diff options
Diffstat (limited to 'src/symtab.c')
-rw-r--r-- | src/symtab.c | 97 |
1 files changed, 83 insertions, 14 deletions
diff --git a/src/symtab.c b/src/symtab.c index 540ea0f..3647a81 100644 --- a/src/symtab.c +++ b/src/symtab.c @@ -33,16 +33,36 @@ static unsigned int hash_size[] = { /* |max_rehash| keeps the number of entries in |hash_size| table. */ static unsigned int max_rehash = sizeof(hash_size) / sizeof(hash_size[0]); +enum symtab_defer_type { + defer_add, + defer_del +}; + struct grecs_symtab { int flags; unsigned int hash_num; /* Index to hash_size table */ size_t elsize; /* Size of an element */ - struct grecs_syment **tab; - unsigned (*hash_fun)(void *, unsigned long hash_num); + size_t elcount; /* Number of elements in use */ + struct grecs_syment **tab; /* Table of element pointers */ + + /* Functions that can be overridden when creating the symtab: */ + unsigned (*hash_fun)(void *, unsigned long); int (*cmp_fun)(const void *, const void *); int (*copy_fun)(void *, void *); - void *(*syment_alloc_fun)(size_t size); + void *(*syment_alloc_fun)(size_t); void (*syment_free_fun) (void *); + + /* Support for deferred operations. When an insertion or deletion + is requested while the symtab is being iterated over, this operation + is deferred until the iteration is finished. */ + + /* Iteration level. Gets increased upon entry to grecs_symtab_foreach, + and decreased right before leaving it. */ + unsigned int itr_level; + /* Two deferment lists keep track of the deferred additions and + removals: + */ + grecs_list_ptr_t defer_list[2]; }; static void @@ -73,6 +93,16 @@ syment_alloc(struct grecs_symtab *st, void *key) return ent; } +static void +symtab_defer_op(struct grecs_symtab *st, enum symtab_defer_type type, + struct grecs_syment *ent) +{ + if (!st->defer_list[type]) { + st->defer_list[type] = grecs_list_create(); + st->defer_list[type]->cmp = st->cmp_fun; + } + grecs_list_append(st->defer_list[type], ent); +} unsigned grecs_hash_string(const char *name, unsigned long hashsize) @@ -218,6 +248,11 @@ grecs_symtab_remove(struct grecs_symtab *st, void *elt) unsigned int pos, i, j, r; struct grecs_syment *entry; + if (st->itr_level) { + if (grecs_list_remove(st->defer_list[defer_add], elt) == 0) + return 0; + } + pos = st->hash_fun(elt, hash_size[st->hash_num]); for (i = pos; (entry = st->tab[i]);) { if (st->cmp_fun(entry, elt) == 0) @@ -231,7 +266,14 @@ grecs_symtab_remove(struct grecs_symtab *st, void *elt) if (!entry) return ENOENT; + if (st->itr_level) { + symtab_defer_op(st, defer_del, entry); + //FIXME: mark the entry as deleted + return 0; + } + syment_free(st, entry); + st->elcount--; for (;;) { st->tab[i] = NULL; @@ -312,10 +354,20 @@ grecs_symtab_lookup_or_install(struct grecs_symtab *st, void *key, errno = ENOMEM; return NULL; } + if (st->itr_level) { + symtab_defer_op(st, defer_add, ent); + } else { st->tab[i] = ent; + st->elcount++; + } return ent; } else return st->tab[i]; + } else if (rc == ENOENT && st->itr_level) { + void *ptr = grecs_list_locate(st->defer_list[defer_add], key); + if (ptr) + return ptr; + rc = ENOENT; } errno = rc; return NULL; @@ -337,6 +389,7 @@ grecs_symtab_clear(struct grecs_symtab *st) st->tab[i] = NULL; } } + st->elcount = 0; } struct grecs_symtab * @@ -350,6 +403,7 @@ grecs_symtab_create(size_t elsize, if (st) { memset(st, 0, sizeof(*st)); st->elsize = elsize; + st->elcount = 0; st->hash_fun = hash_fun ? hash_fun : def_hash; st->cmp_fun = cmp_fun ? cmp_fun : def_cmp; st->copy_fun = copy_fun ? copy_fun : def_copy; @@ -381,39 +435,54 @@ grecs_symtab_free(struct grecs_symtab *st) { if (st) { grecs_symtab_clear(st); + grecs_list_free(st->defer_list[defer_add]); + grecs_list_free(st->defer_list[defer_del]); free(st->tab); free(st); } } size_t -grecs_symtab_count_entries(struct grecs_symtab *st) +grecs_symtab_count(struct grecs_symtab *st) { - unsigned i; - size_t count = 0; - - for (i = 0; i < hash_size[st->hash_num]; i++) - if (st->tab[i]) - count++; - return count; + return st->elcount; } int -grecs_symtab_enumerate(struct grecs_symtab *st, grecs_symtab_enumerator_t fun, +grecs_symtab_foreach(struct grecs_symtab *st, grecs_symtab_enumerator_t fun, void *data) { unsigned i; + struct grecs_syment *ep; if (!st) return 0; + + ++st->itr_level; + for (i = 0; i < hash_size[st->hash_num]; i++) { - struct grecs_syment *ep = st->tab[i]; - if (ep) { + ep = st->tab[i]; + if (ep && !grecs_list_locate(st->defer_list[defer_del], ep)) { int rc = fun(ep, data); if (rc) return rc; } } + + if (--st->itr_level == 0) { + while ((ep = grecs_list_pop(st->defer_list[defer_del])) != NULL) + grecs_symtab_remove(st, ep); + + while ((ep = grecs_list_pop(st->defer_list[defer_add])) != NULL) { + int install = 1; + if (grecs_symtab_get_index(&i, st, ep, + &install) == 0) { + st->tab[i] = ep; + st->elcount++; + } + } + } + return 0; } |