1 # -*- encoding: binary -*-
2 # internal implementation details here, do not rely on them in your code
4 # This class is needed because Net::HTTP streaming is still inefficient
5 # for reading huge response bodies over fast LANs.
6 class MogileFS::HTTPReader < MogileFS::Socket
7 attr_accessor :content_length, :uri
9 # backwards compat, if anybody cares
10 alias mogilefs_size content_length # :nodoc:
12 # this may OOM your system on large files
15 read(@content_length, buf)
16 return buf if buf.size == @content_length
18 raise MogileFS::SizeMismatchError,
19 "read=#{buf.size} bytes, expected=#@content_length from #@uri", []
23 rv = MogileFS.io.copy_stream(self, dest)
24 return rv if rv == @content_length
25 raise MogileFS::SizeMismatchError,
26 "read=#{rv} bytes, expected=#@content_length from #@uri", []
29 def self.first(paths, timeout, count = nil, offset = nil)
33 range_end = count ? offset + count - 1 : ""
34 range = "Range: bytes=#{offset}-#{range_end}\r\n"
39 sock = try(path, timeout, range) and return sock
42 errors << "#{path} - #{e.message} (#{e.class})"
45 raise MogileFS::Error,
46 "all paths failed with GET: #{errors.join(', ')}", []
49 # given a path, this returns a readable socket with ready data from the
50 # body of the response.
51 def self.try(path, timeout, range) # :nodoc:
53 sock = tcp(uri.host, uri.port, timeout)
54 buf = "GET #{uri.request_uri} HTTP/1.0\r\n#{range}\r\n" # no chunking
55 sock.timed_write(buf, timeout)
57 sock.timed_peek(2048, buf, timeout) or
58 raise MogileFS::InvalidResponseError, "EOF while reading header", []
60 head, _ = buf.split(/\r\n\r\n/, 2)
62 # we're dealing with a seriously slow/stupid HTTP server if we can't
63 # get the header in a single recv(2) syscall.
64 if ((range && head =~ %r{\AHTTP/\d+\.\d+\s+206\s*}) ||
65 (!range && head =~ %r{\AHTTP/\d+\.\d+\s+200\s*})) &&
66 head =~ %r{^Content-Length:\s*(\d+)}i
67 sock.content_length = $1.to_i
69 sock.timed_read(head.bytesize + 4, buf, 0)
72 msg = range ? "Expected 206 w/#{range.strip}: " : "header="
74 raise MogileFS::InvalidResponseError, msg, []