Module: Igniter::Store::WireProtocol

Included in:
Codecs::CompactDelta, Codecs::JsonCrc32, FileBackend, NativeFileBackendSnapshotSupport, NetworkBackend, NetworkBackend::Subscription, SegmentedFileBackend, StoreServer, TCPAdapter
Defined in:
lib/igniter/store/wire_protocol.rb

Overview

Shared CRC32-framed binary encoding for WAL files and network transport.

Frame layout:

[4 bytes BE uint32: body_len][body_len bytes: body][4 bytes BE uint32: CRC32(body)]

A frame with a mismatched CRC or truncated body signals corruption / connection loss — the caller should stop reading.

Constant Summary collapse

FRAME_HEADER_SIZE = 
4
FRAME_CRC_SIZE = 
4

Instance Method Summary collapse

Instance Method Details

#encode_frame(body) ⇒ Object 



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# File 'lib/igniter/store/wire_protocol.rb', line 18

def encode_frame(body)
  body_b = body.b
  [body_b.bytesize].pack("N") << body_b << [Zlib.crc32(body)].pack("N")
end

#read_frame(io) ⇒ Object

Reads one frame from io. Returns the body String on success, nil on truncation or CRC mismatch.



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# File 'lib/igniter/store/wire_protocol.rb', line 25

def read_frame(io)
  header = io.read(FRAME_HEADER_SIZE)
  return nil if header.nil? || header.bytesize < FRAME_HEADER_SIZE

  len  = header.unpack1("N")
  body = io.read(len)
  return nil if body.nil? || body.bytesize < len

  crc_bytes = io.read(FRAME_CRC_SIZE)
  return nil if crc_bytes.nil? || crc_bytes.bytesize < FRAME_CRC_SIZE

  return nil unless Zlib.crc32(body) == crc_bytes.unpack1("N")

  body
end