sha1-lookup: make selection of 'middle' less aggressive
[gitweb.git] / builtin-pack-objects.c
index 7dd0d7f82605798a81e731c8e0db1b5c009e1e08..777f272668c39931b330be555f41399adfbce397 100644 (file)
@@ -8,14 +8,17 @@
 #include "tree.h"
 #include "delta.h"
 #include "pack.h"
+#include "pack-revindex.h"
 #include "csum-file.h"
 #include "tree-walk.h"
 #include "diff.h"
 #include "revision.h"
 #include "list-objects.h"
 #include "progress.h"
+#include "refs.h"
 
 #ifdef THREADED_DELTA_SEARCH
+#include "thread-utils.h"
 #include <pthread.h>
 #endif
 
@@ -25,7 +28,8 @@ git-pack-objects [{ -q | --progress | --all-progress }] \n\
        [--window=N] [--window-memory=N] [--depth=N] \n\
        [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
        [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
-       [--stdout | base-name] [--keep-unreachable] [<ref-list | <object-list]";
+       [--stdout | base-name] [--include-tag] [--keep-unreachable] \n\
+       [<ref-list | <object-list]";
 
 struct object_entry {
        struct pack_idx_entry idx;
@@ -61,14 +65,14 @@ static struct pack_idx_entry **written_list;
 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
 
 static int non_empty;
-static int no_reuse_delta, no_reuse_object, keep_unreachable;
+static int no_reuse_delta, no_reuse_object, keep_unreachable, include_tag;
 static int local;
 static int incremental;
 static int allow_ofs_delta;
 static const char *base_name;
 static int progress = 1;
 static int window = 10;
-static uint32_t pack_size_limit;
+static uint32_t pack_size_limit, pack_size_limit_cfg;
 static int depth = 50;
 static int delta_search_threads = 1;
 static int pack_to_stdout;
@@ -91,158 +95,12 @@ static unsigned long window_memory_limit = 0;
 static int *object_ix;
 static int object_ix_hashsz;
 
-/*
- * Pack index for existing packs give us easy access to the offsets into
- * corresponding pack file where each object's data starts, but the entries
- * do not store the size of the compressed representation (uncompressed
- * size is easily available by examining the pack entry header).  It is
- * also rather expensive to find the sha1 for an object given its offset.
- *
- * We build a hashtable of existing packs (pack_revindex), and keep reverse
- * index here -- pack index file is sorted by object name mapping to offset;
- * this pack_revindex[].revindex array is a list of offset/index_nr pairs
- * ordered by offset, so if you know the offset of an object, next offset
- * is where its packed representation ends and the index_nr can be used to
- * get the object sha1 from the main index.
- */
-struct revindex_entry {
-       off_t offset;
-       unsigned int nr;
-};
-struct pack_revindex {
-       struct packed_git *p;
-       struct revindex_entry *revindex;
-};
-static struct  pack_revindex *pack_revindex;
-static int pack_revindex_hashsz;
-
 /*
  * stats
  */
 static uint32_t written, written_delta;
 static uint32_t reused, reused_delta;
 
