HTTP/1.1 parser: request/response, headers, chunked encoding #62

Phase 6: HTTP/1.1 Parser#

Implement HTTP/1.1 message parsing in the net crate (RFC 7230, 7231).

Requirements#

• Request serialization:
  • Request line: METHOD SP Request-URI SP HTTP/1.1 CRLF
  • Headers: field-name: field-value CRLF
  • Required headers: Host, User-Agent, Accept, Connection
  • Optional: Content-Length, Content-Type for request bodies
• Response parsing:
  • Status line: HTTP/1.1 SP status-code SP reason-phrase CRLF
  • Header parsing: case-insensitive field names, multi-line values
  • HttpResponse { status_code, headers, body } type
• Transfer-Encoding: chunked (RFC 7230 §4.1):
  • Parse chunk-size (hex) CRLF chunk-data CRLF
  • Handle last-chunk (size 0) and optional trailers
  • Dechunk response body transparently
• Content-Length handling: read exact number of body bytes
• Header types: Headers collection with case-insensitive lookup
• Content-Type parsing: extract MIME type and charset parameter

Dependencies#

• None (pure parsing, no I/O)

Acceptance Criteria#

• Serialize HTTP/1.1 GET and POST requests
• Parse HTTP/1.1 response status lines
• Parse headers with case-insensitive lookup
• Handle Content-Length bodies
• Handle chunked Transfer-Encoding
• Handle responses with no body (204, 304)
• Parse Content-Type with charset
• Edge cases: empty body, zero Content-Length, missing Content-Length with chunked
• Comprehensive tests (30+ tests)
• cargo clippy and cargo fmt clean