reflog-walk.con commit blame: improve diagnosis for "--reverse NEW" (d993ce1)
   1#include "cache.h"
   2#include "commit.h"
   3#include "refs.h"
   4#include "diff.h"
   5#include "revision.h"
   6#include "string-list.h"
   7#include "reflog-walk.h"
   8
   9struct complete_reflogs {
  10        char *ref;
  11        const char *short_ref;
  12        struct reflog_info {
  13                unsigned char osha1[20], nsha1[20];
  14                char *email;
  15                unsigned long timestamp;
  16                int tz;
  17                char *message;
  18        } *items;
  19        int nr, alloc;
  20};
  21
  22static int read_one_reflog(unsigned char *osha1, unsigned char *nsha1,
  23                const char *email, unsigned long timestamp, int tz,
  24                const char *message, void *cb_data)
  25{
  26        struct complete_reflogs *array = cb_data;
  27        struct reflog_info *item;
  28
  29        ALLOC_GROW(array->items, array->nr + 1, array->alloc);
  30        item = array->items + array->nr;
  31        hashcpy(item->osha1, osha1);
  32        hashcpy(item->nsha1, nsha1);
  33        item->email = xstrdup(email);
  34        item->timestamp = timestamp;
  35        item->tz = tz;
  36        item->message = xstrdup(message);
  37        array->nr++;
  38        return 0;
  39}
  40
  41static struct complete_reflogs *read_complete_reflog(const char *ref)
  42{
  43        struct complete_reflogs *reflogs =
  44                xcalloc(1, sizeof(struct complete_reflogs));
  45        reflogs->ref = xstrdup(ref);
  46        for_each_reflog_ent(ref, read_one_reflog, reflogs);
  47        if (reflogs->nr == 0) {
  48                unsigned char sha1[20];
  49                const char *name;
  50                void *name_to_free;
  51                name = name_to_free = resolve_refdup(ref, RESOLVE_REF_READING,
  52                                                     sha1, NULL);
  53                if (name) {
  54                        for_each_reflog_ent(name, read_one_reflog, reflogs);
  55                        free(name_to_free);
  56                }
  57        }
  58        if (reflogs->nr == 0) {
  59                char *refname = xstrfmt("refs/%s", ref);
  60                for_each_reflog_ent(refname, read_one_reflog, reflogs);
  61                if (reflogs->nr == 0) {
  62                        free(refname);
  63                        refname = xstrfmt("refs/heads/%s", ref);
  64                        for_each_reflog_ent(refname, read_one_reflog, reflogs);
  65                }
  66                free(refname);
  67        }
  68        return reflogs;
  69}
  70
  71static int get_reflog_recno_by_time(struct complete_reflogs *array,
  72        unsigned long timestamp)
  73{
  74        int i;
  75        for (i = array->nr - 1; i >= 0; i--)
  76                if (timestamp >= array->items[i].timestamp)
  77                        return i;
  78        return -1;
  79}
  80
  81struct commit_info_lifo {
  82        struct commit_info {
  83                struct commit *commit;
  84                void *util;
  85        } *items;
  86        int nr, alloc;
  87};
  88
  89static struct commit_info *get_commit_info(struct commit *commit,
  90                struct commit_info_lifo *lifo, int pop)
  91{
  92        int i;
  93        for (i = 0; i < lifo->nr; i++)
  94                if (lifo->items[i].commit == commit) {
  95                        struct commit_info *result = &lifo->items[i];
  96                        if (pop) {
  97                                if (i + 1 < lifo->nr)
  98                                        memmove(lifo->items + i,
  99                                                lifo->items + i + 1,
 100                                                (lifo->nr - i) *
 101                                                sizeof(struct commit_info));
 102                                lifo->nr--;
 103                        }
 104                        return result;
 105                }
 106        return NULL;
 107}
 108
 109static void add_commit_info(struct commit *commit, void *util,
 110                struct commit_info_lifo *lifo)
 111{
 112        struct commit_info *info;
 113        ALLOC_GROW(lifo->items, lifo->nr + 1, lifo->alloc);
 114        info = lifo->items + lifo->nr;
