Add git-show reference
[gitweb.git] / pack-objects.c
index ceb107f63fad491423da8795360331ae0825597a..49357c67357fdc96e0d98b193b88e2137453c7c8 100644 (file)
@@ -5,6 +5,7 @@
 #include "csum-file.h"
 #include "diff.h"
 #include <sys/time.h>
+#include <signal.h>
 
 static const char pack_usage[] = "git-pack-objects [-q] [--no-reuse-delta] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
 
@@ -31,9 +32,6 @@ struct object_entry {
                                 * be used as the base objectto delta huge
                                 * objects against.
                                 */
-       int based_on_preferred; /* current delta candidate is a preferred
-                                * one, or delta against a preferred one.
-                                */
 };
 
 /*
@@ -60,6 +58,7 @@ static int nr_objects = 0, nr_alloc = 0, nr_result = 0;
 static const char *base_name;
 static unsigned char pack_file_sha1[20];
 static int progress = 1;
+static volatile int progress_update = 0;
 
 /*
  * The object names in objects array are hashed with this hashtable,
@@ -97,7 +96,7 @@ static int reused_delta = 0;
 
 static int pack_revindex_ix(struct packed_git *p)
 {
-       unsigned int ui = (unsigned int) p;
+       unsigned long ui = (unsigned long)p;
        int i;
 
        ui = ui ^ (ui >> 16); /* defeat structure alignment */
@@ -334,20 +333,41 @@ static void write_pack_file(void)
        struct sha1file *f;
        unsigned long offset;
        struct pack_header hdr;
+       unsigned last_percent = 999;
+       int do_progress = 0;
 
        if (!base_name)
                f = sha1fd(1, "<stdout>");
-       else
+       else {
                f = sha1create("%s-%s.%s", base_name,
                               sha1_to_hex(object_list_sha1), "pack");
+               do_progress = progress;
+       }
+       if (do_progress)
+               fprintf(stderr, "Writing %d objects.\n", nr_result);
+
        hdr.hdr_signature = htonl(PACK_SIGNATURE);
        hdr.hdr_version = htonl(PACK_VERSION);
        hdr.hdr_entries = htonl(nr_result);
        sha1write(f, &hdr, sizeof(hdr));
        offset = sizeof(hdr);
-       for (i = 0; i < nr_objects; i++)
+       if (!nr_result)
+               goto done;
+       for (i = 0; i < nr_objects; i++) {
                offset = write_one(f, objects + i, offset);
-
+               if (do_progress) {
+                       unsigned percent = written * 100 / nr_result;
+                       if (progress_update || percent != last_percent) {
+                               fprintf(stderr, "%4u%% (%u/%u) done\r",
+                                       percent, written, nr_result);
+                               progress_update = 0;
+                               last_percent = percent;
+                       }
+               }
+       }
+       if (do_progress)
+               fputc('\n', stderr);
+ done:
        sha1close(f, pack_file_sha1, 1);
 }
 
@@ -439,15 +459,74 @@ static void rehash_objects(void)
        }
 }
 
-static int add_object_entry(const unsigned char *sha1, const char *name, int exclude)
+struct name_path {
+       struct name_path *up;
+       const char *elem;
+       int len;
+};
+
+#define DIRBITS 12
+
+static unsigned name_hash(struct name_path *path, const char *name)
+{
+       struct name_path *p = path;
+       const char *n = name + strlen(name);
+       unsigned hash = 0, name_hash = 0, name_done = 0;
+
+       if (n != name && n[-1] == '\n')
+               n--;
+       while (name <= --n) {
+               unsigned char c = *n;
+               if (c == '/' && !name_done) {
+                       name_hash = hash;
+                       name_done = 1;
+                       hash = 0;
+               }
+               hash = hash * 11 + c;
+       }
+       if (!name_done) {
+               name_hash = hash;
+               hash = 0;
+       }
+       for (p = path; p; p = p->up) {
+               hash = hash * 11 + '/';
+               n = p->elem + p->len;
+               while (p->elem <= --n) {
+                       unsigned char c = *n;
+                       hash = hash * 11 + c;
+               }
+       }
+       /*
+        * Make sure "Makefile" and "t/Makefile" are hashed separately
+        * but close enough.
+        */
+       hash = (name_hash<<DIRBITS) | (hash & ((1U<<DIRBITS )-1));
+
+       if (0) { /* debug */
+               n = name + strlen(name);
+               if (n != name && n[-1] == '\n')
+                       n--;
+               while (name <= --n)
+                       fputc(*n, stderr);
+               for (p = path; p; p = p->up) {
+                       fputc('/', stderr);
+                       n = p->elem + p->len;
+                       while (p->elem <= --n)
+                               fputc(*n, stderr);
+               }
+               fprintf(stderr, "\t%08x\n", hash);
+       }
+       return hash;
+}
+
+static int add_object_entry(const unsigned char *sha1, unsigned hash, int exclude)
 {
-       unsigned int hash = 0;
        unsigned int idx = nr_objects;
        struct object_entry *entry;
        struct packed_git *p;
        unsigned int found_offset = 0;
        struct packed_git *found_pack = NULL;
-       int ix;
+       int ix, status = 0;
 
