Merge early part of branch 'np/index-pack' into sp/keep-pack
authorJunio C Hamano <junkio@cox.net>
Sun, 29 Oct 2006 21:44:54 +0000 (13:44 -0800)
committerJunio C Hamano <junkio@cox.net>
Sun, 29 Oct 2006 21:44:54 +0000 (13:44 -0800)
Documentation/git-index-pack.txt
fetch-clone.c
fetch-pack.c
index-pack.c
index 71ce557276fd1bfe5e3ee1d3f03f94e066f23e81..9fa4847d56be0844b91a7cbe76ead6c45a9e5bed 100644 (file)
@@ -8,7 +8,8 @@ git-index-pack - Build pack index file for an existing packed archive
 
 SYNOPSIS
 --------
-'git-index-pack' [-o <index-file>] <pack-file>
+'git-index-pack' [-v] [-o <index-file>] <pack-file>
+'git-index-pack' --stdin [--fix-thin] [-v] [-o <index-file>] [<pack-file>]
 
 
 DESCRIPTION
@@ -21,6 +22,9 @@ objects/pack/ directory of a git repository.
 
 OPTIONS
 -------
+-v::
+       Be verbose about what is going on, including progress status.
+
 -o <index-file>::
        Write the generated pack index into the specified
        file.  Without this option the name of pack index
@@ -29,6 +33,23 @@ OPTIONS
        fails if the name of packed archive does not end
        with .pack).
 
+--stdin::
+       When this flag is provided, the pack is read from stdin
+       instead and a copy is then written to <pack-file>. If
+       <pack-file> is not specified, the pack is written to
+       objects/pack/ directory of the current git repository with
+       a default name determined from the pack content.
+
+--fix-thin::
+       It is possible for gitlink:git-pack-objects[1] to build
+       "thin" pack, which records objects in deltified form based on
+       objects not included in the pack to reduce network traffic.
+       Those objects are expected to be present on the receiving end
+       and they must be included in the pack for that pack to be self
+       contained and indexable. Without this option any attempt to
+       index a thin pack will fail. This option only makes sense in
+       conjonction with --stdin.
+
 
 Author
 ------
index 76b99afcdb8556fec284a621bbdc76223845877e..96cdab43c9038b10ee3e7eba3e3db5efbfbef74b 100644 (file)
@@ -3,97 +3,6 @@
 #include "pkt-line.h"
 #include "sideband.h"
 #include <sys/wait.h>
-#include <sys/time.h>
-
-static int finish_pack(const char *pack_tmp_name, const char *me)
-{
-       int pipe_fd[2];
-       pid_t pid;
-       char idx[PATH_MAX];
-       char final[PATH_MAX];
-       char hash[41];
-       unsigned char sha1[20];
-       char *cp;
-       int err = 0;
-
-       if (pipe(pipe_fd) < 0)
-               die("%s: unable to set up pipe", me);
-
-       strcpy(idx, pack_tmp_name); /* ".git/objects/pack-XXXXXX" */
-       cp = strrchr(idx, '/');
-       memcpy(cp, "/pidx", 5);
-
-       pid = fork();
-       if (pid < 0)
-               die("%s: unable to fork off git-index-pack", me);
-       if (!pid) {
-               close(0);
-               dup2(pipe_fd[1], 1);
-               close(pipe_fd[0]);
-               close(pipe_fd[1]);
-               execl_git_cmd("index-pack", "-o", idx, pack_tmp_name, NULL);
-               error("cannot exec git-index-pack <%s> <%s>",
-                     idx, pack_tmp_name);
-               exit(1);
-       }
-       close(pipe_fd[1]);
-       if (read(pipe_fd[0], hash, 40) != 40) {
-               error("%s: unable to read from git-index-pack", me);
-               err = 1;
-       }
-       close(pipe_fd[0]);
-
-       for (;;) {
-               int status, code;
-
-               if (waitpid(pid, &status, 0) < 0) {
-                       if (errno == EINTR)
-                               continue;
-                       error("waitpid failed (%s)", strerror(errno));
-                       goto error_die;
-               }
-               if (WIFSIGNALED(status)) {
-                       int sig = WTERMSIG(status);
-                       error("git-index-pack died of signal %d", sig);
-                       goto error_die;
-               }
-               if (!WIFEXITED(status)) {
-                       error("git-index-pack died of unnatural causes %d",
-                             status);
-                       goto error_die;
-               }
-               code = WEXITSTATUS(status);
-               if (code) {
-                       error("git-index-pack died with error code %d", code);
-                       goto error_die;
-               }
-               if (err)
-                       goto error_die;
-               break;
-       }
-       hash[40] = 0;
-       if (get_sha1_hex(hash, sha1)) {
-               error("git-index-pack reported nonsense '%s'", hash);
-               goto error_die;
-       }
-       /* Now we have pack in pack_tmp_name[], and
-        * idx in idx[]; rename them to their final names.
-        */
-       snprintf(final, sizeof(final),
-                "%s/pack/pack-%s.pack", get_object_directory(), hash);
-       move_temp_to_file(pack_tmp_name, final);
-       chmod(final, 0444);
-       snprintf(final, sizeof(final),
-                "%s/pack/pack-%s.idx", get_object_directory(), hash);
-       move_temp_to_file(idx, final);
-       chmod(final, 0444);
-       return 0;
-
- error_die:
-       unlink(idx);
-       unlink(pack_tmp_name);
-       exit(1);
-}
 
