#include <stdint.h>
#include <glib.h>
#include <string.h>
+#include <sys/mman.h>
#include "bluesky-private.h"
/* TODO: Unicode handling; for now just do ASCII. */
return g_ascii_strdown(s, -1);
}
+
+gboolean bluesky_inode_is_ready(BlueSkyInode *inode)
+{
+ if (inode == NULL)
+ return FALSE;
+
+ g_mutex_lock(inode->lock);
+ gboolean valid = (inode->type != BLUESKY_PENDING
+ && inode->type != BLUESKY_INVALID);
+
+ g_mutex_unlock(inode->lock);
+
+ return valid;
+}
+
+/**** Reference-counted strings. ****/
+
+/* Create and return a new reference-counted string. The reference count is
+ * initially one. The newly-returned string takes ownership of the memory
+ * pointed at by data, and will call g_free on it when the reference count
+ * drops to zero. */
+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 string;
+}
+
+/* Create a new BlueSkyRCStr from a GString. The GString is destroyed. */
+BlueSkyRCStr *bluesky_string_new_from_gstring(GString *s)
+{
+ gsize len = s->len;
+ 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;
+
+ g_atomic_int_inc(&string->refcount);
+}
+
+void bluesky_string_unref(BlueSkyRCStr *string)
+{
+ if (string == NULL)
+ return;
+
+ if (g_atomic_int_dec_and_test(&string->refcount)) {
+ if (string->mmap == NULL) {
+ g_free(string->data);
+ } else {
+ bluesky_mmap_unref(string->mmap);
+ }
+ g_free(string);
+ }
+}
+
+/* Duplicate and return a new reference-counted string, containing a copy of
+ * the original data, with a reference count of 1. As an optimization, if the
+ * passed-in string already has a reference count of 1, the original is
+ * returned. Can be used to make a mutable copy of a shared string. For this
+ * to truly be safe, it is probably needed that there be some type of lock
+ * protecting access to the string. */
+BlueSkyRCStr *bluesky_string_dup(BlueSkyRCStr *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);
+ return string;
+ } else {
+ return bluesky_string_new(g_memdup(string->data, string->len),
+ string->len);
+ }
+}
+
+/* Resize the data block used by a BlueSkyRCStr. The data pointer might change
+ * after making this call, so it should not be cached across calls to this
+ * function. To avoid confusing any other users, the caller probably ought to
+ * hold the only reference to the string (by calling bluesky_string_dup first
+ * if needed). */
+void bluesky_string_resize(BlueSkyRCStr *string, gsize len)
+{
+ g_assert(string->mmap == NULL);
+
+ if (string->len == len)
+ return;
+
+ g_warn_if_fail(string->refcount == 1);
+
+ string->data = g_realloc(string->data, len);
+ 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;
+}
projects / bluesky.git / blobdiff