contrib: add credential helper for OS X Keychain
[gitweb.git] / fast-import.c
index 8be8a5b73298e2f4a3c7e68a1c824fb0b6cd92e8..8d8ea3c45c0be5481c7b452c27ee0d163d69fb00 100644 (file)
@@ -24,10 +24,12 @@ Format of STDIN stream:
     commit_msg
     ('from' sp committish lf)?
     ('merge' sp committish lf)*
-    file_change*
+    (file_change | ls)*
     lf?;
   commit_msg ::= data;
 
+  ls ::= 'ls' sp '"' quoted(path) '"' lf;
+
   file_change ::= file_clr
     | file_del
     | file_rnm
@@ -132,14 +134,19 @@ Format of STDIN stream:
   ts    ::= # time since the epoch in seconds, ascii base10 notation;
   tz    ::= # GIT style timezone;
 
-     # note: comments may appear anywhere in the input, except
-     # within a data command.  Any form of the data command
-     # always escapes the related input from comment processing.
+     # note: comments, ls and cat requests may appear anywhere
+     # in the input, except within a data command.  Any form
+     # of the data command always escapes the related input
+     # from comment processing.
      #
      # In case it is not clear, the '#' that starts the comment
      # must be the first character on that line (an lf
      # preceded it).
      #
+
+  cat_blob ::= 'cat-blob' sp (hexsha1 | idnum) lf;
+  ls_tree  ::= 'ls' sp (hexsha1 | idnum) sp path_str lf;
+
   comment ::= '#' not_lf* lf;
   not_lf  ::= # Any byte that is not ASCII newline (LF);
 */
@@ -156,14 +163,19 @@ Format of STDIN stream:
 #include "csum-file.h"
 #include "quote.h"
 #include "exec_cmd.h"
+#include "dir.h"
 
 #define PACK_ID_BITS 16
 #define MAX_PACK_ID ((1<<PACK_ID_BITS)-1)
 #define DEPTH_BITS 13
 #define MAX_DEPTH ((1<<DEPTH_BITS)-1)
 
-struct object_entry
-{
+/*
+ * We abuse the setuid bit on directories to mean "do not delta".
+ */
+#define NO_DELTA S_ISUID
+
+struct object_entry {
        struct pack_idx_entry idx;
        struct object_entry *next;
        uint32_t type : TYPE_BITS,
@@ -171,16 +183,14 @@ struct object_entry
                depth : DEPTH_BITS;
 };
 
-struct object_entry_pool
-{
+struct object_entry_pool {
        struct object_entry_pool *next_pool;
        struct object_entry *next_free;
        struct object_entry *end;
        struct object_entry entries[FLEX_ARRAY]; /* more */
 };
 
-struct mark_set
-{
+struct mark_set {
        union {
                struct object_entry *marked[1024];
                struct mark_set *sets[1024];
@@ -188,57 +198,49 @@ struct mark_set
        unsigned int shift;
 };
 
-struct last_object
-{
+struct last_object {
        struct strbuf data;
        off_t offset;
        unsigned int depth;
        unsigned no_swap : 1;
 };
 
-struct mem_pool
-{
+struct mem_pool {
        struct mem_pool *next_pool;
        char *next_free;
        char *end;
        uintmax_t space[FLEX_ARRAY]; /* more */
 };
 
-struct atom_str
-{
+struct atom_str {
        struct atom_str *next_atom;
        unsigned short str_len;
        char str_dat[FLEX_ARRAY]; /* more */
 };
 
 struct tree_content;
-struct tree_entry
-{
+struct tree_entry {
        struct tree_content *tree;
        struct atom_str *name;
-       struct tree_entry_ms
-       {
+       struct tree_entry_ms {
                uint16_t mode;
                unsigned char sha1[20];
        } versions[2];
 };
 
-struct tree_content
-{
+struct tree_content {
        unsigned int entry_capacity; /* must match avail_tree_content */
        unsigned int entry_count;
        unsigned int delta_depth;
        struct tree_entry *entries[FLEX_ARRAY]; /* more */
 };
 
-struct avail_tree_content
-{
+struct avail_tree_content {
        unsigned int entry_capacity; /* must match tree_content */
        struct avail_tree_content *next_avail;
 };
 
-struct branch
-{
+struct branch {
        struct branch *table_next_branch;
        struct branch *active_next_branch;
        const char *name;
@@ -250,16 +252,14 @@ struct branch
        unsigned char sha1[20];
 };
 
-struct tag
-{
+struct tag {
        struct tag *next_tag;
        const char *name;
        unsigned int pack_id;
        unsigned char sha1[20];
 };
 
-struct hash_list
-{
+struct hash_list {
        struct hash_list *next;
        unsigned char sha1[20];
 };
@@ -270,8 +270,7 @@ typedef enum {
        WHENSPEC_NOW
 } whenspec_type;
 
