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-rw-r--r--src/basic/hashmap.c125
-rw-r--r--src/basic/hashmap.h17
2 files changed, 141 insertions, 1 deletions
diff --git a/src/basic/hashmap.c b/src/basic/hashmap.c
index fbc8d397a..876a10eeb 100644
--- a/src/basic/hashmap.c
+++ b/src/basic/hashmap.c
@@ -229,7 +229,8 @@ struct HashmapBase {
unsigned n_direct_entries:3; /* Number of entries in direct storage.
* Only valid if !has_indirect. */
bool from_pool:1; /* whether was allocated from mempool */
- bool dirty:1; /* whether dirtied since cache sync */
+ bool dirty:1; /* whether dirtied since last iterated_cache_get() */
+ bool cached:1; /* whether this hashmap is being cached */
HASHMAP_DEBUG_FIELDS /* optional hashmap_debug_info */
};
@@ -249,6 +250,17 @@ struct Set {
struct HashmapBase b;
};
+typedef struct CacheMem {
+ const void **ptr;
+ size_t n_populated, n_allocated;
+ bool active:1;
+} CacheMem;
+
+struct IteratedCache {
+ HashmapBase *hashmap;
+ CacheMem keys, values;
+};
+
DEFINE_MEMPOOL(hashmap_pool, Hashmap, 8);
DEFINE_MEMPOOL(ordered_hashmap_pool, OrderedHashmap, 8);
/* No need for a separate Set pool */
@@ -744,6 +756,25 @@ bool set_iterate(Set *s, Iterator *i, void **value) {
(idx != IDX_NIL); \
(idx) = hashmap_iterate_entry((h), &(i)))
+IteratedCache *internal_hashmap_iterated_cache_new(HashmapBase *h) {
+ IteratedCache *cache;
+
+ assert(h);
+ assert(!h->cached);
+
+ if (h->cached)
+ return NULL;
+
+ cache = new0(IteratedCache, 1);
+ if (!cache)
+ return NULL;
+
+ cache->hashmap = h;
+ h->cached = true;
+
+ return cache;
+}
+
static void reset_direct_storage(HashmapBase *h) {
const struct hashmap_type_info *hi = &hashmap_type_info[h->type];
void *p;
@@ -1870,3 +1901,95 @@ int set_put_strsplit(Set *s, const char *v, const char *separators, ExtractFlags
}
}
#endif // 0
+
+/* expand the cachemem if needed, return true if newly (re)activated. */
+static int cachemem_maintain(CacheMem *mem, unsigned size) {
+ int r = false;
+
+ assert(mem);
+
+ if (!GREEDY_REALLOC(mem->ptr, mem->n_allocated, size)) {
+ if (size > 0)
+ return -ENOMEM;
+ }
+
+ if (!mem->active)
+ mem->active = r = true;
+
+ return r;
+}
+
+int iterated_cache_get(IteratedCache *cache, const void ***res_keys, const void ***res_values, unsigned *res_n_entries) {
+ bool sync_keys = false, sync_values = false;
+ unsigned size;
+ int r;
+
+ assert(cache);
+ assert(cache->hashmap);
+
+ size = n_entries(cache->hashmap);
+
+ if (res_keys) {
+ r = cachemem_maintain(&cache->keys, size);
+ if (r < 0)
+ return r;
+
+ sync_keys = r;
+ } else
+ cache->keys.active = false;
+
+ if (res_values) {
+ r = cachemem_maintain(&cache->values, size);
+ if (r < 0)
+ return r;
+
+ sync_values = r;
+ } else
+ cache->values.active = false;
+
+ if (cache->hashmap->dirty) {
+ if (cache->keys.active)
+ sync_keys = true;
+ if (cache->values.active)
+ sync_values = true;
+
+ cache->hashmap->dirty = false;
+ }
+
+ if (sync_keys || sync_values) {
+ unsigned i, idx;
+ Iterator iter;
+
+ i = 0;
+ HASHMAP_FOREACH_IDX(idx, cache->hashmap, iter) {
+ struct hashmap_base_entry *e;
+
