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README.md

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smipc for python

This module is a fast ipc library based on shared memory.

For now, only windows is supported.

API

  • init_library(logLevel): void: initializa library and set log level, supported log level: LOG_DISABLE, LOG_BASIC, LOG_ALL.
  • open_channel(cid, mode, chanSz): Channel: create a instance of Channel, cid must be bytes, like: b'test-chan'.
    • Channel implements magic methods for context management __enter__ and __exit__: it opens a channel with specified cid, mode (CHAN_R, CHAN_W) and chanSz (channel size) in __enter__, and closes the channel automatically in __exit__.
    • If there is a channel having the same cid, library will use it directly and the chanSz parameter will be ignored, in another word, chanSz only makes sense when you do create a new channel.
    • A channel only allows one writer and one reader. And both of the read and write operation are not thread-safe, wrap with a lock if you want to do concurrently read or write.
  • Channel.print_status(): void: print current status of the channel in such format: 
    Channel(cid): mode=[R|W] hSharedMem=handleOfSharedMem listener=ifEnableListener syncBuf={RO=ifReaderOpen WO=ifWriterOpen RC=ifReaderClosed WC=ifWriterClosed hREvt=handleOfReadEvent hWEvt=handleOfWriteEvent bufSz=channelSize rc=readCursor wc=WriterCursor state=[empty|full|normal]}
  • Channel.write(data): void: data must be bytes, example: bytes([32, 22, 65]).
    • if the channel is full of unconsumed data, invoking write will be blocked until reader read some data.
  • Channel.read(buf, n, blocking=False): void:
    • use python builtin function create_string_buffer(size) to create buf.
    • n indicates the number of bytes to read from channel.
    • if blocking is set to true, this call won't return until channel read n bytes.
  • clean_library(): void: indicate library to release resources, notice if the opposite end (writer or reader) is still alive, the channel won't be closed.

Example

Blocking transport:

Async trasnport: