From 3e09ac0c10c95bb24a08af62393b4f761e2743d0 Mon Sep 17 00:00:00 2001
From: Eric Wong <normalperson@yhbt.net>
Date: Sat, 24 Aug 2013 09:54:45 +0000
Subject: initial commit

---
 lib/dtas/player/client_handler.rb | 452 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 452 insertions(+)
 create mode 100644 lib/dtas/player/client_handler.rb

(limited to 'lib/dtas/player')

diff --git a/lib/dtas/player/client_handler.rb b/lib/dtas/player/client_handler.rb
new file mode 100644
index 0000000..aabd1ab
--- /dev/null
+++ b/lib/dtas/player/client_handler.rb
@@ -0,0 +1,452 @@
+# -*- encoding: binary -*-
+# :stopdoc:
+# Copyright (C) 2013, Eric Wong <normalperson@yhbt.net>
+# License: GPLv3 or later (https://www.gnu.org/licenses/gpl-3.0.txt)
+module DTAS::Player::ClientHandler
+
+  # returns true on success, wait_ctl arg on error
+  def set_bool(io, kv, v)
+    case v
+    when "false" then yield(false)
+    when "true" then yield(true)
+    else
+      return io.emit("ERR #{kv} must be true or false")
+    end
+    true
+  end
+
+  def adjust_numeric(io, obj, k, v)
+    negate = !!v.sub!(/\A-/, '')
+    case v
+    when %r{\A\+?\d*\.\d+\z}
+      num = v.to_f
+    when %r{\A\+?\d+\z}
+      num = v.to_i
+    else
+      return io.emit("ERR #{k}=#{v} must be a float")
+    end
+    num = -num if negate
+
+    if k.sub!(/\+\z/, '') # increment existing
+      num += obj.__send__(k)
+    elsif k.sub!(/-\z/, '') # decrement existing
+      num = obj.__send__(k) - num
+    # else # normal assignment
+    end
+    obj.__send__("#{k}=", num)
+    true
+  end
+
+  # returns true on success, wait_ctl arg on error
+  def set_int(io, kv, v, null_ok)
+    case v
+    when %r{\A-?\d+\z}
+      yield(v.to_i)
+    when ""
+      null_ok or return io.emit("ERR #{kv} must be defined")
+      yield(nil)
+    else
+      return io.emit("ERR #{kv} must an integer")
+    end
+    true
+  end
+
+  # returns true on success, wait_ctl arg on error
+  def set_uint(io, kv, v, null_ok)
+    case v
+    when %r{\A\d+\z}
+      yield(v.to_i)
+    when %r{\A0x[0-9a-fA-F]+\z}i # hex
+      yield(v.to_i(16))
+    when ""
+      null_ok or return io.emit("ERR #{kv} must be defined")
+      yield(nil)
+    else
+      return io.emit("ERR #{kv} must an non-negative integer")
+    end
+    true
+  end
+
+  def __sink_activate(sink)
+    return if sink.pid
+    @targets.concat(sink.spawn(@format))
+    @targets.sort_by! { |t| t.sink.prio }
+  end
+
+  def drop_sink(sink)
+    @targets.delete_if do |t|
+      if t.sink == sink
+        drop_target(t)
+        true
+      else
+        false
+      end
+    end
+  end
+
+  # called to activate/deactivate a sink
+  def __sink_switch(sink)
+    if sink.active
+      if @current
+        # maybe it's still alive for now, but it's just being killed
+        # do not reactivate it until we've reaped it
+        if sink.pid
+          drop_sink(sink)
+          sink.respawn = true
+        else
+          __sink_activate(sink)
+        end
+      end
+    else
+      drop_sink(sink)
+    end
+    # if we change any sinks, make sure the event loop watches it for
+    # readability again, since we new sinks should be writable, and
+    # we've stopped waiting on killed sinks
+    @srv.wait_ctl(@sink_buf, :wait_readable)
+  end
+
+  # returns a wait_ctl arg
+  def sink_handler(io, msg)
+    name = msg[1]
+    case msg[0]
+    when "ls"
+      io.emit(Shellwords.join(@sinks.keys.sort))
+    when "rm"
+      sink = @sinks.delete(name) or return io.emit("ERR #{name} not found")
+      drop_sink(sink)
+      io.emit("OK")
+    when "ed"
+      sink = @sinks[name] || (new_sink = DTAS::Sink.new)
+
+      # allow things that look like audio device names ("hw:1,0" , "/dev/dsp")
+      # or variable names.
+      sink.valid_name?(name) or return io.emit("ERR sink name invalid")
+
+      sink.name = name
+      active_before = sink.active
+
+      # multiple changes may be made at once
+      msg[2..-1].each do |kv|
+        k, v = kv.split(/=/, 2)
+        case k
+        when %r{\Aenv\.([^=]+)\z}
+          sink.env[$1] = v
+        when %r{\Aenv#([^=]+)\z}
+          v == nil or return io.emit("ERR unset env has no value")
+          sink.env.delete($1)
+        when "prio"
+          rv = set_int(io, kv, v, false) { |i| sink.prio = i }
+          rv == true or return rv
+          @targets.sort_by! { |t| t.sink.prio } if sink.active
+        when "nonblock", "active"
+          rv = set_bool(io, kv, v) { |b| sink.__send__("#{k}=", b) }
+          rv == true or return rv
+        when "pipe_size"
+          rv = set_uint(io, kv, v, true) { |u| sink.__send__("#{k}=", u) }
+          rv == true or return rv
+        when "command" # nothing to validate, this could be "rm -rf /" :>
+          sink.command = v.empty? ? DTAS::Sink::SINK_DEFAULTS["command"] : v
+        end
+      end
+
+      @sinks[name] = new_sink if new_sink # no errors? it's a new sink!
+
+      # start or stop a sink if its active= flag changed.  Additionally,
+      # account for a crashed-but-marked-active sink.  The user may have
+      # fixed the command to not crash it.
+      if (active_before != sink.active) || (sink.active && !sink.pid)
+        __sink_switch(sink)
+      end
+      io.emit("OK")
+    when "cat"
+      sink = @sinks[name] or return io.emit("ERR #{name} not found")
+      io.emit(sink.to_hsh.to_yaml)
+    else
+      io.emit("ERR unknown sink op #{msg[0]}")
+    end
+  end
+
+  def bytes_decoded(src = @current)
+    bytes = src.dst.bytes_xfer - src.dst_zero_byte
+    bytes = bytes < 0 ? 0 : bytes # maybe negative in case of sink errors
+  end
+
+  def __seek_offset_adj(dir, offset)
+    if offset.sub!(/s\z/, '')
+      offset = offset.to_i
+    else # time
+      offset = @current.format.hhmmss_to_samples(offset)
+    end
+    n = __current_decoded_samples + (dir * offset)
+    n = 0 if n < 0
+    "#{n}s"
+  end
+
+  def __current_decoded_samples
+    initial = @current.offset_samples
+    decoded = @format.bytes_to_samples(bytes_decoded)
+    decoded = out_samples(decoded, @format, @current.format)
+    initial + decoded
+  end
+
+  def __current_requeue
+    return unless @current && @current.pid
+
+    # no need to requeue if we're already due to die
+    return if @current.requeued
+    @current.requeued = true
+
+    dst = @current.dst
+    # prepare to seek to the desired point based on the number of bytes which
+    # passed through dst buffer we want the offset for the @current file,
+    # which may have a different rate than our internal @format
+    if @current.respond_to?(:infile)
+      # this offset in the @current.format (not player @format)
+      @queue.unshift([ @current.infile, "#{__current_decoded_samples}s" ])
+    else
+      # DTAS::Source::Command (hash), just rerun it
+      @queue.unshift(@current.to_hsh)
+    end
+    # We also want to hard drop the buffer so we do not get repeated audio.
+    __buf_reset(dst)
+  end
+
+  def out_samples(in_samples, infmt, outfmt)
+    in_rate = infmt.rate
+    out_rate = outfmt.rate
+    return in_samples if in_rate == out_rate # easy!
+    (in_samples * out_rate / in_rate.to_f).round
+  end
+
+  # returns the number of samples we expect from the source
+  # this takes into account sample rate differences between the source
+  # and internal player format
+  def current_expect_samples(in_samples) # @current.samples
+    out_samples(in_samples, @current.format, @format)
+  end
+
+  def rg_handler(io, msg)
+    return io.emit(@rg.to_hsh.to_yaml) if msg.empty?
+    before = @rg.to_hsh
+    msg.each do |kv|
+      k, v = kv.split(/=/, 2)
+      case k
+      when "mode"
+        case v
+        when "off"
+          @rg.mode = nil
+        else
+          DTAS::RGState::RG_MODE.include?(v) or
+            return io.emit("ERR rg mode invalid")
+          @rg.mode = v
+        end
+      when "fallback_track"
+        rv = set_bool(io, kv, v) { |b| @rg.fallback_track = b }
+        rv == true or return rv
+      when %r{(?:gain_threshold|norm_threshold|
+              preamp|norm_level|fallback_gain)[+-]?\z}x
+        rv = adjust_numeric(io, @rg, k, v)
+        rv == true or return rv
+      end
+    end
+    after = @rg.to_hsh
+    __current_requeue if before != after
+    io.emit("OK")
+  end
+
+  def active_sinks
+    sinks = @targets.map { |t| t.sink }
+    sinks.uniq!
+    sinks
+  end
+
+  # show current info about what's playing
+  # returns non-blocking iterator retval
+  def current_handler(io, msg)
+    tmp = {}
+    if @current
+      tmp["current"] = s = @current.to_hsh
+      s["spawn_at"] = @current.spawn_at
+      s["pid"] = @current.pid
+
+      # this offset and samples in the player @format (not @current.format)
+      decoded = @format.bytes_to_samples(bytes_decoded)
+      if @current.respond_to?(:infile)
+        initial = tmp["current_initial"] = @current.offset_samples
+        initial = out_samples(initial, @current.format, @format)
+        tmp["current_expect"] = current_expect_samples(s["samples"])
+        s["format"] = @current.format.to_hash.delete_if { |_,v| v.nil? }
+      else
+        initial = 0
+        tmp["current_expect"] = nil
+        s["format"] = @format.to_hash.delete_if { |_,v| v.nil? }
+      end
+      tmp["current_offset"] = initial + decoded
+    end
+    tmp["current_inflight"] = @sink_buf.inflight
+    tmp["format"] = @format.to_hash.delete_if { |_,v| v.nil? }
+    tmp["paused"] = @paused
+    rg = @rg.to_hsh
+    tmp["rg"] = rg unless rg.empty?
+    if @targets[0]
+      sinks = active_sinks
+      tmp["sinks"] = sinks.map! do |sink|
+        h = sink.to_hsh
+        h["pid"] = sink.pid
+        h
+      end
+    end
+    io.emit(tmp.to_yaml)
+  end
+
+  def __buf_reset(buf)
+    @srv.wait_ctl(buf, :ignore)
+    buf.buf_reset
+    @srv.wait_ctl(buf, :wait_readable)
+  end
+
+  def skip_handler(io, msg)
+    __current_drop
+    echo("skip")
+    io.emit("OK")
+  end
+
+  def play_pause_handler(io, command)
+    prev = @paused
+    __send__("do_#{command}")
+    io.emit({
+      "paused" => {
+        "before" => prev,
+        "after" => @paused,
+      }
+    }.to_yaml)
+  end
+
+  def do_pause
+    return if @paused
+    echo("pause")
+    @paused = true
+    __current_requeue
+  end
+
+  def do_play
+    # no echo, next_source will echo on new track
+    @paused = false
+    return if @current && @current.pid
+    next_source(@queue.shift)
+  end
+
+  def do_play_pause
+    @paused ? do_play : do_pause
+  end
+
+  def do_seek(io, offset)
+    if @current && @current.pid
+      if @current.respond_to?(:infile)
+        begin
+          if offset.sub!(/\A\+/, '')
+            offset = __seek_offset_adj(1, offset)
+          elsif offset.sub!(/\A-/, '')
+            offset = __seek_offset_adj(-1, offset)
+          # else: pass to sox directly
+          end
+        rescue ArgumentError
+          return io.emit("ERR bad time format")
+        end
+        @queue.unshift([ @current.infile, offset ])
+        __buf_reset(@current.dst) # trigger EPIPE
+      else
+        return io.emit("ERR unseekable")
+      end
+    elsif @paused
+      case file = @queue[0]
+      when String
+        @queue[0] = [ file, offset ]
+      when Array
+        file[1] = offset
+      else
+        return io.emit("ERR unseekable")
+      end
+    # unpaused case... what do we do?
+    end
+    io.emit("OK")
+  end
+
+  def restart_pipeline
+    return if @paused
+    __current_requeue
+    @sinks.each_value { |sink| sink.respawn = sink.active }
+    @targets.each { |t| drop_target(t) }.clear
+  end
+
+  def format_handler(io, msg)
+    new_fmt = @format.dup
+    msg.each do |kv|
+      k, v = kv.split(/=/, 2)
+      case k
+      when "type"
+        new_fmt.valid_type?(v) or return io.emit("ERR invalid file type")
+        new_fmt.type = v
+      when "channels", "bits", "rate"
+        rv = set_uint(io, kv, v, false) { |u| new_fmt.__send__("#{k}=", u) }
+        rv == true or return rv
+      when "endian"
+        new_fmt.valid_endian?(v) or return io.emit("ERR invalid endian")
+        new_fmt.endian = v
+      end
+    end
+
+    if new_fmt != @format
+      restart_pipeline # calls __current_requeue
+
+      # we must assign this after __current_requeue since __current_requeue
+      # relies on the old @format for calculation
+      @format = new_fmt
+    end
+    io.emit("OK")
+  end
+
+  def env_handler(io, msg)
+    msg.each do |kv|
+      case kv
+      when %r{\A([^=]+)=(.*)\z}
+        ENV[$1] = $2
+      when %r{\A([^=]+)#}
+        ENV.delete($1)
+      else
+        return io.emit("ERR bad env")
+      end
+    end
+    io.emit("OK")
+  end
+
+  def source_handler(io, msg)
+    case msg.shift
+    when "cat"
+      io.emit({
+        "command" => @srccmd || DTAS::Source::SOURCE_DEFAULTS["command"],
+        "env" => @srcenv,
+      }.to_yaml)
+    when "ed"
+      before = [ @srccmd, @srcenv ].inspect
+      msg.each do |kv|
+        k, v = kv.split(/=/, 2)
+        case k
+        when "command"
+          @srccmd = v.empty? ? nil : v
+        when %r{\Aenv\.([^=]+)\z}
+          @srcenv[$1] = v
+        when %r{\Aenv#([^=]+)\z}
+          v == nil or return io.emit("ERR unset env has no value")
+          @srcenv.delete($1)
+        end
+      end
+      after = [ @srccmd, @srcenv ].inspect
+      __current_requeue if before != after
+      io.emit("OK")
+    else
+      io.emit("ERR unknown source op")
+    end
+  end
+end
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