/
streaming.rb
142 lines (132 loc) · 6.16 KB
/
streaming.rb
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
module ActionController #:nodoc:
# Methods for sending files and streams to the browser instead of rendering.
module Streaming
DEFAULT_SEND_FILE_OPTIONS = {
:type => 'application/octet-stream'.freeze,
:disposition => 'attachment'.freeze,
:stream => true,
:buffer_size => 4096
}.freeze
protected
# Sends the file by streaming it 4096 bytes at a time. This way the
# whole file doesn't need to be read into memory at once. This makes
# it feasible to send even large files.
#
# Be careful to sanitize the path parameter if it coming from a web
# page. send_file(@params['path']) allows a malicious user to
# download any file on your server.
#
# Options:
# * <tt>:filename</tt> - suggests a filename for the browser to use.
# Defaults to File.basename(path).
# * <tt>:type</tt> - specifies an HTTP content type.
# Defaults to 'application/octet-stream'.
# * <tt>:disposition</tt> - specifies whether the file will be shown inline or downloaded.
# Valid values are 'inline' and 'attachment' (default).
# * <tt>:stream</tt> - whether to send the file to the user agent as it is read (true)
# or to read the entire file before sending (false). Defaults to true.
# * <tt>:buffer_size</tt> - specifies size (in bytes) of the buffer used to stream the file.
# Defaults to 4096.
#
# The default Content-Type and Content-Disposition headers are
# set to download arbitrary binary files in as many browsers as
# possible. IE versions 4, 5, 5.5, and 6 are all known to have
# a variety of quirks (especially when downloading over SSL).
#
# Simple download:
# send_file '/path/to.zip'
#
# Show a JPEG in browser:
# send_file '/path/to.jpeg', :type => 'image/jpeg', :disposition => 'inline'
#
# Read about the other Content-* HTTP headers if you'd like to
# provide the user with more information (such as Content-Description).
# http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.11
#
# Also be aware that the document may be cached by proxies and browsers.
# The Pragma and Cache-Control headers declare how the file may be cached
# by intermediaries. They default to require clients to validate with
# the server before releasing cached responses. See
# http://www.mnot.net/cache_docs/ for an overview of web caching and
# http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9
# for the Cache-Control header spec.
def send_file(path, options = {}) #:doc:
raise MissingFile, "Cannot read file #{path}" unless File.file?(path) and File.readable?(path)
options[:length] ||= File.size(path)
options[:filename] ||= File.basename(path)
send_file_headers! options
@performed_render = false
if options[:stream]
render :text => Proc.new { |response, output|
logger.info "Streaming file #{path}" unless logger.nil?
len = options[:buffer_size] || 4096
File.open(path, 'rb') do |file|
if output.respond_to?(:syswrite)
begin
while true
output.syswrite(file.sysread(len))
end
rescue EOFError
end
else
while buf = file.read(len)
output.write(buf)
end
end
end
}
else
logger.info "Sending file #{path}" unless logger.nil?
File.open(path, 'rb') { |file| render :text => file.read }
end
end
# Send binary data to the user as a file download. May set content type, apparent file name,
# and specify whether to show data inline or download as an attachment.
#
# Options:
# * <tt>:filename</tt> - Suggests a filename for the browser to use.
# * <tt>:type</tt> - specifies an HTTP content type.
# Defaults to 'application/octet-stream'.
# * <tt>:disposition</tt> - specifies whether the file will be shown inline or downloaded.
# Valid values are 'inline' and 'attachment' (default).
#
# Generic data download:
# send_data buffer
#
# Download a dynamically-generated tarball:
# send_data generate_tgz('dir'), :filename => 'dir.tgz'
#
# Display an image Active Record in the browser:
# send_data image.data, :type => image.content_type, :disposition => 'inline'
#
# See +send_file+ for more information on HTTP Content-* headers and caching.
def send_data(data, options = {}) #:doc:
logger.info "Sending data #{options[:filename]}" unless logger.nil?
send_file_headers! options.merge(:length => data.size)
@performed_render = false
render :text => data
end
private
def send_file_headers!(options)
options.update(DEFAULT_SEND_FILE_OPTIONS.merge(options))
[:length, :type, :disposition].each do |arg|
raise ArgumentError, ":#{arg} option required" if options[arg].nil?
end
disposition = options[:disposition].dup || 'attachment'
disposition <<= %(; filename="#{options[:filename]}") if options[:filename]
@headers.update(
'Content-Length' => options[:length],
'Content-Type' => options[:type].strip, # fixes a problem with extra '\r' with some browsers
'Content-Disposition' => disposition,
'Content-Transfer-Encoding' => 'binary'
)
# Fix a problem with IE 6.0 on opening downloaded files:
# If Cache-Control: no-cache is set (which Rails does by default),
# IE removes the file it just downloaded from its cache immediately
# after it displays the "open/save" dialog, which means that if you
# hit "open" the file isn't there anymore when the application that
# is called for handling the download is run, so let's workaround that
@headers['Cache-Control'] = 'private' if @headers['Cache-Control'] == 'no-cache'
end
end
end