X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=bluesky%2Fbluesky.h;h=820fa123fc5c0c4f295439a6be6cc0804339e3c4;hb=83fd6b61a6e092a22d4d5e59ed95f05f5e287f11;hp=beec07577d34a3852f37df0225e73d2b3adf2fad;hpb=0ba2a52ec1386c8928b397f775e4a4f97339fa2a;p=bluesky.git diff --git a/bluesky/bluesky.h b/bluesky/bluesky.h index beec075..820fa12 100644 --- a/bluesky/bluesky.h +++ b/bluesky/bluesky.h @@ -63,16 +63,20 @@ void bluesky_init(void); gchar *bluesky_lowercase(const gchar *s); -/* Reference-counted blocks of memory, used for passing data in and out of - * storage backends and in other places. */ +struct _BlueSkyMmap; +typedef struct _BlueSkyMmap BlueSkyMmap; + typedef struct { gint refcount; + BlueSkyMmap *mmap; gchar *data; gsize len; } BlueSkyRCStr; BlueSkyRCStr *bluesky_string_new(gpointer data, gsize len); BlueSkyRCStr *bluesky_string_new_from_gstring(GString *s); +BlueSkyRCStr *bluesky_string_new_from_mmap(BlueSkyMmap *mmap, + int offset, gsize len); void bluesky_string_ref(BlueSkyRCStr *string); void bluesky_string_unref(BlueSkyRCStr *string); BlueSkyRCStr *bluesky_string_dup(BlueSkyRCStr *string); @@ -96,6 +100,12 @@ typedef struct _BlueSkyStore BlueSkyStore; struct _BlueSkyLog; typedef struct _BlueSkyLog BlueSkyLog; +struct _BlueSkyCloudLogState; +typedef struct _BlueSkyCloudLogState BlueSkyCloudLogState; + +struct _BlueSkyCloudLog; +typedef struct _BlueSkyCloudLog BlueSkyCloudLog; + void bluesky_store_init(); BlueSkyStore *bluesky_store_new(const gchar *type); void bluesky_store_free(BlueSkyStore *store); @@ -130,22 +140,41 @@ typedef struct { 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 - * data includes dirty data). Updates to these variables must be made - * atomically. */ - gint cache_total, cache_dirty; + * bytes. Updates to these variables must be made atomically. */ + gint cache_dirty; + + /* Like above, but tracking data stored in the cloudlog entries + * specifically: + * - cache_log_dirty: data uncommitted to journal and cloud + * - cache_log_writeback: data being written to journal + * - cache_log_journal: data committed to journal + * - cache_log_cloud: data written to cloud as well + * Log entries should progress from the top state to the bottom, and are + * only ever counted in one category at a time. */ + gint cache_log_dirty, cache_log_writeback, + cache_log_journal, cache_log_cloud; /* Linked list of inodes, sorted by access/modification times for cache * management. Editing these lists is protected by the filesystem lock; to * 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; + + /* Used to wait for the cache daemon to free up space */ + GCond *flushd_cond; + + /* 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. */ @@ -195,8 +224,9 @@ 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 @@ -206,14 +236,14 @@ typedef struct { /* Last access time to this inode, for controlling cache evictions. */ int64_t access_time; - /* Additional state for tracking cache writeback status. */ - uint64_t change_pending; /* change_count version currently being committed to storage */ + /* Version of the object last serialized and committed to storage. */ + BlueSkyCloudLog *committed_item; /* Pointers to the linked-list elements for this inode in the accessed and * 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; @@ -254,15 +284,14 @@ typedef struct { #define BLUESKY_MAX_FILE_SIZE (BLUESKY_BLOCK_SIZE << 24) typedef enum { BLUESKY_BLOCK_ZERO = 0, /* Data is all zeroes, not explicitly stored */ - BLUESKY_BLOCK_REF = 1, /* Reference to key/value store, not cached */ - BLUESKY_BLOCK_CACHED = 2, /* Data is cached in memory, clean */ - BLUESKY_BLOCK_DIRTY = 3, /* Data needs to be committed to store */ + BLUESKY_BLOCK_REF = 1, /* Reference to cloud log item, data clean */ + BLUESKY_BLOCK_DIRTY = 2, /* Data needs to be committed to store */ } BlueSkyBlockType; typedef struct { BlueSkyBlockType type; - gchar *ref; /* Name of data block in the backing store */ - BlueSkyRCStr *data; /* Pointer to data in memory if cached */ + BlueSkyCloudLog *ref; /* if REF: cloud log entry with data */ + BlueSkyRCStr *dirty; /* if DIRTY: raw data in memory */ } BlueSkyBlock; BlueSkyFS *bluesky_init_fs(gchar *name, BlueSkyStore *store); @@ -295,7 +324,6 @@ void bluesky_file_write(BlueSkyInode *inode, uint64_t offset, void bluesky_file_read(BlueSkyInode *inode, uint64_t offset, char *buf, gint len); -void bluesky_inode_flush(BlueSkyFS *fs, BlueSkyInode *inode); void bluesky_inode_fetch(BlueSkyFS *fs, uint64_t inum); gint bluesky_dirent_compare(gconstpointer a, gconstpointer b,