lib: factor out feature name related code.

database.cc is uncomfortably large, and some of the static data
structures do not need to be shared as much as they are.

This is a somewhat small piece to factor out, but it will turn out to
be helpful to further refactoring.

1 files changed, 2 insertions, 116 deletions

diff --git a/lib/database.cc b/lib/database.cc
index 75189685..e08d43ca 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -39,8 +39,6 @@
 
 using namespace std;
 
-#define ARRAY_SIZE(arr) (sizeof (arr) / sizeof (arr[0]))
-
 typedef struct {
     const char *name;
     const char *prefix;
@@ -458,41 +456,6 @@ _notmuch_database_prefix (notmuch_database_t *notmuch, const char *name)
     return NULL;
 }
 
-static const struct {
-    /* NOTMUCH_FEATURE_* value. */
-    _notmuch_features value;
-    /* Feature name as it appears in the database.  This name should
-     * be appropriate for displaying to the user if an older version
-     * of notmuch doesn't support this feature. */
-    const char *name;
-    /* Compatibility flags when this feature is declared. */
-    const char *flags;
-} feature_names[] = {
-    { NOTMUCH_FEATURE_FILE_TERMS,
-      "multiple paths per message", "rw" },
-    { NOTMUCH_FEATURE_DIRECTORY_DOCS,
-      "relative directory paths", "rw" },
-    /* Header values are not required for reading a database because a
-     * reader can just refer to the message file. */
-    { NOTMUCH_FEATURE_FROM_SUBJECT_ID_VALUES,
-      "from/subject/message-ID in database", "w" },
-    { NOTMUCH_FEATURE_BOOL_FOLDER,
-      "exact folder:/path: search", "rw" },
-    { NOTMUCH_FEATURE_GHOSTS,
-      "mail documents for missing messages", "w" },
-    /* Knowledge of the index mime-types are not required for reading
-     * a database because a reader will just be unable to query
-     * them. */
-    { NOTMUCH_FEATURE_INDEXED_MIMETYPES,
-      "indexed MIME types", "w" },
-    { NOTMUCH_FEATURE_LAST_MOD,
-      "modification tracking", "w" },
-    /* Existing databases will work fine for all queries not involving
-     * 'body:' */
-    { NOTMUCH_FEATURE_UNPREFIX_BODY_ONLY,
-      "index body and headers separately", "w" },
-};
-
 const char *
 notmuch_status_to_string (notmuch_status_t status)
 {
@@ -817,83 +780,6 @@ _notmuch_database_new_revision (notmuch_database_t *notmuch)
     return new_revision;
 }
 
-/* Parse a database features string from the given database version.
- * Returns the feature bit set.
- *
- * For version < 3, this ignores the features string and returns a
- * hard-coded set of features.
- *
- * If there are unrecognized features that are required to open the
- * database in mode (which should be 'r' or 'w'), return a
- * comma-separated list of unrecognized but required features in
- * *incompat_out suitable for presenting to the user.  *incompat_out
- * will be allocated from ctx.
- */
-static _notmuch_features
-_parse_features (const void *ctx, const char *features, unsigned int version,
-		 char mode, char **incompat_out)
-{
-    _notmuch_features res = static_cast<_notmuch_features>(0);
-    unsigned int namelen, i;
-    size_t llen = 0;
-    const char *flags;
-
-    /* Prior to database version 3, features were implied by the
-     * version number. */
-    if (version == 0)
-	return NOTMUCH_FEATURES_V0;
-    else if (version == 1)
-	return NOTMUCH_FEATURES_V1;
-    else if (version == 2)
-	return NOTMUCH_FEATURES_V2;
-
-    /* Parse the features string */
-    while ((features = strtok_len_c (features + llen, "\n", &llen)) != NULL) {
-	flags = strchr (features, '\t');
-	if (! flags || flags > features + llen)
-	    continue;
-	namelen = flags - features;
-
-	for (i = 0; i < ARRAY_SIZE (feature_names); ++i) {
-	    if (strlen (feature_names[i].name) == namelen &&
-		strncmp (feature_names[i].name, features, namelen) == 0) {
-		res |= feature_names[i].value;
-		break;
-	    }
-	}
-
-	if (i == ARRAY_SIZE (feature_names) && incompat_out) {
-	    /* Unrecognized feature */
-	    const char *have = strchr (flags, mode);
-	    if (have && have < features + llen) {
-		/* This feature is required to access this database in
-		 * 'mode', but we don't understand it. */
-		if (! *incompat_out)
-		    *incompat_out = talloc_strdup (ctx, "");
-		*incompat_out = talloc_asprintf_append_buffer (
-		    *incompat_out, "%s%.*s", **incompat_out ? ", " : "",
-		    namelen, features);
-	    }
-	}
-    }
-
-    return res;
-}
-
-static char *
-_print_features (const void *ctx, unsigned int features)
-{
-    unsigned int i;
-    char *res = talloc_strdup (ctx, "");
-
-    for (i = 0; i < ARRAY_SIZE (feature_names); ++i)
-	if (features & feature_names[i].value)
-	    res = talloc_asprintf_append_buffer (
-		res, "%s\t%s\n", feature_names[i].name, feature_names[i].flags);
-
-    return res;
-}
-
 notmuch_status_t
 notmuch_database_open (const char *path,
 		       notmuch_database_mode_t mode,
@@ -1012,7 +898,7 @@ notmuch_database_open_verbose (const char *path,
 
 	/* Check features. */
 	incompat_features = NULL;
-	notmuch->features = _parse_features (
+	notmuch->features = _notmuch_database_parse_features (
 	    local, notmuch->xapian_db->get_metadata ("features").c_str (),
 	    version, mode == NOTMUCH_DATABASE_MODE_READ_WRITE ? 'w' : 'r',
 	    &incompat_features);
@@ -1674,7 +1560,7 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
     }
 
     status = NOTMUCH_STATUS_SUCCESS;
-    db->set_metadata ("features", _print_features (local, notmuch->features));
+    db->set_metadata ("features", _notmuch_database_print_features (local, notmuch->features));
     db->set_metadata ("version", STRINGIFY (NOTMUCH_DATABASE_VERSION));
 
   DONE: