Skip to content

Http2Conn.md

Latest commit

 

History

History
96 lines (71 loc) · 2.24 KB

Http2Conn.md

File metadata and controls

96 lines (71 loc) · 2.24 KB
Raw

Http2Conn

HTTP/2 connection management. Handles connection preface, settings negotiation, flow control, stream allocation, and frame dispatch.

Why Http2Conn?

Ties together framing, stream state machines, HPACK tables, and flow control into a single connection-level abstraction. Processes incoming frames and generates response frames automatically (SETTINGS_ACK, PING_ACK).

Types

H2Conn

CONST MaxStreams = 64;

TYPE H2Conn = RECORD
  localSettings:  Settings;
  remoteSettings: Settings;
  connSendWindow: INTEGER;
  connRecvWindow: INTEGER;
  nextStreamId:   CARDINAL;
  lastPeerStream: CARDINAL;
  goawayCode:     CARDINAL;
  goawaySent:     BOOLEAN;
  goawayRecv:     BOOLEAN;
  streams:    ARRAY [0..63] OF H2Stream;
  streamUsed: ARRAY [0..63] OF BOOLEAN;
  numActive:  CARDINAL;
  streamTable: StreamTransTable;
  dynTableEnc: DynTable;
  dynTableDec: DynTable;
  outBuf:     Buf;
END;

Procedures

Lifecycle

PROCEDURE InitConn(VAR c: H2Conn);
PROCEDURE FreeConn(VAR c: H2Conn);

Connection Preface

PROCEDURE SendPreface(VAR c: H2Conn);

Writes the 24-byte client magic + initial SETTINGS frame to outBuf.

Frame Processing

PROCEDURE ProcessFrame(VAR c: H2Conn; hdr: FrameHeader;
                       payload: BytesView; VAR ok: BOOLEAN);

Dispatches by frame type. Handles SETTINGS (updates remote, sends ACK), PING (echoes with ACK), GOAWAY (marks connection), WINDOW_UPDATE (adjusts windows), RST_STREAM (closes stream), DATA (consumes recv window), HEADERS (drives stream FSM).

Stream Management

PROCEDURE OpenStream(VAR c: H2Conn): CARDINAL;
PROCEDURE FindStream(VAR c: H2Conn; streamId: CARDINAL): CARDINAL;

Client streams use odd IDs starting from 1.

Flow Control

PROCEDURE UpdateConnSendWindow(VAR c: H2Conn; increment: CARDINAL);
PROCEDURE ConsumeConnSendWindow(VAR c: H2Conn; n: CARDINAL): BOOLEAN;

Output

PROCEDURE GetOutput(VAR c: H2Conn): BytesView;
PROCEDURE ClearOutput(VAR c: H2Conn);

Usage

VAR c: H2Conn;
InitConn(c);
SendPreface(c);
(* flush GetOutput(c) to network *)
ClearOutput(c);
(* receive frames, call ProcessFrame *)
(* flush GetOutput(c) after each ProcessFrame *)
FreeConn(c);