medusa.producers.output_producer.__init__() - Code Metrics - Inspection of "Refactoring of planet production phase code." - ospaceteam/outerspace - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#192)

by Marek

created 2018-06-23 22:22 UTC

medusa.producers.output_producer.init() A

↳ Parent: medusa.producers

Complexity

Conditions

Size

Total Lines	2
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	1
eloc	2
nop	1
dl	0
loc	2
rs	10
c	0
b	0
f	0

# -*- Mode: Python; tab-width: 4 -*-

import string

"""
A collection of producers.
Each producer implements a particular feature:  They can be combined
in various ways to get interesting and useful behaviors.

For example, you can feed dynamically-produced output into the compressing
producer, then wrap this with the 'chunked' transfer-encoding producer.
"""

class simple_producer:

    "producer for a string"
    def __init__ (self, data, buffer_size=1024):
        self.data = data
        self.buffer_size = buffer_size

    def more (self):
        if len (self.data) > self.buffer_size:
            result = self.data[:self.buffer_size]
            self.data = self.data[self.buffer_size:]
            return result
        else:
            result = self.data
            self.data = ''
            return result

class scanning_producer:
    "like simple_producer, but more efficient for large strings"
    def __init__ (self, data, buffer_size=1024):
        self.data = data
        self.buffer_size = buffer_size
        self.pos = 0

    def more (self):
        if self.pos < len(self.data):
            lp = self.pos
            rp = min (
                len(self.data),
                self.pos + self.buffer_size
                )
            result = self.data[lp:rp]
            self.pos = self.pos + len(result)
            return result
        else:
            return ''

class lines_producer:

    "producer for a list of lines"

    def __init__ (self, lines):
        self.lines = lines

    def ready (self):
        return len(self.lines)

    def more (self):
        if self.lines:
            chunk = self.lines[:50]
            self.lines = self.lines[50:]
            return string.join (chunk, '\r\n') + '\r\n'
        else:
            return ''

class buffer_list_producer:
    "producer for a list of buffers"

    # i.e., data == string.join (buffers, '')

    def __init__ (self, buffers):

        self.index = 0
        self.buffers = buffers

    def more (self):
        if self.index >= len(self.buffers):
            return ''
        else:
            data = self.buffers[self.index]
            self.index = self.index + 1
            return data

class file_producer:
    "producer wrapper for file[-like] objects"

    # match http_channel's outgoing buffer size
    out_buffer_size = 1<<16

    def __init__ (self, file):
        self.done = 0
        self.file = file

    def more (self):
        if self.done:
            return ''
        else:
            data = self.file.read (self.out_buffer_size)
            if not data:
                self.file.close()
                del self.file
                self.done = 1
                return ''
            else:
                return data

# A simple output producer.  This one does not [yet] have
# the safety feature builtin to the monitor channel:  runaway
# output will not be caught.

# don't try to print from within any of the methods
# of this object.

class output_producer:
    "Acts like an output file; suitable for capturing sys.stdout"
    def __init__ (self):
        self.data = ''

    def write (self, data):
        lines = string.splitfields (data, '\n')
        data = string.join (lines, '\r\n')
        self.data = self.data + data

    def writeline (self, line):
        self.data = self.data + line + '\r\n'

    def writelines (self, lines):
        self.data = self.data + string.joinfields (
            lines,
            '\r\n'
            ) + '\r\n'

    def ready (self):
        return (len (self.data) > 0)

    def flush (self):
        pass

    def softspace (self, *args):
        pass

    def more (self):
        if self.data:
            result = self.data[:512]
            self.data = self.data[512:]
            return result
        else:
            return ''

class composite_producer:
    "combine a fifo of producers into one"
    def __init__ (self, producers):
        self.producers = producers

    def more (self):
        while len(self.producers):
            p = self.producers.first()
            d = p.more()
            if d:
                return d
            else:
                self.producers.pop()
        else:
            return ''


class globbing_producer:
    """
    'glob' the output from a producer into a particular buffer size.
    helps reduce the number of calls to send().  [this appears to
    gain about 30% performance on requests to a single channel]
    """

    def __init__ (self, producer, buffer_size=1<<16):
        self.producer = producer
        self.buffer = ''
        self.buffer_size = buffer_size

    def more (self):
        while len(self.buffer) < self.buffer_size:
            data = self.producer.more()
            if data:
                self.buffer = self.buffer + data
            else:
                break
        r = self.buffer
        self.buffer = ''
        return r


class hooked_producer:
    """
    A producer that will call <function> when it empties,.
    with an argument of the number of bytes produced.  Useful
    for logging/instrumentation purposes.
    """

    def __init__ (self, producer, function):
        self.producer = producer
        self.function = function
        self.bytes = 0

    def more (self):
        if self.producer:
            result = self.producer.more()
            if not result:
                self.producer = None
                self.function (self.bytes)
            else:
                self.bytes = self.bytes + len(result)
            return result
        else:
            return ''

