versions[1].oid, oid))
                                        return 0;
                                e->versions[1].mode = mode;
-                               hashcpy(e->versions[1].sha1, sha1);
+                               oidcpy(&e->versions[1].oid, oid);
                                if (e->tree)
                                        release_tree_content_recursive(e->tree);
                                e->tree = subtree;
@@ -1540,7 +1596,7 @@ static int tree_content_set(
                                if (S_ISDIR(e->versions[0].mode))
                                        e->versions[0].mode |= NO_DELTA;
 
-                               hashclr(root->versions[1].sha1);
+                               oidclr(&root->versions[1].oid);
                                return 1;
                        }
                        if (!S_ISDIR(e->versions[1].mode)) {
@@ -1549,8 +1605,8 @@ static int tree_content_set(
                        }
                        if (!e->tree)
                                load_tree(e);
-                       if (tree_content_set(e, slash1 + 1, sha1, mode, subtree)) {
-                               hashclr(root->versions[1].sha1);
+                       if (tree_content_set(e, slash1 + 1, oid, mode, subtree)) {
+                               oidclr(&root->versions[1].oid);
                                return 1;
                        }
                        return 0;
@@ -1562,18 +1618,18 @@ static int tree_content_set(
        e = new_tree_entry();
        e->name = to_atom(p, n);
        e->versions[0].mode = 0;
-       hashclr(e->versions[0].sha1);
+       oidclr(&e->versions[0].oid);
        t->entries[t->entry_count++] = e;
        if (*slash1) {
                e->tree = new_tree_content(8);
                e->versions[1].mode = S_IFDIR;
-               tree_content_set(e, slash1 + 1, sha1, mode, subtree);
+               tree_content_set(e, slash1 + 1, oid, mode, subtree);
        } else {
                e->tree = subtree;
                e->versions[1].mode = mode;
-               hashcpy(e->versions[1].sha1, sha1);
+               oidcpy(&e->versions[1].oid, oid);
        }
-       hashclr(root->versions[1].sha1);
+       oidclr(&root->versions[1].oid);
        return 1;
 }
 
@@ -1618,7 +1674,7 @@ static int tree_content_remove(
                        if (tree_content_remove(e, slash1 + 1, backup_leaf, 0)) {
                                for (n = 0; n < e->tree->entry_count; n++) {
                                        if (e->tree->entries[n]->versions[1].mode) {
-                                               hashclr(root->versions[1].sha1);
+                                               oidclr(&root->versions[1].oid);
                                                return 1;
                                        }
                                }
@@ -1637,8 +1693,8 @@ static int tree_content_remove(
                release_tree_content_recursive(e->tree);
        e->tree = NULL;
        e->versions[1].mode = 0;
-       hashclr(e->versions[1].sha1);
-       hashclr(root->versions[1].sha1);
+       oidclr(&e->versions[1].oid);
+       oidclr(&root->versions[1].oid);
        return 1;
 }
 
@@ -1683,7 +1739,7 @@ static int tree_content_get(
 
 found_entry:
        memcpy(leaf, e, sizeof(*leaf));
-       if (e->tree && is_null_sha1(e->versions[1].sha1))
+       if (e->tree && is_null_oid(&e->versions[1].oid))
                leaf->tree = dup_tree_content(e->tree);
        else
                leaf->tree = NULL;
@@ -1694,34 +1750,35 @@ static int update_branch(struct branch *b)
 {
        static const char *msg = "fast-import";
        struct ref_transaction *transaction;
-       unsigned char old_sha1[20];
+       struct object_id old_oid;
        struct strbuf err = STRBUF_INIT;
 
-       if (is_null_sha1(b->sha1)) {
+       if (is_null_oid(&b->oid)) {
                if (b->delete)
-                       delete_ref(b->name, NULL, 0);
+                       delete_ref(NULL, b->name, NULL, 0);
                return 0;
        }
-       if (read_ref(b->name, old_sha1))
-               hashclr(old_sha1);
-       if (!force_update && !is_null_sha1(old_sha1)) {
+       if (read_ref(b->name, old_oid.hash))
+               oidclr(&old_oid);
+       if (!force_update && !is_null_oid(&old_oid)) {
                struct commit *old_cmit, *new_cmit;
 
-               old_cmit = lookup_commit_reference_gently(old_sha1, 0);
-               new_cmit = lookup_commit_reference_gently(b->sha1, 0);
+               old_cmit = lookup_commit_reference_gently(&old_oid, 0);
+               new_cmit = lookup_commit_reference_gently(&b->oid, 0);
                if (!old_cmit || !new_cmit)
                        return error("Branch %s is missing commits.", b->name);
 
                if (!in_merge_bases(old_cmit, new_cmit)) {
                        warning("Not updating %s"
                                " (new tip %s does not contain %s)",
-                               b->name, sha1_to_hex(b->sha1), sha1_to_hex(old_sha1));
+                               b->name, oid_to_hex(&b->oid),
+                               oid_to_hex(&old_oid));
                        return -1;
                }
        }
        transaction = ref_transaction_begin(&err);
        if (!transaction ||
-           ref_transaction_update(transaction, b->name, b->sha1, old_sha1,
+           ref_transaction_update(transaction, b->name, b->oid.hash, old_oid.hash,
                                   0, msg, &err) ||
            ref_transaction_commit(transaction, &err)) {
                ref_transaction_free(transaction);
@@ -1763,7 +1820,7 @@ static void dump_tags(void)
                strbuf_addf(&ref_name, "refs/tags/%s", t->name);
 
