+require "sup/rfc2047"
+
module Redwood
-class SourceError < StandardError; end
+class SourceError < StandardError
+ def initialize *a
+ raise "don't instantiate me!" if SourceError.is_a?(self.class)
+ super
+ end
+end
+class OutOfSyncSourceError < SourceError; end
+class FatalSourceError < SourceError; end
class Source
- ## dirty? described whether cur_offset has changed, which means the
- ## source needs to be re-saved to disk.
+ ## Implementing a new source should be easy, because Sup only needs
+ ## to be able to:
+ ## 1. See how many messages it contains
+ ## 2. Get an arbitrary message
+ ## 3. (optional) see whether the source has marked it read or not
##
- ## broken? means no message can be loaded (e.g. IMAP server is
- ## down), so don't even bother.
- bool_reader :usual, :archived, :dirty
- attr_reader :cur_offset, :broken_msg
- attr_accessor :id
+ ## In particular, Sup doesn't need to move messages, mark them as
+ ## read, delete them, or anything else. (Well, it's nice to be able
+ ## to delete them, but that is optional.)
+ ##
+ ## On the other hand, Sup assumes that you can assign each message a
+ ## unique integer id, such that newer messages have higher ids than
+ ## earlier ones, and that those ids stay constant across sessions
+ ## (in the absence of some other client going in and fucking
+ ## everything up). For example, for mboxes I use the file offset of
+ ## the start of the message. If a source does NOT have that
+ ## capability, e.g. IMAP, then you have to do a little more work to
+ ## simulate it.
+ ##
+ ## To write a new source, subclass this class, and implement:
+ ##
+ ## - start_offset
+ ## - end_offset (exclusive!) (or, #done?)
+ ## - load_header offset
+ ## - load_message offset
+ ## - raw_header offset
+ ## - raw_message offset
+ ## - check (optional)
+ ## - next (or each, if you prefer): should return a message and an
+ ## array of labels.
+ ##
+ ## ... where "offset" really means unique id. (You can tell I
+ ## started with mbox.)
+ ##
+ ## All exceptions relating to accessing the source must be caught
+ ## and rethrown as FatalSourceErrors or OutOfSyncSourceErrors.
+ ## OutOfSyncSourceErrors should be used for problems that a call to
+ ## sup-sync will fix (namely someone's been playing with the source
+ ## from another client); FatalSourceErrors can be used for anything
+ ## else (e.g. the imap server is down or the maildir is missing.)
+ ##
+ ## Finally, be sure the source is thread-safe, since it WILL be
+ ## pummelled from multiple threads at once.
+ ##
+ ## Examples for you to look at: mbox/loader.rb, imap.rb, and
+ ## maildir.rb.
- ## You should implement:
+ ## let's begin!
##
- ## start_offset
- ## end_offset
- ## load_header(offset)
- ## load_message(offset)
- ## raw_header(offset)
- ## raw_full_message(offset)
- ## next
+ ## dirty? means cur_offset has changed, so the source info needs to
+ ## be re-saved to sources.yaml.
+ bool_reader :usual, :archived, :dirty
+ attr_reader :uri, :cur_offset
+ attr_accessor :id
def initialize uri, initial_offset=nil, usual=true, archived=false, id=nil
+ raise ArgumentError, "id must be an integer: #{id.inspect}" unless id.is_a? Fixnum if id
+
@uri = uri
- @cur_offset = initial_offset || start_offset
+ @cur_offset = initial_offset
@usual = usual
@archived = archived
@id = id
@dirty = false
- @broken_msg = nil
end
- def broken?; !@broken_msg.nil?; end
- def to_s; @uri; end
+ ## overwrite me if you have a disk incarnation (currently used only for sup-sync-back)
+ def file_path; nil end
+
+ def to_s; @uri.to_s; end
def seek_to! o; self.cur_offset = o; end
def reset!; seek_to! start_offset; end
- def == o; o.to_s == to_s; end
- def done?; cur_offset >= end_offset; end
- def is_source_for? s; to_s == s; end
+ def == o; o.uri == uri; end
+ def done?; start_offset.nil? || (self.cur_offset ||= start_offset) >= end_offset; end
+ def is_source_for? uri; uri == @uri; end
+ ## check should throw a FatalSourceError or an OutOfSyncSourcError
+ ## if it can detect a problem. it is called when the sup starts up
+ ## to proactively notify the user of any source problems.
+ def check; end
+
+ ## yields successive offsets and labels, starting at #cur_offset.
+ ##
+ ## when implementing a source, you can overwrite either #each or #next. the
+ ## default #each just calls next over and over.
def each
+ self.cur_offset ||= start_offset
until done?
