Added mark store/find to fast-import.

Marks are now saved when the mark directive gets used by the frontend
and may be used in place of a SHA1 expression to locate a previous
SHA1 which fast-import may have generated.  This is particularly
useful with commits where the frontend does not (easily) have the
ability to compute the SHA1 for an arbitrary commit but needs it
to generate a branch or tag from that commit.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

diff --git a/fast-import.c b/fast-import.c
index 8598493651d8ead3a586c2be1eca0fe27fdb3348..6e2f106a1ae311047fe91e9464d9d6130d474ed2 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
@@ -121,6 +121,15 @@ struct object_entry_pool
        struct object_entry entries[FLEX_ARRAY]; /* more */
 };
 
+struct mark_set
+{
+       int shift;
+       union {
+               struct object_entry *marked[1024];
+               struct mark_set *sets[1024];
+       } data;
+};
+
 struct last_object
 {
        void *data;
@@ -183,6 +192,7 @@ static unsigned long alloc_count;
 static unsigned long branch_count;
 static unsigned long object_count;
 static unsigned long duplicate_count;
+static unsigned long marks_set_count;
 static unsigned long object_count_by_type[9];
 static unsigned long duplicate_count_by_type[9];
 
@@ -205,6 +215,7 @@ static unsigned char pack_sha1[20];
 static unsigned int object_entry_alloc = 1000;
 static struct object_entry_pool *blocks;
 static struct object_entry *object_table[1 << 16];
+static struct mark_set *marks;
 
 /* Our last blob */
 static struct last_object last_blob;
@@ -224,7 +235,7 @@ static struct branch *active_branches;
 
 /* Input stream parsing */
 static struct strbuf command_buf;
-static unsigned long command_mark;
+static unsigned long next_mark;
 
 
 static void alloc_objects(int cnt)
@@ -335,6 +346,48 @@ static char* pool_strdup(const char *s)
        return r;
 }
 
+static void insert_mark(unsigned long idnum, struct object_entry *oe)
+{
+       struct mark_set *s = marks;
+       while ((idnum >> s->shift) >= 1024) {
+               s = pool_calloc(1, sizeof(struct mark_set));
+               s->shift = marks->shift + 10;
+               s->data.sets[0] = marks;
+               marks = s;
+       }
+       while (s->shift) {
+               unsigned long i = idnum >> s->shift;
+               idnum -= i << s->shift;
+               if (!s->data.sets[i]) {
+                       s->data.sets[i] = pool_calloc(1, sizeof(struct mark_set));
+                       s->data.sets[i]->shift = s->shift - 10;
+               }
+               s = s->data.sets[i];
+       }
+       if (!s->data.marked[idnum])
+               marks_set_count++;
+       s->data.marked[idnum] = oe;
+}
+
+static struct object_entry* find_mark(unsigned long idnum)
+{
+       unsigned long orig_idnum = idnum;
+       struct mark_set *s = marks;
+       struct object_entry *oe = NULL;
+       if ((idnum >> s->shift) < 1024) {
+               while (s && s->shift) {
+                       unsigned long i = idnum >> s->shift;
+                       idnum -= i << s->shift;
+                       s = s->data.sets[i];
+               }
+               if (s)
+                       oe = s->data.marked[idnum];
+       }
+       if (!oe)
+               die("mark :%lu not declared", orig_idnum);
+       return oe;
+}
+
 static struct atom_str* to_atom(const char *s, size_t len)
 {
        unsigned int hc = hc_str(s, len) % atom_table_sz;
@@ -523,7 +576,8 @@ static int store_object(
        void *dat,
        size_t datlen,
        struct last_object *last,
-       unsigned char *sha1out)
+       unsigned char *sha1out,
+       unsigned long mark)
 {
        void *out, *delta;
        struct object_entry *e;
@@ -542,6 +596,8 @@ static int store_object(
                memcpy(sha1out, sha1, sizeof(sha1));
 
        e = insert_object(sha1);
+       if (mark)
+               insert_mark(mark, e);
        if (e->offset) {
                duplicate_count++;
                duplicate_count_by_type[type]++;
@@ -695,7 +751,7 @@ static void store_tree(struct tree_entry *root)
                memcpy(c, e->sha1, 20);
                c += 20;
        }
-       store_object(OBJ_TREE, buf, c - buf, NULL, root->sha1);
+       store_object(OBJ_TREE, buf, c - buf, NULL, root->sha1, 0);
        free(buf);
 }
 
