#line 1 "kcar.rl"
/**
 * Copyright (c) 2009, 2010 Eric Wong (all bugs are Eric's fault)
 * Copyright (c) 2005 Zed A. Shaw
 * You can redistribute it and/or modify it under the same terms as Ruby.
 */
#include "ruby.h"
#include "ext_help.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include "c_util.h"

static VALUE eParserError;
static ID id_sq, id_sq_set;

/** Defines common length and error messages for input length validation. */
#define DEF_MAX_LENGTH(N, length) \
  static const size_t MAX_##N##_LENGTH = length; \
  static const char MAX_##N##_LENGTH_ERR[] = \
    "HTTP element " # N  " is longer than the " # length " allowed length."

/**
 * Validates the max length of given input and throws an ParserError
 * exception if over.
 */
#define VALIDATE_MAX_LENGTH(len, N) do { \
  if (len > MAX_##N##_LENGTH) \
    rb_raise(eParserError, MAX_##N##_LENGTH_ERR); \
} while (0)

/* Defines the maximum allowed lengths for various input elements.*/
DEF_MAX_LENGTH(FIELD_NAME, 256);
DEF_MAX_LENGTH(FIELD_VALUE, 80 * 1024);
DEF_MAX_LENGTH(HEADER, (1024 * (80 + 32)));
DEF_MAX_LENGTH(REASON, 256);

#define UH_FL_CHUNKED  0x1
#define UH_FL_HASBODY  0x2
#define UH_FL_INBODY   0x4
#define UH_FL_HASTRAILER   0x8
#define UH_FL_INTRAILER 0x10
#define UH_FL_INCHUNK  0x20
#define UH_FL_KEEPALIVE 0x40
#define UH_FL_HASHEADER 0x80

struct http_parser {
  int cs; /* Ragel internal state */
  unsigned int flags;
  size_t mark;
  size_t offset;
  union { /* these 2 fields don't nest */
    size_t field;
    size_t query;
  } start;
  union {
    size_t field_len; /* only used during header processing */
    size_t dest_offset; /* only used during body processing */
  } s;
  VALUE cont; /* Qfalse: unset, Qnil: ignored header, T_STRING: append */
  VALUE status; /* String or Qnil */
  union {
    off_t content;
    off_t chunk;
  } len;
};

#define REMAINING (unsigned long)(pe - p)
#define LEN(AT, FPC) (FPC - buffer - hp->AT)
#define MARK(M,FPC) (hp->M = (FPC) - buffer)
#define PTR_TO(F) (buffer + hp->F)
#define STR_NEW(M,FPC) rb_str_new(PTR_TO(M), LEN(M, FPC))
#define STRIPPED_STR_NEW(M,FPC) stripped_str_new(PTR_TO(M), LEN(M, FPC))

#define HP_FL_TEST(hp,fl) ((hp)->flags & (UH_FL_##fl))
#define HP_FL_SET(hp,fl) ((hp)->flags |= (UH_FL_##fl))
#define HP_FL_UNSET(hp,fl) ((hp)->flags &= ~(UH_FL_##fl))
#define HP_FL_ALL(hp,fl) (HP_FL_TEST(hp, fl) == (UH_FL_##fl))

static int is_lws(char c)
{
  return (c == ' ' || c == '\t');
}

static VALUE stripped_str_new(const char *str, long len)
{
  long end;

  for (end = len - 1; end >= 0 && is_lws(str[end]); end--);

  return rb_str_new(str, end + 1);
}

static void finalize_header(struct http_parser *hp)
{
  if ((HP_FL_TEST(hp, HASTRAILER) && ! HP_FL_TEST(hp, CHUNKED)))
    rb_raise(eParserError, "trailer but not chunked");
}