- n, labels = self.next
- raise "no message" unless n
- labels += [:inbox] unless archived?
- yield n, labels
+ offset, labels = self.next
+ yield offset, labels
+ end
+ end
+
+ ## utility method to read a raw email header from an IO stream and turn it
+ ## into a hash of key-value pairs. minor special semantics for certain headers.
+ ##
+ ## THIS IS A SPEED-CRITICAL SECTION. Everything you do here will have a
+ ## significant effect on Sup's processing speed of email from ALL sources.
+ ## Little things like string interpolation, regexp interpolation, += vs <<,
+ ## all have DRAMATIC effects. BE CAREFUL WHAT YOU DO!
+ def self.parse_raw_email_header f
+ header = {}
+ last = nil
+
+ while(line = f.gets)
+ case line
+ ## these three can occur multiple times, and we want the first one
+ when /^(Delivered-To|X-Original-To|Envelope-To):\s*(.*?)\s*$/i; header[last = $1.downcase] ||= $2
+ ## regular header: overwrite (not that we should see more than one)
+ ## TODO: figure out whether just using the first occurrence changes
+ ## anything (which would simplify the logic slightly)
+ when /^([^:\s]+):\s*(.*?)\s*$/i; header[last = $1.downcase] = $2
+ when /^\r*$/; break # blank line signifies end of header
+ else
+ if last
+ header[last] << " " unless header[last].empty?
+ header[last] << line.strip
+ end
+ end
+ end
+
+ %w(subject from to cc bcc).each do |k|
+ v = header[k] or next
+ next unless Rfc2047.is_encoded? v
+ header[k] = begin
+ Rfc2047.decode_to $encoding, v
+ rescue Errno::EINVAL, Iconv::InvalidEncoding, Iconv::IllegalSequence => e
+ #debug "warning: error decoding RFC 2047 header (#{e.class.name}): #{e.message}"
+ v
+ end
end
+ header
end
protected
+ ## convenience function
+ def parse_raw_email_header f; self.class.parse_raw_email_header f end
+
+ def Source.expand_filesystem_uri uri
+ uri.gsub "~", File.expand_path("~")
+ end
+
def cur_offset= o
@cur_offset = o
@dirty = true
end
-
- attr_writer :broken_msg
end
-Redwood::register_yaml(Source, %w(uri cur_offset usual archived id))
+## if you have a @labels instance variable, include this
+## to serialize them nicely as an array, rather than as a
+## nasty set.
+module SerializeLabelsNicely
+ def before_marshal # can return an object
+ c = clone
+ c.instance_eval { @labels = @labels.to_a.map { |l| l.to_s } }
+ c
+ end
+
+ def after_unmarshal!
+ @labels = Set.new(@labels.map { |s| s.to_sym })
+ end
+end
+
+class SourceManager
+ include Singleton
+
+ def initialize
+ @sources = {}
+ @sources_dirty = false
+ @source_mutex = Monitor.new
+ end
+
+ def [](id)
+ @source_mutex.synchronize { @sources[id] }
+ end
+
+ def add_source source
+ @source_mutex.synchronize do
+ raise "duplicate source!" if @sources.include? source
+ @sources_dirty = true
+ max = @sources.max_of { |id, s| s.is_a?(DraftLoader) || s.is_a?(SentLoader) ? 0 : id }
+ source.id ||= (max || 0) + 1
+ ##source.id += 1 while @sources.member? source.id
+ @sources[source.id] = source
+ end
+ end
+
+ def sources
+ ## favour the inbox by listing non-archived sources first
+ @source_mutex.synchronize { @sources.values }.sort_by { |s| s.id }.partition { |s| !s.archived? }.flatten
+ end
+
+ def source_for uri; sources.find { |s| s.is_source_for? uri }; end
+ def usual_sources; sources.find_all { |s| s.usual? }; end
+
+ def load_sources fn=Redwood::SOURCE_FN
+ source_array = (Redwood::load_yaml_obj(fn) || []).map { |o| Recoverable.new o }
+ @source_mutex.synchronize do
+ @sources = Hash[*(source_array).map { |s| [s.id, s] }.flatten]
+ @sources_dirty = false
+ end
+ end
+
+ def save_sources fn=Redwood::SOURCE_FN
+ @source_mutex.synchronize do
+ if @sources_dirty || @sources.any? { |id, s| s.dirty? }
+ bakfn = fn + ".bak"
+ if File.exists? fn
+ File.chmod 0600, fn
+ FileUtils.mv fn, bakfn, :force => true unless File.exists?(bakfn) && File.size(fn) == 0
+ end
+ Redwood::save_yaml_obj sources, fn, true
+ File.chmod 0600, fn
+ end
+ @sources_dirty = false
+ end
+ end
+end
end