                if (ref_transaction_update(transaction, ref_name.buf,
-                                          t->sha1, NULL, 0, msg, &err)) {
+                                          t->oid.hash, NULL, 0, msg, &err)) {
                        failure |= error("%s", err.buf);
                        goto cleanup;
                }
@@ -1792,7 +1849,7 @@ static void dump_marks_helper(FILE *f,
                for (k = 0; k < 1024; k++) {
                        if (m->data.marked[k])
                                fprintf(f, ":%" PRIuMAX " %s\n", base + k,
-                                       sha1_to_hex(m->data.marked[k]->idx.sha1));
+                                       oid_to_hex(&m->data.marked[k]->idx.oid));
                }
        }
 }
@@ -1841,7 +1898,7 @@ static void read_marks(void)
        while (fgets(line, sizeof(line), f)) {
                uintmax_t mark;
                char *end;
-               unsigned char sha1[20];
+               struct object_id oid;
                struct object_entry *e;
 
                end = strchr(line, '\n');
@@ -1850,14 +1907,14 @@ static void read_marks(void)
                *end = 0;
                mark = strtoumax(line + 1, &end, 10);
                if (!mark || end == line + 1
-                       || *end != ' ' || get_sha1_hex(end + 1, sha1))
+                       || *end != ' ' || get_oid_hex(end + 1, &oid))
                        die("corrupt mark line: %s", line);
-               e = find_object(sha1);
+               e = find_object(&oid);
                if (!e) {
-                       enum object_type type = sha1_object_info(sha1, NULL);
+                       enum object_type type = sha1_object_info(oid.hash, NULL);
                        if (type < 0)
-                               die("object not found: %s", sha1_to_hex(sha1));
-                       e = insert_object(sha1);
+                               die("object not found: %s", oid_to_hex(&oid));
+                       e = insert_object(&oid);
                        e->type = type;
                        e->pack_id = MAX_PACK_ID;
                        e->idx.offset = 1; /* just not zero! */
@@ -2065,21 +2122,21 @@ static char *parse_ident(const char *buf)
 
 static void parse_and_store_blob(
        struct last_object *last,
-       unsigned char *sha1out,
+       struct object_id *oidout,
        uintmax_t mark)
 {
        static struct strbuf buf = STRBUF_INIT;
        uintmax_t len;
 
        if (parse_data(&buf, big_file_threshold, &len))
-               store_object(OBJ_BLOB, &buf, last, sha1out, mark);
+               store_object(OBJ_BLOB, &buf, last, oidout, mark);
        else {
                if (last) {
                        strbuf_release(&last->data);
                        last->offset = 0;
                        last->depth = 0;
                }
-               stream_blob(len, sha1out, mark);
+               stream_blob(len, oidout, mark);
                skip_optional_lf();
        }
 }
@@ -2155,26 +2212,30 @@ static void construct_path_with_fanout(const char *hex_sha1,
                path[i++] = '/';
                fanout--;
        }
-       memcpy(path + i, hex_sha1 + j, 40 - j);
-       path[i + 40 - j] = '\0';
+       memcpy(path + i, hex_sha1 + j, GIT_SHA1_HEXSZ - j);
+       path[i + GIT_SHA1_HEXSZ - j] = '\0';
 }
 
 static uintmax_t do_change_note_fanout(
                struct tree_entry *orig_root, struct tree_entry *root,
-               char *hex_sha1, unsigned int hex_sha1_len,
+               char *hex_oid, unsigned int hex_oid_len,
                char *fullpath, unsigned int fullpath_len,
                unsigned char fanout)
 {
-       struct tree_content *t = root->tree;
+       struct tree_content *t;
        struct tree_entry *e, leaf;
-       unsigned int i, tmp_hex_sha1_len, tmp_fullpath_len;
+       unsigned int i, tmp_hex_oid_len, tmp_fullpath_len;
        uintmax_t num_notes = 0;
-       unsigned char sha1[20];
+       struct object_id oid;
        char realpath[60];
 
+       if (!root->tree)
+               load_tree(root);
+       t = root->tree;
+
        for (i = 0; t && i < t->entry_count; i++) {
                e = t->entries[i];
-               tmp_hex_sha1_len = hex_sha1_len + e->name->str_len;
+               tmp_hex_oid_len = hex_oid_len + e->name->str_len;
                tmp_fullpath_len = fullpath_len;
 
                /*
@@ -2186,12 +2247,12 @@ static uintmax_t do_change_note_fanout(
                 * of 2 chars.
                 */
                if (!e->versions[1].mode ||
-                   tmp_hex_sha1_len > 40 ||
+                   tmp_hex_oid_len > GIT_SHA1_HEXSZ ||
                    e->name->str_len % 2)
                        continue;
 
                /* This _may_ be a note entry, or a subdir containing notes */
-               memcpy(hex_sha1 + hex_sha1_len, e->name->str_dat,
+               memcpy(hex_oid + hex_oid_len, e->name->str_dat,
                       e->name->str_len);
                if (tmp_fullpath_len)
                        fullpath[tmp_fullpath_len++] = '/';
@@ -2200,14 +2261,14 @@ static uintmax_t do_change_note_fanout(
                tmp_fullpath_len += e->name->str_len;
                fullpath[tmp_fullpath_len] = '\0';
 