-struct recent_command
-{
+struct recent_command {
        struct recent_command *prev;
        struct recent_command *next;
        char *buf;
@@ -280,7 +279,6 @@ struct recent_command
 /* Configured limits on output */
 static unsigned long max_depth = 10;
 static off_t max_packsize;
-static uintmax_t big_file_threshold = 512 * 1024 * 1024;
 static int force_update;
 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
 static int pack_compression_seen;
@@ -291,6 +289,7 @@ static uintmax_t marks_set_count;
 static uintmax_t object_count_by_type[1 << TYPE_BITS];
 static uintmax_t duplicate_count_by_type[1 << TYPE_BITS];
 static uintmax_t delta_count_by_type[1 << TYPE_BITS];
+static uintmax_t delta_count_attempts_by_type[1 << TYPE_BITS];
 static unsigned long object_count;
 static unsigned long branch_count;
 static unsigned long branch_load_count;
@@ -311,6 +310,7 @@ static unsigned int atom_cnt;
 static struct atom_str **atom_table;
 
 /* The .pack file being generated */
+static struct pack_idx_option pack_idx_opts;
 static unsigned int pack_id;
 static struct sha1file *pack_file;
 static struct packed_git *pack_data;
@@ -325,6 +325,7 @@ static struct mark_set *marks;
 static const char *export_marks_file;
 static const char *import_marks_file;
 static int import_marks_file_from_stream;
+static int import_marks_file_ignore_missing;
 static int relative_marks_paths;
 
 /* Our last blob */
@@ -360,8 +361,17 @@ static unsigned int cmd_save = 100;
 static uintmax_t next_mark;
 static struct strbuf new_data = STRBUF_INIT;
 static int seen_data_command;
+static int require_explicit_termination;
+
+/* Signal handling */
+static volatile sig_atomic_t checkpoint_requested;
+
+/* Where to write output of cat-blob commands */
+static int cat_blob_fd = STDOUT_FILENO;
 
 static void parse_argv(void);
+static void parse_cat_blob(void);
+static void parse_ls(struct branch *b);
 
 static void write_branch_report(FILE *rpt, struct branch *b)
 {
@@ -500,6 +510,32 @@ static NORETURN void die_nicely(const char *err, va_list params)
        exit(128);
 }
 
+#ifndef SIGUSR1        /* Windows, for example */
+
+static void set_checkpoint_signal(void)
+{
+}
+
+#else
+
+static void checkpoint_signal(int signo)
+{
+       checkpoint_requested = 1;
+}
+
+static void set_checkpoint_signal(void)
+{
+       struct sigaction sa;
+
+       memset(&sa, 0, sizeof(sa));
+       sa.sa_handler = checkpoint_signal;
+       sigemptyset(&sa.sa_mask);
+       sa.sa_flags = SA_RESTART;
+       sigaction(SIGUSR1, &sa, NULL);
+}
+
+#endif
+
 static void alloc_objects(unsigned int cnt)
 {
        struct object_entry_pool *b;
@@ -686,13 +722,8 @@ static struct branch *new_branch(const char *name)
 
        if (b)
                die("Invalid attempt to create duplicate branch: %s", name);
-       switch (check_ref_format(name)) {
-       case 0: break; /* its valid */
-       case CHECK_REF_FORMAT_ONELEVEL:
-               break; /* valid, but too few '/', allow anyway */
-       default:
+       if (check_refname_format(name, REFNAME_ALLOW_ONELEVEL))
                die("Branch name doesn't conform to GIT standards: %s", name);
-       }
 
        b = pool_calloc(1, sizeof(struct branch));
        b->name = pool_strdup(name);
@@ -834,6 +865,7 @@ static void start_packfile(void)
        p = xcalloc(1, sizeof(*p) + strlen(tmpfile) + 2);
        strcpy(p->pack_name, tmpfile);
        p->pack_fd = pack_fd;
+       p->do_not_close = 1;
        pack_file = sha1fd(pack_fd, p->pack_name);
 
        hdr.hdr_signature = htonl(PACK_SIGNATURE);
@@ -867,7 +899,7 @@ static const char *create_index(void)
        if (c != last)
                die("internal consistency error creating the index");
 
-       tmpfile = write_idx_file(NULL, idx, object_count, pack_data->sha1);
+       tmpfile = write_idx_file(NULL, idx, object_count, &pack_idx_opts, pack_data->sha1);
        free(idx);
        return tmpfile;
 }
@@ -988,7 +1020,7 @@ static int store_object(
        unsigned char sha1[20];
        unsigned long hdrlen, deltalen;
        git_SHA_CTX c;
-       z_stream s;
+       git_zstream s;
 
        hdrlen = sprintf((char *)hdr,"%s %lu", typename(type),
                (unsigned long)dat->len) + 1;
@@ -1014,6 +1046,7 @@ static int store_object(
        }
 
        if (last && last->data.buf && last->depth < max_depth && dat->len > 20) {
+               delta_count_attempts_by_type[type]++;
                delta = diff_delta(last->data.buf, last->data.len,
                        dat->buf, dat->len,
                        &deltalen, dat->len - 20);
@@ -1021,7 +1054,7 @@ static int store_object(
                delta = NULL;
 
        memset(&s, 0, sizeof(s));
-       deflateInit(&s, pack_compression_level);
+       git_deflate_init(&s, pack_compression_level);
        if (delta) {
                s.next_in = delta;
                s.avail_in = deltalen;
@@ -1029,11 +1062,11 @@ static int store_object(
                s.next_in = (void *)dat->buf;
                s.avail_in = dat->len;
        }
-       s.avail_out = deflateBound(&s, s.avail_in);
+       s.avail_out = git_deflate_bound(&s, s.avail_in);
        s.next_out = out = xmalloc(s.avail_out);
-       while (deflate(&s, Z_FINISH) == Z_OK)
-               /* nothing */;
-       deflateEnd(&s);
+       while (git_deflate(&s, Z_FINISH) == Z_OK)
+               ; /* nothing */
+       git_deflate_end(&s);
 
