accounts: cache key addresses

In order to avoid disk thrashing for Accounts and HasAccount,
address->key file mappings are now cached in memory. This makes it no
longer necessary to keep the key address in the file name. The address
of each key is derived from file content instead.

There are minor user-visible changes:

- "geth account list" now reports key file paths alongside the address.
- If multiple keys are present for an address, unlocking by address is
  not possible. Users are directed to remove the duplicate files
  instead. Unlocking by index is still possible.
- Key files are overwritten written in place when updating the password.

1 files changed, 28 insertions, 0 deletions

diff --git a/accounts/watch_fallback.go b/accounts/watch_fallback.go
new file mode 100644
index 000000000..ff5a2daf1
--- /dev/null
+++ b/accounts/watch_fallback.go
@@ -0,0 +1,28 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build !darwin,!freebsd,!linux,!netbsd,!solaris,!windows
+
+// This is the fallback implementation of directory watching.
+// It is used on unsupported platforms.
+
+package accounts
+
+type watcher struct{ running bool }
+
+func newWatcher(*addrCache) *watcher { return new(watcher) }
+func (*watcher) start()              {}
+func (*watcher) close()              {}