mirror of
https://github.com/mdn/webextensions-examples.git
synced 2026-04-16 06:18:35 +02:00
37 lines
1.3 KiB
Python
Executable File
37 lines
1.3 KiB
Python
Executable File
#!/usr/bin/env python3
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import sys
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import json
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import struct
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# Read a message from stdin and decode it.
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def getMessage():
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rawLength = sys.stdin.buffer.read(4)
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if len(rawLength) == 0:
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sys.exit(0)
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messageLength = struct.unpack('@I', rawLength)[0]
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message = sys.stdin.buffer.read(messageLength).decode('utf-8')
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return json.loads(message)
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# Encode a message for transmission, given its content.
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def encodeMessage(messageContent):
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# https://docs.python.org/3/library/json.html#basic-usage
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# To get the most compact JSON representation, you should specify
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# (',', ':') to eliminate whitespace.
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# We want the most compact representation because the browser rejects
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# messages that exceed 1 MB.
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encodedContent = json.dumps(messageContent, separators=(',', ':')).encode('utf-8')
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encodedLength = struct.pack('@I', len(encodedContent))
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return {'length': encodedLength, 'content': encodedContent}
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# Send an encoded message to stdout
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def sendMessage(encodedMessage):
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sys.stdout.buffer.write(encodedMessage['length'])
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sys.stdout.buffer.write(encodedMessage['content'])
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sys.stdout.buffer.flush()
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while True:
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receivedMessage = getMessage()
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if receivedMessage == "ping":
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sendMessage(encodeMessage("pong"))
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