-               if (tmp_hex_sha1_len == 40 && !get_sha1_hex(hex_sha1, sha1)) {
+               if (tmp_hex_oid_len == GIT_SHA1_HEXSZ && !get_oid_hex(hex_oid, &oid)) {
                        /* This is a note entry */
                        if (fanout == 0xff) {
                                /* Counting mode, no rename */
                                num_notes++;
                                continue;
                        }
-                       construct_path_with_fanout(hex_sha1, fanout, realpath);
+                       construct_path_with_fanout(hex_oid, fanout, realpath);
                        if (!strcmp(fullpath, realpath)) {
                                /* Note entry is in correct location */
                                num_notes++;
@@ -2218,15 +2279,13 @@ static uintmax_t do_change_note_fanout(
                        if (!tree_content_remove(orig_root, fullpath, &leaf, 0))
                                die("Failed to remove path %s", fullpath);
                        tree_content_set(orig_root, realpath,
-                               leaf.versions[1].sha1,
+                               &leaf.versions[1].oid,
                                leaf.versions[1].mode,
                                leaf.tree);
                } else if (S_ISDIR(e->versions[1].mode)) {
                        /* This is a subdir that may contain note entries */
-                       if (!e->tree)
-                               load_tree(e);
                        num_notes += do_change_note_fanout(orig_root, e,
-                               hex_sha1, tmp_hex_sha1_len,
+                               hex_oid, tmp_hex_oid_len,
                                fullpath, tmp_fullpath_len, fanout);
                }
 
@@ -2239,8 +2298,14 @@ static uintmax_t do_change_note_fanout(
 static uintmax_t change_note_fanout(struct tree_entry *root,
                unsigned char fanout)
 {
-       char hex_sha1[40], path[60];
-       return do_change_note_fanout(root, root, hex_sha1, 0, path, 0, fanout);
+       /*
+        * The size of path is due to one slash between every two hex digits,
+        * plus the terminating NUL.  Note that there is no slash at the end, so
+        * the number of slashes is one less than half the number of hex
+        * characters.
+        */
+       char hex_oid[GIT_MAX_HEXSZ], path[GIT_MAX_HEXSZ + (GIT_MAX_HEXSZ / 2) - 1 + 1];
+       return do_change_note_fanout(root, root, hex_oid, 0, path, 0, fanout);
 }
 
 /*
@@ -2301,7 +2366,7 @@ static void file_change_m(const char *p, struct branch *b)
        static struct strbuf uq = STRBUF_INIT;
        const char *endp;
        struct object_entry *oe;
-       unsigned char sha1[20];
+       struct object_id oid;
        uint16_t mode, inline_data = 0;
 
        p = get_mode(p, &mode);
@@ -2324,15 +2389,14 @@ static void file_change_m(const char *p, struct branch *b)
 
        if (*p == ':') {
                oe = find_mark(parse_mark_ref_space(&p));
-               hashcpy(sha1, oe->idx.sha1);
+               oidcpy(&oid, &oe->idx.oid);
        } else if (skip_prefix(p, "inline ", &p)) {
                inline_data = 1;
                oe = NULL; /* not used with inline_data, but makes gcc happy */
        } else {
-               if (get_sha1_hex(p, sha1))
+               if (parse_oid_hex(p, &oid, &p))
                        die("Invalid dataref: %s", command_buf.buf);
-               oe = find_object(sha1);
-               p += 40;
+               oe = find_object(&oid);
                if (*p++ != ' ')
                        die("Missing space after SHA1: %s", command_buf.buf);
        }
@@ -2345,7 +2409,7 @@ static void file_change_m(const char *p, struct branch *b)
        }
 
        /* Git does not track empty, non-toplevel directories. */
-       if (S_ISDIR(mode) && !hashcmp(sha1, EMPTY_TREE_SHA1_BIN) && *p) {
+       if (S_ISDIR(mode) && is_empty_tree_oid(&oid) && *p) {
                tree_content_remove(&b->branch_tree, p, NULL, 0);
                return;
        }
@@ -2372,12 +2436,12 @@ static void file_change_m(const char *p, struct branch *b)
                        p = uq.buf;
                }
                read_next_command();
-               parse_and_store_blob(&last_blob, sha1, 0);
+               parse_and_store_blob(&last_blob, &oid, 0);
        } else {
                enum object_type expected = S_ISDIR(mode) ?
                                                OBJ_TREE: OBJ_BLOB;
                enum object_type type = oe ? oe->type :
-                                       sha1_object_info(sha1, NULL);
+                                       sha1_object_info(oid.hash, NULL);
                if (type < 0)
                        die("%s not found: %s",
                                        S_ISDIR(mode) ?  "Tree" : "Blob",
@@ -2389,10 +2453,10 @@ static void file_change_m(const char *p, struct branch *b)
        }
 
        if (!*p) {
-               tree_content_replace(&b->branch_tree, sha1, mode, NULL);
+               tree_content_replace(&b->branch_tree, &oid, mode, NULL);
                return;
        }
-       tree_content_set(&b->branch_tree, p, sha1, mode, NULL);
+       tree_content_set(&b->branch_tree, p, &oid, mode, NULL);
 }
 
 static void file_change_d(const char *p, struct branch *b)
@@ -2450,13 +2514,13 @@ static void file_change_cr(const char *s, struct branch *b, int rename)
                die("Path %s not in branch", s);
        if (!*d) {      /* C "path/to/subdir" "" */
                tree_content_replace(&b->branch_tree,
-                       leaf.versions[1].sha1,
+                       &leaf.versions[1].oid,
                        leaf.versions[1].mode,
                        leaf.tree);
                return;
        }
        tree_content_set(&b->branch_tree, d,
-               leaf.versions[1].sha1,
+               &leaf.versions[1].oid,
                leaf.versions[1].mode,
                leaf.tree);
 }
@@ -2466,7 +2530,7 @@ static void note_change_n(const char *p, struct branch *b, unsigned char *old_fa
        static struct strbuf uq = STRBUF_INIT;
        struct object_entry *oe;
        struct branch *s;
-       unsigned char sha1[20], commit_sha1[20];
+       struct object_id oid, commit_oid;
        char path[60];
        uint16_t inline_data = 0;
        unsigned char new_fanout;
@@ -2491,15 +2555,14 @@ static void note_change_n(const char *p, struct branch *b, unsigned char *old_fa
        /* <dataref> or 'inline' */
        if (*p == ':') {
                oe = find_mark(parse_mark_ref_space(&p));
-               hashcpy(sha1, oe->idx.sha1);
+               oidcpy(&oid, &oe->idx.oid);
        } else if (skip_prefix(p, "inline ", &p)) {
                inline_data = 1;
                oe = NULL; /* not used with inline_data, but makes gcc happy */
        } else {
-               if (get_sha1_hex(p, sha1))
+               if (parse_oid_hex(p, &oid, &p))
                        die("Invalid dataref: %s", command_buf.buf);
-               oe = find_object(sha1);
-               p += 40;
+               oe = find_object(&oid);
                if (*p++ != ' ')
                        die("Missing space after SHA1: %s", command_buf.buf);
        }
@@ -2507,19 +2570,19 @@ static void note_change_n(const char *p, struct branch *b, unsigned char *old_fa
        /* <commit-ish> */
        s = lookup_branch(p);
        if (s) {
-               if (is_null_sha1(s->sha1))
+               if (is_null_oid(&s->oid))
                        die("Can't add a note on empty branch.");
-               hashcpy(commit_sha1, s->sha1);
+               oidcpy(&commit_oid, &s->oid);
        } else if (*p == ':') {
                uintmax_t commit_mark = parse_mark_ref_eol(p);
                struct object_entry *commit_oe = find_mark(commit_mark);
                if (commit_oe->type != OBJ_COMMIT)
                        die("Mark :%" PRIuMAX " not a commit", commit_mark);
-               hashcpy(commit_sha1, commit_oe->idx.sha1);
-       } else if (!get_sha1(p, commit_sha1)) {
+               oidcpy(&commit_oid, &commit_oe->idx.oid);
+       } else if (!get_oid(p, &commit_oid)) {
                unsigned long size;
-               char *buf = read_object_with_reference(commit_sha1,
-                       commit_type, &size, commit_sha1);
+               char *buf = read_object_with_reference(commit_oid.hash,
+                       commit_type, &size, commit_oid.hash);
                if (!buf || size < 46)
                        die("Not a valid commit: %s", p);
                free(buf);
@@ -2532,13 +2595,13 @@ static void note_change_n(const char *p, struct branch *b, unsigned char *old_fa
                        p = uq.buf;
                }
                read_next_command();
-               parse_and_store_blob(&last_blob, sha1, 0);
+               parse_and_store_blob(&last_blob, &oid, 0);
        } else if (oe) {
                if (oe->type != OBJ_BLOB)
                        die("Not a blob (actually a %s): %s",
                                typename(oe->type), command_buf.buf);
-       } else if (!is_null_sha1(sha1)) {
-               enum object_type type = sha1_object_info(sha1, NULL);
+       } else if (!is_null_oid(&oid)) {
+               enum object_type type = sha1_object_info(oid.hash, NULL);
                if (type < 0)
                        die("Blob not found: %s", command_buf.buf);
                if (type != OBJ_BLOB)
@@ -2546,50 +2609,51 @@ static void note_change_n(const char *p, struct branch *b, unsigned char *old_fa
                            typename(type), command_buf.buf);
        }
 
-       construct_path_with_fanout(sha1_to_hex(commit_sha1), *old_fanout, path);
+       construct_path_with_fanout(oid_to_hex(&commit_oid), *old_fanout, path);
        if (tree_content_remove(&b->branch_tree, path, NULL, 0))
                b->num_notes--;
 
-       if (is_null_sha1(sha1))
+       if (is_null_oid(&oid))
                return; /* nothing to insert */
 
        b->num_notes++;
        new_fanout = convert_num_notes_to_fanout(b->num_notes);
-       construct_path_with_fanout(sha1_to_hex(commit_sha1), new_fanout, path);
-       tree_content_set(&b->branch_tree, path, sha1, S_IFREG | 0644, NULL);
+       construct_path_with_fanout(oid_to_hex(&commit_oid), new_fanout, path);
+       tree_content_set(&b->branch_tree, path, &oid, S_IFREG | 0644, NULL);
 }
 
 static void file_change_deleteall(struct branch *b)
 {
        release_tree_content_recursive(b->branch_tree.tree);
-       hashclr(b->branch_tree.versions[0].sha1);
-       hashclr(b->branch_tree.versions[1].sha1);
+       oidclr(&b->branch_tree.versions[0].oid);
+       oidclr(&b->branch_tree.versions[1].oid);
        load_tree(&b->branch_tree);
        b->num_notes = 0;
 }
 