# HTTP 1.1 emphasizes that an advertised Content-Length header MUST be
# correct.  In the face of Strange Files, it is conceivable that
# reading a 'file' may produce an amount of data not matching that
# reported by os.stat() [text/binary mode issues, perhaps the file is
# being appended to, etc..]  This makes the chunked encoding a True
# Blessing, and it really ought to be used even with normal files.
# How beautifully it blends with the concept of the producer.

class chunked_producer:
    """A producer that implements the 'chunked' transfer coding for HTTP/1.1.
    Here is a sample usage:
        request['Transfer-Encoding'] = 'chunked'
        request.push (
            producers.chunked_producer (your_producer)
            )
        request.done()
    """

    def __init__ (self, producer, footers=None):
        self.producer = producer
        self.footers = footers

    def more (self):
        if self.producer:
            data = self.producer.more()
            if data:
                return '%x\r\n%s\r\n' % (len(data), data)
            else:
                self.producer = None
                if self.footers:
                    return string.join (
                        ['0'] + self.footers,
                        '\r\n'
                        ) + '\r\n\r\n'
                else:
                    return '0\r\n\r\n'
        else:
            return ''

# Unfortunately this isn't very useful right now (Aug 97), because
# apparently the browsers don't do on-the-fly decompression.  Which
# is sad, because this could _really_ speed things up, especially for
# low-bandwidth clients (i.e., most everyone).

try:
    import zlib
except ImportError:
    zlib = None

class compressed_producer:
    """
    Compress another producer on-the-fly, using ZLIB
    [Unfortunately, none of the current browsers seem to support this]
    """

    # Note: It's not very efficient to have the server repeatedly
    # compressing your outgoing files: compress them ahead of time, or
    # use a compress-once-and-store scheme.  However, if you have low
    # bandwidth and low traffic, this may make more sense than
    # maintaining your source files compressed.
    #
    # Can also be used for compressing dynamically-produced output.

    def __init__ (self, producer, level=5):
        self.producer = producer
        self.compressor = zlib.compressobj (level)

    def more (self):
        if self.producer:
            cdata = ''
            # feed until we get some output
            while not cdata:
                data = self.producer.more()
                if not data:
                    self.producer = None
                    return self.compressor.flush()
                else:
                    cdata = self.compressor.compress (data)
            return cdata
        else:
            return ''

class escaping_producer:

    "A producer that escapes a sequence of characters"
    " Common usage: escaping the CRLF.CRLF sequence in SMTP, NNTP, etc..."

    def __init__ (self, producer, esc_from='\r\n.', esc_to='\r\n..'):
        self.producer = producer
        self.esc_from = esc_from
        self.esc_to = esc_to
        self.buffer = ''
        from asynchat import find_prefix_at_end
        self.find_prefix_at_end = find_prefix_at_end

    def more (self):
        esc_from = self.esc_from
        esc_to   = self.esc_to

        buffer = self.buffer + self.producer.more()

        if buffer:
            buffer = string.replace (buffer, esc_from, esc_to)
            i = self.find_prefix_at_end (buffer, esc_from)
            if i:
                # we found a prefix
                self.buffer = buffer[-i:]
                return buffer[:-i]
            else:
                # no prefix, return it all
                self.buffer = ''
                return buffer
        else:
            return buffer


