am: release strbuf on error return in hg_patch_to_mail()
[gitweb.git] / read-cache.c
index e44775182392c5672fd6ec84eb954db339e5a1ea..40da87ea71f088114c5a40893850cc88efee6953 100644 (file)
@@ -5,6 +5,7 @@
  */
 #define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
+#include "config.h"
 #include "tempfile.h"
 #include "lockfile.h"
 #include "cache-tree.h"
@@ -159,9 +160,9 @@ static int ce_compare_data(const struct cache_entry *ce, struct stat *st)
        int fd = git_open_cloexec(ce->name, O_RDONLY);
 
        if (fd >= 0) {
-               unsigned char sha1[20];
-               if (!index_fd(sha1, fd, st, OBJ_BLOB, ce->name, 0))
-                       match = hashcmp(sha1, ce->oid.hash);
+               struct object_id oid;
+               if (!index_fd(&oid, fd, st, OBJ_BLOB, ce->name, 0))
+                       match = oidcmp(&oid, &ce->oid);
                /* index_fd() closed the file descriptor already */
        }
        return match;
@@ -514,9 +515,8 @@ int remove_index_entry_at(struct index_state *istate, int pos)
        istate->cache_nr--;
        if (pos >= istate->cache_nr)
                return 0;
-       memmove(istate->cache + pos,
-               istate->cache + pos + 1,
-               (istate->cache_nr - pos) * sizeof(struct cache_entry *));
+       MOVE_ARRAY(istate->cache + pos, istate->cache + pos + 1,
+                  istate->cache_nr - pos);
        return 1;
 }
 
@@ -689,7 +689,7 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st,
                return 0;
        }
        if (!intent_only) {
-               if (index_path(ce->oid.hash, path, st, HASH_WRITE_OBJECT)) {
+               if (index_path(&ce->oid, path, st, HASH_WRITE_OBJECT)) {
                        free(ce);
                        return error("unable to index file %s", path);
                }
@@ -887,9 +887,32 @@ static int has_file_name(struct index_state *istate,
        return retval;
 }
 
+
+/*
+ * Like strcmp(), but also return the offset of the first change.
+ * If strings are equal, return the length.
+ */
+int strcmp_offset(const char *s1, const char *s2, size_t *first_change)
+{
+       size_t k;
+
+       if (!first_change)
+               return strcmp(s1, s2);
+
+       for (k = 0; s1[k] == s2[k]; k++)
+               if (s1[k] == '\0')
+                       break;
+
+       *first_change = k;
+       return (unsigned char)s1[k] - (unsigned char)s2[k];
+}
+
 /*
  * Do we have another file with a pathname that is a proper
  * subset of the name we're trying to add?
+ *
+ * That is, is there another file in the index with a path
+ * that matches a sub-directory in the given entry?
  */
 static int has_dir_name(struct index_state *istate,
                        const struct cache_entry *ce, int pos, int ok_to_replace)
@@ -898,9 +921,51 @@ static int has_dir_name(struct index_state *istate,
        int stage = ce_stage(ce);
        const char *name = ce->name;
        const char *slash = name + ce_namelen(ce);
+       size_t len_eq_last;
+       int cmp_last = 0;
+
+       /*
+        * We are frequently called during an iteration on a sorted
+        * list of pathnames and while building a new index.  Therefore,
+        * there is a high probability that this entry will eventually
+        * be appended to the index, rather than inserted in the middle.
+        * If we can confirm that, we can avoid binary searches on the
+        * components of the pathname.
+        *
+        * Compare the entry's full path with the last path in the index.
+        */
+       if (istate->cache_nr > 0) {
+               cmp_last = strcmp_offset(name,
+                       istate->cache[istate->cache_nr - 1]->name,
+                       &len_eq_last);
+               if (cmp_last > 0) {
+                       if (len_eq_last == 0) {
+                               /*
+                                * The entry sorts AFTER the last one in the
+                                * index and their paths have no common prefix,
+                                * so there cannot be a F/D conflict.
+                                */
+                               return retval;
+                       } else {
+                               /*
+                                * The entry sorts AFTER the last one in the
+                                * index, but has a common prefix.  Fall through
+                                * to the loop below to disect the entry's path
+                                * and see where the difference is.
+                                */
+                       }
+               } else if (cmp_last == 0) {
+                       /*
+                        * The entry exactly matches the last one in the
+                        * index, but because of multiple stage and CE_REMOVE
+                        * items, we fall through and let the regular search
+                        * code handle it.
+                        */
+               }
+       }
 
        for (;;) {
-               int len;
+               size_t len;
 
                for (;;) {
                        if (*--slash == '/')
@@ -910,6 +975,67 @@ static int has_dir_name(struct index_state *istate,
                }
                len = slash - name;
 
+               if (cmp_last > 0) {
+                       /*
+                        * (len + 1) is a directory boundary (including
+                        * the trailing slash).  And since the loop is
+                        * decrementing "slash", the first iteration is
+                        * the longest directory prefix; subsequent
+                        * iterations consider parent directories.
+                        */
+
+                       if (len + 1 <= len_eq_last) {
+                               /*
+                                * The directory prefix (including the trailing
+                                * slash) also appears as a prefix in the last
+                                * entry, so the remainder cannot collide (because
+                                * strcmp said the whole path was greater).
+                                *
+                                * EQ: last: xxx/A
+                                *     this: xxx/B
+                                *
+                                * LT: last: xxx/file_A
+                                *     this: xxx/file_B
+                                */
+                               return retval;
+                       }
+
+                       if (len > len_eq_last) {
+                               /*
+                                * This part of the directory prefix (excluding
+                                * the trailing slash) is longer than the known
+                                * equal portions, so this sub-directory cannot
+                                * collide with a file.
+                                *
+                                * GT: last: xxxA
+                                *     this: xxxB/file
+                                */
+                               return retval;
+                       }
+
+                       if (istate->cache_nr > 0 &&
+                               ce_namelen(istate->cache[istate->cache_nr - 1]) > len) {
+                               /*
+                                * The directory prefix lines up with part of
+                                * a longer file or directory name, but sorts
+                                * after it, so this sub-directory cannot
+                                * collide with a file.
+                                *
+                                * last: xxx/yy-file (because '-' sorts before '/')
+                                * this: xxx/yy/abc
+                                */
+                               return retval;
+                       }
+
+                       /*
+                        * This is a possible collision. Fall through and
+                        * let the regular search code handle it.
+                        *
+                        * last: xxx
+                        * this: xxx/file
+                        */
+               }
+
                pos = index_name_stage_pos(istate, name, len, stage);
                if (pos >= 0) {
                        /*
@@ -1001,7 +1127,16 @@ static int add_index_entry_with_check(struct index_state *istate, struct cache_e
 
        if (!(option & ADD_CACHE_KEEP_CACHE_TREE))
                cache_tree_invalidate_path(istate, ce->name);
-       pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
+
+       /*
+        * If this entry's path sorts after the last entry in the index,
+        * we can avoid searching for it.
+        */
+       if (istate->cache_nr > 0 &&
+               strcmp(ce->name, istate->cache[istate->cache_nr - 1]->name) > 0)
+               pos = -istate->cache_nr - 1;
+       else
+               pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
 
        /* existing match? Just replace it. */
        if (pos >= 0) {
@@ -1364,6 +1499,7 @@ struct ondisk_cache_entry_extended {
 };
 
 /* These are only used for v3 or lower */
+#define align_padding_size(size, len) ((size + (len) + 8) & ~7) - (size + len)
 #define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7)
 #define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len)
 #define ondisk_cache_entry_extended_size(len) align_flex_name(ondisk_cache_entry_extended,len)
@@ -1371,6 +1507,9 @@ struct ondisk_cache_entry_extended {
                            ondisk_cache_entry_extended_size(ce_namelen(ce)) : \
                            ondisk_cache_entry_size(ce_namelen(ce)))
 
+/* Allow fsck to force verification of the index checksum. */
+int verify_index_checksum;
+
 static int verify_hdr(struct cache_header *hdr, unsigned long size)
 {
        git_SHA_CTX c;
@@ -1382,6 +1521,10 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
        hdr_version = ntohl(hdr->hdr_version);
        if (hdr_version < INDEX_FORMAT_LB || INDEX_FORMAT_UB < hdr_version)
                return error("bad index version %d", hdr_version);
+
+       if (!verify_index_checksum)
+               return 0;
+
        git_SHA1_Init(&c);
        git_SHA1_Update(&c, hdr, size - 20);
        git_SHA1_Final(sha1, &c);
@@ -1682,9 +1825,10 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
  */
 static void freshen_shared_index(char *base_sha1_hex, int warn)
 {
-       const char *shared_index = git_path("sharedindex.%s", base_sha1_hex);
+       char *shared_index = git_pathdup("sharedindex.%s", base_sha1_hex);
        if (!check_and_freshen_file(shared_index, 1) && warn)
                warning("could not freshen shared index '%s'", shared_index);
+       free(shared_index);
 }
 
 int read_index_from(struct index_state *istate, const char *path)
@@ -1751,8 +1895,7 @@ int discard_index(struct index_state *istate)
        free_name_hash(istate);
        cache_tree_free(&(istate->cache_tree));
        istate->initialized = 0;
-       free(istate->cache);
-       istate->cache = NULL;
+       FREE_AND_NULL(istate->cache);
        istate->cache_alloc = 0;
        discard_split_index(istate);
        free_untracked_cache(istate->untracked);
@@ -1890,7 +2033,7 @@ static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
 }
 