/*
 * handles values of the "Connection:" header, keepalive is implied
 * for HTTP/1.1 but needs to be explicitly enabled with HTTP/1.0
 * Additionally, we require GET/HEAD requests to support keepalive.
 */
static void hp_keepalive_connection(struct http_parser *hp, VALUE val)
{
  /* REQUEST_METHOD is always set before any headers */
  if (STR_CSTR_CASE_EQ(val, "keep-alive")) {
    /* basically have HTTP/1.0 masquerade as HTTP/1.1+ */
    HP_FL_SET(hp, KEEPALIVE);
  } else if (STR_CSTR_CASE_EQ(val, "close")) {
    /*
     * it doesn't matter what HTTP version or request method we have,
     * if a server says "Connection: close", we disable keepalive
     */
    HP_FL_UNSET(hp, KEEPALIVE);
  } else {
    /*
     * server could've sent anything, ignore it for now.  Maybe
     * "HP_FL_UNSET(hp, KEEPALIVE);" just in case?
     * Raising an exception might be too mean...
     */
  }
}

static void
http_version(struct http_parser *hp, VALUE hdr, const char *ptr, size_t len)
{
  if (CONST_MEM_EQ("HTTP/1.1", ptr, len)) {
    /* HTTP/1.1 implies keepalive unless "Connection: close" is set */
    HP_FL_SET(hp, KEEPALIVE);
  }
}

static void
status_phrase(struct http_parser *hp, VALUE hdr, const char *ptr, size_t len)
{
  long nr;

  hp->status = rb_str_new(ptr, len);

  /* RSTRING_PTR is null terminated, ptr is not */
  nr = strtol(RSTRING_PTR(hp->status), NULL, 10);

  if (nr < 100 || nr > 999)
    rb_raise(eParserError, "invalid status: %s", RSTRING_PTR(hp->status));

  if ( !((nr >= 100 && nr <= 199) || nr == 204 || nr == 304) )
    HP_FL_SET(hp, HASBODY);
}

static inline void invalid_if_trailer(struct http_parser *hp)
{
  if (HP_FL_TEST(hp, INTRAILER))
    rb_raise(eParserError, "invalid Trailer");
}

static void write_cont_value(struct http_parser *hp,
                             char *buffer, const char *p)
{
  char *vptr;
  long end;
  long len = LEN(mark, p);
  long cont_len;

  if (hp->cont == Qfalse)
    rb_raise(eParserError, "invalid continuation line");

  if (NIL_P(hp->cont))
    return; /* we're ignoring this header (probably Status:) */

  assert(TYPE(hp->cont) == T_STRING && "continuation line is not a string");
  assert(hp->mark > 0 && "impossible continuation line offset");

  if (len == 0)
    return;

  cont_len = RSTRING_LEN(hp->cont);
  if (cont_len > 0) {
    --hp->mark;
    len = LEN(mark, p);
  }

  vptr = PTR_TO(mark);

  /* normalize tab to space */
  if (cont_len > 0) {
    assert((' ' == *vptr || '\t' == *vptr) && "invalid leading white space");
    *vptr = ' ';
  }
  for (end = len - 1; end >= 0 && is_lws(vptr[end]); end--);
  rb_str_buf_cat(hp->cont, vptr, end + 1);
}

static void write_value(VALUE hdr, struct http_parser *hp,
                        const char *buffer, const char *p)
{
  VALUE f, v;
  VALUE hclass;
  const char *fptr = PTR_TO(start.field);
  size_t flen = hp->s.field_len;
  const char *vptr;
  size_t vlen;

  HP_FL_SET(hp, HASHEADER);

  /* Rack does not like Status headers, so we never send them */
  if (CSTR_CASE_EQ(fptr, flen, "status")) {
    hp->cont = Qnil;
    return;
  }

  vptr = PTR_TO(mark);
  vlen = LEN(mark, p);
  VALIDATE_MAX_LENGTH(vlen, FIELD_VALUE);
  VALIDATE_MAX_LENGTH(flen, FIELD_NAME);
  f = rb_str_new(fptr, (long)flen);
  v = stripped_str_new(vptr, (long)vlen);