 static pid_t setup_sideband(int sideband, const char *me, int fd[2], int xd[2])
 {
@@ -128,7 +37,7 @@ static pid_t setup_sideband(int sideband, const char *me, int fd[2], int xd[2])
        return side_pid;
 }
 
-int receive_unpack_pack(int xd[2], const char *me, int quiet, int sideband)
+static int get_pack(int xd[2], const char *me, int sideband, const char **argv)
 {
        int status;
        pid_t pid, side_pid;
@@ -142,135 +51,37 @@ int receive_unpack_pack(int xd[2], const char *me, int quiet, int sideband)
                dup2(fd[0], 0);
                close(fd[0]);
                close(fd[1]);
-               execl_git_cmd("unpack-objects", quiet ? "-q" : NULL, NULL);
-               die("git-unpack-objects exec failed");
+               execv_git_cmd(argv);
+               die("%s exec failed", argv[0]);
        }
        close(fd[0]);
        close(fd[1]);
        while (waitpid(pid, &status, 0) < 0) {
                if (errno != EINTR)
-                       die("waiting for git-unpack-objects: %s",
-                           strerror(errno));
+                       die("waiting for %s: %s", argv[0], strerror(errno));
        }
        if (WIFEXITED(status)) {
                int code = WEXITSTATUS(status);
                if (code)
-                       die("git-unpack-objects died with error code %d",
-                           code);
+                       die("%s died with error code %d", argv[0], code);
                return 0;
        }
        if (WIFSIGNALED(status)) {
                int sig = WTERMSIG(status);
-               die("git-unpack-objects died of signal %d", sig);
+               die("%s died of signal %d", argv[0], sig);
        }
-       die("git-unpack-objects died of unnatural causes %d", status);
+       die("%s died of unnatural causes %d", argv[0], status);
 }
 
-/*
- * We average out the download speed over this many "events", where
- * an event is a minimum of about half a second. That way, we get
- * a reasonably stable number.
- */
-#define NR_AVERAGE (4)
-
-/*
- * A "binary msec" is a power-of-two-msec, aka 1/1024th of a second.
- * Keeping the time in that format means that "bytes / msecs" means
- * the same as kB/s (modulo rounding).
- *
- * 1000512 is a magic number (usecs in a second, rounded up by half
- * of 1024, to make "rounding" come out right ;)
- */
-#define usec_to_binarymsec(x) ((int)(x) / (1000512 >> 10))
+int receive_unpack_pack(int xd[2], const char *me, int quiet, int sideband)
+{
+       const char *argv[3] = { "unpack-objects", quiet ? "-q" : NULL, NULL };
+       return get_pack(xd, me, sideband, argv);
+}
 