 115        info->commit = commit;
 116        info->util = util;
 117        lifo->nr++;
 118}
 119
 120struct commit_reflog {
 121        int recno;
 122        enum selector_type {
 123                SELECTOR_NONE,
 124                SELECTOR_INDEX,
 125                SELECTOR_DATE
 126        } selector;
 127        struct complete_reflogs *reflogs;
 128};
 129
 130struct reflog_walk_info {
 131        struct commit_info_lifo reflogs;
 132        struct string_list complete_reflogs;
 133        struct commit_reflog *last_commit_reflog;
 134};
 135
 136void init_reflog_walk(struct reflog_walk_info **info)
 137{
 138        *info = xcalloc(1, sizeof(struct reflog_walk_info));
 139}
 140
 141int add_reflog_for_walk(struct reflog_walk_info *info,
 142                struct commit *commit, const char *name)
 143{
 144        unsigned long timestamp = 0;
 145        int recno = -1;
 146        struct string_list_item *item;
 147        struct complete_reflogs *reflogs;
 148        char *branch, *at = strchr(name, '@');
 149        struct commit_reflog *commit_reflog;
 150        enum selector_type selector = SELECTOR_NONE;
 151
 152        if (commit->object.flags & UNINTERESTING)
 153                die ("Cannot walk reflogs for %s", name);
 154
 155        branch = xstrdup(name);
 156        if (at && at[1] == '{') {
 157                char *ep;
 158                branch[at - name] = '\0';
 159                recno = strtoul(at + 2, &ep, 10);
 160                if (*ep != '}') {
 161                        recno = -1;
 162                        timestamp = approxidate(at + 2);
 163                        selector = SELECTOR_DATE;
 164                }
 165                else
 166                        selector = SELECTOR_INDEX;
 167        } else
 168                recno = 0;
 169
 170        item = string_list_lookup(&info->complete_reflogs, branch);
 171        if (item)
 172                reflogs = item->util;
 173        else {
 174                if (*branch == '\0') {
 175                        unsigned char sha1[20];
 176                        free(branch);
 177                        branch = resolve_refdup("HEAD", 0, sha1, NULL);
 178                        if (!branch)
 179                                die ("No current branch");
 180
 181                }
 182                reflogs = read_complete_reflog(branch);
 183                if (!reflogs || reflogs->nr == 0) {
 184                        unsigned char sha1[20];
 185                        char *b;
 186                        if (dwim_log(branch, strlen(branch), sha1, &b) == 1) {
 187                                if (reflogs) {
 188                                        free(reflogs->ref);
 189                                        free(reflogs);
 190                                }
 191                                free(branch);
 192                                branch = b;
 193                                reflogs = read_complete_reflog(branch);
 194                        }
 195                }
 196                if (!reflogs || reflogs->nr == 0)
 197                        return -1;
 198                string_list_insert(&info->complete_reflogs, branch)->util
 199                        = reflogs;
 200        }
 201
 202        commit_reflog = xcalloc(1, sizeof(struct commit_reflog));
 203        if (recno < 0) {
 204                commit_reflog->recno = get_reflog_recno_by_time(reflogs, timestamp);
 205                if (commit_reflog->recno < 0) {
 206                        free(branch);
 207                        free(commit_reflog);
 208                        return -1;
 209                }
 210        } else
 211                commit_reflog->recno = reflogs->nr - recno - 1;
 212        commit_reflog->selector = selector;
 213        commit_reflog->reflogs = reflogs;
 214
 215        add_commit_info(commit, commit_reflog, &info->reflogs);
 216        return 0;
 217}
 218
 219void fake_reflog_parent(struct reflog_walk_info *info, struct commit *commit)
 220{
 221        struct commit_info *commit_info =
 222                get_commit_info(commit, &info->reflogs, 0);
 223        struct commit_reflog *commit_reflog;
 224        struct object *logobj;
 225        struct reflog_info *reflog;
 226
 227        info->last_commit_reflog = NULL;
