Begin adding write support.

[bluesky.git] / bluesky.h

diff --git a/bluesky.h b/bluesky.h
index 068173f..c85fd70 100644 (file)
--- a/bluesky.h
+++ b/bluesky.h
@@ -14,8 +14,7 @@
 
 /* File types.  The numeric values are chosen to match with those used in
  * NFSv3. */
-enum BlueSkyFileType {
-    BLUESKY_INVALID = 0,
+typedef enum {
     BLUESKY_REGULAR = 1,
     BLUESKY_DIRECTORY = 2,
     BLUESKY_BLOCK = 3,
@@ -23,7 +22,7 @@ enum BlueSkyFileType {
     BLUESKY_SYMLINK = 5,
     BLUESKY_SOCKET = 6,
     BLUESKY_FIFO = 7,
-};
+} BlueSkyFileType;
 
 /* Filesystem state.  Each filesystem which is exported is represented by a
  * single bluesky_fs structure in memory. */
@@ -35,6 +34,9 @@ typedef struct {
     uint64_t next_inum;         /* Next available inode for allocation */
 } BlueSkyFS;
 
+/* Inode number of the root directory. */
+#define BLUESKY_ROOT_INUM 1
+
 /* Timestamp, measured in microseconds since the Unix epoch. */
 typedef int64_t bluesky_time;
 
@@ -45,7 +47,7 @@ typedef struct {
     gint refcnt;                /* May be accessed atomically without lock */
     GMutex *lock;
 
-    int type;
+    BlueSkyFileType type;
     uint32_t mode;
     uint32_t uid, gid;
     uint32_t nlink;
@@ -63,9 +65,11 @@ typedef struct {
 
     /* File-specific fields */
     uint64_t size;
+    GArray *blocks;
 
     /* Directory-specific fields */
     GSequence *dirents;
+    uint64_t parent_inum;       /* inode for ".."; 0 if the root directory */
 } BlueSkyInode;
 
 /* A directory entry.  The name is UTF-8 and is a freshly-allocated string.
@@ -76,11 +80,34 @@ typedef struct {
     gchar *name;
     uint64_t hash;
     uint64_t inum;
-} BlueSkyDirent ;
+} BlueSkyDirent;
+
+/* File data is divided into fixed-size blocks (except the last block which may
+ * be short?).  These blocks are backed by storage in a key/value store, but
+ * may also be dirty if modifications have been made in-memory that have not
+ * been committed. */
+#define BLUESKY_BLOCK_SIZE 32768ULL
+#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 */
+} BlueSkyBlockType;
+
+typedef struct {
+    BlueSkyBlockType type;
+    gchar *ref;                 /* Name of data block in the backing store */
+    gchar *data;                /* Pointer to data in memory */
+} BlueSkyBlock;
 
+BlueSkyFS *bluesky_new_fs(gchar *name);
 int64_t bluesky_get_current_time();
 uint64_t bluesky_fs_alloc_inode(BlueSkyFS *fs);
-BlueSkyInode *bluesky_new_inode(uint64_t inum);
+BlueSkyInode *bluesky_new_inode(uint64_t inum, BlueSkyFileType type);
+
+BlueSkyInode *bluesky_get_inode(BlueSkyFS *fs, uint64_t inum);
+void bluesky_insert_inode(BlueSkyFS *fs, BlueSkyInode *inode);
 
 void bluesky_dirent_destroy(gpointer dirent);
 uint64_t bluesky_directory_hash(gchar *name);
@@ -89,4 +116,6 @@ gboolean bluesky_directory_insert(BlueSkyInode *dir, gchar *name,
                                   uint64_t inum);
 void bluesky_directory_dump(BlueSkyInode *dir);
 
+void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size);
+
 #endif