        /* Determine if we should auto-checkpoint. */
        if ((max_packsize && (pack_size + 60 + s.total_out) > max_packsize)
@@ -1049,14 +1082,14 @@ static int store_object(
                        delta = NULL;
 
                        memset(&s, 0, sizeof(s));
-                       deflateInit(&s, pack_compression_level);
+                       git_deflate_init(&s, pack_compression_level);
                        s.next_in = (void *)dat->buf;
                        s.avail_in = dat->len;
-                       s.avail_out = deflateBound(&s, s.avail_in);
+                       s.avail_out = git_deflate_bound(&s, s.avail_in);
                        s.next_out = out = xrealloc(out, s.avail_out);
-                       while (deflate(&s, Z_FINISH) == Z_OK)
-                               /* nothing */;
-                       deflateEnd(&s);
+                       while (git_deflate(&s, Z_FINISH) == Z_OK)
+                               ; /* nothing */
+                       git_deflate_end(&s);
                }
        }
 
@@ -1134,7 +1167,7 @@ static void stream_blob(uintmax_t len, unsigned char *sha1out, uintmax_t mark)
        off_t offset;
        git_SHA_CTX c;
        git_SHA_CTX pack_file_ctx;
-       z_stream s;
+       git_zstream s;
        int status = Z_OK;
 
        /* Determine if we should auto-checkpoint. */
@@ -1158,7 +1191,7 @@ static void stream_blob(uintmax_t len, unsigned char *sha1out, uintmax_t mark)
        crc32_begin(pack_file);
 
        memset(&s, 0, sizeof(s));
-       deflateInit(&s, pack_compression_level);
+       git_deflate_init(&s, pack_compression_level);
 
        hdrlen = encode_in_pack_object_header(OBJ_BLOB, len, out_buf);
        if (out_sz <= hdrlen)
@@ -1180,7 +1213,7 @@ static void stream_blob(uintmax_t len, unsigned char *sha1out, uintmax_t mark)
                        len -= n;
                }
 
-               status = deflate(&s, len ? 0 : Z_FINISH);
+               status = git_deflate(&s, len ? 0 : Z_FINISH);
 
                if (!s.avail_out || status == Z_STREAM_END) {
                        size_t n = s.next_out - out_buf;
@@ -1199,7 +1232,7 @@ static void stream_blob(uintmax_t len, unsigned char *sha1out, uintmax_t mark)
                        die("unexpected deflate failure: %d", status);
                }
        }
-       deflateEnd(&s);
+       git_deflate_end(&s);
        git_SHA1_Final(sha1, &c);
 
        if (sha1out)
@@ -1385,8 +1418,9 @@ static void mktree(struct tree_content *t, int v, struct strbuf *b)
                struct tree_entry *e = t->entries[i];
                if (!e->versions[v].mode)
                        continue;
-               strbuf_addf(b, "%o %s%c", (unsigned int)e->versions[v].mode,
-                                       e->name->str_dat, '\0');
+               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);
        }
 }
@@ -1396,7 +1430,7 @@ static void store_tree(struct tree_entry *root)
        struct tree_content *t = root->tree;
        unsigned int i, j, del;
        struct last_object lo = { STRBUF_INIT, 0, 0, /* no_swap */ 1 };
-       struct object_entry *le;
+       struct object_entry *le = NULL;
 
        if (!is_null_sha1(root->versions[1].sha1))
                return;
@@ -1406,7 +1440,8 @@ static void store_tree(struct tree_entry *root)
                        store_tree(t->entries[i]);
        }
 
-       le = find_object(root->versions[0].sha1);
+       if (!(root->versions[0].mode & NO_DELTA))
+               le = find_object(root->versions[0].sha1);
        if (S_ISDIR(root->versions[0].mode) && le && le->pack_id == pack_id) {
                mktree(t, 0, &old_tree);
                lo.data = old_tree;
@@ -1432,6 +1467,21 @@ static void store_tree(struct tree_entry *root)
        t->entry_count -= del;
 }
 
+static void tree_content_replace(
+       struct tree_entry *root,
+       const unsigned char *sha1,
+       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);
+       if (root->tree)
+               release_tree_content_recursive(root->tree);
+       root->tree = newtree;
+}
+
 static int tree_content_set(
        struct tree_entry *root,
        const char *p,
@@ -1439,7 +1489,7 @@ static int tree_content_set(
        const uint16_t mode,
        struct tree_content *subtree)
 {
-       struct tree_content *t = root->tree;
+       struct tree_content *t;
        const char *slash1;
        unsigned int i, n;
        struct tree_entry *e;
@@ -1454,9 +1504,12 @@ static int tree_content_set(
        if (!slash1 && !S_ISDIR(mode) && subtree)
                die("Non-directories cannot have subtrees");
 
