+ string->len = len;
+}
+
+/* Cache LRU list management functions. These manage the doubly-linked list of
+ * inodes sorted by accessed/modified time. The FS lock should be held while
+ * calling these.
+ *
+ * _remove will unlink an inode from the linked list.
+ *
+ * _prepend and _append insert an inode at the head or tail of the linked list,
+ * and return a pointer to the linked list element (which should be stored in
+ * the inode); the inode should not already be in the list.
+ *
+ * _head and _tail simply return the first or last item inode in the list. */
+void bluesky_list_unlink(GList *head, GList *item)
+{
+ if (item == NULL)
+ return;
+
+ if (head->prev == item)
+ head->prev = item->prev;
+ head->next = g_list_delete_link(head->next, item);
+}
+
+GList *bluesky_list_prepend(GList *head, BlueSkyInode *inode)
+{
+ head->next = g_list_prepend(head->next, inode);
+ if (head->prev == NULL)
+ head->prev = g_list_last(head->next);
+ return head->next;
+}
+
+GList *bluesky_list_append(GList *head, BlueSkyInode *inode)
+{
+ if (head->next == NULL)
+ return bluesky_list_prepend(head, inode);
+
+ g_assert(head->prev != NULL && head->prev->next == NULL);
+
+ GList *link = g_list_alloc();
+ link->data = inode;
+ link->next = NULL;
+ link->prev = head->prev;
+ head->prev->next = link;
+ head->prev = link;
+ return link;
+}
+
+BlueSkyInode *bluesky_list_head(GList *head)
+{
+ if (head->next == NULL)
+ return NULL;
+ else
+ return (BlueSkyInode *)head->next->data;
+}
+
+BlueSkyInode *bluesky_list_tail(GList *head)
+{
+ if (head->prev == NULL)
+ return NULL;
+ 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;
+}
+
+/* Look up the first rangeset item starting at or following the given address.
+ * Can be used to iterate through a rangeset. */
+const BlueSkyRangesetItem *bluesky_rangeset_lookup_next(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 (item->start < offset) {
+ i = g_sequence_iter_next(i);
+ if (g_sequence_iter_is_end(i))
+ item = NULL;
+ else
+ item = (BlueSkyRangesetItem *)g_sequence_get(i);
+ }
+ return item;
+}
+
+/* Determine the full extent of a rangeset--the smallest offset covered and the
+ * length needed to extend to the end of the last item. */
+void bluesky_rangeset_get_extents(BlueSkyRangeset *rangeset,
+ uint64_t *start, uint64_t *length)
+{
+ GSequenceIter *i;
+ BlueSkyRangesetItem *item;
+
+ i = g_sequence_get_begin_iter(rangeset->seq);
+ if (g_sequence_iter_is_end(i)) {
+ *start = 0;
+ *length = 0;
+ return;
+ }
+
+ item = (BlueSkyRangesetItem *)g_sequence_get(i);
+ *start = item->start;
+
+ i = g_sequence_get_end_iter(rangeset->seq);
+ i = g_sequence_iter_prev(i);
+ item = (BlueSkyRangesetItem *)g_sequence_get(i);
+ *length = (item->start + item->length) - *start;
+}
+
+/**** Request response-time tracking. ****/
+/* TODO: Locking */
+typedef struct {
+ int tid;
+ bluesky_time_hires timestamp;
+ char *message;
+} RTEvent;
+
+/* To catch attempts to access to invalid profile structures. */
+#define PROFILE_MAGIC 0x439929d8
+
+static FILE *profiling_file = NULL;
+
+BlueSkyProfile *bluesky_profile_new()
+{
+ BlueSkyProfile *profile = g_new0(BlueSkyProfile, 1);
+ profile->lock = g_mutex_new();
+ profile->magic = PROFILE_MAGIC;
+ return profile;
+}
+
+void bluesky_profile_free(BlueSkyProfile *profile)
+{
+ if (profile->magic != PROFILE_MAGIC) {
+ g_warning("Access to invalid BlueSkyProfile object!");
+ return;
+ }
+ while (profile->events != NULL) {
+ RTEvent *event = (RTEvent *)profile->events->data;
+ g_free(event->message);
+ g_free(event);
+ profile->events = g_list_delete_link(profile->events, profile->events);
+ }
+ profile->magic = 0;
+ g_mutex_free(profile->lock);
+ g_free(profile->description);
+ g_free(profile);
+}
+
+void bluesky_profile_add_event(BlueSkyProfile *profile, char *message)
+{
+ if (profiling_file == NULL)
+ return;
+
+ g_return_if_fail(profile != NULL);
+
+ if (profile->magic != PROFILE_MAGIC) {
+ g_warning("Access to invalid BlueSkyProfile object!");
+ return;
+ }
+ g_mutex_lock(profile->lock);
+ RTEvent *event = g_new(RTEvent, 1);
+ event->timestamp = bluesky_now_hires();
+ /* FIXME: Non-portable */
+ event->tid = syscall(SYS_gettid);
+ event->message = message;
+ profile->events = g_list_prepend(profile->events, event);
+ g_mutex_unlock(profile->lock);
+}
+
+static GStaticMutex profiling_print_lock = G_STATIC_MUTEX_INIT;
+
+void bluesky_profile_set_output(FILE *stream)
+{
+ profiling_file = stream;
+}
+
+void bluesky_profile_print(BlueSkyProfile *profile)
+{
+ FILE *stream = profiling_file;
+ if (stream == NULL)
+ return;
+
+ g_return_if_fail(profile != NULL);
+
+ if (profile->magic != PROFILE_MAGIC) {
+ g_warning("Access to invalid BlueSkyProfile object!");
+ return;
+ }
+
+ g_mutex_lock(profile->lock);
+ g_static_mutex_lock(&profiling_print_lock);
+ fprintf(stream, "Event Timeline: %s\n", profile->description);
+ GList *link = g_list_last(profile->events);
+ bluesky_time_hires last_time = 0;
+ while (link != NULL) {
+ RTEvent *event = (RTEvent *)link->data;
+ fprintf(stream, " [%d] [%"PRIi64" ns]: %s\n",
+ event->tid, event->timestamp - last_time, event->message);
+ last_time = event->timestamp;
+ link = link->prev;
+ }
+ g_static_mutex_unlock(&profiling_print_lock);
+ g_mutex_unlock(profile->lock);
+}
+
+static GStaticPrivate per_thread_profile = G_STATIC_PRIVATE_INIT;
+
+BlueSkyProfile *bluesky_profile_get()
+{
+ return (BlueSkyProfile *)g_static_private_get(&per_thread_profile);
+}
+
+void bluesky_profile_set(BlueSkyProfile *profile)
+{
+ g_static_private_set(&per_thread_profile, profile, NULL);