  /* needs more tests for error-checking here */
  /*
   * TODO:
   * some of these tests might be too strict for real-world HTTP servers,
   * report real-world examples as we find them:
   */
  if (STR_CSTR_CASE_EQ(f, "connection")) {
    hp_keepalive_connection(hp, v);
  } else if (STR_CSTR_CASE_EQ(f, "content-length")) {
    if (! HP_FL_TEST(hp, HASBODY))
      rb_raise(eParserError, "Content-Length with no body expected");
    if (HP_FL_TEST(hp, CHUNKED))
      rb_raise(eParserError,
               "Content-Length when chunked Transfer-Encoding is set");
    hp->len.content = parse_length(vptr, vlen);

    if (hp->len.content < 0)
      rb_raise(eParserError, "invalid Content-Length");

    invalid_if_trailer(hp);
  } else if (STR_CSTR_CASE_EQ(f, "transfer-encoding")) {
    if (STR_CSTR_CASE_EQ(v, "chunked")) {
      if (! HP_FL_TEST(hp, HASBODY))
        rb_raise(eParserError,
                 "chunked Transfer-Encoding with no body expected");
      if (hp->len.content >= 0)
        rb_raise(eParserError,
                 "chunked Transfer-Encoding when Content-Length is set");

      hp->len.chunk = 0;
      HP_FL_SET(hp, CHUNKED);
    }
    invalid_if_trailer(hp);
  } else if (STR_CSTR_CASE_EQ(f, "trailer")) {
    if (! HP_FL_TEST(hp, HASBODY))
      rb_raise(eParserError, "trailer with no body");
    HP_FL_SET(hp, HASTRAILER);
    invalid_if_trailer(hp);
  }

  hclass = CLASS_OF(hdr);
  if (hclass == rb_cArray) {
    rb_ary_push(hdr, rb_ary_new3(2, f, v));
    hp->cont = v;
  } else {
    /* hash-ish, try rb_hash_* first and fall back to slow rb_funcall */
    VALUE e;

    /* try to read the existing value */
    if (hclass == rb_cHash)
      e = rb_hash_aref(hdr, f);
    else
      e = rb_funcall(hdr, id_sq, 1, f);

    if (NIL_P(e)) {
      /* new value, freeze it since it speeds up MRI slightly */
      OBJ_FREEZE(f);

      if (hclass == rb_cHash)
        rb_hash_aset(hdr, f, v);
      else
        rb_funcall(hdr, id_sq_set, 2, f, v);

      hp->cont = v;
    } else {
      /*
       * existing value, append to it, Rack 1.x uses newlines to represent
       * repeated cookies:
       *    { 'Set-Cookie' => "a=b\nc=d" }
       * becomes:
       *    "Set-Cookie: a=b\r\nSet-Cookie: c=d\r\n"
       */
      rb_str_buf_cat(e, "\n", 1);
      hp->cont = rb_str_buf_append(e, v);
    }
  }
}

/** Machine **/


#line 363 "kcar.rl"


/** Data **/

#line 309 "kcar.c"
static const int http_parser_start = 1;
static const int http_parser_first_final = 44;
static const int http_parser_error = 0;

static const int http_parser_en_ChunkedBody = 22;
static const int http_parser_en_ChunkedBody_chunk_chunk_end = 27;
static const int http_parser_en_Trailers = 36;
static const int http_parser_en_main = 1;


#line 367 "kcar.rl"

static void http_parser_init(struct http_parser *hp)
{
  int cs = 0;
  memset(hp, 0, sizeof(struct http_parser));
  hp->cont = Qfalse; /* zero on MRI, should be optimized away by above */
  hp->status = Qnil;
  hp->len.content = -1;
  
#line 330 "kcar.c"
	{
	cs = http_parser_start;
	}

#line 376 "kcar.rl"
  hp->cs = cs;
}

/** exec **/
static void http_parser_execute(struct http_parser *hp,
  VALUE hdr, char *buffer, size_t len)
{
  const char *p, *pe;
  int cs = hp->cs;
  size_t off = hp->offset;

  if (cs == http_parser_first_final)
    return;

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

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

  assert((void *)(pe - p) == (void *)(len - off) &&
         "pointers aren't same distance");

  if (HP_FL_TEST(hp, INCHUNK)) {
    HP_FL_UNSET(hp, INCHUNK);
    goto skip_chunk_data_hack;
  }
  
