From: Daira Hopwood <daira@jacaranda.org>
Date: Thu, 2 Apr 2015 15:15:39 +0000 (+0100)
Subject: Copyediting.
X-Git-Url: https://git.rkrishnan.org/%5B/%5D%20/%5B%5E?a=commitdiff_plain;h=9b623d6341c8e3404b5b9df8fbdf56e0a30064b9;p=tahoe-lafs%2Ftahoe-lafs.git

Copyediting.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>
---

diff --git a/docs/proposed/magic-folder/filesystem-integration.rst b/docs/proposed/magic-folder/filesystem-integration.rst
index b2642f03..eae12b5e 100644
--- a/docs/proposed/magic-folder/filesystem-integration.rst
+++ b/docs/proposed/magic-folder/filesystem-integration.rst
@@ -1,10 +1,10 @@
-Magic Folders local filesystem integration design
-=================================================
+Magic Folder local filesystem integration design
+================================================
 
 *Scope*
 
 This document describes how to integrate the local filesystem with Magic
-Folders in an efficient and reliable manner. For now we ignore Remote to
+Folder in an efficient and reliable manner. For now we ignore Remote to
 Local synchronization; the design and implementation of this is scheduled
 for a later time. We also ignore multiple writers for the same Magic
 Folder, which may or may not be supported in future. The design here will
@@ -20,15 +20,15 @@ under the local directory and adds every file to a first-in first-out
 "scan queue". When processing the scan queue, redundant uploads are
 avoided by using the same mechanism the Tahoe backup command uses: we
 keep track of previous uploads by recording each file's metadata such as
-size, CTIME and MTIME. This information is stored in a database referred
-to from now on as the magic folder db. Using this recorded state, we
-ensure that when Magic Folder is subsequently started, the local
-directory tree can be scanned quickly by comparing current filesystem
-metadata with the previously recorded metadata. Each file referenced in
-the scan queue is uploaded only if its metadata differs at the time it is
-processed. If a change event is detected for a file that is already
-queued (and therefore will be processed later), the redundant event is
-ignored.
+size, ``ctime`` and ``mtime``. This information is stored in a database,
+referred to from now on as the magic folder db. Using this recorded
+state, we ensure that when Magic Folder is subsequently started, the
+local directory tree can be scanned quickly by comparing current
+filesystem metadata with the previously recorded metadata. Each file
+referenced in the scan queue is uploaded only if its metadata differs at
+the time it is processed. If a change event is detected for a file that
+is already queued (and therefore will be processed later), the redundant
+event is ignored.
 
 To implement the magic folder db, we will use an SQLite schema that
 initially is the existing Tahoe-LAFS backup schema. This schema may
@@ -39,31 +39,33 @@ database file and separate mutex lock just for Magic Folder. This avoids
 usability problems related to mutual exclusion. (If a single file and
 lock were used, a backup would block Magic Folder updates for a long
 time, and a user would not be able to tell when backups are possible
-because Magic Folder acquires a lock at arbitrary times.)
+because Magic Folder would acquire a lock at arbitrary times.)
 
 
 *Eventual consistency property*
 
-It is not possible to prevent local writes to a file while it is being
-read in order to upload it. Such writes will result in temporary
-inconsistency. Eventual consistency is reached when the queue of pending
-uploads is empty. That is, a consistent snapshot will be achieved
-eventually when local writes to the target folder cease for a
-sufficiently long period of time.
+During the process of reading a file in order to upload it, it is not
+possible to prevent further local writes. Such writes will result in
+temporary inconsistency (that is, the uploaded file will not reflect
+what the contents of the local file were at any specific time). Eventual
+consistency is reached when the queue of pending uploads is empty. That
+is, a consistent snapshot will be achieved eventually when local writes
+to the target folder cease for a sufficiently long period of time.
 
 
 *Detecting filesystem changes*
 
-For the Linux implementation we will use the inotify Linux kernel
+For the Linux implementation, we will use the inotify Linux kernel
 subsystem to gather events on the local Magic Folder directory tree. This
 implementation was already present in Tahoe-LAFS 1.9.0, but needs to be
-changed to gather directory creation and move events, as well as events
-indicating that a file has been written.
+changed to gather directory creation and move events, in addition to the
+events indicating that a file has been written that are gathered by the
+current code.
 
-For the Windows implementation we will use the ``ReadDirectoryChangesW``
-Win32 API. The prototype implementation simulates the inotify API in
-terms of ``ReadDirectoryChangesW``, allowing most of the code to be
-shared across platforms.
+For the Windows implementation, we will use the ``ReadDirectoryChangesW``
+Win32 API. The prototype implementation simulates a Python interface to
+the inotify API in terms of ``ReadDirectoryChangesW``, allowing most of
+the code to be shared across platforms.
 
 When we detect the creation of a new directory below the local Magic
 Folder directory, we create it in the Tahoe-LAFS filesystem, and also
@@ -75,23 +77,23 @@ is moved to be under the local Magic Folder directory.
 
 *User interface*
 
-The Magic Folders local filesystem integration will initially have a
+The Magic Folder local filesystem integration will initially have a
 provisional configuration file-based interface that may not be ideal from
 a usability perspective. Creating our local filesystem integration in
-this manner will allow us to use and test it indepently of the rest of
+this manner will allow us to use and test it independently of the rest of
 the Magic Folder software components. We will focus greater attention on
 user interface design as a later milestone in our development roadmap.
 
 The configuration file, ``tahoe.cfg``, must define a target local
 directory to be synchronized. Provisionally, this configuration will
-replace the current "drop-upload" section::
+replace the current ``[drop_upload]`` section::
 
- [magic_folders]
+ [magic_folder]
  enabled = true
  local.directory = "/home/human"
 
-When a filesystem directory is first "added" to Magic Folders, the user
-needs to create the remote Tahoe-LAFS directory using ``tahoe   mkdir``,
+When a filesystem directory is first configured for Magic Folder, the user
+needs to create the remote Tahoe-LAFS directory using ``tahoe mkdir``,
 and configure the Magic-Folder-enabled node with its URI (e.g. by putting
 it in a file ``private/magic_folder_dircap``). If there are existing
 files in the local directory, they will be uploaded as a result of the