Preparatory work before implementing proper cloud writing.

[bluesky.git] / bluesky / bluesky.h

diff --git a/bluesky/bluesky.h b/bluesky/bluesky.h
index 59a33c5..f72c6d0 100644 (file)
--- a/bluesky/bluesky.h
+++ b/bluesky/bluesky.h
@@ -41,6 +41,16 @@ extern BlueSkyOptions bluesky_options;
  * limit */
 extern int bluesky_max_threads;
 
+/* A general-purpose counter for gathering run-time statistics. */
+struct bluesky_stats {
+    const char *name;
+    int64_t count;
+    int64_t sum;
+};
+struct bluesky_stats *bluesky_stats_new(const char *name);
+void bluesky_stats_add(struct bluesky_stats *stats, int64_t value);
+void bluesky_stats_dump_all();
+
 /* BlueSky status and error codes.  Various frontends should translate these to
  * the appropriate error code for whatever protocol they implement. */
 typedef enum {
@@ -83,6 +93,12 @@ BlueSkyRCStr *bluesky_crypt_decrypt(BlueSkyRCStr *in, const uint8_t *key);
 struct _BlueSkyStore;
 typedef struct _BlueSkyStore BlueSkyStore;
 
+struct _BlueSkyLog;
+typedef struct _BlueSkyLog BlueSkyLog;
+
+struct _BlueSkyCloudLogState;
+typedef struct _BlueSkyCloudLogState BlueSkyCloudLogState;
+
 void bluesky_store_init();
 BlueSkyStore *bluesky_store_new(const gchar *type);
 void bluesky_store_free(BlueSkyStore *store);
@@ -116,6 +132,8 @@ typedef struct {
     uint64_t next_inum;         /* Next available inode for allocation */
 
     BlueSkyStore *store;
+    BlueSkyLog *log;
+    BlueSkyCloudLogState *log_state;
 
     /* Accounting for memory used for caches.  Space is measured in blocks, not
      * bytes.  We track both total data in the caches and dirty data (total
@@ -128,7 +146,16 @@ typedef struct {
      * avoid deadlock do not attempt to take any other locks while the FS lock
      * is held for list editing purposes.  Items at the head of the list are
      * most recently accessed/modified. */
-    GList dirty_list, accessed_list;
+    GList unlogged_list;        // Changes not yet synced to journal
+    GList dirty_list;           // Not yet written to cloud storage
+    GList accessed_list;        // All in-memory inodes
+
+    /* Mutex for the flush daemon, to prevent concurrent execution. */
+    GMutex *flushd_lock;
+
+    /* Mapping of object identifiers (blocks, inodes) to physical location (in
+     * the local cache or in the logs in the cloud). */
+    GHashTable *locations;
 } BlueSkyFS;
 
 /* Inode number of the root directory. */
@@ -178,8 +205,9 @@ typedef struct {
     /* change_count is increased with every operation which modifies the inode,
      * and can be used to determine if cached data is still valid.
      * change_commit is the value of change_count when the inode was last
-     * committed to stable storage. */
-    uint64_t change_count, change_commit;
+     * committed to stable storage (the log).
+     * change_cloud tracks which version was last commited to cloud storage. */
+    uint64_t change_count, change_commit, change_cloud;
 
     /* Timestamp for controlling when modified data is flushed to stable
      * storage.  When an inode is first modified from a clean state, this is
@@ -196,7 +224,7 @@ typedef struct {
      * dirty linked lists.  We re-use the GList structure, using ->next to
      * point to the head of the list and ->prev to point to the tail.  The data
      * element is unused. */
-    GList *accessed_list, *dirty_list;
+    GList *unlogged_list, *accessed_list, *dirty_list;
 
     int64_t atime;              /* Microseconds since the Unix epoch */
     int64_t ctime;
@@ -251,6 +279,8 @@ typedef struct {
 BlueSkyFS *bluesky_init_fs(gchar *name, BlueSkyStore *store);
 void bluesky_superblock_flush(BlueSkyFS *fs);
 
+gboolean bluesky_inode_is_ready(BlueSkyInode *inode);
+
 int64_t bluesky_get_current_time();
 void bluesky_inode_update_ctime(BlueSkyInode *inode, gboolean update_mtime);
 uint64_t bluesky_fs_alloc_inode(BlueSkyFS *fs);
@@ -283,7 +313,9 @@ gint bluesky_dirent_compare(gconstpointer a, gconstpointer b,
                             gpointer unused);
 
 void bluesky_flushd_invoke(BlueSkyFS *fs);
+void bluesky_flushd_invoke_conditional(BlueSkyFS *fs);
 void bluesky_inode_do_sync(BlueSkyInode *inode);
+void bluesky_flushd_thread_launch(BlueSkyFS *fs);
 
 void bluesky_debug_dump(BlueSkyFS *fs);