1 files changed, 190 insertions, 0 deletions
diff --git a/lib/puke/core.rb b/lib/puke/core.rb
new file mode 100644
index 0000000..c37b17a
--- /dev/null
+++ b/lib/puke/core.rb
@@ -0,0 +1,190 @@
+require "gdbm"
+require "fileutils"
+require "tempfile"
+require "time"
+
+module Puke
+  class << self
+    attr_reader :datadir, :listen_address, :listen_port, :secret
+    def verbose?() @verbose end
+  end
+
+  module_function
+
+  def setup(verbose: false, datadir:, listen:, secret: nil)
+    @verbose = verbose
+    @datadir = datadir
+    l = listen.split(":")
+    @listen_address = l[0]
+    @listen_port = Integer(l[1])
+    @secret = secret
+
+    FileUtils.mkdir_p(@datadir)
+    FileUtils.mkdir_p(File.join(@datadir, "tmp"))
+    gpath = File.join(@datadir, "puke.gdbm")
+    @gdbm = GDBM.new(gpath, 0644, GDBM::WRCREAT)
+  end
+
+  def close
+    @gdbm.close
+    @gdbm = :closed
+  end
+
+  def tmpdir
+    File.join(datadir, "tmp")
+  end
+
+  # Returns the largest tid ever, or -1 if no messages are stored
+  def last_tid
+    @gdbm.fetch("last-tid", "-1").to_i
+  end
+
+  def thread(tid)
+    @gdbm.fetch("t#{tid}").split("\0")
+  end
+
+  def mid?(mid)
+    @gdbm["m#{mid}"]&.split("\0")&.first
+  end
+
+  def metadata(mid)
+    tid, subject, date = @gdbm["m#{mid}"].split("\0")
+    { mid: mid, tid: tid.to_i, subject: subject, date: Time.rfc2822(date) }
+  end
+
+  def read(mid)
+    File.read(File.join(datadir, mangle_mid(mid) + ".mbox"))
+  end
+
+  CreateMutex = Thread::Mutex.new
+  def create(io, is_raw = false)
+    t = Tempfile.open("unnamed", tmpdir)
+    if is_raw
+      # Is this really correct??
+      t << "From mboxrd Thu Jan  1 00:00:00 1970\n"
+      io.each_line do |line|
+        t << line.gsub(/\A(>*)From /, "\\1>From ").gsub(/\r\n\z/, "\n")
+      end
+      t << "\n"
+    else
+      IO.copy_stream(io, t)
+    end
+    t.rewind
+    mid, tid, subject, date = parse_file(t)
+    fpath = File.join(datadir, mangle_mid(mid) + ".mbox")
+
+    # A mutex is used here in case two threads try to store the same message
+    CreateMutex.synchronize {
+      # File.exist?(fpath) is needed here because of the mangling...
+      if Puke.mid?(mid) or File.exist?(fpath)
+        existing = Puke.metadata(mid)
+        if (!tid || tid == existing[:tid]) && subject == existing[:subject] &&
+            date == existing[:date]
+          raise "duplicate message"
+        else
+          # TODO: Oops, how to deal with this case?
+          raise "duplicate Message-ID; subject=#{existing[:subject]} and " \
+            "subject=#{subject}"
+        end
+      end
+
+      unless tid
+        tid = last_tid + 1
+        @gdbm["last-tid"] = tid.to_s
+        @gdbm["t#{tid}"] = mid
+      else
+        # TODO: Hmph
+        l = Puke.thread(tid).map { |m| Puke.metadata(m) } << {
+          mid: mid, date: date, subject: subject }
+        l.sort_by! { |i| [i[:date], i[:subject]] }
+        @gdbm["t#{tid}"] = l.map { |i| i[:mid] }.join("\0")
+      end
+      @gdbm["m#{mid}"] = [tid, subject, date.rfc2822].join("\0")
+      File.link(t, fpath)
+    }
+    mid
+  ensure
+    t and t.close!
+  end
+
+  def parse_file(io)
+    # We can assume the input is in mboxrd format
+    mid = nil
+    parents = []
+    subject = nil
+    date = nil
+
+    state = nil
+    io.each_line do |line|
+      # We use \0 as a delimiter so don't allow that
+      line.delete("\0")
+
+      if line == "\n"
+        # End of headers
+        break
+      elsif line.start_with?(" ") || line.start_with?("\t")
+        case state
+        when nil
+          # This is invalid and must not happen...
+        when :subject
+          subject << line.chomp
+        when :references
+          parents.concat(line.scan(/(<[^<>]+>)/).flatten)
+        end
+      else
+        h, c = line.split(":", 2)
+        h.downcase!
+        c or next # Hmm, invalid header?
+        c.strip!
+
+        case h
+        when "date"
+          date = c
+          state = nil
+        when "message-id"
+          next if mid
+          mid = c
+          state = nil
+        when "in-reply-to"
+          parents.unshift(c)
+          state = nil
+        when "references"
+          parents.concat(c.scan(/(<[^<>]+>)/).flatten)
+          state = :references
+        when "subject"
+          next if subject
+          subject = c
+          state = :subject
+        else
+          state = nil
+        end
+      end
+    end
+
+    mid or raise "Message-ID not found"
+    # Strip < and >
+    /\A<(?<imid>.+@.+)>\z/ =~ mid and mid.ascii_only? or
+      raise "Message-ID is invalid"
+    mid = imid
+    subject or raise "Subject not found"
+    date or raise "Date not found"
+    date = Time.rfc2822(date)
+
+    # TODO: Implement saner threading algorithm
+    tid = nil
+    parents.each do |pmid|
+      # Strip < and >
+      /\A<(?<ipmid>.+@.+)>\z/ =~ pmid and pmid.ascii_only? or next
+      pmid = ipmid
+      item = @gdbm["m#{pmid}"] or next
+      tid, = item.split("\0")
+      break
+    end
+
+    [mid, tid, subject, date]
+  end
+
+  def mangle_mid(mid)
+    mid.tr("/", "_")
+  end
+end