Merge branch 'jc/reflog-reverse-walk'
authorJunio C Hamano <gitster@pobox.com>
Tue, 26 Mar 2013 20:15:56 +0000 (13:15 -0700)
committerJunio C Hamano <gitster@pobox.com>
Tue, 26 Mar 2013 20:15:56 +0000 (13:15 -0700)
An internal function used to implement "git checkout @{-1}" was
hard to use correctly.

* jc/reflog-reverse-walk:
refs.c: fix fread error handling
reflog: add for_each_reflog_ent_reverse() API
for_each_recent_reflog_ent(): simplify opening of a reflog file
for_each_reflog_ent(): extract a helper to process a single entry

1  2 
refs.c
refs.h
sha1_name.c
diff --combined refs.c
index e2b760d0baffd6db6b49e6014a58efa062f1a119,aa79c93045f3582e6d901d475f70f696c50bcb11..de2d8eb866062649a0d0f23a77e350bca1a182cd
--- 1/refs.c
--- 2/refs.c
+++ b/refs.c
@@@ -3,7 -3,6 +3,7 @@@
  #include "object.h"
  #include "tag.h"
  #include "dir.h"
 +#include "string-list.h"
  
  /*
   * Make sure "ref" is something reasonable to have under ".git/refs/";
@@@ -334,12 -333,14 +334,12 @@@ struct string_slice 
  
  static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
  {
 -      struct string_slice *key = (struct string_slice *)key_;
 -      struct ref_entry *ent = *(struct ref_entry **)ent_;
 -      int entlen = strlen(ent->name);
 -      int cmplen = key->len < entlen ? key->len : entlen;
 -      int cmp = memcmp(key->str, ent->name, cmplen);
 +      const struct string_slice *key = key_;
 +      const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
 +      int cmp = strncmp(key->str, ent->name, key->len);
        if (cmp)
                return cmp;
 -      return key->len - entlen;
 +      return '\0' - (unsigned char)ent->name[key->len];
  }
  
  /*
@@@ -803,38 -804,11 +803,38 @@@ static const char *parse_ref_line(char 
        return line;
  }
  
 +/*
 + * Read f, which is a packed-refs file, into dir.
 + *
 + * A comment line of the form "# pack-refs with: " may contain zero or
 + * more traits. We interpret the traits as follows:
 + *
 + *   No traits:
 + *
 + *      Probably no references are peeled. But if the file contains a
 + *      peeled value for a reference, we will use it.
 + *
 + *   peeled:
 + *
 + *      References under "refs/tags/", if they *can* be peeled, *are*
 + *      peeled in this file. References outside of "refs/tags/" are
 + *      probably not peeled even if they could have been, but if we find
 + *      a peeled value for such a reference we will use it.
 + *
 + *   fully-peeled:
 + *
 + *      All references in the file that can be peeled are peeled.
 + *      Inversely (and this is more important), any references in the
 + *      file for which no peeled value is recorded is not peelable. This
 + *      trait should typically be written alongside "peeled" for
 + *      compatibility with older clients, but we do not require it
 + *      (i.e., "peeled" is a no-op if "fully-peeled" is set).
 + */
  static void read_packed_refs(FILE *f, struct ref_dir *dir)
  {
        struct ref_entry *last = NULL;
        char refline[PATH_MAX];
 -      int flag = REF_ISPACKED;
 +      enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
  
        while (fgets(refline, sizeof(refline), f)) {
                unsigned char sha1[20];
  
                if (!strncmp(refline, header, sizeof(header)-1)) {
                        const char *traits = refline + sizeof(header) - 1;
 -                      if (strstr(traits, " peeled "))
 -                              flag |= REF_KNOWS_PEELED;
 +                      if (strstr(traits, " fully-peeled "))
 +                              peeled = PEELED_FULLY;
 +                      else if (strstr(traits, " peeled "))
 +                              peeled = PEELED_TAGS;
                        /* perhaps other traits later as well */
                        continue;
                }
  
                refname = parse_ref_line(refline, sha1);
                if (refname) {
 -                      last = create_ref_entry(refname, sha1, flag, 1);
 +                      last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
 +                      if (peeled == PEELED_FULLY ||
 +                          (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
 +                              last->flag |= REF_KNOWS_PEELED;
                        add_ref(dir, last);
                        continue;
                }
                    refline[0] == '^' &&
                    strlen(refline) == 42 &&
                    refline[41] == '\n' &&
 -                  !get_sha1_hex(refline + 1, sha1))
 +                  !get_sha1_hex(refline + 1, sha1)) {
                        hashcpy(last->u.value.peeled, sha1);
 +                      /*
 +                       * Regardless of what the file header said,
 +                       * we definitely know the value of *this*
 +                       * reference:
 +                       */
 +                      last->flag |= REF_KNOWS_PEELED;
 +              }
        }
  }
  