 static void parse_from_commit(struct branch *b, char *buf, unsigned long size)
 {
-       if (!buf || size < 46)
-               die("Not a valid commit: %s", sha1_to_hex(b->sha1));
+       if (!buf || size < GIT_SHA1_HEXSZ + 6)
+               die("Not a valid commit: %s", oid_to_hex(&b->oid));
        if (memcmp("tree ", buf, 5)
-               || get_sha1_hex(buf + 5, b->branch_tree.versions[1].sha1))
-               die("The commit %s is corrupt", sha1_to_hex(b->sha1));
-       hashcpy(b->branch_tree.versions[0].sha1,
-               b->branch_tree.versions[1].sha1);
+               || get_oid_hex(buf + 5, &b->branch_tree.versions[1].oid))
+               die("The commit %s is corrupt", oid_to_hex(&b->oid));
+       oidcpy(&b->branch_tree.versions[0].oid,
+              &b->branch_tree.versions[1].oid);
 }
 
 static void parse_from_existing(struct branch *b)
 {
-       if (is_null_sha1(b->sha1)) {
-               hashclr(b->branch_tree.versions[0].sha1);
-               hashclr(b->branch_tree.versions[1].sha1);
+       if (is_null_oid(&b->oid)) {
+               oidclr(&b->branch_tree.versions[0].oid);
+               oidclr(&b->branch_tree.versions[1].oid);
        } else {
                unsigned long size;
                char *buf;
 
-               buf = read_object_with_reference(b->sha1,
-                       commit_type, &size, b->sha1);
+               buf = read_object_with_reference(b->oid.hash,
+                                                commit_type, &size,
+                                                b->oid.hash);
                parse_from_commit(b, buf, size);
                free(buf);
        }
@@ -2599,28 +2663,28 @@ static int parse_from(struct branch *b)
 {
        const char *from;
        struct branch *s;
-       unsigned char sha1[20];
+       struct object_id oid;
 
        if (!skip_prefix(command_buf.buf, "from ", &from))
                return 0;
 
-       hashcpy(sha1, b->branch_tree.versions[1].sha1);
+       oidcpy(&oid, &b->branch_tree.versions[1].oid);
 
        s = lookup_branch(from);
        if (b == s)
                die("Can't create a branch from itself: %s", b->name);
        else if (s) {
-               unsigned char *t = s->branch_tree.versions[1].sha1;
-               hashcpy(b->sha1, s->sha1);
-               hashcpy(b->branch_tree.versions[0].sha1, t);
-               hashcpy(b->branch_tree.versions[1].sha1, t);
+               struct object_id *t = &s->branch_tree.versions[1].oid;
+               oidcpy(&b->oid, &s->oid);
+               oidcpy(&b->branch_tree.versions[0].oid, t);
+               oidcpy(&b->branch_tree.versions[1].oid, t);
        } else if (*from == ':') {
                uintmax_t idnum = parse_mark_ref_eol(from);
                struct object_entry *oe = find_mark(idnum);
                if (oe->type != OBJ_COMMIT)
                        die("Mark :%" PRIuMAX " not a commit", idnum);
-               if (hashcmp(b->sha1, oe->idx.sha1)) {
-                       hashcpy(b->sha1, oe->idx.sha1);
+               if (oidcmp(&b->oid, &oe->idx.oid)) {
+                       oidcpy(&b->oid, &oe->idx.oid);
                        if (oe->pack_id != MAX_PACK_ID) {
                                unsigned long size;
                                char *buf = gfi_unpack_entry(oe, &size);
@@ -2629,15 +2693,15 @@ static int parse_from(struct branch *b)
                        } else
                                parse_from_existing(b);
                }
-       } else if (!get_sha1(from, b->sha1)) {
+       } else if (!get_oid(from, &b->oid)) {
                parse_from_existing(b);
-               if (is_null_sha1(b->sha1))
+               if (is_null_oid(&b->oid))
                        b->delete = 1;
        }
        else
                die("Invalid ref name or SHA1 expression: %s", from);
 
-       if (b->branch_tree.tree && hashcmp(sha1, b->branch_tree.versions[1].sha1)) {
+       if (b->branch_tree.tree && oidcmp(&oid, &b->branch_tree.versions[1].oid)) {
                release_tree_content_recursive(b->branch_tree.tree);
                b->branch_tree.tree = NULL;
        }
@@ -2657,17 +2721,17 @@ static struct hash_list *parse_merge(unsigned int *count)
                n = xmalloc(sizeof(*n));
                s = lookup_branch(from);
                if (s)
-                       hashcpy(n->sha1, s->sha1);
+                       oidcpy(&n->oid, &s->oid);
                else if (*from == ':') {
                        uintmax_t idnum = parse_mark_ref_eol(from);
                        struct object_entry *oe = find_mark(idnum);
                        if (oe->type != OBJ_COMMIT)
                                die("Mark :%" PRIuMAX " not a commit", idnum);
-                       hashcpy(n->sha1, oe->idx.sha1);
-               } else if (!get_sha1(from, n->sha1)) {
+                       oidcpy(&n->oid, &oe->idx.oid);
+               } else if (!get_oid(from, &n->oid)) {
                        unsigned long size;
-                       char *buf = read_object_with_reference(n->sha1,
-                               commit_type, &size, n->sha1);
+                       char *buf = read_object_with_reference(n->oid.hash,
+                               commit_type, &size, n->oid.hash);
                        if (!buf || size < 46)
                                die("Not a valid commit: %s", from);
                        free(buf);
@@ -2754,17 +2818,19 @@ static void parse_new_commit(const char *arg)
 