+       if (!root->tree)
+               load_tree(root);
+       t = root->tree;
        for (i = 0; i < t->entry_count; i++) {
                e = t->entries[i];
-               if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
+               if (e->name->str_len == n && !strncmp_icase(p, e->name->str_dat, n)) {
                        if (!slash1) {
                                if (!S_ISDIR(mode)
                                                && e->versions[1].mode == mode
@@ -1467,6 +1520,23 @@ static int tree_content_set(
                                if (e->tree)
                                        release_tree_content_recursive(e->tree);
                                e->tree = subtree;
+
+                               /*
+                                * We need to leave e->versions[0].sha1 alone
+                                * to avoid modifying the preimage tree used
+                                * when writing out the parent directory.
+                                * But after replacing the subdir with a
+                                * completely different one, it's not a good
+                                * delta base any more, and besides, we've
+                                * thrown away the tree entries needed to
+                                * make a delta against it.
+                                *
+                                * So let's just explicitly disable deltas
+                                * for the subtree.
+                                */
+                               if (S_ISDIR(e->versions[0].mode))
+                                       e->versions[0].mode |= NO_DELTA;
+
                                hashclr(root->versions[1].sha1);
                                return 1;
                        }
@@ -1509,7 +1579,7 @@ static int tree_content_remove(
        const char *p,
        struct tree_entry *backup_leaf)
 {
-       struct tree_content *t = root->tree;
+       struct tree_content *t;
        const char *slash1;
        unsigned int i, n;
        struct tree_entry *e;
@@ -1520,9 +1590,12 @@ static int tree_content_remove(
        else
                n = strlen(p);
 
+       if (!root->tree)
+               load_tree(root);
+       t = root->tree;
        for (i = 0; i < t->entry_count; i++) {
                e = t->entries[i];
-               if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
+               if (e->name->str_len == n && !strncmp_icase(p, e->name->str_dat, n)) {
                        if (slash1 && !S_ISDIR(e->versions[1].mode))
                                /*
                                 * If p names a file in some subdirectory, and a
@@ -1567,7 +1640,7 @@ static int tree_content_get(
        const char *p,
        struct tree_entry *leaf)
 {
-       struct tree_content *t = root->tree;
+       struct tree_content *t;
        const char *slash1;
        unsigned int i, n;
        struct tree_entry *e;
@@ -1578,9 +1651,12 @@ static int tree_content_get(
        else
                n = strlen(p);
 
+       if (!root->tree)
+               load_tree(root);
+       t = root->tree;
        for (i = 0; i < t->entry_count; i++) {
                e = t->entries[i];
-               if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
+               if (e->name->str_len == n && !strncmp_icase(p, e->name->str_dat, n)) {
                        if (!slash1) {
                                memcpy(leaf, e, sizeof(*leaf));
                                if (e->tree && is_null_sha1(e->versions[1].sha1))
@@ -1735,7 +1811,11 @@ static void read_marks(void)
 {
        char line[512];
        FILE *f = fopen(import_marks_file, "r");
-       if (!f)
+       if (f)
+               ;
+       else if (import_marks_file_ignore_missing && errno == ENOENT)
+               return; /* Marks file does not exist */
+       else
                die_errno("cannot read '%s'", import_marks_file);
        while (fgets(line, sizeof(line), f)) {
                uintmax_t mark;
@@ -1776,7 +1856,7 @@ static int read_next_command(void)
                return EOF;
        }
 
-       do {
+       for (;;) {
                if (unread_command_buf) {
                        unread_command_buf = 0;
                } else {
@@ -1809,9 +1889,14 @@ static int read_next_command(void)
                        rc->prev->next = rc;
                        cmd_tail = rc;
                }
-       } while (command_buf.buf[0] == '#');
-
-       return 0;
+               if (!prefixcmp(command_buf.buf, "cat-blob ")) {
+                       parse_cat_blob();
+                       continue;
+               }
+               if (command_buf.buf[0] == '#')
+                       continue;
+               return 0;
+       }
 }
 
 static void skip_optional_lf(void)
@@ -1906,32 +1991,41 @@ static int validate_raw_date(const char *src, char *result, int maxlen)
 
 static char *parse_ident(const char *buf)
 {
-       const char *gt;
+       const char *ltgt;
        size_t name_len;
        char *ident;
 
-       gt = strrchr(buf, '>');
-       if (!gt)
+       /* ensure there is a space delimiter even if there is no name */
+       if (*buf == '<')
+               --buf;
+
+       ltgt = buf + strcspn(buf, "<>");
+       if (*ltgt != '<')
+               die("Missing < in ident string: %s", buf);
+       if (ltgt != buf && ltgt[-1] != ' ')
+               die("Missing space before < in ident string: %s", buf);
+       ltgt = ltgt + 1 + strcspn(ltgt + 1, "<>");
+       if (*ltgt != '>')
                die("Missing > in ident string: %s", buf);
-       gt++;
-       if (*gt != ' ')
+       ltgt++;
+       if (*ltgt != ' ')
                die("Missing space after > in ident string: %s", buf);
-       gt++;
-       name_len = gt - buf;
+       ltgt++;
+       name_len = ltgt - buf;
        ident = xmalloc(name_len + 24);
        strncpy(ident, buf, name_len);
 
        switch (whenspec) {
        case WHENSPEC_RAW:
-               if (validate_raw_date(gt, ident + name_len, 24) < 0)
-                       die("Invalid raw date \"%s\" in ident: %s", gt, buf);
+               if (validate_raw_date(ltgt, ident + name_len, 24) < 0)
+                       die("Invalid raw date \"%s\" in ident: %s", ltgt, buf);
                break;
        case WHENSPEC_RFC2822:
-               if (parse_date(gt, ident + name_len, 24) < 0)
-                       die("Invalid rfc2822 date \"%s\" in ident: %s", gt, buf);
+               if (parse_date(ltgt, ident + name_len, 24) < 0)
+                       die("Invalid rfc2822 date \"%s\" in ident: %s", ltgt, buf);
                break;
        case WHENSPEC_NOW:
-               if (strcmp("now", gt))
+               if (strcmp("now", ltgt))
                        die("Date in ident must be 'now': %s", buf);
                datestamp(ident + name_len, 24);
                break;
@@ -2210,6 +2304,10 @@ static void file_change_m(struct branch *b)
                                command_buf.buf);
        }
 
