#include <iconv.h>
#include <errno.h>
+#include <stdio.h>
#include <string.h>
#include <stdlib.h>
return iconv_close (cd);
}
+
+#define ICONV_CACHE_SIZE (16)
+
+struct _iconv_cache_bucket {
+ gchar *key;
+ guint32 refcount;
+ gboolean used;
+ iconv_t cd;
+};
+
+static GList *iconv_cache_list;
+static GHashTable *iconv_cache;
+static GHashTable *iconv_open_hash;
+static guint iconv_cache_size = 0;
+G_LOCK_DEFINE_STATIC (iconv_cache_lock);
+
+/* caller *must* hold the iconv_cache_lock */
+static void
+iconv_cache_init (void)
+{
+ static gboolean initialized = FALSE;
+
+ if (initialized)
+ return;
+
+ iconv_cache_list = NULL;
+ iconv_cache = g_hash_table_new (g_str_hash, g_str_equal);
+ iconv_open_hash = g_hash_table_new (g_direct_hash, g_direct_equal);
+
+ initialized = TRUE;
+}
+
+
+/**
+ * iconv_cache_bucket_new:
+ * @key: cache key
+ * @cd: iconv descriptor
+ *
+ * Creates a new cache bucket, inserts it into the cache and
+ * increments the cache size.
+ *
+ * Returns a pointer to the newly allocated cache bucket.
+ **/
+struct _iconv_cache_bucket *
+iconv_cache_bucket_new (const gchar *key, iconv_t cd)
+{
+ struct _iconv_cache_bucket *bucket;
+
+ bucket = g_new (struct _iconv_cache_bucket, 1);
+ bucket->key = g_strdup (key);
+ bucket->refcount = 1;
+ bucket->used = TRUE;
+ bucket->cd = cd;
+
+ g_hash_table_insert (iconv_cache, bucket->key, bucket);
+
+ /* FIXME: if we sorted the list so items with few refcounts were
+ first, then we could expire them faster in iconv_cache_expire_unused () */
+ iconv_cache_list = g_list_prepend (iconv_cache_list, bucket);
+
+ iconv_cache_size++;
+
+ return bucket;
+}
+
+
+/**
+ * iconv_cache_bucket_expire:
+ * @node: cache bucket's node
+ * @bucket: cache bucket
+ *
+ * Expires a single cache bucket @bucket. This should only ever be
+ * called on a bucket that currently has no used iconv descriptors
+ * open.
+ *
+ * @node is not a required argument. If @node is not supplied, we
+ * search for it ourselves.
+ **/
+static void
+iconv_cache_bucket_expire (GList *node, struct _iconv_cache_bucket *bucket)
+{
+ g_hash_table_remove (iconv_cache, bucket->key);
+
+ if (node == NULL)
+ node = g_list_find (iconv_cache_list, bucket);
+
+ g_assert (node != NULL);
+
+ if (node->prev)
+ {
+ node->prev->next = node->next;
+ if (node->next)
+ node->next->prev = node->prev;
+ }
+ else
+ {
+ iconv_cache_list = node->next;
+ if (node->next)
+ node->next->prev = NULL;
+ }
+
+ g_list_free_1 (node);
+
+ g_free (bucket->key);
+ g_iconv_close (bucket->cd);
+ g_free (bucket);
+
+ iconv_cache_size--;
+}
+
+
+/**
+ * iconv_cache_expire_unused:
+ *
+ * Expires as many unused cache buckets as it needs to in order to get
+ * the total number of buckets < ICONV_CACHE_SIZE.