        /* build the tree and the commit */
        store_tree(&b->branch_tree);
-       hashcpy(b->branch_tree.versions[0].sha1,
-               b->branch_tree.versions[1].sha1);
+       oidcpy(&b->branch_tree.versions[0].oid,
+              &b->branch_tree.versions[1].oid);
 
        strbuf_reset(&new_data);
        strbuf_addf(&new_data, "tree %s\n",
-               sha1_to_hex(b->branch_tree.versions[1].sha1));
-       if (!is_null_sha1(b->sha1))
-               strbuf_addf(&new_data, "parent %s\n", sha1_to_hex(b->sha1));
+               oid_to_hex(&b->branch_tree.versions[1].oid));
+       if (!is_null_oid(&b->oid))
+               strbuf_addf(&new_data, "parent %s\n",
+                           oid_to_hex(&b->oid));
        while (merge_list) {
                struct hash_list *next = merge_list->next;
-               strbuf_addf(&new_data, "parent %s\n", sha1_to_hex(merge_list->sha1));
+               strbuf_addf(&new_data, "parent %s\n",
+                           oid_to_hex(&merge_list->oid));
                free(merge_list);
                merge_list = next;
        }
@@ -2777,7 +2843,7 @@ static void parse_new_commit(const char *arg)
        free(author);
        free(committer);
 
-       if (!store_object(OBJ_COMMIT, &new_data, NULL, b->sha1, next_mark))
+       if (!store_object(OBJ_COMMIT, &new_data, NULL, &b->oid, next_mark))
                b->pack_id = pack_id;
        b->last_commit = object_count_by_type[OBJ_COMMIT];
 }
@@ -2790,7 +2856,7 @@ static void parse_new_tag(const char *arg)
        struct branch *s;
        struct tag *t;
        uintmax_t from_mark = 0;
-       unsigned char sha1[20];
+       struct object_id oid;
        enum object_type type;
        const char *v;
 
@@ -2809,20 +2875,20 @@ static void parse_new_tag(const char *arg)
                die("Expected from command, got %s", command_buf.buf);
        s = lookup_branch(from);
        if (s) {
-               if (is_null_sha1(s->sha1))
+               if (is_null_oid(&s->oid))
                        die("Can't tag an empty branch.");
-               hashcpy(sha1, s->sha1);
+               oidcpy(&oid, &s->oid);
                type = OBJ_COMMIT;
        } else if (*from == ':') {
                struct object_entry *oe;
                from_mark = parse_mark_ref_eol(from);
                oe = find_mark(from_mark);
                type = oe->type;
-               hashcpy(sha1, oe->idx.sha1);
-       } else if (!get_sha1(from, sha1)) {
-               struct object_entry *oe = find_object(sha1);
+               oidcpy(&oid, &oe->idx.oid);
+       } else if (!get_oid(from, &oid)) {
+               struct object_entry *oe = find_object(&oid);
                if (!oe) {
-                       type = sha1_object_info(sha1, NULL);
+                       type = sha1_object_info(oid.hash, NULL);
                        if (type < 0)
                                die("Not a valid object: %s", from);
                } else
@@ -2848,7 +2914,7 @@ static void parse_new_tag(const char *arg)
                    "object %s\n"
                    "type %s\n"
                    "tag %s\n",
-                   sha1_to_hex(sha1), typename(type), t->name);
+                   oid_to_hex(&oid), typename(type), t->name);
        if (tagger)
                strbuf_addf(&new_data,
                            "tagger %s\n", tagger);
@@ -2856,7 +2922,7 @@ static void parse_new_tag(const char *arg)
        strbuf_addbuf(&new_data, &msg);
        free(tagger);
 
-       if (store_object(OBJ_TAG, &new_data, NULL, t->sha1, 0))
+       if (store_object(OBJ_TAG, &new_data, NULL, &t->oid, 0))
                t->pack_id = MAX_PACK_ID;
        else
                t->pack_id = pack_id;
@@ -2868,9 +2934,9 @@ static void parse_reset_branch(const char *arg)
 
        b = lookup_branch(arg);
        if (b) {
-               hashclr(b->sha1);
-               hashclr(b->branch_tree.versions[0].sha1);
-               hashclr(b->branch_tree.versions[1].sha1);
+               oidclr(&b->oid);
+               oidclr(&b->branch_tree.versions[0].oid);
+               oidclr(&b->branch_tree.versions[1].oid);
                if (b->branch_tree.tree) {
                        release_tree_content_recursive(b->branch_tree.tree);
                        b->branch_tree.tree = NULL;
@@ -2886,11 +2952,11 @@ static void parse_reset_branch(const char *arg)
 
 static void cat_blob_write(const char *buf, unsigned long size)
 {
-       if (write_in_full(cat_blob_fd, buf, size) != size)
+       if (write_in_full(cat_blob_fd, buf, size) < 0)
                die_errno("Write to frontend failed");
 }
 