+       if (!*p) {
+               tree_content_replace(&b->branch_tree, sha1, mode, NULL);
+               return;
+       }
        tree_content_set(&b->branch_tree, p, sha1, mode, NULL);
 }
 
@@ -2268,6 +2366,13 @@ static void file_change_cr(struct branch *b, int rename)
                tree_content_get(&b->branch_tree, s, &leaf);
        if (!leaf.versions[1].mode)
                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].mode,
+                       leaf.tree);
+               return;
+       }
        tree_content_set(&b->branch_tree, d,
                leaf.versions[1].sha1,
                leaf.versions[1].mode,
@@ -2306,6 +2411,8 @@ static void note_change_n(struct branch *b, unsigned char old_fanout)
        /* <committish> */
        s = lookup_branch(p);
        if (s) {
+               if (is_null_sha1(s->sha1))
+                       die("Can't add a note on empty branch.");
                hashcpy(commit_sha1, s->sha1);
        } else if (*p == ':') {
                uintmax_t commit_mark = strtoumax(p + 1, NULL, 10);
@@ -2533,6 +2640,8 @@ static void parse_new_commit(void)
                        note_change_n(b, prev_fanout);
                else if (!strcmp("deleteall", command_buf.buf))
                        file_change_deleteall(b);
+               else if (!prefixcmp(command_buf.buf, "ls "))
+                       parse_ls(b);
                else {
                        unread_command_buf = 1;
                        break;
@@ -2605,6 +2714,8 @@ static void parse_new_tag(void)
        from = strchr(command_buf.buf, ' ') + 1;
        s = lookup_branch(from);
        if (s) {
+               if (is_null_sha1(s->sha1))
+                       die("Can't tag an empty branch.");
                hashcpy(sha1, s->sha1);
                type = OBJ_COMMIT;
        } else if (*from == ':') {
@@ -2614,13 +2725,13 @@ static void parse_new_tag(void)
                type = oe->type;
                hashcpy(sha1, oe->idx.sha1);
        } else if (!get_sha1(from, sha1)) {
-               unsigned long size;
-               char *buf;
-
-               buf = read_sha1_file(sha1, &type, &size);
-               if (!buf || size < 46)
-                       die("Not a valid commit: %s", from);
-               free(buf);
+               struct object_entry *oe = find_object(sha1);
+               if (!oe) {
+                       type = sha1_object_info(sha1, NULL);
+                       if (type < 0)
+                               die("Not a valid object: %s", from);
+               } else
+                       type = oe->type;
        } else
                die("Invalid ref name or SHA1 expression: %s", from);
        read_next_command();
@@ -2681,14 +2792,247 @@ static void parse_reset_branch(void)
                unread_command_buf = 1;
 }
 