+ **/
+static void
+iconv_cache_expire_unused (void)
+{
+ struct _iconv_cache_bucket *bucket;
+ GList *node, *next;
+
+ node = iconv_cache_list;
+ while (node && iconv_cache_size >= ICONV_CACHE_SIZE)
+ {
+ next = node->next;
+
+ bucket = node->data;
+ if (bucket->refcount == 0)
+ iconv_cache_bucket_expire (node, bucket);
+
+ node = next;
+ }
+}
+
static GIConv
open_converter (const gchar *to_codeset,
- const gchar *from_codeset,
+ const gchar *from_codeset,
GError **error)
{
- GIConv cd = g_iconv_open (to_codeset, from_codeset);
-
- if (cd == (iconv_t) -1)
+ struct _iconv_cache_bucket *bucket;
+ gchar *key;
+ GIConv cd;
+
+ /* create our key */
+ key = g_alloca (strlen (from_codeset) + strlen (to_codeset) + 2);
+ sprintf (key, "%s:%s", from_codeset, to_codeset);
+
+ G_LOCK (iconv_cache_lock);
+
+ /* make sure the cache has been initialized */
+ iconv_cache_init ();
+
+ bucket = g_hash_table_lookup (iconv_cache, key);
+ if (bucket)
{
- /* Something went wrong. */
- if (errno == EINVAL)
- g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_NO_CONVERSION,
- _("Conversion from character set '%s' to '%s' is not supported"),
- from_codeset, to_codeset);
+ if (bucket->used)
+ {
+ cd = g_iconv_open (to_codeset, from_codeset);
+ if (cd == (iconv_t) -1)
+ goto error;
+ }
else
- g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_FAILED,
- _("Could not open converter from '%s' to '%s': %s"),
- from_codeset, to_codeset, strerror (errno));
+ {
+ cd = bucket->cd;
+ bucket->used = TRUE;
+
+ /* reset the descriptor */
+ g_iconv (cd, NULL, NULL, NULL, NULL);
+ }
+
+ bucket->refcount++;
}
-
+ else
+ {
+ cd = g_iconv_open (to_codeset, from_codeset);
+ if (cd == (iconv_t) -1)
+ goto error;
+
+ iconv_cache_expire_unused ();
+
+ bucket = iconv_cache_bucket_new (key, cd);
+ }
+
+ g_hash_table_insert (iconv_open_hash, cd, bucket->key);
+
+ G_UNLOCK (iconv_cache_lock);
+
+ return cd;
+
+ error:
+
+ G_UNLOCK (iconv_cache_lock);
+
+ /* Something went wrong. */
+ if (errno == EINVAL)
+ g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_NO_CONVERSION,
+ _("Conversion from character set '%s' to '%s' is not supported"),
+ from_codeset, to_codeset);
+ else
+ g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_FAILED,
+ _("Could not open converter from '%s' to '%s': %s"),
+ from_codeset, to_codeset, strerror (errno));
+
return cd;
+}
+static int
+close_converter (GIConv converter)
+{
+ struct _iconv_cache_bucket *bucket;
+ const gchar *key;
+ iconv_t cd;
+
+ cd = (iconv_t) converter;
+
+ if (cd == (iconv_t) -1)
+ return 0;
+
+ G_LOCK (iconv_cache_lock);
+
+ key = g_hash_table_lookup (iconv_open_hash, cd);
+ if (key)
+ {
+ g_hash_table_remove (iconv_open_hash, cd);
+
+ bucket = g_hash_table_lookup (iconv_cache, key);
+ g_assert (bucket);
+
+ bucket->refcount--;
+
+ if (cd == bucket->cd)
+ bucket->used = FALSE;
+ else
+ g_iconv_close (cd);
+
+ if (!bucket->refcount && iconv_cache_size > ICONV_CACHE_SIZE)
+ {
+ /* expire this cache bucket */
+ iconv_cache_bucket_expire (NULL, bucket);
+ }
+ }
+ else
+ {
+ G_UNLOCK (iconv_cache_lock);
+
+ g_warning ("This iconv context wasn't opened using open_converter");
+
+ return g_iconv_close (converter);
+ }
+
+ G_UNLOCK (iconv_cache_lock);
+
+ return 0;
}
+
/**
* g_convert:
* @str: the string to convert
g_return_val_if_fail (str != NULL, NULL);
g_return_val_if_fail (to_codeset != NULL, NULL);
g_return_val_if_fail (from_codeset != NULL, NULL);
-
+
cd = open_converter (to_codeset, from_codeset, error);
if (cd == (GIConv) -1)
bytes_read, bytes_written,
error);
- g_iconv_close (cd);
+ close_converter (cd);
return res;
}
bytes_read, &inbytes_remaining, error);
if (!utf8)
{
- g_iconv_close (cd);
+ close_converter (cd);
if (bytes_written)
*bytes_written = 0;
return NULL;
*/
*outp = '\0';
- g_iconv_close (cd);
+ close_converter (cd);
if (bytes_written)
*bytes_written = outp - dest; /* Doesn't include '\0' */
projects / platform / upstream / glib.git / commitdiff