+ e = bucket_at(cache->hashmap, idx);
+
+ if (sync_keys)
+ cache->keys.ptr[i] = e->key;
+ if (sync_values)
+ cache->values.ptr[i] = entry_value(cache->hashmap, e);
+ i++;
+ }
+ }
+
+ if (res_keys)
+ *res_keys = cache->keys.ptr;
+ if (res_values)
+ *res_values = cache->values.ptr;
+ if (res_n_entries)
+ *res_n_entries = size;
+
+ return 0;
+}
+
+IteratedCache *iterated_cache_free(IteratedCache *cache) {
+ if (cache) {
+ free(cache->keys.ptr);
+ free(cache->values.ptr);
+ free(cache);
+ }
+
+ return NULL;
+}
diff --git a/src/basic/hashmap.h b/src/basic/hashmap.h
index 0eb763944..b67491039 100644
--- a/src/basic/hashmap.h
+++ b/src/basic/hashmap.h
@@ -53,6 +53,8 @@ typedef struct Hashmap Hashmap; /* Maps keys to values */
typedef struct OrderedHashmap OrderedHashmap; /* Like Hashmap, but also remembers entry insertion order */
typedef struct Set Set; /* Stores just keys */
+typedef struct IteratedCache IteratedCache; /* Caches the iterated order of one of the above */
+
/* Ideally the Iterator would be an opaque struct, but it is instantiated
* by hashmap users, so the definition has to be here. Do not use its fields
* directly. */
@@ -126,6 +128,9 @@ static inline OrderedHashmap *ordered_hashmap_free_free_free(OrderedHashmap *h)
return (void*)hashmap_free_free_free(PLAIN_HASHMAP(h));
}
+IteratedCache *iterated_cache_free(IteratedCache *cache);
+int iterated_cache_get(IteratedCache *cache, const void ***res_keys, const void ***res_values, unsigned *res_n_entries);
+
HashmapBase *internal_hashmap_copy(HashmapBase *h);
static inline Hashmap *hashmap_copy(Hashmap *h) {
return (Hashmap*) internal_hashmap_copy(HASHMAP_BASE(h));
@@ -139,6 +144,14 @@ int internal_ordered_hashmap_ensure_allocated(OrderedHashmap **h, const struct h
#define hashmap_ensure_allocated(h, ops) internal_hashmap_ensure_allocated(h, ops HASHMAP_DEBUG_SRC_ARGS)
#define ordered_hashmap_ensure_allocated(h, ops) internal_ordered_hashmap_ensure_allocated(h, ops HASHMAP_DEBUG_SRC_ARGS)
+IteratedCache *internal_hashmap_iterated_cache_new(HashmapBase *h);
+static inline IteratedCache *hashmap_iterated_cache_new(Hashmap *h) {
+ return (IteratedCache*) internal_hashmap_iterated_cache_new(HASHMAP_BASE(h));
+}
+static inline IteratedCache *ordered_hashmap_iterated_cache_new(OrderedHashmap *h) {
+ return (IteratedCache*) internal_hashmap_iterated_cache_new(HASHMAP_BASE(h));
+}
+
int hashmap_put(Hashmap *h, const void *key, void *value);
static inline int ordered_hashmap_put(OrderedHashmap *h, const void *key, void *value) {
return hashmap_put(PLAIN_HASHMAP(h), key, value);
@@ -394,3 +407,7 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(OrderedHashmap*, ordered_hashmap_free_free_free);
#define _cleanup_ordered_hashmap_free_ _cleanup_(ordered_hashmap_freep)
#define _cleanup_ordered_hashmap_free_free_ _cleanup_(ordered_hashmap_free_freep)
#define _cleanup_ordered_hashmap_free_free_free_ _cleanup_(ordered_hashmap_free_free_freep)
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(IteratedCache*, iterated_cache_free);
+
+#define _cleanup_iterated_cache_free_ _cleanup_(iterated_cache_freep)