-static void parse_checkpoint(void)
+static void cat_blob_write(const char *buf, unsigned long size)
+{
+       if (write_in_full(cat_blob_fd, buf, size) != size)
+               die_errno("Write to frontend failed");
+}
+
+static void cat_blob(struct object_entry *oe, unsigned char sha1[20])
+{
+       struct strbuf line = STRBUF_INIT;
+       unsigned long size;
+       enum object_type type = 0;
+       char *buf;
+
+       if (!oe || oe->pack_id == MAX_PACK_ID) {
+               buf = read_sha1_file(sha1, &type, &size);
+       } else {
+               type = oe->type;
+               buf = gfi_unpack_entry(oe, &size);
+       }
+
+       /*
+        * Output based on batch_one_object() from cat-file.c.
+        */
+       if (type <= 0) {
+               strbuf_reset(&line);
+               strbuf_addf(&line, "%s missing\n", sha1_to_hex(sha1));
+               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));
+       if (type != OBJ_BLOB)
+               die("Object %s is a %s but a blob was expected.",
+                   sha1_to_hex(sha1), typename(type));
+       strbuf_reset(&line);
+       strbuf_addf(&line, "%s %s %lu\n", sha1_to_hex(sha1),
+                                               typename(type), size);
+       cat_blob_write(line.buf, line.len);
+       strbuf_release(&line);
+       cat_blob_write(buf, size);
+       cat_blob_write("\n", 1);
+       if (oe && oe->pack_id == pack_id) {
+               last_blob.offset = oe->idx.offset;
+               strbuf_attach(&last_blob.data, buf, size, size);
+               last_blob.depth = oe->depth;
+       } else
+               free(buf);
+}
+
+static void parse_cat_blob(void)
+{
+       const char *p;
+       struct object_entry *oe = oe;
+       unsigned char sha1[20];
+
+       /* cat-blob SP <object> LF */
+       p = command_buf.buf + strlen("cat-blob ");
+       if (*p == ':') {
+               char *x;
+               oe = find_mark(strtoumax(p + 1, &x, 10));
+               if (x == p + 1)
+                       die("Invalid mark: %s", command_buf.buf);
+               if (!oe)
+                       die("Unknown mark: %s", command_buf.buf);
+               if (*x)
+                       die("Garbage after mark: %s", command_buf.buf);
+               hashcpy(sha1, oe->idx.sha1);
+       } else {
+               if (get_sha1_hex(p, sha1))
+                       die("Invalid SHA1: %s", command_buf.buf);
+               if (p[40])
+                       die("Garbage after SHA1: %s", command_buf.buf);
+               oe = find_object(sha1);
+       }
+
+       cat_blob(oe, sha1);
+}
+
+static struct object_entry *dereference(struct object_entry *oe,
+                                       unsigned char sha1[20])
+{
+       unsigned long size;
+       char *buf = NULL;
+       if (!oe) {
+               enum object_type type = sha1_object_info(sha1, NULL);
+               if (type < 0)
+                       die("object not found: %s", sha1_to_hex(sha1));
+               /* cache it! */
+               oe = insert_object(sha1);
+               oe->type = type;
+               oe->pack_id = MAX_PACK_ID;
+               oe->idx.offset = 1;
+       }
+       switch (oe->type) {
+       case OBJ_TREE:  /* easy case. */
+               return oe;
+       case OBJ_COMMIT:
+       case OBJ_TAG:
+               break;
+       default:
+               die("Not a treeish: %s", command_buf.buf);
+       }
+
+       if (oe->pack_id != MAX_PACK_ID) {       /* in a pack being written */
+               buf = gfi_unpack_entry(oe, &size);
+       } else {
+               enum object_type unused;
+               buf = read_sha1_file(sha1, &unused, &size);
+       }
+       if (!buf)
+               die("Can't load object %s", sha1_to_hex(sha1));
+
+       /* Peel one layer. */
+       switch (oe->type) {
+       case OBJ_TAG:
+               if (size < 40 + strlen("object ") ||
+                   get_sha1_hex(buf + strlen("object "), sha1))
+                       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))
+                       die("Invalid SHA1 in commit: %s", command_buf.buf);
+       }
+
+       free(buf);
+       return find_object(sha1);
+}
+
+static struct object_entry *parse_treeish_dataref(const char **p)
+{
+       unsigned char sha1[20];
+       struct object_entry *e;
+
+       if (**p == ':') {       /* <mark> */
+               char *endptr;
+               e = find_mark(strtoumax(*p + 1, &endptr, 10));
+               if (endptr == *p + 1)
+                       die("Invalid mark: %s", command_buf.buf);
+               if (!e)
+                       die("Unknown mark: %s", command_buf.buf);
+               *p = endptr;
+               hashcpy(sha1, e->idx.sha1);
+       } else {        /* <sha1> */
+               if (get_sha1_hex(*p, sha1))
+                       die("Invalid SHA1: %s", command_buf.buf);
+               e = find_object(sha1);
+               *p += 40;
+       }
+
+       while (!e || e->type != OBJ_TREE)
+               e = dereference(e, sha1);
+       return e;
+}
+
+static void print_ls(int mode, const unsigned char *sha1, const char *path)
+{
+       static struct strbuf line = STRBUF_INIT;
+
+       /* See show_tree(). */
+       const char *type =
+               S_ISGITLINK(mode) ? commit_type :
+               S_ISDIR(mode) ? tree_type :
+               blob_type;
+
+       if (!mode) {
+               /* missing SP path LF */
+               strbuf_reset(&line);
+               strbuf_addstr(&line, "missing ");
+               quote_c_style(path, &line, NULL, 0);
+               strbuf_addch(&line, '\n');
+       } else {
+               /* mode SP type SP object_name TAB path LF */
+               strbuf_reset(&line);
+               strbuf_addf(&line, "%06o %s %s\t",
+                               mode & ~NO_DELTA, type, sha1_to_hex(sha1));
+               quote_c_style(path, &line, NULL, 0);
+               strbuf_addch(&line, '\n');
+       }
+       cat_blob_write(line.buf, line.len);
+}
+
+static void parse_ls(struct branch *b)
 {
+       const char *p;
+       struct tree_entry *root = NULL;
+       struct tree_entry leaf = {NULL};
+
+       /* ls SP (<treeish> SP)? <path> */
+       p = command_buf.buf + strlen("ls ");
+       if (*p == '"') {
+               if (!b)
+                       die("Not in a commit: %s", command_buf.buf);
+               root = &b->branch_tree;
+       } else {
+               struct object_entry *e = parse_treeish_dataref(&p);
+               root = new_tree_entry();
+               hashcpy(root->versions[1].sha1, e->idx.sha1);
+               load_tree(root);
+               if (*p++ != ' ')
+                       die("Missing space after tree-ish: %s", command_buf.buf);
+       }
+       if (*p == '"') {
+               static struct strbuf uq = STRBUF_INIT;
+               const char *endp;
+               strbuf_reset(&uq);
+               if (unquote_c_style(&uq, p, &endp))
+                       die("Invalid path: %s", command_buf.buf);
+               if (*endp)
+                       die("Garbage after path in: %s", command_buf.buf);
+               p = uq.buf;
+       }
+       tree_content_get(root, p, &leaf);
+       /*
+        * A directory in preparation would have a sha1 of zero
+        * until it is saved.  Save, for simplicity.
+        */
+       if (S_ISDIR(leaf.versions[1].mode))
+               store_tree(&leaf);
+
+       print_ls(leaf.versions[1].mode, leaf.versions[1].sha1, p);
+       if (!b || root != &b->branch_tree)
+               release_tree_entry(root);
+}
+
+static void checkpoint(void)
+{
+       checkpoint_requested = 0;
        if (object_count) {
                cycle_packfile();
                dump_branches();
                dump_tags();
                dump_marks();
        }
+}
+
+static void parse_checkpoint(void)
+{
+       checkpoint_requested = 1;
        skip_optional_lf();
 }
 