 int receive_keep_pack(int xd[2], const char *me, int quiet, int sideband)
 {
-       char tmpfile[PATH_MAX];
-       int ofd, ifd, fd[2];
-       unsigned long total;
-       static struct timeval prev_tv;
-       struct average {
-               unsigned long bytes;
-               unsigned long time;
-       } download[NR_AVERAGE] = { {0, 0}, };
-       unsigned long avg_bytes, avg_time;
-       int idx = 0;
-
-       setup_sideband(sideband, me, fd, xd);
-
-       ifd = fd[0];
-       snprintf(tmpfile, sizeof(tmpfile),
-                "%s/pack/tmp-XXXXXX", get_object_directory());
-       ofd = mkstemp(tmpfile);
-       if (ofd < 0)
-               return error("unable to create temporary file %s", tmpfile);
-
-       gettimeofday(&prev_tv, NULL);
-       total = 0;
-       avg_bytes = 0;
-       avg_time = 0;
-       while (1) {
-               char buf[8192];
-               ssize_t sz, wsz, pos;
-               sz = read(ifd, buf, sizeof(buf));
-               if (sz == 0)
-                       break;
-               if (sz < 0) {
-                       if (errno != EINTR && errno != EAGAIN) {
-                               error("error reading pack (%s)", strerror(errno));
-                               close(ofd);
-                               unlink(tmpfile);
-                               return -1;
-                       }
-                       sz = 0;
-               }
-               pos = 0;
-               while (pos < sz) {
-                       wsz = write(ofd, buf + pos, sz - pos);
-                       if (wsz < 0) {
-                               error("error writing pack (%s)",
-                                     strerror(errno));
-                               close(ofd);
-                               unlink(tmpfile);
-                               return -1;
-                       }
-                       pos += wsz;
-               }
-               total += sz;
-               if (!quiet) {
-                       static unsigned long last;
-                       struct timeval tv;
-                       unsigned long diff = total - last;
-                       /* not really "msecs", but a power-of-two millisec (1/1024th of a sec) */
-                       unsigned long msecs;
-
-                       gettimeofday(&tv, NULL);
-                       msecs = tv.tv_sec - prev_tv.tv_sec;
-                       msecs <<= 10;
-                       msecs += usec_to_binarymsec(tv.tv_usec - prev_tv.tv_usec);
-
-                       if (msecs > 500) {
-                               prev_tv = tv;
-                               last = total;
-
-                               /* Update averages ..*/
-                               avg_bytes += diff;
-                               avg_time += msecs;
-                               avg_bytes -= download[idx].bytes;
-                               avg_time -= download[idx].time;
-                               download[idx].bytes = diff;
-                               download[idx].time = msecs;
-                               idx++;
-                               if (idx >= NR_AVERAGE)
-                                       idx = 0;
-
-                               fprintf(stderr, "%4lu.%03luMB  (%lu kB/s)      \r",
-                                       total >> 20,
-                                       1000*((total >> 10) & 1023)>>10,
-                                       avg_bytes / avg_time );
-                       }
-               }
-       }
-       close(ofd);
-       return finish_pack(tmpfile, me);
+       const char *argv[5] = { "index-pack", "--stdin", "--fix-thin",
+                               quiet ? NULL : "-v", NULL };
+       return get_pack(xd, me, sideband, argv);
 }
index 474d54520eae356a8987349b1e36186a30914966..8720ed42e92b685e881eb30743d57e64dd03c6ed 100644 (file)
@@ -518,8 +518,6 @@ int main(int argc, char **argv)
        }
        if (!dest)
                usage(fetch_pack_usage);
-       if (keep_pack)
-               use_thin_pack = 0;
        pid = git_connect(fd, dest, exec);
        if (pid < 0)
                return 1;
index e33f60524f240f288df7dc6d398486d1d6e7e5ee..866a0540560c085cd9feadb277b5b5e1e7891310 100644 (file)
@@ -6,9 +6,11 @@
 #include "commit.h"
 #include "tag.h"
 #include "tree.h"
+#include <sys/time.h>
+#include <signal.h>
 
 static const char index_pack_usage[] =
-"git-index-pack [-o index-file] pack-file";
+"git-index-pack [-v] [-o <index-file>] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
 
 struct object_entry
 {
@@ -33,37 +35,83 @@ union delta_base {
 
 struct delta_entry
 {
-       struct object_entry *obj;
        union delta_base base;
+       int obj_no;
 };
 
-static const char *pack_name;
 static struct object_entry *objects;
 static struct delta_entry *deltas;
 static int nr_objects;
 static int nr_deltas;
+static int nr_resolved_deltas;
+
+static int from_stdin;
+static int verbose;
+
+static volatile sig_atomic_t progress_update;
+
+static void progress_interval(int signum)
+{
+       progress_update = 1;
+}
+
+static void setup_progress_signal(void)
+{
+       struct sigaction sa;
+       struct itimerval v;
+
+       memset(&sa, 0, sizeof(sa));
+       sa.sa_handler = progress_interval;
+       sigemptyset(&sa.sa_mask);
+       sa.sa_flags = SA_RESTART;
+       sigaction(SIGALRM, &sa, NULL);
+
+       v.it_interval.tv_sec = 1;
+       v.it_interval.tv_usec = 0;
+       v.it_value = v.it_interval;
+       setitimer(ITIMER_REAL, &v, NULL);
+
+}
+
+static unsigned display_progress(unsigned n, unsigned total, unsigned last_pc)
+{
+       unsigned percent = n * 100 / total;
+       if (percent != last_pc || progress_update) {
+               fprintf(stderr, "%4u%% (%u/%u) done\r", percent, n, total);
+               progress_update = 0;
+       }
+       return percent;
+}
 
 /* We always read in 4kB chunks. */
 static unsigned char input_buffer[4096];
 static unsigned long input_offset, input_len, consumed_bytes;
 static SHA_CTX input_ctx;
-static int input_fd;
+static int input_fd, output_fd, mmap_fd;
+
+/* Discard current buffer used content. */
+static void flush()
+{
+       if (input_offset) {
+               if (output_fd >= 0)
+                       write_or_die(output_fd, input_buffer, input_offset);
+               SHA1_Update(&input_ctx, input_buffer, input_offset);
+               memcpy(input_buffer, input_buffer + input_offset, input_len);
+               input_offset = 0;
+       }
+}
 
 /*
  * Make sure at least "min" bytes are available in the buffer, and
  * return the pointer to the buffer.
  */
-static void * fill(int min)
+static void *fill(int min)
 {
        if (min <= input_len)
                return input_buffer + input_offset;
        if (min > sizeof(input_buffer))
                die("cannot fill %d bytes", min);
-       if (input_offset) {
-               SHA1_Update(&input_ctx, input_buffer, input_offset);
-               memcpy(input_buffer, input_buffer + input_offset, input_len);
-               input_offset = 0;
-       }
+       flush();
        do {
                int ret = xread(input_fd, input_buffer + input_len,
                                sizeof(input_buffer) - input_len);
@@ -86,13 +134,31 @@ static void use(int bytes)
        consumed_bytes += bytes;
 }
 
-static void open_pack_file(void)
+static const char *open_pack_file(const char *pack_name)
 {
-       input_fd = open(pack_name, O_RDONLY);
-       if (input_fd < 0)
-               die("cannot open packfile '%s': %s", pack_name,
-                   strerror(errno));
+       if (from_stdin) {
+               input_fd = 0;
+               if (!pack_name) {
+                       static char tmpfile[PATH_MAX];
+                       snprintf(tmpfile, sizeof(tmpfile),
+                                "%s/pack_XXXXXX", get_object_directory());
+                       output_fd = mkstemp(tmpfile);
+                       pack_name = xstrdup(tmpfile);
+               } else
+                       output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
+               if (output_fd < 0)
+                       die("unable to create %s: %s\n", pack_name, strerror(errno));
+               mmap_fd = output_fd;
+       } else {
+               input_fd = open(pack_name, O_RDONLY);
+               if (input_fd < 0)
+                       die("cannot open packfile '%s': %s",
+                           pack_name, strerror(errno));
+               output_fd = -1;
+               mmap_fd = input_fd;
+       }
        SHA1_Init(&input_ctx);
+       return pack_name;
 }
 
 static void parse_pack_header(void)
@@ -101,14 +167,12 @@ static void parse_pack_header(void)
 
        /* Header consistency check */
        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
-               die("packfile '%s' signature mismatch", pack_name);
+               die("pack signature mismatch");
        if (!pack_version_ok(hdr->hdr_version))
-               die("packfile '%s' version %d unsupported",
-                   pack_name, ntohl(hdr->hdr_version));
+               die("pack version %d unsupported", ntohl(hdr->hdr_version));
 
        nr_objects = ntohl(hdr->hdr_entries);
        use(sizeof(struct pack_header));
-       /*fprintf(stderr, "Indexing %d objects\n", nr_objects);*/
 }
 
 static void bad_object(unsigned long offset, const char *format,
@@ -122,8 +186,7 @@ static void bad_object(unsigned long offset, const char *format, ...)
        va_start(params, format);
        vsnprintf(buf, sizeof(buf), format, params);
        va_end(params);
-       die("packfile '%s': bad object at offset %lu: %s",
-           pack_name, offset, buf);
+       die("pack has bad object at offset %lu: %s", offset, buf);
 }
 
 static void *unpack_entry_data(unsigned long offset, unsigned long size)
@@ -212,7 +275,7 @@ static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_
        return unpack_entry_data(obj->offset, obj->size);
 }
 
-static void * get_data_from_pack(struct object_entry *obj)
+static void *get_data_from_pack(struct object_entry *obj)
 {
        unsigned long from = obj[0].offset + obj[0].hdr_size;
        unsigned long len = obj[1].offset - from;
@@ -222,9 +285,9 @@ static void * get_data_from_pack(struct object_entry *obj)
        int st;
 
        map = mmap(NULL, len + pg_offset, PROT_READ, MAP_PRIVATE,
-                  input_fd, from - pg_offset);
+                  mmap_fd, from - pg_offset);
        if (map == MAP_FAILED)
-               die("cannot mmap packfile '%s': %s", pack_name, strerror(errno));
+               die("cannot mmap pack file: %s", strerror(errno));
        data = xmalloc(obj->size);
        memset(&stream, 0, sizeof(stream));
        stream.next_out = data;
@@ -261,8 +324,8 @@ static int find_delta(const union delta_base *base)
         return -first-1;
 }
 
-static int find_delta_childs(const union delta_base *base,
-                            int *first_index, int *last_index)
+static int find_delta_children(const union delta_base *base,
+                              int *first_index, int *last_index)
 {
        int first = find_delta(base);
        int last = first;
@@ -304,10 +367,9 @@ static void sha1_object(const void *data, unsigned long size,
        SHA1_Final(sha1, &ctx);
 }
 