@@@ -1240,8 -1202,6 +1240,8 @@@ int peel_ref(const char *refname, unsig
        if (current_ref && (current_ref->name == refname
                || !strcmp(current_ref->name, refname))) {
                if (current_ref->flag & REF_KNOWS_PEELED) {
 +                      if (is_null_sha1(current_ref->u.value.peeled))
 +                          return -1;
                        hashcpy(sha1, current_ref->u.value.peeled);
                        return 0;
                }
        }
  
  fallback:
 -      o = parse_object(base);
 -      if (o && o->type == OBJ_TAG) {
 -              o = deref_tag(o, refname, 0);
 +      o = lookup_unknown_object(base);
 +      if (o->type == OBJ_NONE) {
 +              int type = sha1_object_info(base, NULL);
 +              if (type < 0)
 +                      return -1;
 +              o->type = type;
 +      }
 +
 +      if (o->type == OBJ_TAG) {
 +              o = deref_tag_noverify(o);
                if (o) {
                        hashcpy(sha1, o->sha1);
                        return 0;
@@@ -1782,8 -1735,7 +1782,8 @@@ static struct lock_file packlock
  static int repack_without_ref(const char *refname)
  {
        struct repack_without_ref_sb data;
 -      struct ref_dir *packed = get_packed_refs(get_ref_cache(NULL));
 +      struct ref_cache *refs = get_ref_cache(NULL);
 +      struct ref_dir *packed = get_packed_refs(refs);
        if (find_ref(packed, refname) == NULL)
                return 0;
        data.refname = refname;
                unable_to_lock_error(git_path("packed-refs"), errno);
                return error("cannot delete '%s' from packed refs", refname);
        }
 +      clear_packed_ref_cache(refs);
 +      packed = get_packed_refs(refs);
        do_for_each_ref_in_dir(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
        return commit_lock_file(&packlock);
  }
@@@ -1803,24 -1753,32 +1803,24 @@@ int delete_ref(const char *refname, con
        struct ref_lock *lock;
        int err, i = 0, ret = 0, flag = 0;
  
 -      lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
 +      lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
        if (!lock)
                return 1;
        if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
                /* loose */
 -              const char *path;
 -
 -              if (!(delopt & REF_NODEREF)) {
 -                      i = strlen(lock->lk->filename) - 5; /* .lock */
 -                      lock->lk->filename[i] = 0;
 -                      path = lock->lk->filename;
 -              } else {
 -                      path = git_path("%s", refname);
 -              }
 -              err = unlink_or_warn(path);
 +              i = strlen(lock->lk->filename) - 5; /* .lock */
 +              lock->lk->filename[i] = 0;
 +              err = unlink_or_warn(lock->lk->filename);
                if (err && errno != ENOENT)
                        ret = 1;
  
 -              if (!(delopt & REF_NODEREF))
 -                      lock->lk->filename[i] = '.';
 +              lock->lk->filename[i] = '.';
        }
        /* removing the loose one could have resurrected an earlier
         * packed one.  Also, if it was not loose we need to repack
         * without it.
         */
 -      ret |= repack_without_ref(refname);
 +      ret |= repack_without_ref(lock->ref_name);
  
        unlink_or_warn(git_path("logs/%s", lock->ref_name));
        invalidate_ref_cache(NULL);
@@@ -2332,59 -2290,117 +2332,117 @@@ int read_ref_at(const char *refname, un
        return 1;
  }
  
- int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
+ static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
+ {
+       unsigned char osha1[20], nsha1[20];
+       char *email_end, *message;
+       unsigned long timestamp;
+       int tz;
+       /* old SP new SP name <email> SP time TAB msg LF */
+       if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
+           get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
+           get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
+           !(email_end = strchr(sb->buf + 82, '>')) ||
+           email_end[1] != ' ' ||
+           !(timestamp = strtoul(email_end + 2, &message, 10)) ||
+           !message || message[0] != ' ' ||
+           (message[1] != '+' && message[1] != '-') ||
+           !isdigit(message[2]) || !isdigit(message[3]) ||
+           !isdigit(message[4]) || !isdigit(message[5]))
+               return 0; /* corrupt? */
+       email_end[1] = '\0';
+       tz = strtol(message + 1, NULL, 10);
+       if (message[6] != '\t')
+               message += 6;
+       else
+               message += 7;
+       return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
+ }
+ static char *find_beginning_of_line(char *bob, char *scan)
+ {
+       while (bob < scan && *(--scan) != '\n')
+               ; /* keep scanning backwards */
+       /*
+        * Return either beginning of the buffer, or LF at the end of
+        * the previous line.
+        */
+       return scan;
+ }
+ int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
  {
-       const char *logfile;
-       FILE *logfp;
        struct strbuf sb = STRBUF_INIT;
-       int ret = 0;
+       FILE *logfp;
+       long pos;
+       int ret = 0, at_tail = 1;
  
-       logfile = git_path("logs/%s", refname);
-       logfp = fopen(logfile, "r");
+       logfp = fopen(git_path("logs/%s", refname), "r");
        if (!logfp)
                return -1;
  
-       if (ofs) {
-               struct stat statbuf;
-               if (fstat(fileno(logfp), &statbuf) ||
-                   statbuf.st_size < ofs ||
-                   fseek(logfp, -ofs, SEEK_END) ||
-                   strbuf_getwholeline(&sb, logfp, '\n')) {
-                       fclose(logfp);
-                       strbuf_release(&sb);
-                       return -1;
+       /* Jump to the end */
+       if (fseek(logfp, 0, SEEK_END) < 0)
+               return error("cannot seek back reflog for %s: %s",
+                            refname, strerror(errno));
+       pos = ftell(logfp);
+       while (!ret && 0 < pos) {
+               int cnt;
+               size_t nread;
+               char buf[BUFSIZ];
+               char *endp, *scanp;
+               /* Fill next block from the end */
+               cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
+               if (fseek(logfp, pos - cnt, SEEK_SET))
+                       return error("cannot seek back reflog for %s: %s",
+                                    refname, strerror(errno));
+               nread = fread(buf, cnt, 1, logfp);
+               if (nread != 1)
+                       return error("cannot read %d bytes from reflog for %s: %s",
+                                    cnt, refname, strerror(errno));
+               pos -= cnt;
+               scanp = endp = buf + cnt;
+               if (at_tail && scanp[-1] == '\n')
+                       /* Looking at the final LF at the end of the file */
+                       scanp--;
+               at_tail = 0;
+               while (buf < scanp) {
+                       /*
+                        * terminating LF of the previous line, or the beginning
+                        * of the buffer.
+                        */
+                       char *bp;
+                       bp = find_beginning_of_line(buf, scanp);
+                       if (*bp != '\n') {
+                               strbuf_splice(&sb, 0, 0, buf, endp - buf);
+                               if (pos)
+                                       break; /* need to fill another block */
+                               scanp = buf - 1; /* leave loop */
+                       } else {
+                               /*
+                                * (bp + 1) thru endp is the beginning of the
+                                * current line we have in sb
+                                */
+                               strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
+                               scanp = bp;
+                               endp = bp + 1;
+                       }
+                       ret = show_one_reflog_ent(&sb, fn, cb_data);
+                       strbuf_reset(&sb);
+                       if (ret)
+                               break;
                }
-       }
  
-       while (!strbuf_getwholeline(&sb, logfp, '\n')) {
-               unsigned char osha1[20], nsha1[20];
-               char *email_end, *message;
-               unsigned long timestamp;
-               int tz;
-               /* old SP new SP name <email> SP time TAB msg LF */
-               if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
-                   get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
-                   get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
-                   !(email_end = strchr(sb.buf + 82, '>')) ||
-                   email_end[1] != ' ' ||
-                   !(timestamp = strtoul(email_end + 2, &message, 10)) ||
-                   !message || message[0] != ' ' ||
-                   (message[1] != '+' && message[1] != '-') ||
-                   !isdigit(message[2]) || !isdigit(message[3]) ||
-                   !isdigit(message[4]) || !isdigit(message[5]))
-                       continue; /* corrupt? */
-               email_end[1] = '\0';
-               tz = strtol(message + 1, NULL, 10);
-               if (message[6] != '\t')
-                       message += 6;
-               else
-                       message += 7;
-               ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
-                        cb_data);
-               if (ret)
-                       break;
        }
+       if (!ret && sb.len)
+               ret = show_one_reflog_ent(&sb, fn, cb_data);
        fclose(logfp);
        strbuf_release(&sb);
        return ret;
  
  int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
  {
-       return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
- }
+       FILE *logfp;
+       struct strbuf sb = STRBUF_INIT;
+       int ret = 0;
+       logfp = fopen(git_path("logs/%s", refname), "r");
+       if (!logfp)
+               return -1;
  