@@ -2710,7 +3054,8 @@ static char* make_fast_import_path(const char *path)
        return strbuf_detach(&abs_path, NULL);
 }
 
-static void option_import_marks(const char *marks, int from_stream)
+static void option_import_marks(const char *marks,
+                                       int from_stream, int ignore_missing)
 {
        if (import_marks_file) {
                if (from_stream)
@@ -2724,6 +3069,7 @@ static void option_import_marks(const char *marks, int from_stream)
        import_marks_file = make_fast_import_path(marks);
        safe_create_leading_directories_const(import_marks_file);
        import_marks_file_from_stream = from_stream;
+       import_marks_file_ignore_missing = ignore_missing;
 }
 
 static void option_date_format(const char *fmt)
@@ -2738,16 +3084,25 @@ static void option_date_format(const char *fmt)
                die("unknown --date-format argument %s", fmt);
 }
 
+static unsigned long ulong_arg(const char *option, const char *arg)
+{
+       char *endptr;
+       unsigned long rv = strtoul(arg, &endptr, 0);
+       if (strchr(arg, '-') || endptr == arg || *endptr)
+               die("%s: argument must be a non-negative integer", option);
+       return rv;
+}
+
 static void option_depth(const char *depth)
 {
-       max_depth = strtoul(depth, NULL, 0);
+       max_depth = ulong_arg("--depth", depth);
        if (max_depth > MAX_DEPTH)
                die("--depth cannot exceed %u", MAX_DEPTH);
 }
 
 static void option_active_branches(const char *branches)
 {
-       max_active_branches = strtoul(branches, NULL, 0);
+       max_active_branches = ulong_arg("--active-branches", branches);
 }
 
 static void option_export_marks(const char *marks)
@@ -2756,6 +3111,14 @@ static void option_export_marks(const char *marks)
        safe_create_leading_directories_const(export_marks_file);
 }
 
+static void option_cat_blob_fd(const char *fd)
+{
+       unsigned long n = ulong_arg("--cat-blob-fd", fd);
+       if (n > (unsigned long) INT_MAX)
+               die("--cat-blob-fd cannot exceed %d", INT_MAX);
+       cat_blob_fd = (int) n;
+}
+
 static void option_export_pack_edges(const char *edges)
 {
        if (pack_edges)
@@ -2806,16 +3169,23 @@ static int parse_one_feature(const char *feature, int from_stream)
        if (!prefixcmp(feature, "date-format=")) {
                option_date_format(feature + 12);
        } else if (!prefixcmp(feature, "import-marks=")) {
-               option_import_marks(feature + 13, from_stream);
+               option_import_marks(feature + 13, from_stream, 0);
+       } else if (!prefixcmp(feature, "import-marks-if-exists=")) {
+               option_import_marks(feature + strlen("import-marks-if-exists="),
+                                       from_stream, 1);
        } else if (!prefixcmp(feature, "export-marks=")) {
                option_export_marks(feature + 13);
-       } else if (!prefixcmp(feature, "relative-marks")) {
+       } else if (!strcmp(feature, "cat-blob")) {
+               ; /* Don't die - this feature is supported */
+       } else if (!strcmp(feature, "relative-marks")) {
                relative_marks_paths = 1;
-       } else if (!prefixcmp(feature, "no-relative-marks")) {
+       } else if (!strcmp(feature, "no-relative-marks")) {
                relative_marks_paths = 0;
-       } else if (!prefixcmp(feature, "force")) {
+       } else if (!strcmp(feature, "done")) {
+               require_explicit_termination = 1;
+       } else if (!strcmp(feature, "force")) {
                force_update = 1;
-       } else if (!strcmp(feature, "notes")) {
+       } else if (!strcmp(feature, "notes") || !strcmp(feature, "ls")) {
                ; /* do nothing; we have the feature */
        } else {
                return 0;
@@ -2869,20 +3239,16 @@ static int git_pack_config(const char *k, const char *v, void *cb)
                return 0;
        }
        if (!strcmp(k, "pack.indexversion")) {
-               pack_idx_default_version = git_config_int(k, v);
-               if (pack_idx_default_version > 2)
+               pack_idx_opts.version = git_config_int(k, v);
+               if (pack_idx_opts.version > 2)
                        die("bad pack.indexversion=%"PRIu32,
-                           pack_idx_default_version);
+                           pack_idx_opts.version);
                return 0;
        }
        if (!strcmp(k, "pack.packsizelimit")) {
                max_packsize = git_config_ulong(k, v);
                return 0;
        }
-       if (!strcmp(k, "core.bigfilethreshold")) {
-               long n = git_config_int(k, v);
-               big_file_threshold = 0 < n ? n : 0;
-       }
        return git_default_config(k, v, cb);
 }
 