-static void resolve_delta(struct delta_entry *delta, void *base_data,
+static void resolve_delta(struct object_entry *delta_obj, void *base_data,
                          unsigned long base_size, enum object_type type)
 {
-       struct object_entry *obj = delta->obj;
        void *delta_data;
        unsigned long delta_size;
        void *result;
@@ -315,29 +377,34 @@ static void resolve_delta(struct delta_entry *delta, void *base_data,
        union delta_base delta_base;
        int j, first, last;
 
-       obj->real_type = type;
-       delta_data = get_data_from_pack(obj);
-       delta_size = obj->size;
+       delta_obj->real_type = type;
+       delta_data = get_data_from_pack(delta_obj);
+       delta_size = delta_obj->size;
        result = patch_delta(base_data, base_size, delta_data, delta_size,
                             &result_size);
        free(delta_data);
        if (!result)
-               bad_object(obj->offset, "failed to apply delta");
-       sha1_object(result, result_size, type, obj->sha1);
-
-       hashcpy(delta_base.sha1, obj->sha1);
-       if (!find_delta_childs(&delta_base, &first, &last)) {
-               for (j = first; j <= last; j++)
-                       if (deltas[j].obj->type == OBJ_REF_DELTA)
-                               resolve_delta(&deltas[j], result, result_size, type);
+               bad_object(delta_obj->offset, "failed to apply delta");
+       sha1_object(result, result_size, type, delta_obj->sha1);
+       nr_resolved_deltas++;
+
+       hashcpy(delta_base.sha1, delta_obj->sha1);
+       if (!find_delta_children(&delta_base, &first, &last)) {
+               for (j = first; j <= last; j++) {
+                       struct object_entry *child = objects + deltas[j].obj_no;
+                       if (child->real_type == OBJ_REF_DELTA)
+                               resolve_delta(child, result, result_size, type);
+               }
        }
 
        memset(&delta_base, 0, sizeof(delta_base));
-       delta_base.offset = obj->offset;
-       if (!find_delta_childs(&delta_base, &first, &last)) {
-               for (j = first; j <= last; j++)
-                       if (deltas[j].obj->type == OBJ_OFS_DELTA)
-                               resolve_delta(&deltas[j], result, result_size, type);
+       delta_base.offset = delta_obj->offset;
+       if (!find_delta_children(&delta_base, &first, &last)) {
+               for (j = first; j <= last; j++) {
+                       struct object_entry *child = objects + deltas[j].obj_no;
+                       if (child->real_type == OBJ_OFS_DELTA)
+                               resolve_delta(child, result, result_size, type);
+               }
        }
 
        free(result);
@@ -353,7 +420,7 @@ static int compare_delta_entry(const void *a, const void *b)
 /* Parse all objects and return the pack content SHA1 hash */
 static void parse_pack_objects(unsigned char *sha1)
 {
-       int i;
+       int i, percent = -1;
        struct delta_entry *delta = deltas;
        void *data;
        struct stat st;
@@ -362,34 +429,43 @@ static void parse_pack_objects(unsigned char *sha1)
         * First pass:
         * - find locations of all objects;
         * - calculate SHA1 of all non-delta objects;
-        * - remember base SHA1 for all deltas.
+        * - remember base (SHA1 or offset) for all deltas.
         */
+       if (verbose)
+               fprintf(stderr, "Indexing %d objects.\n", nr_objects);
        for (i = 0; i < nr_objects; i++) {
                struct object_entry *obj = &objects[i];
                data = unpack_raw_entry(obj, &delta->base);
                obj->real_type = obj->type;
                if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
                        nr_deltas++;
-                       delta->obj = obj;
+                       delta->obj_no = i;
                        delta++;
                } else
                        sha1_object(data, obj->size, obj->type, obj->sha1);
                free(data);
+               if (verbose)
+                       percent = display_progress(i+1, nr_objects, percent);
        }
        objects[i].offset = consumed_bytes;
+       if (verbose)
+               fputc('\n', stderr);
 
        /* Check pack integrity */
-       SHA1_Update(&input_ctx, input_buffer, input_offset);
+       flush();
        SHA1_Final(sha1, &input_ctx);
        if (hashcmp(fill(20), sha1))
-               die("packfile '%s' SHA1 mismatch", pack_name);
+               die("pack is corrupted (SHA1 mismatch)");
        use(20);
 
        /* If input_fd is a file, we should have reached its end now. */
        if (fstat(input_fd, &st))
-               die("cannot fstat packfile '%s': %s", pack_name, strerror(errno));
+               die("cannot fstat packfile: %s", strerror(errno));
        if (S_ISREG(st.st_mode) && st.st_size != consumed_bytes)
-               die("packfile '%s' has junk at the end", pack_name);
+               die("pack has junk at the end");
+
+       if (!nr_deltas)
+               return;
 