-static int pack_revindex_ix(struct packed_git *p)
-{
-       unsigned long ui = (unsigned long)p;
-       int i;
-
-       ui = ui ^ (ui >> 16); /* defeat structure alignment */
-       i = (int)(ui % pack_revindex_hashsz);
-       while (pack_revindex[i].p) {
-               if (pack_revindex[i].p == p)
-                       return i;
-               if (++i == pack_revindex_hashsz)
-                       i = 0;
-       }
-       return -1 - i;
-}
-
-static void prepare_pack_ix(void)
-{
-       int num;
-       struct packed_git *p;
-       for (num = 0, p = packed_git; p; p = p->next)
-               num++;
-       if (!num)
-               return;
-       pack_revindex_hashsz = num * 11;
-       pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
-       for (p = packed_git; p; p = p->next) {
-               num = pack_revindex_ix(p);
-               num = - 1 - num;
-               pack_revindex[num].p = p;
-       }
-       /* revindex elements are lazily initialized */
-}
-
-static int cmp_offset(const void *a_, const void *b_)
-{
-       const struct revindex_entry *a = a_;
-       const struct revindex_entry *b = b_;
-       return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
-}
-
-/*
- * Ordered list of offsets of objects in the pack.
- */
-static void prepare_pack_revindex(struct pack_revindex *rix)
-{
-       struct packed_git *p = rix->p;
-       int num_ent = p->num_objects;
-       int i;
-       const char *index = p->index_data;
-
-       rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
-       index += 4 * 256;
-
-       if (p->index_version > 1) {
-               const uint32_t *off_32 =
-                       (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
-               const uint32_t *off_64 = off_32 + p->num_objects;
-               for (i = 0; i < num_ent; i++) {
-                       uint32_t off = ntohl(*off_32++);
-                       if (!(off & 0x80000000)) {
-                               rix->revindex[i].offset = off;
-                       } else {
-                               rix->revindex[i].offset =
-                                       ((uint64_t)ntohl(*off_64++)) << 32;
-                               rix->revindex[i].offset |=
-                                       ntohl(*off_64++);
-                       }
-                       rix->revindex[i].nr = i;
-               }
-       } else {
-               for (i = 0; i < num_ent; i++) {
-                       uint32_t hl = *((uint32_t *)(index + 24 * i));
-                       rix->revindex[i].offset = ntohl(hl);
-                       rix->revindex[i].nr = i;
-               }
-       }
-
-       /* This knows the pack format -- the 20-byte trailer
-        * follows immediately after the last object data.
-        */
-       rix->revindex[num_ent].offset = p->pack_size - 20;
-       rix->revindex[num_ent].nr = -1;
-       qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
-}
-
-static struct revindex_entry * find_packed_object(struct packed_git *p,
-                                                 off_t ofs)
-{
-       int num;
-       int lo, hi;
-       struct pack_revindex *rix;
-       struct revindex_entry *revindex;
-       num = pack_revindex_ix(p);
-       if (num < 0)
-               die("internal error: pack revindex uninitialized");
-       rix = &pack_revindex[num];
-       if (!rix->revindex)
-               prepare_pack_revindex(rix);
-       revindex = rix->revindex;
-       lo = 0;
-       hi = p->num_objects + 1;
-       do {
-               int mi = (lo + hi) / 2;
-               if (revindex[mi].offset == ofs) {
-                       return revindex + mi;
-               }
-               else if (ofs < revindex[mi].offset)
-                       hi = mi;
-               else
-                       lo = mi + 1;
-       } while (lo < hi);
-       die("internal error: pack revindex corrupt");
-}
-
-static const unsigned char *find_packed_object_name(struct packed_git *p,
-                                                   off_t ofs)
-{
-       struct revindex_entry *entry = find_packed_object(p, ofs);
-       return nth_packed_object_sha1(p, entry->nr);
-}
 
 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 {
@@ -445,7 +303,7 @@ static unsigned long write_object(struct sha1file *f,
                        /* nothing */;
                deflateEnd(&stream);
                datalen = stream.total_out;
-               deflateEnd(&stream);
+
                /*
                 * The object header is a byte of 'type' followed by zero or
                 * more bytes of length.
@@ -509,7 +367,7 @@ static unsigned long write_object(struct sha1file *f,
                }
                hdrlen = encode_header(obj_type, entry->size, header);
                offset = entry->in_pack_offset;
-               revidx = find_packed_object(p, offset);
+               revidx = find_pack_revindex(p, offset);
                datalen = revidx[1].offset - offset;
                if (!pack_to_stdout && p->index_version > 1 &&
                    check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
@@ -596,6 +454,7 @@ static void write_pack_file(void)
        struct pack_header hdr;
        int do_progress = progress >> pack_to_stdout;
        uint32_t nr_remaining = nr_result;
+       time_t last_mtime = 0;
 
        if (do_progress)
                progress_state = start_progress("Writing objects", nr_result);
@@ -646,6 +505,7 @@ static void write_pack_file(void)
 
                if (!pack_to_stdout) {
                        mode_t mode = umask(0);
+                       struct stat st;
                        char *idx_tmp_name, tmpname[PATH_MAX];
 
                        umask(mode);
@@ -653,6 +513,7 @@ static void write_pack_file(void)
 