#line 363 "kcar.c"
	{
	if ( p == pe )
		goto _test_eof;
	switch ( cs )
	{
case 1:
	if ( (*p) == 72 )
		goto tr0;
	goto st0;
st0:
cs = 0;
	goto _out;
tr0:
#line 303 "kcar.rl"
	{MARK(mark, p); }
	goto st2;
st2:
	if ( ++p == pe )
		goto _test_eof2;
case 2:
#line 384 "kcar.c"
	if ( (*p) == 84 )
		goto st3;
	goto st0;
st3:
	if ( ++p == pe )
		goto _test_eof3;
case 3:
	if ( (*p) == 84 )
		goto st4;
	goto st0;
st4:
	if ( ++p == pe )
		goto _test_eof4;
case 4:
	if ( (*p) == 80 )
		goto st5;
	goto st0;
st5:
	if ( ++p == pe )
		goto _test_eof5;
case 5:
	if ( (*p) == 47 )
		goto st6;
	goto st0;
st6:
	if ( ++p == pe )
		goto _test_eof6;
case 6:
	if ( 48 <= (*p) && (*p) <= 57 )
		goto st7;
	goto st0;
st7:
	if ( ++p == pe )
		goto _test_eof7;
case 7:
	if ( (*p) == 46 )
		goto st8;
	if ( 48 <= (*p) && (*p) <= 57 )
		goto st7;
	goto st0;
st8:
	if ( ++p == pe )
		goto _test_eof8;
case 8:
	if ( 48 <= (*p) && (*p) <= 57 )
		goto st9;
	goto st0;
st9:
	if ( ++p == pe )
		goto _test_eof9;
case 9:
	if ( (*p) == 32 )
		goto tr9;
	if ( 48 <= (*p) && (*p) <= 57 )
		goto st9;
	goto st0;
tr9:
#line 310 "kcar.rl"
	{ http_version(hp, hdr, PTR_TO(mark), LEN(mark, p)); }
	goto st10;
st10:
	if ( ++p == pe )
		goto _test_eof10;
case 10:
#line 449 "kcar.c"
	if ( (*p) == 32 )
		goto st10;
	if ( 48 <= (*p) && (*p) <= 57 )
		goto tr11;
	goto st0;
tr11:
#line 303 "kcar.rl"
	{MARK(mark, p); }
	goto st11;
st11:
	if ( ++p == pe )
		goto _test_eof11;
case 11:
#line 463 "kcar.c"
	switch( (*p) ) {
		case 10: goto tr12;
		case 13: goto tr13;
		case 32: goto st20;
	}
	if ( 48 <= (*p) && (*p) <= 57 )
		goto st11;
	goto st0;
tr12:
#line 311 "kcar.rl"
	{ status_phrase(hp, hdr, PTR_TO(mark), LEN(mark, p)); }
	goto st12;
tr22:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
#line 309 "kcar.rl"
	{ write_cont_value(hp, buffer, p); }
	goto st12;
tr25:
#line 309 "kcar.rl"
	{ write_cont_value(hp, buffer, p); }
	goto st12;
tr32:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
#line 308 "kcar.rl"
	{ write_value(hdr, hp, buffer, p); }
	goto st12;
tr35:
#line 308 "kcar.rl"
	{ write_value(hdr, hp, buffer, p); }
	goto st12;
st12:
	if ( ++p == pe )
		goto _test_eof12;
case 12:
#line 500 "kcar.c"
	switch( (*p) ) {
		case 9: goto st13;
		case 10: goto tr17;
		case 13: goto st16;
		case 32: goto st13;
		case 33: goto tr19;
		case 124: goto tr19;
		case 126: goto tr19;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto tr19;
		} else if ( (*p) >= 35 )
			goto tr19;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto tr19;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto tr19;
		} else
			goto tr19;
	} else
		goto tr19;
	goto st0;
tr21:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
	goto st13;
st13:
	if ( ++p == pe )
		goto _test_eof13;
case 13:
#line 536 "kcar.c"
	switch( (*p) ) {
		case 9: goto tr21;
		case 10: goto tr22;
		case 13: goto tr23;
		case 32: goto tr21;
	}
	goto tr20;
tr20:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
	goto st14;
st14:
	if ( ++p == pe )
		goto _test_eof14;
case 14:
#line 552 "kcar.c"
	switch( (*p) ) {
		case 10: goto tr25;
		case 13: goto tr26;
	}
	goto st14;
tr13:
#line 311 "kcar.rl"
	{ status_phrase(hp, hdr, PTR_TO(mark), LEN(mark, p)); }
	goto st15;
tr23:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
#line 309 "kcar.rl"
	{ write_cont_value(hp, buffer, p); }
	goto st15;
tr26:
#line 309 "kcar.rl"
	{ write_cont_value(hp, buffer, p); }
	goto st15;
tr33:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
#line 308 "kcar.rl"
	{ write_value(hdr, hp, buffer, p); }
	goto st15;
tr36:
#line 308 "kcar.rl"
	{ write_value(hdr, hp, buffer, p); }
	goto st15;
st15:
	if ( ++p == pe )
		goto _test_eof15;
case 15:
#line 586 "kcar.c"
	if ( (*p) == 10 )
		goto st12;
	goto st0;
tr17:
#line 318 "kcar.rl"
	{
    finalize_header(hp);
    cs = http_parser_first_final;