-static void cat_blob(struct object_entry *oe, unsigned char sha1[20])
+static void cat_blob(struct object_entry *oe, struct object_id *oid)
 {
        struct strbuf line = STRBUF_INIT;
        unsigned long size;
@@ -2898,7 +2964,7 @@ static void cat_blob(struct object_entry *oe, unsigned char sha1[20])
        char *buf;
 
        if (!oe || oe->pack_id == MAX_PACK_ID) {
-               buf = read_sha1_file(sha1, &type, &size);
+               buf = read_sha1_file(oid->hash, &type, &size);
        } else {
                type = oe->type;
                buf = gfi_unpack_entry(oe, &size);
@@ -2909,19 +2975,19 @@ static void cat_blob(struct object_entry *oe, unsigned char sha1[20])
         */
        if (type <= 0) {
                strbuf_reset(&line);
-               strbuf_addf(&line, "%s missing\n", sha1_to_hex(sha1));
+               strbuf_addf(&line, "%s missing\n", oid_to_hex(oid));
                cat_blob_write(line.buf, line.len);
                strbuf_release(&line);
                free(buf);
                return;
        }
        if (!buf)
-               die("Can't read object %s", sha1_to_hex(sha1));
+               die("Can't read object %s", oid_to_hex(oid));
        if (type != OBJ_BLOB)
                die("Object %s is a %s but a blob was expected.",
-                   sha1_to_hex(sha1), typename(type));
+                   oid_to_hex(oid), typename(type));
        strbuf_reset(&line);
-       strbuf_addf(&line, "%s %s %lu\n", sha1_to_hex(sha1),
+       strbuf_addf(&line, "%s %s %lu\n", oid_to_hex(oid),
                                                typename(type), size);
        cat_blob_write(line.buf, line.len);
        strbuf_release(&line);
@@ -2938,7 +3004,7 @@ static void cat_blob(struct object_entry *oe, unsigned char sha1[20])
 static void parse_get_mark(const char *p)
 {
        struct object_entry *oe = oe;
-       char output[42];
+       char output[GIT_MAX_HEXSZ + 2];
 
        /* get-mark SP <object> LF */
        if (*p != ':')
@@ -2948,43 +3014,43 @@ static void parse_get_mark(const char *p)
        if (!oe)
                die("Unknown mark: %s", command_buf.buf);
 
-       snprintf(output, sizeof(output), "%s\n", sha1_to_hex(oe->idx.sha1));
-       cat_blob_write(output, 41);
+       xsnprintf(output, sizeof(output), "%s\n", oid_to_hex(&oe->idx.oid));
+       cat_blob_write(output, GIT_SHA1_HEXSZ + 1);
 }
 
 static void parse_cat_blob(const char *p)
 {
        struct object_entry *oe = oe;
-       unsigned char sha1[20];
+       struct object_id oid;
 
        /* cat-blob SP <object> LF */
        if (*p == ':') {
                oe = find_mark(parse_mark_ref_eol(p));
                if (!oe)
                        die("Unknown mark: %s", command_buf.buf);
-               hashcpy(sha1, oe->idx.sha1);
+               oidcpy(&oid, &oe->idx.oid);
        } else {
-               if (get_sha1_hex(p, sha1))
+               if (parse_oid_hex(p, &oid, &p))
                        die("Invalid dataref: %s", command_buf.buf);
-               if (p[40])
+               if (*p)
                        die("Garbage after SHA1: %s", command_buf.buf);
-               oe = find_object(sha1);
+               oe = find_object(&oid);
        }
 
-       cat_blob(oe, sha1);
+       cat_blob(oe, &oid);
 }
 
 static struct object_entry *dereference(struct object_entry *oe,
-                                       unsigned char sha1[20])
+                                       struct object_id *oid)
 {
        unsigned long size;
        char *buf = NULL;
        if (!oe) {
-               enum object_type type = sha1_object_info(sha1, NULL);
+               enum object_type type = sha1_object_info(oid->hash, NULL);
                if (type < 0)
-                       die("object not found: %s", sha1_to_hex(sha1));
+                       die("object not found: %s", oid_to_hex(oid));
                /* cache it! */
-               oe = insert_object(sha1);
+               oe = insert_object(oid);
                oe->type = type;
                oe->pack_id = MAX_PACK_ID;
                oe->idx.offset = 1;
@@ -3003,49 +3069,48 @@ static struct object_entry *dereference(struct object_entry *oe,
                buf = gfi_unpack_entry(oe, &size);
        } else {
                enum object_type unused;
-               buf = read_sha1_file(sha1, &unused, &size);
+               buf = read_sha1_file(oid->hash, &unused, &size);
        }
        if (!buf)
-               die("Can't load object %s", sha1_to_hex(sha1));
+               die("Can't load object %s", oid_to_hex(oid));
 