+       while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
+               ret = show_one_reflog_ent(&sb, fn, cb_data);
+       fclose(logfp);
+       strbuf_release(&sb);
+       return ret;
+ }
  /*
   * Call fn for each reflog in the namespace indicated by name.  name
   * must be empty or end with '/'.  Name will be used as a scratch
@@@ -2594,46 -2621,3 +2663,46 @@@ char *shorten_unambiguous_ref(const cha
        free(short_name);
        return xstrdup(refname);
  }
 +
 +static struct string_list *hide_refs;
 +
 +int parse_hide_refs_config(const char *var, const char *value, const char *section)
 +{
 +      if (!strcmp("transfer.hiderefs", var) ||
 +          /* NEEDSWORK: use parse_config_key() once both are merged */
 +          (!prefixcmp(var, section) && var[strlen(section)] == '.' &&
 +           !strcmp(var + strlen(section), ".hiderefs"))) {
 +              char *ref;
 +              int len;
 +
 +              if (!value)
 +                      return config_error_nonbool(var);
 +              ref = xstrdup(value);
 +              len = strlen(ref);
 +              while (len && ref[len - 1] == '/')
 +                      ref[--len] = '\0';
 +              if (!hide_refs) {
 +                      hide_refs = xcalloc(1, sizeof(*hide_refs));
 +                      hide_refs->strdup_strings = 1;
 +              }
 +              string_list_append(hide_refs, ref);
 +      }
 +      return 0;
 +}
 +
 +int ref_is_hidden(const char *refname)
 +{
 +      struct string_list_item *item;
 +
 +      if (!hide_refs)
 +              return 0;
 +      for_each_string_list_item(item, hide_refs) {
 +              int len;
 +              if (prefixcmp(refname, item->string))
 +                      continue;
 +              len = strlen(item->string);
 +              if (!refname[len] || refname[len] == '/')
 +                      return 1;
 +      }
 +      return 0;
 +}
diff --combined refs.h
index 1b2e2d3a98dea86bbe54dd21782ce58681636c32,a62b9dbd59e4efe0fc2d9ff9cbe3567d531221c4..a35eafc4ee15493c1473d71b5c2e83a1f9137c1a
--- 1/refs.h
--- 2/refs.h
+++ b/refs.h
@@@ -103,7 -103,7 +103,7 @@@ extern int read_ref_at(const char *refn
  /* iterate over reflog entries */
  typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
  int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
- int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long, void *cb_data);
+ int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
  
  /*
   * Calls the specified function for each reflog file until it returns nonzero,
@@@ -147,7 -147,4 +147,7 @@@ int update_ref(const char *action, cons
                const unsigned char *sha1, const unsigned char *oldval,
                int flags, enum action_on_err onerr);
  
 +extern int parse_hide_refs_config(const char *var, const char *value, const char *);
 +extern int ref_is_hidden(const char *);
 +
  #endif /* REFS_H */
diff --combined sha1_name.c
index c50630a3ea793e0cfd2510b8813129a1685428f4,635cd131a65f894d5e81acfb729f85ba487d9867..2fbda48e02f167d08aa19210951712b85f40b602
@@@ -856,8 -856,8 +856,8 @@@ static int get_sha1_oneline(const char 
  }
  
  struct grab_nth_branch_switch_cbdata {
-       long cnt, alloc;
-       struct strbuf *buf;
+       int remaining;
+       struct strbuf buf;
  };
  
  static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
        struct grab_nth_branch_switch_cbdata *cb = cb_data;
        const char *match = NULL, *target = NULL;
        size_t len;
-       int nth;
  
        if (!prefixcmp(message, "checkout: moving from ")) {
                match = message + strlen("checkout: moving from ");
  
        if (!match || !target)
                return 0;
-       len = target - match;
-       nth = cb->cnt++ % cb->alloc;
-       strbuf_reset(&cb->buf[nth]);
-       strbuf_add(&cb->buf[nth], match, len);
+       if (--(cb->remaining) == 0) {
+               len = target - match;
+               strbuf_reset(&cb->buf);
+               strbuf_add(&cb->buf, match, len);
+               return 1; /* we are done */
+       }
        return 0;
  }
  
