From ddbc56b1b361f73b8f2466f3a3141d5dfdab7926 Mon Sep 17 00:00:00 2001
From: warner <>
Date: Tue, 1 Jul 2008 00:25:59 +0000
Subject: [PATCH] [Imported from Trac: page AccountingDesign, version 7]

---
 AccountingDesign.md | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/AccountingDesign.md b/AccountingDesign.md
index 3d25d36..6a0b38d 100644
--- a/AccountingDesign.md
+++ b/AccountingDesign.md
@@ -168,3 +168,46 @@ authority is being delegated. The fields we'll define for v1 are:
    exactly one lease on the resulting share.
  * other attenuations: TBD (things like until=, SI=, UEBhash=, operation=,
    max-size=)
+
+## Lease Tables
+
+The server will maintain a "lease table", to provide efficient lookup by
+account. This primarilly supports the "how much is Bob using?" question, and
+will (in a future version) support the reconcilliation operation.
+
+To avoid revising the v1 share file format (which only offers a 4-byte
+"ownerid" field), the server maintains a second table that maps from these
+4-byte "pubkeyid" numbers to the full pubkey, and puts an additional column
+in the lease table to map from pubkey to pubkeyid.
+
+ * `NODEDIR/accounting/pubkeyids`: 32 bytes per pubkeyid, assigned
+   sequentially. `pubkey[4]` is the 32 bytes at offset 4*32.
+ * `NODEDIR/accounting/usage/base32(PUBKEY)`: one file per pubkey.
+   Contents are:
+   * bytes 0-3: pubkeyid
+   * bytes 4-11: total size
+   * bytes 12-19: total number of files
+   * (deferred until v1.3): reconcilliation list (variable length list of SIs)
+
+The lease table may be switched to use an intermediate prefix directory
+later, to make lookup more efficient (some native filesystems get slow when
+you put thousands or tens-of-thousands of files in a single directory).
+
+For ext3, a 300k-entry lease table is likely to use 1.2GB . For something
+like reiserfs3 that can pack small files, it might take juse 18MB. A SQL
+representation would probably be fairly compact too.
+
+### Pet Name Table
+
+The "Usage/Aggregator" component (described below) can display a "pet name"
+along with each key, to make the results more meaningful ("Bob using 73MB"
+instead of "pubkey j7sta2uvcr345znqwfwlxitnii is using 73MB"). This is more
+likely to be used by the friendnet case than the commercial grid (in which
+this functionality will most likely exist in an external database). The "pet
+name table" may contain other information about the public keys to which
+storage has been delegated.
+
+ * `NODEDIR/?/petnames`: one line per pubkey, each line is:
+   * `base32(pubkey): PETNAME\n`
+ * if multiple pubkeys map to the same pet name, their usage will be added
+   together at display time.