1		# -- Mode: Python; tab-width: 4 --
2
3		import string
4
5		"""
6		A collection of producers.
7		Each producer implements a particular feature: They can be combined
8		in various ways to get interesting and useful behaviors.
9
10		For example, you can feed dynamically-produced output into the compressing
11		producer, then wrap this with the 'chunked' transfer-encoding producer.
12		"""
13
14	View Code Duplication	class simple_producer:
		0 ignored issues – show Duplication introduced 2018-06-13 22:14 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
15		"producer for a string"
16		def __init__ (self, data, buffer_size=1024):
17		self.data = data
18		self.buffer_size = buffer_size
19
20		def more (self):
21		if len (self.data) > self.buffer_size:
22		result = self.data[:self.buffer_size]
23		self.data = self.data[self.buffer_size:]
24		return result
25		else:
26		result = self.data
27		self.data = ''
28		return result
29
30		class scanning_producer:
31		"like simple_producer, but more efficient for large strings"
32		def __init__ (self, data, buffer_size=1024):
33		self.data = data
34		self.buffer_size = buffer_size
35		self.pos = 0
36
37		def more (self):
38		if self.pos < len(self.data):
39		lp = self.pos
40		rp = min (
41		len(self.data),
42		self.pos + self.buffer_size
43		)
44		result = self.data[lp:rp]
45		self.pos = self.pos + len(result)
46		return result
47		else:
48		return ''
49
50	View Code Duplication	class lines_producer:
		0 ignored issues – show Duplication introduced 2018-06-13 22:14 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
51		"producer for a list of lines"
52
53		def __init__ (self, lines):
54		self.lines = lines
55
56		def ready (self):
57		return len(self.lines)
58
59		def more (self):
60		if self.lines:
61		chunk = self.lines[:50]
62		self.lines = self.lines[50:]
63		return string.join (chunk, '\r\n') + '\r\n'
64		else:
65		return ''
66
67		class buffer_list_producer:
68		"producer for a list of buffers"
69
70		# i.e., data == string.join (buffers, '')
71
72		def __init__ (self, buffers):
73
74		self.index = 0
75		self.buffers = buffers
76
77		def more (self):
78		if self.index >= len(self.buffers):
79		return ''
80		else:
81		data = self.buffers[self.index]
82		self.index = self.index + 1
83		return data
84
85		class file_producer:
86		"producer wrapper for file[-like] objects"
87
88		# match http_channel's outgoing buffer size
89		out_buffer_size = 1<<16
90
91		def __init__ (self, file):
92		self.done = 0
93		self.file = file
94
95		def more (self):
96		if self.done:
97		return ''
98		else:
99		data = self.file.read (self.out_buffer_size)
100		if not data:
101		self.file.close()
102		del self.file
103		self.done = 1
104		return ''
105		else:
106		return data
107
108		# A simple output producer. This one does not [yet] have
109		# the safety feature builtin to the monitor channel: runaway
110		# output will not be caught.
111
112		# don't try to print from within any of the methods
113		# of this object.
114
115		class output_producer:
116		"Acts like an output file; suitable for capturing sys.stdout"
117		def __init__ (self):
118		self.data = ''
119
120		def write (self, data):
121		lines = string.splitfields (data, '\n')
122		data = string.join (lines, '\r\n')
123		self.data = self.data + data
124
125		def writeline (self, line):
126		self.data = self.data + line + '\r\n'
127
128		def writelines (self, lines):
129		self.data = self.data + string.joinfields (
130		lines,
131		'\r\n'
132		) + '\r\n'
133
134		def ready (self):
135		return (len (self.data) > 0)
136
137		def flush (self):
138		pass
139
140		def softspace (self, *args):
141		pass
142
143		def more (self):
144		if self.data:
145		result = self.data[:512]
146		self.data = self.data[512:]
147		return result
148		else:
149		return ''
150
151		class composite_producer:
152		"combine a fifo of producers into one"
153		def __init__ (self, producers):
154		self.producers = producers
155
156		def more (self):
157		while len(self.producers):
158		p = self.producers.first()
159		d = p.more()
160		if d:
161		return d
162		else:
163		self.producers.pop()
164		else:
165		return ''
166
167
168		class globbing_producer:
169		"""
170		'glob' the output from a producer into a particular buffer size.
171		helps reduce the number of calls to send(). [this appears to
172		gain about 30% performance on requests to a single channel]
173		"""
174
175		def __init__ (self, producer, buffer_size=1<<16):
176		self.producer = producer
177		self.buffer = ''
178		self.buffer_size = buffer_size
179
180		def more (self):
181		while len(self.buffer) < self.buffer_size:
182		data = self.producer.more()
183		if data:
184		self.buffer = self.buffer + data
185		else:
186		break
187		r = self.buffer
188		self.buffer = ''
189		return r
190
191
192		class hooked_producer:
193		"""
194		A producer that will call <function> when it empties,.
195		with an argument of the number of bytes produced. Useful
196		for logging/instrumentation purposes.
197		"""
198
199		def __init__ (self, producer, function):
200		self.producer = producer
201		self.function = function
202		self.bytes = 0
203
204		def more (self):
205		if self.producer:
206		result = self.producer.more()
207		if not result:
208		self.producer = None
209		self.function (self.bytes)
210		else:
211		self.bytes = self.bytes + len(result)
212		return result
213		else:
214		return ''
215
216		# HTTP 1.1 emphasizes that an advertised Content-Length header MUST be
217		# correct. In the face of Strange Files, it is conceivable that
218		# reading a 'file' may produce an amount of data not matching that
219		# reported by os.stat() [text/binary mode issues, perhaps the file is
220		# being appended to, etc..] This makes the chunked encoding a True
221		# Blessing, and it really ought to be used even with normal files.
222		# How beautifully it blends with the concept of the producer.
223
224		class chunked_producer:
225		"""A producer that implements the 'chunked' transfer coding for HTTP/1.1.
226		Here is a sample usage:
227		request['Transfer-Encoding'] = 'chunked'
228		request.push (
229		producers.chunked_producer (your_producer)
230		)
231		request.done()
232		"""
233
234		def __init__ (self, producer, footers=None):
235		self.producer = producer
236		self.footers = footers
237
238		def more (self):
239		if self.producer:
240		data = self.producer.more()
241		if data:
242		return '%x\r\n%s\r\n' % (len(data), data)
243		else:
244		self.producer = None
245		if self.footers:
246		return string.join (
247		['0'] + self.footers,
248		'\r\n'
249		) + '\r\n\r\n'
250		else:
251		return '0\r\n\r\n'
252		else:
253		return ''
254
255		# Unfortunately this isn't very useful right now (Aug 97), because
256		# apparently the browsers don't do on-the-fly decompression. Which
257		# is sad, because this could _really_ speed things up, especially for
258		# low-bandwidth clients (i.e., most everyone).
259
260		try:
261		import zlib
262		except ImportError:
263		zlib = None
264
265		class compressed_producer:
266		"""
267		Compress another producer on-the-fly, using ZLIB
268		[Unfortunately, none of the current browsers seem to support this]
269		"""
270
271		# Note: It's not very efficient to have the server repeatedly
272		# compressing your outgoing files: compress them ahead of time, or
273		# use a compress-once-and-store scheme. However, if you have low
274		# bandwidth and low traffic, this may make more sense than
275		# maintaining your source files compressed.
276		#
277		# Can also be used for compressing dynamically-produced output.
278
279		def __init__ (self, producer, level=5):
280		self.producer = producer
281		self.compressor = zlib.compressobj (level)
282
283		def more (self):
284		if self.producer:
285		cdata = ''
286		# feed until we get some output
287		while not cdata:
288		data = self.producer.more()
289		if not data:
290		self.producer = None
291		return self.compressor.flush()
292		else:
293		cdata = self.compressor.compress (data)
294		return cdata
295		else:
296		return ''
297
298		class escaping_producer:
299
300		"A producer that escapes a sequence of characters"
301		" Common usage: escaping the CRLF.CRLF sequence in SMTP, NNTP, etc..."
302
303		def __init__ (self, producer, esc_from='\r\n.', esc_to='\r\n..'):
304		self.producer = producer
305		self.esc_from = esc_from
306		self.esc_to = esc_to
307		self.buffer = ''
308		from asynchat import find_prefix_at_end
309		self.find_prefix_at_end = find_prefix_at_end
310
311		def more (self):
312		esc_from = self.esc_from
313		esc_to = self.esc_to
314
315		buffer = self.buffer + self.producer.more()
316
317		if buffer:
318		buffer = string.replace (buffer, esc_from, esc_to)
319		i = self.find_prefix_at_end (buffer, esc_from)
320		if i:
321		# we found a prefix
322		self.buffer = buffer[-i:]
323		return buffer[:-i]
324		else:
325		# no prefix, return it all
326		self.buffer = ''
327		return buffer
328		else:
329		return buffer
330

ospaceteam / outerspace

Pull Request — master (#192)

medusa.producers.output_producer.__init__() A

Complexity

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Duplication

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medusa.producers.output_producer.init() A