diff options
Diffstat (limited to 'src/symtab.c')
-rw-r--r-- | src/symtab.c | 113 |
1 files changed, 91 insertions, 22 deletions
diff --git a/src/symtab.c b/src/symtab.c index 540ea0f..3647a81 100644 --- a/src/symtab.c +++ b/src/symtab.c @@ -30,22 +30,42 @@ static unsigned int hash_size[] = { 7, 17, 37, 101, 229, 487, 1009, 2039, 4091, 8191, 16411 }; /* |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); + unsigned int hash_num; /* Index to hash_size table */ + size_t elsize; /* Size of an element */ + 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 syment_free(struct grecs_symtab *st, void *ptr) { if (st->syment_free_fun) @@ -69,13 +89,23 @@ syment_alloc(struct grecs_symtab *st, void *key) errno = ec; return NULL; } } 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) { unsigned i; @@ -98,14 +128,14 @@ grecs_hash_string_ci(const char *name, unsigned long hashsize) return i % hashsize; } static unsigned def_hash(void *data, unsigned long hashsize) { - struct grecs_syment *sym = data; - return grecs_hash_string(sym->name, hashsize); + struct grecs_syment *sym = data; + return grecs_hash_string(sym->name, hashsize); } static int def_cmp(const void *a, const void *b) { struct grecs_syment const *syma = a; @@ -215,12 +245,17 @@ grecs_symtab_strerror(int rc) int 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) break; if (++i >= hash_size[st->hash_num]) i = 0; @@ -228,13 +263,20 @@ grecs_symtab_remove(struct grecs_symtab *st, void *elt) return ENOENT; } 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; j = i; do { @@ -309,16 +351,26 @@ grecs_symtab_lookup_or_install(struct grecs_symtab *st, void *key, if (install && *install == 1) { struct grecs_syment *ent = syment_alloc(st, key); if (!ent) { errno = ENOMEM; return NULL; } - st->tab[i] = ent; + 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; } void @@ -334,12 +386,13 @@ grecs_symtab_clear(struct grecs_symtab *st) struct grecs_syment *elem = st->tab[i]; if (elem) { syment_free(st, elem); st->tab[i] = NULL; } } + st->elcount = 0; } struct grecs_symtab * grecs_symtab_create(size_t elsize, unsigned (*hash_fun)(void *, unsigned long), int (*cmp_fun)(const void *, const void *), @@ -347,12 +400,13 @@ grecs_symtab_create(size_t elsize, void *(*alloc_fun)(size_t), void (*free_fun)(void *)) { struct grecs_symtab *st = malloc(sizeof(*st)); 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; st->syment_alloc_fun = alloc_fun; if (free_fun) st->syment_free_fun = free_fun; @@ -378,45 +432,60 @@ grecs_symtab_create_default(size_t elsize) void 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, - void *data) +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; } |