 228        if (!commit_info)
 229                return;
 230
 231        commit_reflog = commit_info->util;
 232        if (commit_reflog->recno < 0) {
 233                commit->parents = NULL;
 234                return;
 235        }
 236        info->last_commit_reflog = commit_reflog;
 237
 238        do {
 239                reflog = &commit_reflog->reflogs->items[commit_reflog->recno];
 240                commit_reflog->recno--;
 241                logobj = parse_object(reflog->osha1);
 242        } while (commit_reflog->recno && (logobj && logobj->type != OBJ_COMMIT));
 243
 244        if (!logobj || logobj->type != OBJ_COMMIT) {
 245                commit_info->commit = NULL;
 246                commit->parents = NULL;
 247                return;
 248        }
 249        commit_info->commit = (struct commit *)logobj;
 250
 251        commit->parents = xcalloc(1, sizeof(struct commit_list));
 252        commit->parents->item = commit_info->commit;
 253}
 254
 255void get_reflog_selector(struct strbuf *sb,
 256                         struct reflog_walk_info *reflog_info,
 257                         const struct date_mode *dmode, int force_date,
 258                         int shorten)
 259{
 260        struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
 261        struct reflog_info *info;
 262        const char *printed_ref;
 263
 264        if (!commit_reflog)
 265                return;
 266
 267        if (shorten) {
 268                if (!commit_reflog->reflogs->short_ref)
 269                        commit_reflog->reflogs->short_ref
 270                                = shorten_unambiguous_ref(commit_reflog->reflogs->ref, 0);
 271                printed_ref = commit_reflog->reflogs->short_ref;
 272        } else {
 273                printed_ref = commit_reflog->reflogs->ref;
 274        }
 275
 276        strbuf_addf(sb, "%s@{", printed_ref);
 277        if (commit_reflog->selector == SELECTOR_DATE ||
 278            (commit_reflog->selector == SELECTOR_NONE && force_date)) {
 279                info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
 280                strbuf_addstr(sb, show_date(info->timestamp, info->tz, dmode));
 281        } else {
 282                strbuf_addf(sb, "%d", commit_reflog->reflogs->nr
 283                            - 2 - commit_reflog->recno);
 284        }
 285
 286        strbuf_addch(sb, '}');
 287}
 288
 289void get_reflog_message(struct strbuf *sb,
 290                        struct reflog_walk_info *reflog_info)
 291{
 292        struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
 293        struct reflog_info *info;
 294        size_t len;
 295
 296        if (!commit_reflog)
 297                return;
 298
 299        info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
 300        len = strlen(info->message);
 301        if (len > 0)
 302                len--; /* strip away trailing newline */
 303        strbuf_add(sb, info->message, len);
 304}
 305
 306const char *get_reflog_ident(struct reflog_walk_info *reflog_info)
 307{
 308        struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
 309        struct reflog_info *info;
 310
 311        if (!commit_reflog)
 312                return NULL;
 313
 314        info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
 315        return info->email;
 316}
 317
 318void show_reflog_message(struct reflog_walk_info *reflog_info, int oneline,
 319                         const struct date_mode *dmode, int force_date)
 320{
 321        if (reflog_info && reflog_info->last_commit_reflog) {
 322                struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
 323                struct reflog_info *info;
 324                struct strbuf selector = STRBUF_INIT;
 325
 326                info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
 327                get_reflog_selector(&selector, reflog_info, dmode, force_date, 0);
 328                if (oneline) {
 329                        printf("%s: %s", selector.buf, info->message);
 330                }
 331                else {
 332                        printf("Reflog: %s (%s)\nReflog message: %s",
 333                               selector.buf, info->email, info->message);
 334                }
 335
 336                strbuf_release(&selector);
 337        }
 338}