 /* Copy miscellaneous fields but not the name */
-static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
+static void copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
                                       struct cache_entry *ce)
 {
        short flags;
@@ -1914,32 +2057,35 @@ static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
                struct ondisk_cache_entry_extended *ondisk2;
                ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
                ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
-               return ondisk2->name;
-       }
-       else {
-               return ondisk->name;
        }
 }
 
 static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
-                         struct strbuf *previous_name)
+                         struct strbuf *previous_name, struct ondisk_cache_entry *ondisk)
 {
        int size;
-       struct ondisk_cache_entry *ondisk;
        int saved_namelen = saved_namelen; /* compiler workaround */
-       char *name;
        int result;
+       static unsigned char padding[8] = { 0x00 };
 
        if (ce->ce_flags & CE_STRIP_NAME) {
                saved_namelen = ce_namelen(ce);
                ce->ce_namelen = 0;
        }
 
+       if (ce->ce_flags & CE_EXTENDED)
+               size = offsetof(struct ondisk_cache_entry_extended, name);
+       else
+               size = offsetof(struct ondisk_cache_entry, name);
+
        if (!previous_name) {
-               size = ondisk_ce_size(ce);
-               ondisk = xcalloc(1, size);
-               name = copy_cache_entry_to_ondisk(ondisk, ce);
-               memcpy(name, ce->name, ce_namelen(ce));
+               int len = ce_namelen(ce);
+               copy_cache_entry_to_ondisk(ondisk, ce);
+               result = ce_write(c, fd, ondisk, size);
+               if (!result)
+                       result = ce_write(c, fd, ce->name, len);
+               if (!result)
+                       result = ce_write(c, fd, padding, align_padding_size(size, len));
        } else {
                int common, to_remove, prefix_size;
                unsigned char to_remove_vi[16];
@@ -1952,16 +2098,12 @@ static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
                to_remove = previous_name->len - common;
                prefix_size = encode_varint(to_remove, to_remove_vi);
 
-               if (ce->ce_flags & CE_EXTENDED)
-                       size = offsetof(struct ondisk_cache_entry_extended, name);
-               else
-                       size = offsetof(struct ondisk_cache_entry, name);
-               size += prefix_size + (ce_namelen(ce) - common + 1);
-
-               ondisk = xcalloc(1, size);
-               name = copy_cache_entry_to_ondisk(ondisk, ce);
-               memcpy(name, to_remove_vi, prefix_size);
-               memcpy(name + prefix_size, ce->name + common, ce_namelen(ce) - common);
+               copy_cache_entry_to_ondisk(ondisk, ce);
+               result = ce_write(c, fd, ondisk, size);
+               if (!result)
+                       result = ce_write(c, fd, to_remove_vi, prefix_size);
+               if (!result)
+                       result = ce_write(c, fd, ce->name + common, ce_namelen(ce) - common + 1);
 
                strbuf_splice(previous_name, common, to_remove,
                              ce->name + common, ce_namelen(ce) - common);
@@ -1971,8 +2113,6 @@ static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
                ce->ce_flags &= ~CE_STRIP_NAME;
        }
 
-       result = ce_write(c, fd, ondisk, size);
-       free(ondisk);
        return result;
 }
 
@@ -2044,16 +2184,19 @@ void update_index_if_able(struct index_state *istate, struct lock_file *lockfile
                rollback_lock_file(lockfile);
 }
 
-static int do_write_index(struct index_state *istate, int newfd,
+static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
                          int strip_extensions)
 {
+       int newfd = tempfile->fd;
        git_SHA_CTX c;
        struct cache_header hdr;
-       int i, err, removed, extended, hdr_version;
+       int i, err = 0, removed, extended, hdr_version;
        struct cache_entry **cache = istate->cache;
        int entries = istate->cache_nr;
        struct stat st;
+       struct ondisk_cache_entry_extended ondisk;
        struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
+       int drop_cache_tree = 0;
 
        for (i = removed = extended = 0; i < entries; i++) {
                if (cache[i]->ce_flags & CE_REMOVE)
@@ -2088,6 +2231,7 @@ static int do_write_index(struct index_state *istate, int newfd,
                return -1;
 