        if (!exclude) {
                for (p = packed_git; p; p = p->next) {
@@ -467,13 +546,6 @@ static int add_object_entry(const unsigned char *sha1, const char *name, int exc
        if ((entry = locate_object_entry(sha1)) != NULL)
                goto already_added;
 
-       while (*name) {
-               unsigned char c = *name++;
-               if (isspace(c))
-                       continue;
-               hash = hash * 11 + c;
-       }
-
        if (idx >= nr_alloc) {
                unsigned int needed = (idx + 1024) * 3 / 2;
                objects = xrealloc(objects, needed * sizeof(*entry));
@@ -493,8 +565,13 @@ static int add_object_entry(const unsigned char *sha1, const char *name, int exc
                        die("internal error in object hashing.");
                object_ix[-1 - ix] = idx + 1;
        }
+       status = 1;
 
  already_added:
+       if (progress_update) {
+               fprintf(stderr, "Counting objects...%d\r", nr_objects);
+               progress_update = 0;
+       }
        if (exclude)
                entry->preferred_base = 1;
        else {
@@ -503,15 +580,15 @@ static int add_object_entry(const unsigned char *sha1, const char *name, int exc
                        entry->in_pack_offset = found_offset;
                }
        }
-       return 1;
+       return status;
 }
 
-static void add_pbase_tree(struct tree_desc *tree)
+static void add_pbase_tree(struct tree_desc *tree, struct name_path *up)
 {
        while (tree->size) {
                const unsigned char *sha1;
                const char *name;
-               unsigned mode;
+               unsigned mode, hash;
                unsigned long size;
                char type[20];
 
@@ -521,14 +598,23 @@ static void add_pbase_tree(struct tree_desc *tree)
                        continue;
                if (sha1_object_info(sha1, type, &size))
                        continue;
-               add_object_entry(sha1, name, 1);
+
+               hash = name_hash(up, name);
+               if (!add_object_entry(sha1, hash, 1))
+                       continue;
+
                if (!strcmp(type, "tree")) {
                        struct tree_desc sub;
                        void *elem;
+                       struct name_path me;
+
                        elem = read_sha1_file(sha1, type, &sub.size);
                        sub.buf = elem;
                        if (sub.buf) {
-                               add_pbase_tree(&sub);
+                               me.up = up;
+                               me.elem = name;
+                               me.len = strlen(name);
+                               add_pbase_tree(&sub, &me);
                                free(elem);
                        }
                }
@@ -539,12 +625,13 @@ static void add_preferred_base(unsigned char *sha1)
 {
        struct tree_desc tree;
        void *elem;
+
        elem = read_object_with_reference(sha1, "tree", &tree.size, NULL);
        tree.buf = elem;
        if (!tree.buf)
                return;
-       add_object_entry(sha1, "", 1);
-       add_pbase_tree(&tree);
+       if (add_object_entry(sha1, name_hash(NULL, ""), 1))
+               add_pbase_tree(&tree, NULL);
        free(elem);
 }
 
@@ -631,10 +718,23 @@ static void get_object_details(void)
        prepare_pack_ix();
        for (i = 0, entry = objects; i < nr_objects; i++, entry++)
                check_object(entry);
-       for (i = 0, entry = objects; i < nr_objects; i++, entry++)
-               if (!entry->delta && entry->delta_child)
-                       entry->delta_limit =
-                               check_delta_limit(entry, 1);
+
+       if (nr_objects == nr_result) {
+               /*
+                * Depth of objects that depend on the entry -- this
+                * is subtracted from depth-max to break too deep
+                * delta chain because of delta data reusing.
+                * However, we loosen this restriction when we know we
+                * are creating a thin pack -- it will have to be
+                * expanded on the other end anyway, so do not
+                * artificially cut the delta chain and let it go as
+                * deep as it wants.
+                */
+               for (i = 0, entry = objects; i < nr_objects; i++, entry++)
+                       if (!entry->delta && entry->delta_child)
+                               entry->delta_limit =
+                                       check_delta_limit(entry, 1);
+       }
 }
 
 typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
@@ -665,7 +765,7 @@ static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
        return memcmp(a->sha1, b->sha1, 20);
 }
 
