class Larch::IMAP::Mailbox

Represents an IMAP mailbox.

Constants

FETCH_BLOCK_SIZE

Maximum number of message headers to fetch with a single IMAP command.

REGEX_MESSAGE_ID

Regex to capture a Message-Id header.

SCAN_INTERVAL

Minimum time (in seconds) allowed between mailbox scans.

Attributes

attr[R]
db_mailbox[R]
delim[R]
flags[R]
imap[R]
name[R]
perm_flags[R]
state[R]
subscribed[R]

Public Class Methods

new(imap, name, delim, subscribed, *attr) click to toggle source
# File lib/larch/imap/mailbox.rb, line 16
def initialize(imap, name, delim, subscribed, *attr)
  raise ArgumentError, "must provide a Larch::IMAP instance" unless imap.is_a?(Larch::IMAP)

  @attr       = attr.flatten
  @delim      = delim
  @flags      = []
  @imap       = imap
  @last_scan  = nil
  @name       = name
  @name_utf7  = Net::IMAP.encode_utf7(@name)
  @perm_flags = []
  @subscribed = subscribed

  # Valid mailbox states are :closed (no mailbox open), :examined (mailbox
  # open and read-only), or :selected (mailbox open and read-write).
  @state = :closed

  # Create/update this mailbox in the database.
  mb_data = {
    :name       => @name,
    :delim      => @delim,
    :attr       => @attr.map{|a| a.to_s }.join(','),
    :subscribed => @subscribed ? 1 : 0
  }

  @db_mailbox = imap.db_account.mailboxes_dataset.filter(:name => @name).first

  if @db_mailbox
    @db_mailbox.update(mb_data)
  else
    @db_mailbox = Database::Mailbox.create(mb_data)
    imap.db_account.add_mailbox(@db_mailbox)
  end

  # Create private convenience methods (debug, info, warn, etc.) to make
  # logging easier.
  Logger::LEVELS.each_key do |level|
    next if Mailbox.private_method_defined?(level)

    Mailbox.class_eval do
      define_method(level) do |msg|
        Larch.log.log(level, "#{@imap.options[:log_label]} #{@name}: #{msg}")
      end

      private level
    end
  end
end

Public Instance Methods

<<(message)
Alias for: append
[](guid, peek = false)
Alias for: fetch
append(message) click to toggle source

Appends the specified Larch::IMAP::Message to this mailbox if it doesn't already exist. Returns true if the message was appended successfully, false if the message already exists in the mailbox.

# File lib/larch/imap/mailbox.rb, line 68
def append(message)
  raise ArgumentError, "must provide a Larch::IMAP::Message object" unless message.is_a?(Larch::IMAP::Message)
  return false if has_guid?(message.guid)

  @imap.safely do
    unless imap_select(!!@imap.options[:create_mailbox])
      raise Larch::IMAP::Error, "mailbox cannot contain messages: #{@name}"
    end

    debug "appending message: #{message.guid}"
    @imap.conn.append(@name_utf7, message.rfc822, get_supported_flags(message.flags), message.internaldate) unless @imap.options[:dry_run]
  end

  true
end
Also aliased as: <<
delete_message(guid) click to toggle source

Deletes the message in this mailbox with the specified guid. Returns true on success, false on failure.

# File lib/larch/imap/mailbox.rb, line 87
def delete_message(guid)
  if @imap.quirks[:gmail]
    return false unless db_message = fetch_db_message(guid)

    debug "moving message to Gmail trash: #{guid}"

    @imap.safely { @imap.conn.uid_copy(db_message.uid, '[Gmail]/Trash') } &&
        set_flags(guid, [:Deleted], true)
  else
    set_flags(guid, [:Deleted], true)
  end
end
each_db_message() { |db_message| ... } click to toggle source

Iterates through messages in this mailbox, yielding a Larch::Database::Message object for each to the provided block.

# File lib/larch/imap/mailbox.rb, line 102
def each_db_message # :yields: db_message
  scan
  @db_mailbox.messages_dataset.all {|db_message| yield db_message }
end
each_guid() { |guid| ... } click to toggle source

Iterates through messages in this mailbox, yielding the Larch message guid of each to the provided block.

# File lib/larch/imap/mailbox.rb, line 109
def each_guid # :yields: guid
  each_db_message {|db_message| yield db_message.guid }
end
each_mailbox() { |mailbox| ... } click to toggle source

Iterates through mailboxes that are first-level children of this mailbox, yielding a Larch::IMAP::Mailbox object for each to the provided block.

# File lib/larch/imap/mailbox.rb, line 115
def each_mailbox # :yields: mailbox
  mailboxes.each {|mb| yield mb }
end
expunge() click to toggle source

Expunges this mailbox, permanently removing all messages with the Deleted flag.

# File lib/larch/imap/mailbox.rb, line 121
def expunge
  return false unless imap_select

  @imap.safely do
    debug "expunging deleted messages"

    @last_scan = nil
    @imap.conn.expunge unless @imap.options[:dry_run]
  end
end
fetch(guid, peek = false) click to toggle source

Returns a Larch::IMAP::Message struct representing the message with the specified Larch guid, or nil if the specified guid was not found in this mailbox.

# File lib/larch/imap/mailbox.rb, line 135
def fetch(guid, peek = false)
  scan

  unless db_message = fetch_db_message(guid)
    warning "message not found in local db: #{guid}"
    return nil
  end

  debug "#{peek ? 'peeking at' : 'fetching'} message: #{guid}"

  imap_uid_fetch([db_message.uid], [(peek ? 'BODY.PEEK[]' : 'BODY[]'), 'FLAGS', 'INTERNALDATE', 'ENVELOPE']) do |fetch_data|
    data = fetch_data.first
    check_response_fields(data, 'BODY[]', 'FLAGS', 'INTERNALDATE', 'ENVELOPE')

    return Message.new(guid, data.attr['ENVELOPE'], data.attr['BODY[]'],
        data.attr['FLAGS'], Time.parse(data.attr['INTERNALDATE']))
  end

  warning "message not found on server: #{guid}"
  return nil
end
Also aliased as: []
fetch_db_message(guid) click to toggle source

Returns a Larch::Database::Message object representing the message with the specified Larch guid, or nil if the specified guide was not found in this mailbox.

# File lib/larch/imap/mailbox.rb, line 161
def fetch_db_message(guid)
  scan
  @db_mailbox.messages_dataset.filter(:guid => guid).first
end
has_guid?(guid) click to toggle source

Returns true if a message with the specified Larch guid exists in this mailbox, false otherwise.

# File lib/larch/imap/mailbox.rb, line 168
def has_guid?(guid)
  scan
  @db_mailbox.messages_dataset.filter(:guid => guid).count > 0
end
length() click to toggle source

Gets the number of messages in this mailbox.

# File lib/larch/imap/mailbox.rb, line 174
def length
  scan
  @db_mailbox.messages_dataset.count
end
Also aliased as: size
mailboxes() click to toggle source

Returns an Array of Larch::IMAP::Mailbox objects representing mailboxes that are first-level children of this mailbox.

# File lib/larch/imap/mailbox.rb, line 182
def mailboxes
  return [] if @attr.include?(:Noinferiors)

  all        = @imap.safely{ @imap.conn.list('', "#{@name_utf7}#{@delim}%") } || []
  subscribed = @imap.safely{ @imap.conn.lsub('', "#{@name_utf7}#{@delim}%") } || []

  all.map{|mb| Mailbox.new(@imap, mb.name, mb.delim,
      subscribed.any?{|s| s.name == mb.name}, mb.attr) }
end
peek(guid) click to toggle source

Same as fetch, but doesn't mark the message as seen.

# File lib/larch/imap/mailbox.rb, line 193
def peek(guid)
  fetch(guid, true)
end
reset() click to toggle source

Resets the mailbox state.

# File lib/larch/imap/mailbox.rb, line 198
def reset
  @state = :closed
end
scan() click to toggle source

Fetches message headers from this mailbox.

# File lib/larch/imap/mailbox.rb, line 203
def scan
  now = Time.now.to_i
  return if @last_scan && (now - @last_scan) < SCAN_INTERVAL

  first_scan = @last_scan.nil?
  @last_scan = now

  # Compare the mailbox's current status with its last known status.
  begin
    return unless status = imap_status('MESSAGES', 'UIDNEXT', 'UIDVALIDITY')
  rescue Error => e
    return if @imap.options[:create_mailbox]
    raise
  end

  flag_range = nil
  full_range = nil

  if @db_mailbox.uidvalidity && @db_mailbox.uidnext &&
      status['UIDVALIDITY'] == @db_mailbox.uidvalidity

    # The UIDVALIDITY is the same as what we saw last time we scanned this
    # mailbox, which means that all the existing messages in the database are
    # still valid. We only need to request headers for new messages.
    #
    # If this is the first scan of this mailbox during this Larch session,
    # then we'll also update the flags of all messages in the mailbox.

    flag_range = 1...@db_mailbox.uidnext if first_scan
    full_range = @db_mailbox.uidnext...status['UIDNEXT']

  else

    # The UIDVALIDITY has changed or this is the first time we've scanned this
    # mailbox (ever). Either way, all existing messages in the database are no
    # longer valid, so we have to throw them out and re-request everything.

    @db_mailbox.remove_all_messages
    full_range = 1...status['UIDNEXT']
  end

  @db_mailbox.update(:uidvalidity => status['UIDVALIDITY'])

  need_flag_scan = flag_range && flag_range.max && flag_range.min && flag_range.max - flag_range.min >= 0
  need_full_scan = full_range && full_range.max && full_range.min && full_range.max - full_range.min >= 0

  return unless need_flag_scan || need_full_scan

  fetch_flags(flag_range) if need_flag_scan

  if need_full_scan
    fetch_headers(full_range, {
      :progress_start => @db_mailbox.messages_dataset.count + 1,
      :progress_total => status['MESSAGES']
    })
  end

  @db_mailbox.update(:uidnext => status['UIDNEXT'])
  return
end
set_flags(guid, flags, merge = false) click to toggle source

Sets the IMAP flags for the message specified by guid. flags should be an array of symbols for standard flags, strings for custom flags.

If merge is true, the specified flags will be merged with the message's existing flags. Otherwise, all existing flags will be cleared and replaced with the specified flags.

Note that the :Recent flag cannot be manually set or removed.

Returns true on success, false on failure.

# File lib/larch/imap/mailbox.rb, line 274
def set_flags(guid, flags, merge = false)
  raise ArgumentError, "flags must be an Array" unless flags.is_a?(Array)

  return false unless db_message = fetch_db_message(guid)

  merged_flags    = merge ? (db_message.flags + flags).uniq : flags
  supported_flags = get_supported_flags(merged_flags)

  return true if db_message.flags == supported_flags

  return false if !imap_select
  @imap.safely { @imap.conn.uid_store(db_message.uid, 'FLAGS.SILENT', supported_flags) } unless @imap.options[:dry_run]

  true
end
size()
Alias for: length
subscribe(force = false) click to toggle source

Subscribes to this mailbox.

# File lib/larch/imap/mailbox.rb, line 291
def subscribe(force = false)
  return false if subscribed? && !force

  @imap.safely { @imap.conn.subscribe(@name_utf7) } unless @imap.options[:dry_run]
  @subscribed = true
  @db_mailbox.update(:subscribed => 1)

  true
end
subscribed?() click to toggle source

Returns true if this mailbox is subscribed, false otherwise.

# File lib/larch/imap/mailbox.rb, line 302
def subscribed?
  @subscribed
end
unsubscribe(force = false) click to toggle source

Unsubscribes from this mailbox.

# File lib/larch/imap/mailbox.rb, line 307
def unsubscribe(force = false)
  return false unless subscribed? || force

  @imap.safely { @imap.conn.unsubscribe(@name_utf7) } unless @imap.options[:dry_run]
  @subscribed = false
  @db_mailbox.update(:subscribed => 0)

  true
end

Private Instance Methods

check_response_fields(data, *fields) click to toggle source

Checks the specified Net::IMAP::FetchData object and raises a Larch::IMAP::Error unless it contains all the specified fields.

data can be a single object or an Array of objects; if it's an Array, then only the first object in the Array will be checked.

# File lib/larch/imap/mailbox.rb, line 324
def check_response_fields(data, *fields)
  check_data = data.is_a?(Array) ? data.first : data

  fields.each do |f|
    raise Error, "required data not in IMAP response: #{f}" unless check_data.attr.has_key?(f)
  end

  true
end
create_guid(data) click to toggle source

Creates a globally unique id suitable for identifying a specific message on any mail server (we hope) based on the given IMAP FETCH data.

If the given message data includes a valid Message-Id header, then that will be used to generate an MD5 hash. Otherwise, the hash will be generated based on the message's RFC822.SIZE and INTERNALDATE.

# File lib/larch/imap/mailbox.rb, line 340
def create_guid(data)
  if message_id = parse_message_id(data.attr['BODY[HEADER.FIELDS (MESSAGE-ID)]'])
    Digest::MD5.hexdigest(message_id)
  else
    check_response_fields(data, 'RFC822.SIZE', 'INTERNALDATE')

    Digest::MD5.hexdigest(sprintf('%d%d', data.attr['RFC822.SIZE'],
        Time.parse(data.attr['INTERNALDATE']).to_i))
  end
end
fetch_flags(flag_range) click to toggle source

Fetches the latest flags from the server for the specified range of message UIDs.

# File lib/larch/imap/mailbox.rb, line 371
def fetch_flags(flag_range)
  return unless imap_examine

  info "fetching latest message flags..."

  # Load the expected UIDs and their flags into a Hash for quicker lookups.
  expected_uids = {}
  @db_mailbox.messages_dataset.all do |db_message|
    expected_uids[db_message.uid] = db_message.flags
  end

  imap_uid_fetch(flag_range, "(UID FLAGS)", 16384) do |fetch_data|
    # Check the fields in the first response to ensure that everything we
    # asked for is there.
    check_response_fields(fetch_data.first, 'UID', 'FLAGS') unless fetch_data.empty?

    Larch.db.transaction do
      fetch_data.each do |data|
        uid         = data.attr['UID']
        flags       = data.attr['FLAGS']
        local_flags = expected_uids[uid]

        # If we haven't seen this message before, or if its flags have
        # changed, update the database.
        unless local_flags && local_flags == flags
          @db_mailbox.messages_dataset.filter(:uid => uid).update(:flags => flags.map{|f| f.to_s }.join(','))
        end

        expected_uids.delete(uid)
      end
    end
  end

  # Any UIDs that are in the database but weren't in the response have been
  # deleted from the server, so we need to delete them from the database as
  # well.
  unless expected_uids.empty?
    debug "removing #{expected_uids.length} deleted messages from the database..."

    Larch.db.transaction do
      expected_uids.each_key do |uid|
        @db_mailbox.messages_dataset.filter(:uid => uid).destroy
      end
    end
  end

  expected_uids = nil
  fetch_data    = nil
end
fetch_headers(header_range, options = {}) click to toggle source

Fetches the latest headers from the server for the specified range of message UIDs.

# File lib/larch/imap/mailbox.rb, line 423
def fetch_headers(header_range, options = {})
  return unless imap_examine

  options = {
    :progress_start => 0,
    :progress_total => 0
  }.merge(options)

  fetched       = 0
  progress      = 0
  show_progress = options[:progress_total] - options[:progress_start] > FETCH_BLOCK_SIZE * 4

  info "fetching message headers #{options[:progress_start]} through #{options[:progress_total]}..."

  last_good_uid = nil

  imap_uid_fetch(header_range, "(UID BODY.PEEK[HEADER.FIELDS (MESSAGE-ID)] RFC822.SIZE INTERNALDATE FLAGS)") do |fetch_data|
    # Check the fields in the first response to ensure that everything we
    # asked for is there.
    check_response_fields(fetch_data, 'UID', 'RFC822.SIZE', 'INTERNALDATE', 'FLAGS')

    Larch.db.transaction do
      fetch_data.each do |data|
        uid = data.attr['UID']

        Database::Message.create(
          :mailbox_id   => @db_mailbox.id,
          :guid         => create_guid(data),
          :uid          => uid,
          :message_id   => parse_message_id(data.attr['BODY[HEADER.FIELDS (MESSAGE-ID)]']),
          :rfc822_size  => data.attr['RFC822.SIZE'].to_i,
          :internaldate => Time.parse(data.attr['INTERNALDATE']).to_i,
          :flags        => data.attr['FLAGS']
        )

        last_good_uid = uid
      end

      # Set this mailbox's uidnext value to the last known good UID that
      # was stored in the database, plus 1. This will allow Larch to
      # resume where the error occurred on the next attempt rather than
      # having to start over.
      @db_mailbox.update(:uidnext => last_good_uid + 1)
    end

    if show_progress
      fetched       += fetch_data.length
      last_progress  = progress
      progress       = ((100 / (options[:progress_total] - options[:progress_start]).to_f) * fetched).round

      info "#{progress}% complete" if progress > last_progress
    end
  end
end
get_supported_flags(flags) click to toggle source

Returns only the flags from the specified flags array that can be set in this mailbox. Emits a warning message for any unsupported flags.

# File lib/larch/imap/mailbox.rb, line 353
def get_supported_flags(flags)
  supported_flags = flags.dup

  supported_flags.delete_if do |flag|
    # The \Recent flag is read-only, so we shouldn't try to set it.
    next true if flag == :Recent

    unless @flags.include?(flag) || @perm_flags.include?(:*) || @perm_flags.include?(flag)
      warning "flag not supported on destination: #{flag}"
      true
    end
  end

  supported_flags
end
imap_examine(force = false) click to toggle source

Examines this mailbox. If force is true, the mailbox will be examined even if it is already selected (which isn't necessary unless you want to ensure that it's in a read-only state).

Returns false if this mailbox cannot be examined, which may be the case if the Noselect attribute is set.