    if (HP_FL_TEST(hp, CHUNKED))
      cs = http_parser_en_ChunkedBody;

    /*
     * go back to Ruby so we can call the Rack application, we'll reenter
     * the parser iff the body needs to be processed.
     */
    goto post_exec;
  }
	goto st44;
st44:
	if ( ++p == pe )
		goto _test_eof44;
case 44:
#line 610 "kcar.c"
	goto st0;
st16:
	if ( ++p == pe )
		goto _test_eof16;
case 16:
	if ( (*p) == 10 )
		goto tr17;
	goto st0;
tr19:
#line 305 "kcar.rl"
	{ MARK(start.field, p); }
	goto st17;
st17:
	if ( ++p == pe )
		goto _test_eof17;
case 17:
#line 627 "kcar.c"
	switch( (*p) ) {
		case 33: goto st17;
		case 58: goto tr29;
		case 124: goto st17;
		case 126: goto st17;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto st17;
		} else if ( (*p) >= 35 )
			goto st17;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto st17;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto st17;
		} else
			goto st17;
	} else
		goto st17;
	goto st0;
tr31:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
	goto st18;
tr29:
#line 306 "kcar.rl"
	{ hp->s.field_len = LEN(start.field, p); }
	goto st18;
st18:
	if ( ++p == pe )
		goto _test_eof18;
case 18:
#line 664 "kcar.c"
	switch( (*p) ) {
		case 9: goto tr31;
		case 10: goto tr32;
		case 13: goto tr33;
		case 32: goto tr31;
	}
	goto tr30;
tr30:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
	goto st19;
st19:
	if ( ++p == pe )
		goto _test_eof19;
case 19:
#line 680 "kcar.c"
	switch( (*p) ) {
		case 10: goto tr35;
		case 13: goto tr36;
	}
	goto st19;
st20:
	if ( ++p == pe )
		goto _test_eof20;
case 20:
	if ( (*p) == 10 )
		goto st0;
	goto st21;
st21:
	if ( ++p == pe )
		goto _test_eof21;
case 21:
	switch( (*p) ) {
		case 10: goto tr12;
		case 13: goto tr13;
	}
	goto st21;
st22:
	if ( ++p == pe )
		goto _test_eof22;
case 22:
	if ( (*p) == 48 )
		goto tr38;
	if ( (*p) < 65 ) {
		if ( 49 <= (*p) && (*p) <= 57 )
			goto tr39;
	} else if ( (*p) > 70 ) {
		if ( 97 <= (*p) && (*p) <= 102 )
			goto tr39;
	} else
		goto tr39;
	goto st0;
tr38:
#line 313 "kcar.rl"
	{
    hp->len.chunk = step_incr(hp->len.chunk, (*p), 16);
    if (hp->len.chunk < 0)
      rb_raise(eParserError, "invalid chunk size");
  }
	goto st23;
st23:
	if ( ++p == pe )
		goto _test_eof23;
case 23:
#line 729 "kcar.c"
	switch( (*p) ) {
		case 10: goto tr40;
		case 13: goto st24;
		case 48: goto tr38;
		case 59: goto st33;
	}
	if ( (*p) < 65 ) {
		if ( 49 <= (*p) && (*p) <= 57 )
			goto tr39;
	} else if ( (*p) > 70 ) {
		if ( 97 <= (*p) && (*p) <= 102 )
			goto tr39;
	} else
		goto tr39;
	goto st0;
tr40:
#line 337 "kcar.rl"
	{
    HP_FL_SET(hp, INTRAILER);
    cs = http_parser_en_Trailers;
    ++p;
    assert(p <= pe && "buffer overflow after chunked body");
    goto post_exec;
  }
	goto st45;
