Copyright (c) 2005 Zed A. Shaw
You can redistribute it and/or modify it under the same terms as Ruby.

include “http11_parser.h” include <stdio.h> include <assert.h> include <stdlib.h> include <ctype.h> include <string.h>

define LEN(AT, FPC) (FPC - buffer - parser->AT) define MARK(M,FPC) (parser->M = (FPC) - buffer) define PTR_TO(F) (buffer + parser->F) define L(M) fprintf(stderr, “” # M “n”);

machine

%%{

machine httpclient_parser;

action mark {MARK(mark, fpc); }

action start_field { MARK(field_start, fpc); }

action write_field { 
  parser->field_len = LEN(field_start, fpc);
}

action start_value { MARK(mark, fpc); }

action write_value { 
  parser->http_field(parser->data, PTR_TO(field_start), parser->field_len, PTR_TO(mark), LEN(mark, fpc));
}

action reason_phrase { 
  parser->reason_phrase(parser->data, PTR_TO(mark), LEN(mark, fpc));
}

action status_code { 
  parser->status_code(parser->data, PTR_TO(mark), LEN(mark, fpc));
}

action http_version { 
  parser->http_version(parser->data, PTR_TO(mark), LEN(mark, fpc));
}

action chunk_size {
  parser->chunk_size(parser->data, PTR_TO(mark), LEN(mark, fpc));
}

action last_chunk {
  parser->last_chunk(parser->data, NULL, 0);
}

action done { 
  parser->body_start = fpc - buffer + 1; 
  if(parser->header_done != NULL)
    parser->header_done(parser->data, fpc + 1, pe - fpc - 1);
  fbreak;
}

# line endings

CRLF = "\r\n";

# character types

CTL = (cntrl | 127);
tspecials = ("(" | ")" | "<" | ">" | "@" | "," | ";" | ":" | "\\" | "\"" | "/" | "[" | "]" | "?" | "=" | "{" | "}" | " " | "\t");

# elements

token = (ascii -- (CTL | tspecials));

Reason_Phrase = (any -- CRLF)* >mark %reason_phrase;
Status_Code = digit{3} >mark %status_code;
http_number = (digit+ "." digit+) ;
HTTP_Version = ("HTTP/" http_number) >mark %http_version ;
Status_Line = HTTP_Version " " Status_Code " "? Reason_Phrase :> CRLF;

field_name = token+ >start_field %write_field;
field_value = any* >start_value %write_value;
message_header = field_name ":" " "* field_value :> CRLF;

Response =    Status_Line (message_header)* (CRLF @done);

chunk_ext_val = token+;
chunk_ext_name = token+;
chunk_extension = (";" chunk_ext_name >start_field %write_field %start_value ("=" chunk_ext_val >start_value)? %write_value )*;
last_chunk = "0"? chunk_extension :> (CRLF @last_chunk @done);
chunk_size = xdigit+;
chunk = chunk_size >mark %chunk_size chunk_extension space* :> (CRLF @done);
Chunked_Header = (chunk | last_chunk);

main := Response | Chunked_Header;

}%%

/** Data **/ %% write data;

int httpclient_parser_init(httpclient_parser *parser) {

int cs = 0;
%% write init;
parser->cs = cs;
parser->body_start = 0;
parser->content_len = 0;
parser->mark = 0;
parser->nread = 0;
parser->field_len = 0;
parser->field_start = 0;    

return(1);

}

/** exec **/ size_t httpclient_parser_execute(httpclient_parser *parser, const char *buffer, size_t len, size_t off) {

const char *p, *pe;
int cs = parser->cs;

assert(off <= len && "offset past end of buffer");

p = buffer+off;
pe = buffer+len;

assert(*pe == '\0' && "pointer does not end on NUL");
assert(pe - p == len - off && "pointers aren't same distance");

%% write exec;

parser->cs = cs;
parser->nread += p - (buffer + off);

assert(p <= pe && "buffer overflow after parsing execute");
assert(parser->nread <= len && "nread longer than length");
assert(parser->body_start <= len && "body starts after buffer end");
assert(parser->mark < len && "mark is after buffer end");
assert(parser->field_len <= len && "field has length longer than whole buffer");
assert(parser->field_start < len && "field starts after buffer end");

if(parser->body_start) {
  /* final \r\n combo encountered so stop right here */
  %%write eof;
  parser->nread++;
}

return(parser->nread);

}

int httpclient_parser_finish(httpclient_parser *parser) {

int cs = parser->cs;

%%write eof;

parser->cs = cs;

if (httpclient_parser_has_error(parser) ) {
  return -1;
} else if (httpclient_parser_is_finished(parser) ) {
  return 1;
} else {
  return 0;
}

}

int httpclient_parser_has_error(httpclient_parser *parser) {

return parser->cs == httpclient_parser_error;

}

int httpclient_parser_is_finished(httpclient_parser *parser) {

return parser->cs == httpclient_parser_first_final;

}