  static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf)
  {
        long nth;
-       int i, retval;
+       int retval;
        struct grab_nth_branch_switch_cbdata cb;
        const char *brace;
        char *num_end;
        brace = strchr(name, '}');
        if (!brace)
                return -1;
-       nth = strtol(name+3, &num_end, 10);
+       nth = strtol(name + 3, &num_end, 10);
        if (num_end != brace)
                return -1;
        if (nth <= 0)
                return -1;
-       cb.alloc = nth;
-       cb.buf = xmalloc(nth * sizeof(struct strbuf));
-       for (i = 0; i < nth; i++)
-               strbuf_init(&cb.buf[i], 20);
-       cb.cnt = 0;
+       cb.remaining = nth;
+       strbuf_init(&cb.buf, 20);
        retval = 0;
-       for_each_recent_reflog_ent("HEAD", grab_nth_branch_switch, 40960, &cb);
-       if (cb.cnt < nth) {
-               cb.cnt = 0;
-               for_each_reflog_ent("HEAD", grab_nth_branch_switch, &cb);
-       }
-       if (cb.cnt < nth)
-               goto release_return;
-       i = cb.cnt % nth;
-       strbuf_reset(buf);
-       strbuf_add(buf, cb.buf[i].buf, cb.buf[i].len);
-       retval = brace-name+1;
- release_return:
-       for (i = 0; i < nth; i++)
-               strbuf_release(&cb.buf[i]);
-       free(cb.buf);
+       if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
+               strbuf_reset(buf);
+               strbuf_add(buf, cb.buf.buf, cb.buf.len);
+               retval = brace - name + 1;
+       }
  
+       strbuf_release(&cb.buf);
        return retval;
  }
  
@@@ -1137,8 -1125,7 +1125,8 @@@ int get_sha1_blob(const char *name, uns
  static void diagnose_invalid_sha1_path(const char *prefix,
                                       const char *filename,
                                       const unsigned char *tree_sha1,
 -                                     const char *object_name)
 +                                     const char *object_name,
 +                                     int object_name_len)
  {
        struct stat st;
        unsigned char sha1[20];
                prefix = "";
  
        if (!lstat(filename, &st))
 -              die("Path '%s' exists on disk, but not in '%s'.",
 -                  filename, object_name);
 +              die("Path '%s' exists on disk, but not in '%.*s'.",
 +                  filename, object_name_len, object_name);
        if (errno == ENOENT || errno == ENOTDIR) {
                char *fullname = xmalloc(strlen(filename)
                                             + strlen(prefix) + 1);
                if (!get_tree_entry(tree_sha1, fullname,
                                    sha1, &mode)) {
                        die("Path '%s' exists, but not '%s'.\n"
 -                          "Did you mean '%s:%s' aka '%s:./%s'?",
 +                          "Did you mean '%.*s:%s' aka '%.*s:./%s'?",
                            fullname,
                            filename,
 -                          object_name,
 +                          object_name_len, object_name,
                            fullname,
 -                          object_name,
 +                          object_name_len, object_name,
                            filename);
                }
 -              die("Path '%s' does not exist in '%s'",
 -                  filename, object_name);
 +              die("Path '%s' does not exist in '%.*s'",
 +                  filename, object_name_len, object_name);
        }
  }
  
@@@ -1333,8 -1320,13 +1321,8 @@@ static int get_sha1_with_context_1(cons
        }
        if (*cp == ':') {
                unsigned char tree_sha1[20];
 -              char *object_name = NULL;
 -              if (only_to_die) {
 -                      object_name = xmalloc(cp-name+1);
 -                      strncpy(object_name, name, cp-name);
 -                      object_name[cp-name] = '\0';
 -              }
 -              if (!get_sha1_1(name, cp-name, tree_sha1, GET_SHA1_TREEISH)) {
 +              int len = cp - name;
 +              if (!get_sha1_1(name, len, tree_sha1, GET_SHA1_TREEISH)) {
                        const char *filename = cp+1;
                        char *new_filename = NULL;
  
                        ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
                        if (ret && only_to_die) {
                                diagnose_invalid_sha1_path(prefix, filename,
 -                                                         tree_sha1, object_name);
 -                              free(object_name);
 +                                                         tree_sha1,
 +                                                         name, len);
                        }
                        hashcpy(oc->tree, tree_sha1);
                        strncpy(oc->path, filename,
                        return ret;
                } else {
                        if (only_to_die)
 -                              die("Invalid object name '%s'.", object_name);
 +                              die("Invalid object name '%.*s'.", len, name);
                }
        }
        return ret;