        /* Peel one layer. */
        switch (oe->type) {
        case OBJ_TAG:
-               if (size < 40 + strlen("object ") ||
-                   get_sha1_hex(buf + strlen("object "), sha1))
+               if (size < GIT_SHA1_HEXSZ + strlen("object ") ||
+                   get_oid_hex(buf + strlen("object "), oid))
                        die("Invalid SHA1 in tag: %s", command_buf.buf);
                break;
        case OBJ_COMMIT:
-               if (size < 40 + strlen("tree ") ||
-                   get_sha1_hex(buf + strlen("tree "), sha1))
+               if (size < GIT_SHA1_HEXSZ + strlen("tree ") ||
+                   get_oid_hex(buf + strlen("tree "), oid))
                        die("Invalid SHA1 in commit: %s", command_buf.buf);
        }
 
        free(buf);
-       return find_object(sha1);
+       return find_object(oid);
 }
 
 static struct object_entry *parse_treeish_dataref(const char **p)
 {
-       unsigned char sha1[20];
+       struct object_id oid;
        struct object_entry *e;
 
        if (**p == ':') {       /* <mark> */
                e = find_mark(parse_mark_ref_space(p));
                if (!e)
                        die("Unknown mark: %s", command_buf.buf);
-               hashcpy(sha1, e->idx.sha1);
+               oidcpy(&oid, &e->idx.oid);
        } else {        /* <sha1> */
-               if (get_sha1_hex(*p, sha1))
+               if (parse_oid_hex(*p, &oid, p))
                        die("Invalid dataref: %s", command_buf.buf);
-               e = find_object(sha1);
-               *p += 40;
+               e = find_object(&oid);
                if (*(*p)++ != ' ')
                        die("Missing space after tree-ish: %s", command_buf.buf);
        }
 
        while (!e || e->type != OBJ_TREE)
-               e = dereference(e, sha1);
+               e = dereference(e, &oid);
        return e;
 }
 
@@ -3089,8 +3154,8 @@ static void parse_ls(const char *p, struct branch *b)
        } else {
                struct object_entry *e = parse_treeish_dataref(&p);
                root = new_tree_entry();
-               hashcpy(root->versions[1].sha1, e->idx.sha1);
-               if (!is_null_sha1(root->versions[1].sha1))
+               oidcpy(&root->versions[1].oid, &e->idx.oid);
+               if (!is_null_oid(&root->versions[1].oid))
                        root->versions[1].mode = S_IFDIR;
                load_tree(root);
        }
@@ -3112,7 +3177,7 @@ static void parse_ls(const char *p, struct branch *b)
        if (S_ISDIR(leaf.versions[1].mode))
                store_tree(&leaf);
 
-       print_ls(leaf.versions[1].mode, leaf.versions[1].sha1, p);
+       print_ls(leaf.versions[1].mode, leaf.versions[1].oid.hash, p);
        if (leaf.tree)
                release_tree_content_recursive(leaf.tree);
        if (!b || root != &b->branch_tree)
@@ -3124,10 +3189,10 @@ static void checkpoint(void)
        checkpoint_requested = 0;
        if (object_count) {
                cycle_packfile();
-               dump_branches();
-               dump_tags();
-               dump_marks();
        }
+       dump_branches();
+       dump_tags();
+       dump_marks();
 }
 
 static void parse_checkpoint(void)
@@ -3148,7 +3213,7 @@ static char* make_fast_import_path(const char *path)
 {
        if (!relative_marks_paths || is_absolute_path(path))
                return xstrdup(path);
-       return xstrdup(git_path("info/fast-import/%s", path));
+       return git_pathdup("info/fast-import/%s", path);
 }
 
 static void option_import_marks(const char *marks,
@@ -3220,9 +3285,7 @@ static void option_export_pack_edges(const char *edges)
 {
        if (pack_edges)
                fclose(pack_edges);
-       pack_edges = fopen(edges, "a");
-       if (!pack_edges)
-               die_errno("Cannot open '%s'", edges);
+       pack_edges = xfopen(edges, "a");
 }
 
 static int parse_one_option(const char *option)
@@ -3319,21 +3382,13 @@ static void parse_option(const char *option)
 static void git_pack_config(void)
 {
        int indexversion_value;
+       int limit;
        unsigned long packsizelimit_value;
 
        if (!git_config_get_ulong("pack.depth", &max_depth)) {
                if (max_depth > MAX_DEPTH)
                        max_depth = MAX_DEPTH;
        }
-       if (!git_config_get_int("pack.compression", &pack_compression_level)) {
-               if (pack_compression_level == -1)
-                       pack_compression_level = Z_DEFAULT_COMPRESSION;
-               else if (pack_compression_level < 0 ||
-                        pack_compression_level > Z_BEST_COMPRESSION)
-                       git_die_config("pack.compression",
-                                       "bad pack compression level %d", pack_compression_level);
-               pack_compression_seen = 1;
-       }
        if (!git_config_get_int("pack.indexversion", &indexversion_value)) {
                pack_idx_opts.version = indexversion_value;
                if (pack_idx_opts.version > 2)
@@ -3343,6 +3398,11 @@ static void git_pack_config(void)
        if (!git_config_get_ulong("pack.packsizelimit", &packsizelimit_value))
                max_packsize = packsizelimit_value;
 
+       if (!git_config_get_int("fastimport.unpacklimit", &limit))
+               unpack_limit = limit;
+       else if (!git_config_get_int("transfer.unpacklimit", &limit))
+               unpack_limit = limit;
+
        git_config(git_default_config, NULL);
 }
 
@@ -3393,8 +3453,6 @@ int cmd_main(int argc, const char **argv)
        setup_git_directory();
        reset_pack_idx_option(&pack_idx_opts);
        git_pack_config();
-       if (!pack_compression_seen && core_compression_seen)
-               pack_compression_level = core_compression_level;
 
        alloc_objects(object_entry_alloc);
        strbuf_init(&command_buf, 0);