                        idx_tmp_name = write_idx_file(NULL, written_list,
                                                      nr_written, sha1);
+
                        snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
                                 base_name, sha1_to_hex(sha1));
                        if (adjust_perm(pack_tmp_name, mode))
@@ -661,6 +522,28 @@ static void write_pack_file(void)
                        if (rename(pack_tmp_name, tmpname))
                                die("unable to rename temporary pack file: %s",
                                    strerror(errno));
+
+                       /*
+                        * Packs are runtime accessed in their mtime
+                        * order since newer packs are more likely to contain
+                        * younger objects.  So if we are creating multiple
+                        * packs then we should modify the mtime of later ones
+                        * to preserve this property.
+                        */
+                       if (stat(tmpname, &st) < 0) {
+                               warning("failed to stat %s: %s",
+                                       tmpname, strerror(errno));
+                       } else if (!last_mtime) {
+                               last_mtime = st.st_mtime;
+                       } else {
+                               struct utimbuf utb;
+                               utb.actime = st.st_atime;
+                               utb.modtime = --last_mtime;
+                               if (utime(tmpname, &utb) < 0)
+                                       warning("failed utime() on %s: %s",
+                                               tmpname, strerror(errno));
+                       }
+
                        snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
                                 base_name, sha1_to_hex(sha1));
                        if (adjust_perm(idx_tmp_name, mode))
@@ -669,6 +552,7 @@ static void write_pack_file(void)
                        if (rename(idx_tmp_name, tmpname))
                                die("unable to rename temporary index file: %s",
                                    strerror(errno));
+
                        free(idx_tmp_name);
                        free(pack_tmp_name);
                        puts(sha1_to_hex(sha1));
@@ -1161,8 +1045,11 @@ static void check_object(struct object_entry *entry)
                                die("delta base offset out of bound for %s",
                                    sha1_to_hex(entry->idx.sha1));
                        ofs = entry->in_pack_offset - ofs;
-                       if (!no_reuse_delta && !entry->preferred_base)
-                               base_ref = find_packed_object_name(p, ofs);
+                       if (!no_reuse_delta && !entry->preferred_base) {
+                               struct revindex_entry *revidx;
+                               revidx = find_pack_revindex(p, ofs);
+                               base_ref = nth_packed_object_sha1(p, revidx->nr);
+                       }
                        entry->in_pack_header_size = used + used_0;
                        break;
                }
@@ -1239,9 +1126,11 @@ static void get_object_details(void)
                sorted_by_offset[i] = objects + i;
        qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
 
-       prepare_pack_ix();
+       init_pack_revindex();
+
        for (i = 0; i < nr_objects; i++)
                check_object(sorted_by_offset[i]);
+
        free(sorted_by_offset);
 }
 
@@ -1428,8 +1317,7 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
         * accounting lock.  Compiler will optimize the strangeness
         * away when THREADED_DELTA_SEARCH is not defined.
         */
-       if (trg_entry->delta_data)
-               free(trg_entry->delta_data);
+       free(trg_entry->delta_data);
        cache_lock();
        if (trg_entry->delta_data) {
                delta_cache_size -= trg_entry->delta_size;
@@ -1594,6 +1482,15 @@ static void find_deltas(struct object_entry **list, unsigned *list_size,
 
 #ifdef THREADED_DELTA_SEARCH
 
+/*
+ * The main thread waits on the condition that (at least) one of the workers
+ * has stopped working (which is indicated in the .working member of
+ * struct thread_params).
+ * When a work thread has completed its work, it sets .working to 0 and
+ * signals the main thread and waits on the condition that .data_ready
+ * becomes 1.
+ */
+
 struct thread_params {
        pthread_t thread;
        struct object_entry **list;
@@ -1601,37 +1498,50 @@ struct thread_params {
        unsigned remaining;
        int window;
        int depth;
+       int working;
+       int data_ready;
+       pthread_mutex_t mutex;
+       pthread_cond_t cond;
        unsigned *processed;
 };
 
-static pthread_mutex_t data_request  = PTHREAD_MUTEX_INITIALIZER;
-static pthread_mutex_t data_ready    = PTHREAD_MUTEX_INITIALIZER;
-static pthread_mutex_t data_provider = PTHREAD_MUTEX_INITIALIZER;
-static struct thread_params *data_requester;
+static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
 
 static void *threaded_find_deltas(void *arg)
 {
        struct thread_params *me = arg;
 
-       for (;;) {
-               pthread_mutex_lock(&data_request);
-               data_requester = me;
-               pthread_mutex_unlock(&data_provider);
-               pthread_mutex_lock(&data_ready);
-               pthread_mutex_unlock(&data_request);
-
-               if (!me->remaining)
-                       return NULL;
-
+       while (me->remaining) {
                find_deltas(me->list, &me->remaining,
                            me->window, me->depth, me->processed);
+
+               progress_lock();
+               me->working = 0;
+               pthread_cond_signal(&progress_cond);
+               progress_unlock();
+
+               /*
+                * We must not set ->data_ready before we wait on the
+                * condition because the main thread may have set it to 1
+                * before we get here. In order to be sure that new
+                * work is available if we see 1 in ->data_ready, it
+                * was initialized to 0 before this thread was spawned
+                * and we reset it to 0 right away.
+                */
+               pthread_mutex_lock(&me->mutex);
+               while (!me->data_ready)
+                       pthread_cond_wait(&me->cond, &me->mutex);
+               me->data_ready = 0;
+               pthread_mutex_unlock(&me->mutex);
        }
+       /* leave ->working 1 so that this doesn't get more work assigned */
+       return NULL;
 }
 
 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
                           int window, int depth, unsigned *processed)
 {
-       struct thread_params *target, p[delta_search_threads];
+       struct thread_params p[delta_search_threads];
        int i, ret, active_threads = 0;
 
        if (delta_search_threads <= 1) {
@@ -1639,49 +1549,43 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
                return;
        }
 
-       pthread_mutex_lock(&data_provider);
-       pthread_mutex_lock(&data_ready);
-
-       /* Start work threads. */
+       /* Partition the work amongst work threads. */
        for (i = 0; i < delta_search_threads; i++) {
+               unsigned sub_size = list_size / (delta_search_threads - i);
+
                p[i].window = window;
                p[i].depth = depth;
                p[i].processed = processed;
-               p[i].remaining = 0;
-               ret = pthread_create(&p[i].thread, NULL,
-                                    threaded_find_deltas, &p[i]);
-               if (ret)
-                       die("unable to create thread: %s", strerror(ret));
-               active_threads++;
-       }
-
-       /* Then partition the work amongst them. */
-       for (i = 0; i < delta_search_threads; i++) {
-               unsigned sub_size = list_size / (delta_search_threads - i);
-
-               pthread_mutex_lock(&data_provider);
-               target = data_requester;
-               if (!sub_size) {
-                       pthread_mutex_unlock(&data_ready);
-                       pthread_join(target->thread, NULL);
-                       active_threads--;
-                       continue;
-               }
+               p[i].working = 1;
+               p[i].data_ready = 0;
 
                /* try to split chunks on "path" boundaries */
-               while (sub_size < list_size && list[sub_size]->hash &&
+               while (sub_size && sub_size < list_size &&
+                      list[sub_size]->hash &&
                       list[sub_size]->hash == list[sub_size-1]->hash)
                        sub_size++;
 
-               target->list = list;
-               target->list_size = sub_size;
-               target->remaining = sub_size;
-               pthread_mutex_unlock(&data_ready);
+               p[i].list = list;
+               p[i].list_size = sub_size;
+               p[i].remaining = sub_size;
 
                list += sub_size;
                list_size -= sub_size;
        }
 
+       /* Start work threads. */
+       for (i = 0; i < delta_search_threads; i++) {
+               if (!p[i].list_size)
+                       continue;
+               pthread_mutex_init(&p[i].mutex, NULL);
+               pthread_cond_init(&p[i].cond, NULL);
+               ret = pthread_create(&p[i].thread, NULL,
+                                    threaded_find_deltas, &p[i]);
+               if (ret)
+                       die("unable to create thread: %s", strerror(ret));
+               active_threads++;
+       }
+
        /*
         * Now let's wait for work completion.  Each time a thread is done
         * with its work, we steal half of the remaining work from the
@@ -1690,13 +1594,21 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
         * until the remaining object list segments are simply too short
         * to be worth splitting anymore.
         */
-       do {
+       while (active_threads) {
+               struct thread_params *target = NULL;
                struct thread_params *victim = NULL;
                unsigned sub_size = 0;
-               pthread_mutex_lock(&data_provider);
-               target = data_requester;
 
                progress_lock();
+               for (;;) {
+                       for (i = 0; !target && i < delta_search_threads; i++)
+                               if (!p[i].working)
+                                       target = &p[i];
+                       if (target)
+                               break;
+                       pthread_cond_wait(&progress_cond, &progress_mutex);
+               }
+
                for (i = 0; i < delta_search_threads; i++)
                        if (p[i].remaining > 2*window &&
                            (!victim || victim->remaining < p[i].remaining))
@@ -1723,23 +1635,41 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
                        victim->list_size -= sub_size;
                        victim->remaining -= sub_size;
                }
-               progress_unlock();
-
                target->list_size = sub_size;
                target->remaining = sub_size;
-               pthread_mutex_unlock(&data_ready);
+               target->working = 1;
+               progress_unlock();
+
+               pthread_mutex_lock(&target->mutex);
+               target->data_ready = 1;
+               pthread_cond_signal(&target->cond);
+               pthread_mutex_unlock(&target->mutex);
 
                if (!sub_size) {
                        pthread_join(target->thread, NULL);
+                       pthread_cond_destroy(&target->cond);
+                       pthread_mutex_destroy(&target->mutex);
                        active_threads--;
                }
-       } while (active_threads);
+       }
 }
 
 #else
 #define ll_find_deltas(l, s, w, d, p)  find_deltas(l, &s, w, d, p)
 #endif
 