-static struct object_entry **create_final_object_list()
+static struct object_entry **create_final_object_list(void)
 {
        struct object_entry **list;
        int i, j;
@@ -721,8 +821,6 @@ static int try_delta(struct unpacked *cur, struct unpacked *old, unsigned max_de
 {
        struct object_entry *cur_entry = cur->entry;
        struct object_entry *old_entry = old->entry;
-       int old_preferred = (old_entry->preferred_base ||
-                            old_entry->based_on_preferred);
        unsigned long size, oldsize, delta_size, sizediff;
        long max_size;
        void *delta_buf;
@@ -748,11 +846,10 @@ static int try_delta(struct unpacked *cur, struct unpacked *old, unsigned max_de
        }
 
        size = cur_entry->size;
-       if (size < 50)
-               return -1;
        oldsize = old_entry->size;
        sizediff = oldsize > size ? oldsize - size : size - oldsize;
-       if (sizediff > size / 8)
+
+       if (size < 50)
                return -1;
        if (old_entry->depth >= max_depth)
                return 0;
@@ -765,27 +862,8 @@ static int try_delta(struct unpacked *cur, struct unpacked *old, unsigned max_de
         * delete).
         */
        max_size = size / 2 - 20;
-       if (cur_entry->delta) {
-               if (cur_entry->based_on_preferred) {
-                       if (old_preferred)
-                               max_size = cur_entry->delta_size-1;
-                       else
-                               /* trying with non-preferred one when we
-                                * already have a delta based on preferred
-                                * one is pointless.
-                                */
-                               return 0;
-               }
-               else if (!old_preferred)
-                       max_size = cur_entry->delta_size-1;
-               else
-                       /* otherwise...  even if delta with a
-                        * preferred one produces a bigger result than
-                        * what we currently have, which is based on a
-                        * non-preferred one, it is OK.
-                        */
-                       ;
-       }
+       if (cur_entry->delta)
+               max_size = cur_entry->delta_size-1;
        if (sizediff >= max_size)
                return -1;
        delta_buf = diff_delta(old->data, oldsize,
@@ -795,22 +873,29 @@ static int try_delta(struct unpacked *cur, struct unpacked *old, unsigned max_de
        cur_entry->delta = old_entry;
        cur_entry->delta_size = delta_size;
        cur_entry->depth = old_entry->depth + 1;
-       cur_entry->based_on_preferred = old_preferred;
        free(delta_buf);
        return 0;
 }
 
+static void progress_interval(int signum)
+{
+       signal(SIGALRM, progress_interval);
+       progress_update = 1;
+}
+
 static void find_deltas(struct object_entry **list, int window, int depth)
 {
        int i, idx;
        unsigned int array_size = window * sizeof(struct unpacked);
        struct unpacked *array = xmalloc(array_size);
-       int eye_candy;
+       unsigned processed = 0;
+       unsigned last_percent = 999;
 
        memset(array, 0, array_size);
        i = nr_objects;
        idx = 0;
-       eye_candy = i - (nr_objects / 20);
+       if (progress)
+               fprintf(stderr, "Deltifying %d objects.\n", nr_result);
 
        while (--i >= 0) {
                struct object_entry *entry = list[i];
@@ -819,9 +904,17 @@ static void find_deltas(struct object_entry **list, int window, int depth)
                char type[10];
                int j;
 
-               if (progress && i <= eye_candy) {
-                       eye_candy -= nr_objects / 20;
-                       fputc('.', stderr);
+               if (!entry->preferred_base)
+                       processed++;
+
+               if (progress) {
+                       unsigned percent = processed * 100 / nr_result;
+                       if (percent != last_percent || progress_update) {
+                               fprintf(stderr, "%4u%% (%u/%u) done\r",
+                                       percent, processed, nr_result);
+                               progress_update = 0;
+                               last_percent = percent;
+                       }
                }
 
                if (entry->delta)
@@ -848,11 +941,23 @@ static void find_deltas(struct object_entry **list, int window, int depth)
                        if (try_delta(n, m, depth) < 0)
                                break;
                }
+#if 0
+               /* if we made n a delta, and if n is already at max
+                * depth, leaving it in the window is pointless.  we
+                * should evict it first.
+                * ... in theory only; somehow this makes things worse.
+                */
+               if (entry->delta && depth <= entry->depth)
+                       continue;
+#endif
                idx++;
                if (idx >= window)
                        idx = 0;
        }
 