        /* Sort deltas by base SHA1/offset for fast searching */
        qsort(deltas, nr_deltas, sizeof(struct delta_entry),
@@ -403,6 +479,8 @@ static void parse_pack_objects(unsigned char *sha1)
         *   recursively checking if the resulting object is used as a base
         *   for some more deltas.
         */
+       if (verbose)
+               fprintf(stderr, "Resolving %d deltas.\n", nr_deltas);
        for (i = 0; i < nr_objects; i++) {
                struct object_entry *obj = &objects[i];
                union delta_base base;
@@ -411,32 +489,179 @@ static void parse_pack_objects(unsigned char *sha1)
                if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
                        continue;
                hashcpy(base.sha1, obj->sha1);
-               ref = !find_delta_childs(&base, &ref_first, &ref_last);
+               ref = !find_delta_children(&base, &ref_first, &ref_last);
                memset(&base, 0, sizeof(base));
                base.offset = obj->offset;
-               ofs = !find_delta_childs(&base, &ofs_first, &ofs_last);
+               ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
                if (!ref && !ofs)
                        continue;
                data = get_data_from_pack(obj);
                if (ref)
-                       for (j = ref_first; j <= ref_last; j++)
-                               if (deltas[j].obj->type == OBJ_REF_DELTA)
-                                       resolve_delta(&deltas[j], data,
+                       for (j = ref_first; j <= ref_last; j++) {
+                               struct object_entry *child = objects + deltas[j].obj_no;
+                               if (child->real_type == OBJ_REF_DELTA)
+                                       resolve_delta(child, data,
                                                      obj->size, obj->type);
+                       }
                if (ofs)
-                       for (j = ofs_first; j <= ofs_last; j++)
-                               if (deltas[j].obj->type == OBJ_OFS_DELTA)
-                                       resolve_delta(&deltas[j], data,
+                       for (j = ofs_first; j <= ofs_last; j++) {
+                               struct object_entry *child = objects + deltas[j].obj_no;
+                               if (child->real_type == OBJ_OFS_DELTA)
+                                       resolve_delta(child, data,
                                                      obj->size, obj->type);
+                       }
                free(data);
+               if (verbose)
+                       percent = display_progress(nr_resolved_deltas,
+                                                  nr_deltas, percent);
+       }
+       if (verbose && nr_resolved_deltas == nr_deltas)
+               fputc('\n', stderr);
+}
+
+static int write_compressed(int fd, void *in, unsigned int size)
+{
+       z_stream stream;
+       unsigned long maxsize;
+       void *out;
+
+       memset(&stream, 0, sizeof(stream));
+       deflateInit(&stream, zlib_compression_level);
+       maxsize = deflateBound(&stream, size);
+       out = xmalloc(maxsize);
+
+       /* Compress it */
+       stream.next_in = in;
+       stream.avail_in = size;
+       stream.next_out = out;
+       stream.avail_out = maxsize;
+       while (deflate(&stream, Z_FINISH) == Z_OK);
+       deflateEnd(&stream);
+
+       size = stream.total_out;
+       write_or_die(fd, out, size);
+       free(out);
+       return size;
+}
+
+static void append_obj_to_pack(void *buf,
+                              unsigned long size, enum object_type type)
+{
+       struct object_entry *obj = &objects[nr_objects++];
+       unsigned char header[10];
+       unsigned long s = size;
+       int n = 0;
+       unsigned char c = (type << 4) | (s & 15);
+       s >>= 4;
+       while (s) {
+               header[n++] = c | 0x80;
+               c = s & 0x7f;
+               s >>= 7;
        }
+       header[n++] = c;
+       write_or_die(output_fd, header, n);
+       obj[1].offset = obj[0].offset + n;
+       obj[1].offset += write_compressed(output_fd, buf, size);
+       sha1_object(buf, size, type, obj->sha1);
+}
+
+static int delta_pos_compare(const void *_a, const void *_b)
+{
+       struct delta_entry *a = *(struct delta_entry **)_a;
+       struct delta_entry *b = *(struct delta_entry **)_b;
+       return a->obj_no - b->obj_no;
+}
 
-       /* Check for unresolved deltas */
+static void fix_unresolved_deltas(int nr_unresolved)
+{
+       struct delta_entry **sorted_by_pos;
+       int i, n = 0, percent = -1;
+
+       /*
+        * Since many unresolved deltas may well be themselves base objects
+        * for more unresolved deltas, we really want to include the
+        * smallest number of base objects that would cover as much delta
+        * as possible by picking the
+        * trunc deltas first, allowing for other deltas to resolve without
+        * additional base objects.  Since most base objects are to be found
+        * before deltas depending on them, a good heuristic is to start
+        * resolving deltas in the same order as their position in the pack.
+        */
+       sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
        for (i = 0; i < nr_deltas; i++) {
-               if (deltas[i].obj->real_type == OBJ_REF_DELTA ||
-                   deltas[i].obj->real_type == OBJ_OFS_DELTA)
-                       die("packfile '%s' has unresolved deltas",  pack_name);
+               if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
+                       continue;
+               sorted_by_pos[n++] = &deltas[i];
        }
+       qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
+
+       for (i = 0; i < n; i++) {
+               struct delta_entry *d = sorted_by_pos[i];
+               void *data;
+               unsigned long size;
+               char type[10];
+               enum object_type obj_type;
+               int j, first, last;
+
+               if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
+                       continue;
+               data = read_sha1_file(d->base.sha1, type, &size);
+               if (!data)
+                       continue;
+               if      (!strcmp(type, blob_type))   obj_type = OBJ_BLOB;
+               else if (!strcmp(type, tree_type))   obj_type = OBJ_TREE;
+               else if (!strcmp(type, commit_type)) obj_type = OBJ_COMMIT;
+               else if (!strcmp(type, tag_type))    obj_type = OBJ_TAG;
+               else die("base object %s is of type '%s'",
+                        sha1_to_hex(d->base.sha1), type);
+
+               find_delta_children(&d->base, &first, &last);
+               for (j = first; j <= last; j++) {
+                       struct object_entry *child = objects + deltas[j].obj_no;
+                       if (child->real_type == OBJ_REF_DELTA)
+                               resolve_delta(child, data, size, obj_type);
+               }
+
+               append_obj_to_pack(data, size, obj_type);
+               free(data);
+               if (verbose)
+                       percent = display_progress(nr_resolved_deltas,
+                                                  nr_deltas, percent);
+       }
+       free(sorted_by_pos);
+       if (verbose)
+               fputc('\n', stderr);
+}
+
+static void readjust_pack_header_and_sha1(unsigned char *sha1)
+{
+       struct pack_header hdr;
+       SHA_CTX ctx;
+       int size;
+
+       /* Rewrite pack header with updated object number */
+       if (lseek(output_fd, 0, SEEK_SET) != 0)
+               die("cannot seek back: %s", strerror(errno));
+       if (xread(output_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
+               die("cannot read pack header back: %s", strerror(errno));
+       hdr.hdr_entries = htonl(nr_objects);
+       if (lseek(output_fd, 0, SEEK_SET) != 0)
+               die("cannot seek back: %s", strerror(errno));
+       write_or_die(output_fd, &hdr, sizeof(hdr));
+       if (lseek(output_fd, 0, SEEK_SET) != 0)
+               die("cannot seek back: %s", strerror(errno));
+
+       /* Recompute and store the new pack's SHA1 */
+       SHA1_Init(&ctx);
+       do {
+               unsigned char *buf[4096];
+               size = xread(output_fd, buf, sizeof(buf));
+               if (size < 0)
+                       die("cannot read pack data back: %s", strerror(errno));
+               SHA1_Update(&ctx, buf, size);
+       } while (size > 0);
+       SHA1_Final(sha1, &ctx);
+       write_or_die(output_fd, sha1, 20);
 }
 
 static int sha1_compare(const void *_a, const void *_b)
@@ -450,12 +675,12 @@ static int sha1_compare(const void *_a, const void *_b)
  * On entry *sha1 contains the pack content SHA1 hash, on exit it is
  * the SHA1 hash of sorted object names.
  */
-static void write_index_file(const char *index_name, unsigned char *sha1)
+static const char *write_index_file(const char *index_name, unsigned char *sha1)
 {
        struct sha1file *f;
        struct object_entry **sorted_by_sha, **list, **last;
        unsigned int array[256];
-       int i;
+       int i, fd;
        SHA_CTX ctx;
 
        if (nr_objects) {
@@ -472,8 +697,19 @@ static void write_index_file(const char *index_name, unsigned char *sha1)
        else
                sorted_by_sha = list = last = NULL;
 
-       unlink(index_name);
-       f = sha1create("%s", index_name);
+       if (!index_name) {
+               static char tmpfile[PATH_MAX];
+               snprintf(tmpfile, sizeof(tmpfile),
+                        "%s/index_XXXXXX", get_object_directory());
+               fd = mkstemp(tmpfile);
+               index_name = xstrdup(tmpfile);
+       } else {
+               unlink(index_name);
+               fd = open(index_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
+       }
+       if (fd < 0)
+               die("unable to create %s: %s", index_name, strerror(errno));
+       f = sha1fd(fd, index_name);
 