# File lib/larch/imap/mailbox.rb, line 484
def imap_examine(force = false)
  return false if @attr.include?(:Noselect)
  return true if @state == :examined || (!force && @state == :selected)

  @imap.safely do
    begin
      @imap.conn.close unless @state == :closed
      @state = :closed

      debug "examining mailbox"
      @imap.conn.examine(@name_utf7)
      refresh_flags

      @state = :examined

    rescue Net::IMAP::NoResponseError => e
      raise Error, "unable to examine mailbox: #{e.message}"
    end
  end

  return true
end
imap_select(create = false) click to toggle source

Selects the mailbox if it is not already selected. If the mailbox does not exist and create is true, it will be created. Otherwise, a Larch::IMAP::Error will be raised.

Returns false if this mailbox cannot be selected, which may be the case if the Noselect attribute is set.

# File lib/larch/imap/mailbox.rb, line 513
def imap_select(create = false)
  return false if @attr.include?(:Noselect)
  return true if @state == :selected

  @imap.safely do
    begin
      @imap.conn.close unless @state == :closed
      @state = :closed

      debug "selecting mailbox"
      @imap.conn.select(@name_utf7)
      refresh_flags

      @state = :selected

    rescue Net::IMAP::NoResponseError => e
      raise Error, "unable to select mailbox: #{e.message}" unless create

      info "creating mailbox: #{@name}"

      begin
        @imap.conn.create(@name_utf7) unless @imap.options[:dry_run]
        retry
      rescue => e
        raise Error, "unable to create mailbox: #{e.message}"
      end
    end
  end

  return true
end
imap_status(*attr) click to toggle source

Sends an IMAP STATUS command and returns the status of the requested attributes. Supported attributes include:

- MESSAGES
- RECENT
- UIDNEXT
- UIDVALIDITY
- UNSEEN
# File lib/larch/imap/mailbox.rb, line 553
def imap_status(*attr)
  @imap.safely do
    begin
      debug "getting mailbox status"
      @imap.conn.status(@name_utf7, attr)
    rescue Net::IMAP::NoResponseError => e
      raise Error, "unable to get status of mailbox: #{e.message}"
    end
  end
end
imap_uid_fetch(set, fields, block_size = FETCH_BLOCK_SIZE) { |fetch_data| ... } click to toggle source

Fetches the specified fields for the specified set of UIDs, which can be a number, Range, or Array of UIDs.

If set is a number, an Array containing a single Net::IMAP::FetchData object will be yielded to the given block.

If set is a Range or Array of UIDs, Arrays of up to block_size Net::IMAP::FetchData objects will be yielded until all requested messages have been fetched.

However, if set is a Range with an end value of -1, a single Array containing all requested messages will be yielded, since it's impossible to divide an infinite range into finite blocks.

# File lib/larch/imap/mailbox.rb, line 577
def imap_uid_fetch(set, fields, block_size = FETCH_BLOCK_SIZE, &block) # :yields: fetch_data
  if set.is_a?(Numeric) || (set.is_a?(Range) && set.last < 0)
    data = @imap.safely do
      imap_examine
      @imap.conn.uid_fetch(set, fields)
    end

    yield data unless data.nil?
    return
  end

  blocks = []
  pos    = 0

  if set.is_a?(Array)
    while pos < set.length
      blocks += set[pos, block_size]
      pos    += block_size
    end

  elsif set.is_a?(Range)
    pos = set.min - 1

    while pos < set.max
      blocks << ((pos + 1)..[set.max, pos += block_size].min)
    end
  end

  blocks.each do |block|
    data = @imap.safely do
      imap_examine

      begin
        data = @imap.conn.uid_fetch(block, fields)

      rescue Net::IMAP::NoResponseError => e
        raise unless e.message == 'Some messages could not be FETCHed (Failure)'

        # Workaround for stupid Gmail shenanigans.
        warning "Gmail error: '#{e.message}'; continuing anyway"
      end

      next data
    end

    yield data unless data.nil?
  end
end
parse_message_id(str) click to toggle source

Parses a Message-Id header out of str and returns it, or nil if str doesn't contain a valid Message-Id header.

# File lib/larch/imap/mailbox.rb, line 628
def parse_message_id(str)
  return str =~ REGEX_MESSAGE_ID ? $1 : nil
end
refresh_flags() click to toggle source

Refreshes the list of valid flags for this mailbox.

# File lib/larch/imap/mailbox.rb, line 633
def refresh_flags
  return unless @imap.conn.responses.has_key?('FLAGS') &&
      @imap.conn.responses.has_key?('PERMANENTFLAGS')

  @flags      = Array(@imap.conn.responses['FLAGS'].first)
  @perm_flags = Array(@imap.conn.responses['PERMANENTFLAGS'].first)
end