@@ -2905,6 +3271,11 @@ static void parse_argv(void)
                if (parse_one_feature(a + 2, 0))
                        continue;
 
+               if (!prefixcmp(a + 2, "cat-blob-fd=")) {
+                       option_cat_blob_fd(a + 2 + strlen("cat-blob-fd="));
+                       continue;
+               }
+
                die("unknown option %s", a);
        }
        if (i != global_argc)
@@ -2925,6 +3296,7 @@ int main(int argc, const char **argv)
                usage(fast_import_usage);
 
        setup_git_directory();
+       reset_pack_idx_option(&pack_idx_opts);
        git_config(git_pack_config, NULL);
        if (!pack_compression_seen && core_compression_seen)
                pack_compression_level = core_compression_level;
@@ -2947,9 +3319,12 @@ int main(int argc, const char **argv)
        prepare_packed_git();
        start_packfile();
        set_die_routine(die_nicely);
+       set_checkpoint_signal();
        while (read_next_command() != EOF) {
                if (!strcmp("blob", command_buf.buf))
                        parse_new_blob();
+               else if (!prefixcmp(command_buf.buf, "ls "))
+                       parse_ls(NULL);
                else if (!prefixcmp(command_buf.buf, "commit "))
                        parse_new_commit();
                else if (!prefixcmp(command_buf.buf, "tag "))
@@ -2958,6 +3333,8 @@ int main(int argc, const char **argv)
                        parse_reset_branch();
                else if (!strcmp("checkpoint", command_buf.buf))
                        parse_checkpoint();
+               else if (!strcmp("done", command_buf.buf))
+                       break;
                else if (!prefixcmp(command_buf.buf, "progress "))
                        parse_progress();
                else if (!prefixcmp(command_buf.buf, "feature "))
@@ -2968,12 +3345,18 @@ int main(int argc, const char **argv)
                        /* ignore non-git options*/;
                else
                        die("Unsupported command: %s", command_buf.buf);
+
+               if (checkpoint_requested)
+                       checkpoint();
        }
 
        /* argv hasn't been parsed yet, do so */
        if (!seen_data_command)
                parse_argv();
 
+       if (require_explicit_termination && feof(stdin))
+               die("stream ends early");
+
        end_packfile();
 
        dump_branches();
@@ -2995,10 +3378,10 @@ int main(int argc, const char **argv)
                fprintf(stderr, "---------------------------------------------------------------------\n");
                fprintf(stderr, "Alloc'd objects: %10" PRIuMAX "\n", alloc_count);
                fprintf(stderr, "Total objects:   %10" PRIuMAX " (%10" PRIuMAX " duplicates                  )\n", total_count, duplicate_count);
-               fprintf(stderr, "      blobs  :   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas)\n", object_count_by_type[OBJ_BLOB], duplicate_count_by_type[OBJ_BLOB], delta_count_by_type[OBJ_BLOB]);
-               fprintf(stderr, "      trees  :   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas)\n", object_count_by_type[OBJ_TREE], duplicate_count_by_type[OBJ_TREE], delta_count_by_type[OBJ_TREE]);
-               fprintf(stderr, "      commits:   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas)\n", object_count_by_type[OBJ_COMMIT], duplicate_count_by_type[OBJ_COMMIT], delta_count_by_type[OBJ_COMMIT]);
-               fprintf(stderr, "      tags   :   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas)\n", object_count_by_type[OBJ_TAG], duplicate_count_by_type[OBJ_TAG], delta_count_by_type[OBJ_TAG]);
+               fprintf(stderr, "      blobs  :   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas of %10" PRIuMAX" attempts)\n", object_count_by_type[OBJ_BLOB], duplicate_count_by_type[OBJ_BLOB], delta_count_by_type[OBJ_BLOB], delta_count_attempts_by_type[OBJ_BLOB]);
+               fprintf(stderr, "      trees  :   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas of %10" PRIuMAX" attempts)\n", object_count_by_type[OBJ_TREE], duplicate_count_by_type[OBJ_TREE], delta_count_by_type[OBJ_TREE], delta_count_attempts_by_type[OBJ_TREE]);
+               fprintf(stderr, "      commits:   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas of %10" PRIuMAX" attempts)\n", object_count_by_type[OBJ_COMMIT], duplicate_count_by_type[OBJ_COMMIT], delta_count_by_type[OBJ_COMMIT], delta_count_attempts_by_type[OBJ_COMMIT]);
+               fprintf(stderr, "      tags   :   %10" PRIuMAX " (%10" PRIuMAX " duplicates %10" PRIuMAX " deltas of %10" PRIuMAX" attempts)\n", object_count_by_type[OBJ_TAG], duplicate_count_by_type[OBJ_TAG], delta_count_by_type[OBJ_TAG], delta_count_attempts_by_type[OBJ_TAG]);
                fprintf(stderr, "Total branches:  %10lu (%10lu loads     )\n", branch_count, branch_load_count);
                fprintf(stderr, "      marks:     %10" PRIuMAX " (%10" PRIuMAX " unique    )\n", (((uintmax_t)1) << marks->shift) * 1024, marks_set_count);
                fprintf(stderr, "      atoms:     %10u\n", atom_cnt);