class SourceError < StandardError; 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 is typically quite easy, because Sup
+ ## only needs to be able to:
+ ## 1. See how many messages it contains
+ ## 2. Get an arbirtrary 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, mbox file is corrupt and needs to be rescanned.
-
- ## When writing a new source, you should implement:
+ ## In particular, Sup doesn't need to move messages, mark them as
+ ## read, delete them, or anything else. (Well, at some point it will
+ ## need to delete them, but that will be an optional capability.)
+ ##
+ ## 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!)
+ ## - load_header offset
+ ## - load_message offset
+ ## - raw_header offset
+ ## - raw_full_message offset
+ ## - next (or each, if you prefer)
+ ##
+ ## ... where "offset" really means unique id. (You can tell I
+ ## started with mbox.)
##
- ## start_offset
- ## end_offset
- ## load_header(offset)
- ## load_message(offset)
- ## raw_header(offset)
- ## raw_full_message(offset)
- ## next (or each, if you prefer)
+ ## You can throw SourceErrors from any of those, but we don't catch
+ ## anything else, so make sure you catch *all* errors and reraise
+ ## them as SourceErrors, and set broken_msg to something if the
+ ## source needs to be rescanned.
+ ##
+ ## Also, be sure to make the source thread-safe, since it WILL be
+ ## pummeled from multiple threads at once.
+ ##
+ ## Two examples for you to look at, though sadly neither of them is
+ ## as simple as I'd like: mbox/loader.rb and imap.rb
+
- ## you can throw SourceErrors from any of those, but we don't catch
- ## anything else, so make sure you catch all non-fatal errors and
- ## reraise them as source errors.
+ ## dirty? described whether cur_offset has changed, which means the
+ ## source info needs to be re-saved to sources.yaml.
+ ##
+ ## broken? means no message can be loaded, e.g. IMAP server is
+ ## down, mbox file is corrupt and needs to be rescanned, etc.
bool_reader :usual, :archived, :dirty
attr_reader :uri, :cur_offset, :broken_msg
attr_accessor :id
end
def broken?; !@broken_msg.nil?; end
- def to_s; @uri; end
+ def to_s; @uri.to_s; end
def seek_to! o; self.cur_offset = o; end
def reset!
return if broken?
true
end
end
- def is_source_for? s; to_s == s; end
+ def is_source_for? uri; URI(self.uri) == URI(uri); end
def each
return if broken?