#include <stdint.h>
#include <glib.h>
#include <string.h>
+#include <sys/mman.h>
#include "bluesky-private.h"
BlueSkyRCStr *bluesky_string_new(gpointer data, gsize len)
{
BlueSkyRCStr *string = g_new(BlueSkyRCStr, 1);
+ string->mmap = NULL;
string->data = data;
string->len = len;
g_atomic_int_set(&string->refcount, 1);
return bluesky_string_new(g_string_free(s, FALSE), len);
}
+/* Create a new BlueSkyRCStr from a memory-mapped buffer. */
+BlueSkyRCStr *bluesky_string_new_from_mmap(BlueSkyCacheFile *mmap,
+ int offset, gsize len)
+{
+ g_assert(offset + len <= mmap->len);
+
+ BlueSkyRCStr *string = g_new(BlueSkyRCStr, 1);
+ string->mmap = mmap;
+ g_atomic_int_inc(&mmap->mapcount);
+ string->data = (char *)mmap->addr + offset;
+ string->len = len;
+ g_atomic_int_set(&string->refcount, 1);
+ return string;
+}
+
void bluesky_string_ref(BlueSkyRCStr *string)
{
if (string == NULL)
return;
if (g_atomic_int_dec_and_test(&string->refcount)) {
- g_free(string->data);
+ if (string->mmap == NULL) {
+ g_free(string->data);
+ } else {
+ bluesky_mmap_unref(string->mmap);
+ }
g_free(string);
}
}
if (string == NULL)
return NULL;
+ if (string->mmap != NULL) {
+ BlueSkyRCStr *s;
+ s = bluesky_string_new(g_memdup(string->data, string->len),
+ string->len);
+ bluesky_string_unref(string);
+ return s;
+ }
+
if (g_atomic_int_dec_and_test(&string->refcount)) {
/* There are no other shared copies, so return this one. */
g_atomic_int_inc(&string->refcount);
* if needed). */
void bluesky_string_resize(BlueSkyRCStr *string, gsize len)
{
+ g_assert(string->mmap == NULL);
+
if (string->len == len)
return;
else
return (BlueSkyInode *)head->prev->data;
}
+
+/**** Range sets. ****/
+
+/* These are a data structure which can track a set of discontiguous integer
+ * ranges--such as the partitioning of the inode number space or the bytes in a
+ * log file into objects. This current prototype implementation just tracks
+ * the starting offset with a hash table and doesn't track the length, but
+ * should be extended later to track properly. */
+
+struct BlueSkyRangeset {
+ GSequence *seq;
+};
+
+static gint compare64(gconstpointer a, gconstpointer b, gpointer user_data)
+{
+ uint64_t x = *(uint64_t *)a;
+ uint64_t y = *(uint64_t *)b;
+
+ if (x < y)
+ return -1;
+ else if (x > y)
+ return 1;
+ else
+ return 0;
+}
+
+BlueSkyRangeset *bluesky_rangeset_new()
+{
+ BlueSkyRangeset *rangeset = g_new(BlueSkyRangeset, 1);
+ rangeset->seq = g_sequence_new(g_free);
+ return rangeset;
+}
+
+void bluesky_rangeset_free(BlueSkyRangeset *rangeset)
+{
+ g_sequence_free(rangeset->seq);
+ g_free(rangeset);
+}
+
+gboolean bluesky_rangeset_insert(BlueSkyRangeset *rangeset,
+ uint64_t start, uint64_t length,
+ gpointer data)
+{
+ GSequenceIter *i;
+ i = g_sequence_search(rangeset->seq, &start, compare64, NULL);
+ i = g_sequence_iter_prev(i);
+
+ /* TODO: Checks that no other item overlaps. */
+
+ BlueSkyRangesetItem *item = g_new(BlueSkyRangesetItem, 1);
+ item->start = start;
+ item->length = length;
+ item->data = data;
+ g_sequence_insert_sorted(rangeset->seq, item, compare64, NULL);
+
+ return TRUE;
+}
+
+const BlueSkyRangesetItem *bluesky_rangeset_lookup(BlueSkyRangeset *rangeset,
+ uint64_t offset)
+{
+ GSequenceIter *i;
+ i = g_sequence_search(rangeset->seq, &offset, compare64, NULL);
+ i = g_sequence_iter_prev(i);
+ if (g_sequence_iter_is_end(i))
+ return NULL;
+
+ BlueSkyRangesetItem *item = (BlueSkyRangesetItem *)g_sequence_get(i);
+ if (offset >= item->start && offset < item->start + item->length)
+ return item;
+ else
+ return NULL;
+}