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| author | Jeff Garzik <jeff@garzik.org> | 2006-08-06 08:09:12 -0400 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2006-08-06 08:09:12 -0400 |
| commit | 79b3742f9529d948c9d8e0bf5253098d885233f1 (patch) | |
| tree | a8eb5bfa6ab12e28ee7d48b166ee90ea86207385 | |
| parent | 9b5287ecb52dc2aefe429b5d09b4bc33e238ba2a (diff) | |
| download | dbfs-79b3742f9529d948c9d8e0bf5253098d885233f1.tar.gz | |
Update docs.
| -rw-r--r-- | NEWS | 8 | ||||
| -rw-r--r-- | SCHEMA | 47 |
2 files changed, 51 insertions, 4 deletions
@@ -1,4 +1,12 @@ +Version 0.5 -- Not yet released. + +- Still completely untested. Probably doesn't work. +- Implement rename, statfs, fsync, fsyncdir, setattr ops. +- Implement write op. +- Special case handling of all-zero blocks. +- Add GPL copyright headers to source code. + Version 0.4 -- August 5, 2006 - Still completely untested. Probably doesn't work. @@ -9,12 +9,23 @@ DB_HOME: database home dir, for transaction database + logs DB_PASSWORD: if present, AES-encrypt database with this password db4 environment ---------------- - "metadata": metadata database +=============== + "metadata": metadata page size 512 little endian byte order + "hash": hash refence counts + page size 512 + little endian byte order + "data": user data storage + page size 2048 + little endian byte order optionally encrypted w/ DB4 AES encryption + +database "metadata" +=================== + + inode ----- key: /inode/%Lu (%Lu == inode number) @@ -36,8 +47,14 @@ guint64 mtime: file last-modified time struct dbfs_extent blocks[0]: array of extents, describing inode data struct dbfs_extent: -dbfs_blk_id_t id: 20-byte sha1 hash of data -guint64 size: size of data block +dbfs_blk_id_t id: 20-byte sha1 hash of DB-returned data block +guint32 off: fragment's offset into DB-returned data +guint32 len: length of fragment + +NOTE: sha1 hash covers the entire data block, as originally written to +the database. File modifications may cause 'off' and 'len' to change, +which implies that 'id' is no longer the sha1 hash of the current +fragment. directories @@ -84,3 +101,25 @@ guint32 namelen length of attribute name char name[0] UTF8 attribute name (namelen bytes) 0-7 bytes alignment padding + + +database "data" +=============== +Used for all data storage. Each file is broken up into chunks of no +more than DBFS_MAX_EXT_LEN (4MB) bytes, called extents. + +key: 20-byte SHA-1 hash of data contents +value: variable-length binary data + + + +database "hash" +=============== +Used for keeping a reference count of each item in database "data". + +key: 20-byte SHA-1 hash of data contents +value: struct dbfs_hashref + +struct dbfs_hashref: +guint32 refs Object reference count. + |