+static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+       unsigned char peeled[20];
+
+       if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
+           !peel_ref(path, peeled)        && /* peelable? */
+           !is_null_sha1(peeled)          && /* annotated tag? */
+           locate_object_entry(peeled))      /* object packed? */
+               add_object_entry(sha1, OBJ_TAG, NULL, 0);
+       return 0;
+}
+
 static void prepare_pack(int window, int depth)
 {
        struct object_entry **delta_list;
@@ -1822,11 +1752,11 @@ static int git_pack_config(const char *k, const char *v)
        }
        if (!strcmp(k, "pack.threads")) {
                delta_search_threads = git_config_int(k, v);
-               if (delta_search_threads < 1)
+               if (delta_search_threads < 0)
                        die("invalid number of threads specified (%d)",
                            delta_search_threads);
 #ifndef THREADED_DELTA_SEARCH
-               if (delta_search_threads > 1)
+               if (delta_search_threads != 1)
                        warning("no threads support, ignoring %s", k);
 #endif
                return 0;
@@ -1837,6 +1767,10 @@ static int git_pack_config(const char *k, const char *v)
                        die("bad pack.indexversion=%d", pack_idx_default_version);
                return 0;
        }
+       if (!strcmp(k, "pack.packsizelimit")) {
+               pack_size_limit_cfg = git_config_ulong(k, v);
+               return 0;
+       }
        return git_default_config(k, v);
 }
 
@@ -1979,12 +1913,11 @@ static void get_object_list(int ac, const char **av)
 
        init_revisions(&revs, NULL);
        save_commit_buffer = 0;
-       track_object_refs = 0;
        setup_revisions(ac, av, &revs, NULL);
 
        while (fgets(line, sizeof(line), stdin) != NULL) {
                int len = strlen(line);
-               if (line[len - 1] == '\n')
+               if (len && line[len - 1] == '\n')
                        line[--len] = 0;
                if (!len)
                        break;
@@ -1999,7 +1932,8 @@ static void get_object_list(int ac, const char **av)
                        die("bad revision '%s'", line);
        }
 
-       prepare_revision_walk(&revs);
+       if (prepare_revision_walk(&revs))
+               die("revision walk setup failed");
        mark_edges_uninteresting(revs.commits, &revs, show_edge);
        traverse_commit_list(&revs, show_commit, show_object);
 
@@ -2066,6 +2000,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                }
                if (!prefixcmp(arg, "--max-pack-size=")) {
                        char *end;
+                       pack_size_limit_cfg = 0;
                        pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
                        if (!arg[16] || *end)
                                usage(pack_usage);
@@ -2086,10 +2021,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                if (!prefixcmp(arg, "--threads=")) {
                        char *end;
                        delta_search_threads = strtoul(arg+10, &end, 0);
-                       if (!arg[10] || *end || delta_search_threads < 1)
+                       if (!arg[10] || *end || delta_search_threads < 0)
                                usage(pack_usage);
 #ifndef THREADED_DELTA_SEARCH
-                       if (delta_search_threads > 1)
+                       if (delta_search_threads != 1)
                                warning("no threads support, "
                                        "ignoring %s", arg);
 #endif
@@ -2138,6 +2073,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                        keep_unreachable = 1;
                        continue;
                }
+               if (!strcmp("--include-tag", arg)) {
+                       include_tag = 1;
+                       continue;
+               }
                if (!strcmp("--unpacked", arg) ||
                    !prefixcmp(arg, "--unpacked=") ||
                    !strcmp("--reflog", arg) ||
@@ -2190,12 +2129,20 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
        if (pack_to_stdout != !base_name)
                usage(pack_usage);
 
+       if (!pack_to_stdout && !pack_size_limit)
+               pack_size_limit = pack_size_limit_cfg;
+
        if (pack_to_stdout && pack_size_limit)
                die("--max-pack-size cannot be used to build a pack for transfer.");
 
        if (!pack_to_stdout && thin)
                die("--thin cannot be used to build an indexable pack.");
 
+#ifdef THREADED_DELTA_SEARCH
+       if (!delta_search_threads)      /* --threads=0 means autodetect */
+               delta_search_threads = online_cpus();
+#endif
+
        prepare_packed_git();
 
        if (progress)
@@ -2206,6 +2153,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
                rp_av[rp_ac] = NULL;
                get_object_list(rp_ac, rp_av);
        }
+       if (include_tag && nr_result)
+               for_each_ref(add_ref_tag, NULL);
        stop_progress(&progress_state);
 
        if (non_empty && !nr_result)