        previous_name = (hdr_version == 4) ? &previous_name_buf : NULL;
+
        for (i = 0; i < entries; i++) {
                struct cache_entry *ce = cache[i];
                if (ce->ce_flags & CE_REMOVE)
@@ -2103,13 +2247,21 @@ static int do_write_index(struct index_state *istate, int newfd,
                        if (allow)
                                warning(msg, ce->name);
                        else
-                               return error(msg, ce->name);
+                               err = error(msg, ce->name);
+
+                       drop_cache_tree = 1;
                }
-               if (ce_write_entry(&c, newfd, ce, previous_name) < 0)
-                       return -1;
+               if (ce_write_entry(&c, newfd, ce, previous_name, (struct ondisk_cache_entry *)&ondisk) < 0)
+                       err = -1;
+
+               if (err)
+                       break;
        }
        strbuf_release(&previous_name_buf);
 
+       if (err)
+               return err;
+
        /* Write extension data here */
        if (!strip_extensions && istate->split_index) {
                struct strbuf sb = STRBUF_INIT;
@@ -2122,7 +2274,7 @@ static int do_write_index(struct index_state *istate, int newfd,
                if (err)
                        return -1;
        }
-       if (!strip_extensions && istate->cache_tree) {
+       if (!strip_extensions && !drop_cache_tree && istate->cache_tree) {
                struct strbuf sb = STRBUF_INIT;
 
                cache_tree_write(&sb, istate->cache_tree);
@@ -2155,7 +2307,11 @@ static int do_write_index(struct index_state *istate, int newfd,
                        return -1;
        }
 
-       if (ce_flush(&c, newfd, istate->sha1) || fstat(newfd, &st))
+       if (ce_flush(&c, newfd, istate->sha1))
+               return -1;
+       if (close_tempfile(tempfile))
+               return error(_("could not close '%s'"), tempfile->filename.buf);
+       if (stat(tempfile->filename.buf, &st))
                return -1;
        istate->timestamp.sec = (unsigned int)st.st_mtime;
        istate->timestamp.nsec = ST_MTIME_NSEC(st);
@@ -2178,7 +2334,7 @@ static int commit_locked_index(struct lock_file *lk)
 static int do_write_locked_index(struct index_state *istate, struct lock_file *lock,
                                 unsigned flags)
 {
-       int ret = do_write_index(istate, get_lock_file_fd(lock), 0);
+       int ret = do_write_index(istate, &lock->tempfile, 0);
        if (ret)
                return ret;
        assert((flags & (COMMIT_LOCK | CLOSE_LOCK)) !=
@@ -2229,7 +2385,7 @@ static int should_delete_shared_index(const char *shared_index_path)
        if (!expiration)
                return 0;
        if (stat(shared_index_path, &st))
-               return error_errno(_("could not stat '%s"), shared_index_path);
+               return error_errno(_("could not stat '%s'"), shared_index_path);
        if (st.st_mtime > expiration)
                return 0;
 
@@ -2275,11 +2431,19 @@ static int write_shared_index(struct index_state *istate,
                return do_write_locked_index(istate, lock, flags);
        }
        move_cache_to_base_index(istate);
-       ret = do_write_index(si->base, fd, 1);
+       ret = do_write_index(si->base, &temporary_sharedindex, 1);
        if (ret) {
                delete_tempfile(&temporary_sharedindex);
                return ret;
        }
+       ret = adjust_shared_perm(get_tempfile_path(&temporary_sharedindex));
+       if (ret) {
+               int save_errno = errno;
+               error("cannot fix permission bits on %s", get_tempfile_path(&temporary_sharedindex));
+               delete_tempfile(&temporary_sharedindex);
+               errno = save_errno;
+               return ret;
+       }
        ret = rename_tempfile(&temporary_sharedindex,
                              git_path("sharedindex.%s", sha1_to_hex(si->base->sha1)));
        if (!ret) {
@@ -2458,8 +2622,7 @@ void *read_blob_data_from_index(const struct index_state *istate,
 
 void stat_validity_clear(struct stat_validity *sv)
 {
-       free(sv->sd);
-       sv->sd = NULL;
+       FREE_AND_NULL(sv->sd);
 }
 
 int stat_validity_check(struct stat_validity *sv, const char *path)
@@ -2485,3 +2648,9 @@ void stat_validity_update(struct stat_validity *sv, int fd)
                fill_stat_data(sv->sd, &st);
        }
 }
+
+void move_index_extensions(struct index_state *dst, struct index_state *src)
+{
+       dst->untracked = src->untracked;
+       src->untracked = NULL;
+}