        /*
         * Write the first-level table (the list is sorted,
@@ -513,12 +749,64 @@ static void write_index_file(const char *index_name, unsigned char *sha1)
        sha1close(f, NULL, 1);
        free(sorted_by_sha);
        SHA1_Final(sha1, &ctx);
+       return index_name;
+}
+
+static void final(const char *final_pack_name, const char *curr_pack_name,
+                 const char *final_index_name, const char *curr_index_name,
+                 unsigned char *sha1)
+{
+       char name[PATH_MAX];
+       int err;
+
+       if (!from_stdin) {
+               close(input_fd);
+       } else {
+               err = close(output_fd);
+               if (err)
+                       die("error while closing pack file: %s", strerror(errno));
+               chmod(curr_pack_name, 0444);
+
+               /*
+                * Let's just mimic git-unpack-objects here and write
+                * the last part of the buffer to stdout.
+                */
+               while (input_len) {
+                       err = xwrite(1, input_buffer + input_offset, input_len);
+                       if (err <= 0)
+                               break;
+                       input_len -= err;
+                       input_offset += err;
+               }
+       }
+
+       if (final_pack_name != curr_pack_name) {
+               if (!final_pack_name) {
+                       snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
+                                get_object_directory(), sha1_to_hex(sha1));
+                       final_pack_name = name;
+               }
+               if (move_temp_to_file(curr_pack_name, final_pack_name))
+                       die("cannot store pack file");
+       }
+
+       chmod(curr_index_name, 0444);
+       if (final_index_name != curr_index_name) {
+               if (!final_index_name) {
+                       snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
+                                get_object_directory(), sha1_to_hex(sha1));
+                       final_index_name = name;
+               }
+               if (move_temp_to_file(curr_index_name, final_index_name))
+                       die("cannot store index file");
+       }
 }
 
 int main(int argc, char **argv)
 {
-       int i;
-       char *index_name = NULL;
+       int i, fix_thin_pack = 0;
+       const char *curr_pack, *pack_name = NULL;
+       const char *curr_index, *index_name = NULL;
        char *index_name_buf = NULL;
        unsigned char sha1[20];
 
@@ -526,7 +814,13 @@ int main(int argc, char **argv)
                const char *arg = argv[i];
 
                if (*arg == '-') {
-                       if (!strcmp(arg, "-o")) {
+                       if (!strcmp(arg, "--stdin")) {
+                               from_stdin = 1;
+                       } else if (!strcmp(arg, "--fix-thin")) {
+                               fix_thin_pack = 1;
+                       } else if (!strcmp(arg, "-v")) {
+                               verbose = 1;
+                       } else if (!strcmp(arg, "-o")) {
                                if (index_name || (i+1) >= argc)
                                        usage(index_pack_usage);
                                index_name = argv[++i];
@@ -540,9 +834,11 @@ int main(int argc, char **argv)
                pack_name = arg;
        }
 
-       if (!pack_name)
+       if (!pack_name && !from_stdin)
                usage(index_pack_usage);
-       if (!index_name) {
+       if (fix_thin_pack && !from_stdin)
+               die("--fix-thin cannot be used without --stdin");
+       if (!index_name && pack_name) {
                int len = strlen(pack_name);
                if (!has_extension(pack_name, ".pack"))
                        die("packfile name '%s' does not end with '.pack'",
@@ -553,17 +849,43 @@ int main(int argc, char **argv)
                index_name = index_name_buf;
        }
 
-       open_pack_file();
+       curr_pack = open_pack_file(pack_name);
        parse_pack_header();
-       objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
-       deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
+       objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
+       deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
+       if (verbose)
+               setup_progress_signal();
        parse_pack_objects(sha1);
+       if (nr_deltas != nr_resolved_deltas) {
+               if (fix_thin_pack) {
+                       int nr_unresolved = nr_deltas - nr_resolved_deltas;
+                       int nr_objects_initial = nr_objects;
+                       if (nr_unresolved <= 0)
+                               die("confusion beyond insanity");
+                       objects = xrealloc(objects,
+                                          (nr_objects + nr_unresolved + 1)
+                                          * sizeof(*objects));
+                       fix_unresolved_deltas(nr_unresolved);
+                       if (verbose)
+                               fprintf(stderr, "%d objects were added to complete this thin pack.\n",
+                                       nr_objects - nr_objects_initial);
+                       readjust_pack_header_and_sha1(sha1);
+               }
+               if (nr_deltas != nr_resolved_deltas)
+                       die("pack has %d unresolved deltas",
+                           nr_deltas - nr_resolved_deltas);
+       } else {
+               /* Flush remaining pack final 20-byte SHA1. */
+               flush();
+       }
        free(deltas);
-       write_index_file(index_name, sha1);
+       curr_index = write_index_file(index_name, sha1);
+       final(pack_name, curr_pack, index_name, curr_index, sha1);
        free(objects);
        free(index_name_buf);
 
-       printf("%s\n", sha1_to_hex(sha1));
+       if (!from_stdin)
+               printf("%s\n", sha1_to_hex(sha1));
 
        return 0;
 }