diff options
| -rw-r--r-- | NEWS.md | 2 | ||||
| -rw-r--r-- | libdb/db_store.c | 90 |
2 files changed, 62 insertions, 30 deletions
@@ -21,6 +21,8 @@ Improvements: * Maintain multi keys in sorted order, improving database reproducibility. * Pick a more consistent name for the target of a whatis entry in the database. + * Extend rules for when to replace one database entry with another, + producing more stable behaviour. man-db 2.10.2 (17 March 2022) ============================= diff --git a/libdb/db_store.c b/libdb/db_store.c index eae5c271..3805f38a 100644 --- a/libdb/db_store.c +++ b/libdb/db_store.c @@ -80,6 +80,12 @@ int ATTRIBUTE_CONST compare_ids (char a, char b, int promote_links) return 0; } +enum replace_action { + REPLACE_YES = 0, + REPLACE_NO, + REPLACE_FAIL +}; + /* The do_we_replace logic. Decide, for some existing key, whether it should * be replaced with some new contents. Check that names and section * extensions match before calling this. @@ -89,40 +95,67 @@ static int replace_if_necessary (MYDBM_FILE dbf, struct mandata *olddata, datum newkey, datum newcont) { + enum replace_action action; + /* It's OK to replace ULT_MAN with SO_MAN if the mtime is newer. It * isn't OK to replace a real page (either ULT_MAN or SO_MAN) with a * whatis reference; if the real page really went away then * purge_missing will catch that in time, but a real page that still * exists should always take precedence. + * + * Tie-break whatis references by lexicographical sort of + * the pointed-to page names, which isn't great but at least + * gives us something reproducible. + * + * TODO: name fields should be collated with the requested name */ - if (compare_ids (newdata->id, olddata->id, 1) <= 0 && - timespec_cmp (newdata->mtime, olddata->mtime) > 0) { - debug ("replace_if_necessary(): newer mtime; replacing\n"); - if (MYDBM_REPLACE (dbf, newkey, newcont)) - gripe_replace_key (dbf, MYDBM_DPTR (newkey)); - return 0; - } - if (compare_ids (newdata->id, olddata->id, 0) < 0) { - if (MYDBM_REPLACE (dbf, newkey, newcont)) - gripe_replace_key (dbf, MYDBM_DPTR (newkey)); - return 0; + debug ("replace_if_necessary: stronger ID; replacing\n"); + action = REPLACE_YES; + } else if (compare_ids (newdata->id, olddata->id, 1) <= 0 && + timespec_cmp (newdata->mtime, olddata->mtime) > 0) { + debug ("replace_if_necessary: newer mtime; replacing\n"); + action = REPLACE_YES; + } else if (compare_ids (newdata->id, olddata->id, 1) <= 0 && + timespec_cmp (newdata->mtime, olddata->mtime) < 0) { + debug ("replace_if_necessary: older mtime; not replacing\n"); + action = REPLACE_NO; + } else if (compare_ids (newdata->id, olddata->id, 0) > 0) { + debug ("replace_if_necessary: weaker ID; not replacing\n"); + action = REPLACE_NO; + } else if (newdata->pointer && olddata->pointer && + strcmp (newdata->pointer, olddata->pointer) < 0) { + debug ("replace_if_necessary: pointer '%s' < '%s'; " + "replacing\n", newdata->pointer, olddata->pointer); + action = REPLACE_YES; + } else if (newdata->pointer && olddata->pointer && + strcmp (newdata->pointer, olddata->pointer) > 0) { + debug ("replace_if_necessary: pointer '%s' > '%s'; " + "not replacing\n", newdata->pointer, olddata->pointer); + action = REPLACE_NO; + } else if (!STREQ (dash_if_unset (newdata->comp), + olddata->comp)) { + debug ("replace_if_necessary: differing compression " + "extensions (%s != %s); failing\n", + dash_if_unset (newdata->comp), olddata->comp); + action = REPLACE_FAIL; + } else { + debug ("replace_if_necessary: match; not replacing\n"); + action = REPLACE_NO; } - /* TODO: name fields should be collated with the requested name */ - - if (newdata->id == olddata->id) { - if (STREQ (dash_if_unset (newdata->comp), olddata->comp)) - return 0; /* same file */ - else { - debug ("ignoring differing compression " - "extensions: %s\n", MYDBM_DPTR (newkey)); - return 1; /* differing exts */ - } + switch (action) { + case REPLACE_YES: + if (MYDBM_REPLACE (dbf, newkey, newcont)) + gripe_replace_key (dbf, MYDBM_DPTR (newkey)); + return 0; + case REPLACE_NO: + /* Insert if missing, but ignore failures. */ + MYDBM_INSERT (dbf, newkey, newcont); + return 0; + default: + return 1; } - - debug ("ignoring differing ids: %s\n", MYDBM_DPTR (newkey)); - return 0; } /* The complement of split_content */ @@ -225,6 +258,7 @@ int dbstore (MYDBM_FILE dbf, struct mandata *in, const char *base) gl_list_t refs; struct name_ext *ref; char *value; + int ret = 0; memset (&oldkey, 0, sizeof oldkey); memset (&oldcont, 0, sizeof oldcont); @@ -271,7 +305,6 @@ int dbstore (MYDBM_FILE dbf, struct mandata *in, const char *base) if (MYDBM_INSERT (dbf, newkey, newcont)) { datum cont; struct mandata *info; - int ret; MYDBM_FREE_DPTR (oldcont); cont = MYDBM_FETCH (dbf, newkey); @@ -341,8 +374,6 @@ int dbstore (MYDBM_FILE dbf, struct mandata *in, const char *base) into db */ if (STREQ (old_name, base) && STREQ (old->ext, in->ext)) { - int ret; - if (!STREQ (base, MYDBM_DPTR (oldkey))) in->name = xstrdup (base); newcont = make_content (in); @@ -384,8 +415,7 @@ int dbstore (MYDBM_FILE dbf, struct mandata *in, const char *base) newkey = make_multi_key (base, in->ext); newcont = make_content (in); - if (MYDBM_REPLACE (dbf, newkey, newcont)) - gripe_replace_key (dbf, MYDBM_DPTR (newkey)); + ret = replace_if_necessary (dbf, in, old, newkey, newcont); MYDBM_FREE_DPTR (newkey); MYDBM_FREE_DPTR (newcont); @@ -419,5 +449,5 @@ int dbstore (MYDBM_FILE dbf, struct mandata *in, const char *base) } MYDBM_FREE_DPTR (oldkey); - return 0; + return ret; } |