+       if (progress)
+               fputc('\n', stderr);
+
        for (i = 0; i < window; ++i)
                free(array[i].data);
        free(array);
@@ -860,18 +965,10 @@ static void find_deltas(struct object_entry **list, int window, int depth)
 
 static void prepare_pack(int window, int depth)
 {
-       if (progress)
-               fprintf(stderr, "Packing %d objects", nr_result);
        get_object_details();
-       if (progress)
-               fputc('.', stderr);
-
        sorted_by_type = create_sorted_list(type_size_sort);
        if (window && depth)
                find_deltas(sorted_by_type, window+1, depth);
-       if (progress)
-               fputc('\n', stderr);
-       write_pack_file();
 }
 
 static int reuse_cached_pack(unsigned char *sha1, int pack_to_stdout)
@@ -935,10 +1032,6 @@ int main(int argc, char **argv)
        int window = 10, depth = 10, pack_to_stdout = 0;
        struct object_entry **list;
        int i;
-       struct timeval prev_tv;
-       int eye_candy = 0;
-       int eye_candy_incr = 500;
-
 
        setup_git_directory();
 
@@ -995,29 +1088,20 @@ int main(int argc, char **argv)
                usage(pack_usage);
 
        prepare_packed_git();
+
        if (progress) {
+               struct itimerval v;
+               v.it_interval.tv_sec = 1;
+               v.it_interval.tv_usec = 0;
+               v.it_value = v.it_interval;
+               signal(SIGALRM, progress_interval);
+               setitimer(ITIMER_REAL, &v, NULL);
                fprintf(stderr, "Generating pack...\n");
-               gettimeofday(&prev_tv, NULL);
        }
+
        while (fgets(line, sizeof(line), stdin) != NULL) {
                unsigned char sha1[20];
 
-               if (progress && (eye_candy <= nr_objects)) {
-                       fprintf(stderr, "Counting objects...%d\r", nr_objects);
-                       if (eye_candy && (50 <= eye_candy_incr)) {
-                               struct timeval tv;
-                               int time_diff;
-                               gettimeofday(&tv, NULL);
-                               time_diff = (tv.tv_sec - prev_tv.tv_sec);
-                               time_diff <<= 10;
-                               time_diff += (tv.tv_usec - prev_tv.tv_usec);
-                               if ((1 << 9) < time_diff)
-                                       eye_candy_incr += 50;
-                               else if (50 < eye_candy_incr)
-                                       eye_candy_incr -= 50;
-                       }
-                       eye_candy += eye_candy_incr;
-               }
                if (line[0] == '-') {
                        if (get_sha1_hex(line+1, sha1))
                                die("expected edge sha1, got garbage:\n %s",
@@ -1027,14 +1111,14 @@ int main(int argc, char **argv)
                }
                if (get_sha1_hex(line, sha1))
                        die("expected sha1, got garbage:\n %s", line);
-               add_object_entry(sha1, line+40, 0);
+               add_object_entry(sha1, name_hash(NULL, line+41), 0);
        }
        if (progress)
                fprintf(stderr, "Done counting %d objects.\n", nr_objects);
-       if (non_empty && !nr_objects)
+       sorted_by_sha = create_final_object_list();
+       if (non_empty && !nr_result)
                return 0;
 
-       sorted_by_sha = create_final_object_list();
        SHA1_Init(&ctx);
        list = sorted_by_sha;
        for (i = 0; i < nr_result; i++) {
@@ -1048,7 +1132,16 @@ int main(int argc, char **argv)
        if (reuse_cached_pack(object_list_sha1, pack_to_stdout))
                ;
        else {
-               prepare_pack(window, depth);
+               if (nr_result)
+                       prepare_pack(window, depth);
+               if (progress && pack_to_stdout) {
+                       /* the other end usually displays progress itself */
+                       struct itimerval v = {{0,},};
+                       setitimer(ITIMER_REAL, &v, NULL);
+                       signal(SIGALRM, SIG_IGN );
+                       progress_update = 0;
+               }
+               write_pack_file();
                if (!pack_to_stdout) {
                        write_index_file();
                        puts(sha1_to_hex(object_list_sha1));