@@ -921,11 +977,11 @@ static void read_next_command()
 static void cmd_mark()
 {
        if (!strncmp("mark :", command_buf.buf, 6)) {
-               command_mark = strtoul(command_buf.buf + 6, NULL, 10);
+               next_mark = strtoul(command_buf.buf + 6, NULL, 10);
                read_next_command();
        }
        else
-               command_mark = 0;
+               next_mark = 0;
 }
 
 static void* cmd_data (size_t *size)
@@ -956,16 +1012,15 @@ static void* cmd_data (size_t *size)
 
 static void cmd_new_blob()
 {
-       size_t datlen;
-       void *dat;
-       unsigned char sha1[20];
+       size_t l;
+       void *d;
 
        read_next_command();
        cmd_mark();
-       dat = cmd_data(&datlen);
+       d = cmd_data(&l);
 
-       if (store_object(OBJ_BLOB, dat, datlen, &last_blob, sha1))
-               free(dat);
+       if (store_object(OBJ_BLOB, d, l, &last_blob, NULL, next_mark))
+               free(d);
 }
 
 static void unload_one_branch()
@@ -1031,9 +1086,16 @@ static void file_change_m(struct branch *b)
                die("Corrupt mode: %s", command_buf.buf);
        }
 
-       if (get_sha1_hex(p, sha1))
-               die("Invalid SHA1: %s", command_buf.buf);
-       p += 40;
+       if (*p == ':') {
+               char *x;
+               oe = find_mark(strtoul(p + 1, &x, 10));
+               p = x;
+       } else {
+               if (get_sha1_hex(p, sha1))
+                       die("Invalid SHA1: %s", command_buf.buf);
+               oe = find_object(sha1);
+               p += 40;
+       }
        if (*p++ != ' ')
                die("Missing space after SHA1: %s", command_buf.buf);
 
@@ -1044,7 +1106,6 @@ static void file_change_m(struct branch *b)
                p = p_uq;
        }
 
-       oe = find_object(sha1);
        if (oe) {
                if (oe->type != OBJ_BLOB)
                        die("Not a blob (actually a %s): %s",
@@ -1161,7 +1222,7 @@ static void cmd_new_commit()
        free(committer);
        free(msg);
 
-       store_object(OBJ_COMMIT, body, sp - body, NULL, b->sha1);
+       store_object(OBJ_COMMIT, body, sp - body, NULL, b->sha1, next_mark);
        free(body);
        b->last_commit = object_count_by_type[OBJ_COMMIT];
 }
@@ -1205,6 +1266,13 @@ static void cmd_new_branch()
                else if (s) {
                        memcpy(b->sha1, s->sha1, 20);
                        memcpy(b->branch_tree.sha1, s->branch_tree.sha1, 20);
+               } else if (*from == ':') {
+                       unsigned long idnum = strtoul(from + 1, NULL, 10);
+                       struct object_entry *oe = find_mark(idnum);
+                       if (oe->type != OBJ_COMMIT)
+                               die("Mark :%lu not a commit", idnum);
+                       memcpy(b->sha1, oe->sha1, 20);
+                       memcpy(b->branch_tree.sha1, null_sha1, 20);
                } else if (!get_sha1(from, b->sha1)) {
                        if (!memcmp(b->sha1, null_sha1, 20))
                                memcpy(b->branch_tree.sha1, null_sha1, 20);
@@ -1285,6 +1353,7 @@ int main(int argc, const char **argv)
        atom_table = xcalloc(atom_table_sz, sizeof(struct atom_str*));
        branch_table = xcalloc(branch_table_sz, sizeof(struct branch*));
        avail_tree_table = xcalloc(avail_tree_table_sz, sizeof(struct avail_tree_content*));
+       marks = pool_calloc(1, sizeof(struct mark_set));
 
        for (;;) {
                read_next_command();
@@ -1314,7 +1383,8 @@ int main(int argc, const char **argv)
        fprintf(stderr, "      commits:   %10lu (%10lu duplicates)\n", object_count_by_type[OBJ_COMMIT], duplicate_count_by_type[OBJ_COMMIT]);
        fprintf(stderr, "      tags   :   %10lu (%10lu duplicates)\n", object_count_by_type[OBJ_TAG], duplicate_count_by_type[OBJ_TAG]);
        fprintf(stderr, "Total branches:  %10lu\n", branch_count);
-       fprintf(stderr, "Total atoms:     %10u\n", atom_cnt);
+       fprintf(stderr, "      atoms:     %10u\n", atom_cnt);
+       fprintf(stderr, "      marks:     %10u (%10lu unique    )\n", (1 << marks->shift) * 1024, marks_set_count);
        fprintf(stderr, "Memory total:    %10lu KiB\n", (total_allocd + alloc_count*sizeof(struct object_entry))/1024);
        fprintf(stderr, "       pools:    %10lu KiB\n", total_allocd/1024);
        fprintf(stderr, "     objects:    %10lu KiB\n", (alloc_count*sizeof(struct object_entry))/1024);