st45:
	if ( ++p == pe )
		goto _test_eof45;
case 45:
#line 759 "kcar.c"
	goto st0;
st24:
	if ( ++p == pe )
		goto _test_eof24;
case 24:
	if ( (*p) == 10 )
		goto tr40;
	goto st0;
tr39:
#line 313 "kcar.rl"
	{
    hp->len.chunk = step_incr(hp->len.chunk, (*p), 16);
    if (hp->len.chunk < 0)
      rb_raise(eParserError, "invalid chunk size");
  }
	goto st25;
st25:
	if ( ++p == pe )
		goto _test_eof25;
case 25:
#line 780 "kcar.c"
	switch( (*p) ) {
		case 10: goto st26;
		case 13: goto st29;
		case 59: goto st30;
	}
	if ( (*p) < 65 ) {
		if ( 48 <= (*p) && (*p) <= 57 )
			goto tr39;
	} else if ( (*p) > 70 ) {
		if ( 97 <= (*p) && (*p) <= 102 )
			goto tr39;
	} else
		goto tr39;
	goto st0;
st26:
	if ( ++p == pe )
		goto _test_eof26;
case 26:
	goto tr46;
tr46:
#line 345 "kcar.rl"
	{
  skip_chunk_data_hack: {
    size_t nr = MIN((size_t)hp->len.chunk, REMAINING);
    memcpy(RSTRING_PTR(hdr) + hp->s.dest_offset, p, nr);
    hp->s.dest_offset += nr;
    hp->len.chunk -= nr;
    p += nr;
    assert(hp->len.chunk >= 0 && "negative chunk length");
    if ((size_t)hp->len.chunk > REMAINING) {
      HP_FL_SET(hp, INCHUNK);
      goto post_exec;
    } else {
      p--;
      {goto st27;}
    }
  }}
	goto st27;
st27:
	if ( ++p == pe )
		goto _test_eof27;
case 27:
#line 823 "kcar.c"
	switch( (*p) ) {
		case 10: goto st22;
		case 13: goto st28;
	}
	goto st0;
st28:
	if ( ++p == pe )
		goto _test_eof28;
case 28:
	if ( (*p) == 10 )
		goto st22;
	goto st0;
st29:
	if ( ++p == pe )
		goto _test_eof29;
case 29:
	if ( (*p) == 10 )
		goto st26;
	goto st0;
st30:
	if ( ++p == pe )
		goto _test_eof30;
case 30:
	switch( (*p) ) {
		case 10: goto st26;
		case 13: goto st29;
		case 32: goto st30;
		case 33: goto st31;
		case 59: goto st30;
		case 61: goto st32;
		case 124: goto st31;
		case 126: goto st31;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto st31;
		} else if ( (*p) >= 35 )
			goto st31;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto st31;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto st31;
		} else
			goto st31;
	} else
		goto st31;
	goto st0;
st31:
	if ( ++p == pe )
		goto _test_eof31;
case 31:
	switch( (*p) ) {
		case 10: goto st26;
		case 13: goto st29;
		case 33: goto st31;
		case 59: goto st30;
		case 61: goto st32;
		case 124: goto st31;
		case 126: goto st31;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto st31;
		} else if ( (*p) >= 35 )
			goto st31;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto st31;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto st31;
		} else
			goto st31;
	} else
		goto st31;
	goto st0;
st32:
	if ( ++p == pe )
		goto _test_eof32;
case 32:
	switch( (*p) ) {
		case 10: goto st26;
		case 13: goto st29;
		case 33: goto st32;
		case 59: goto st30;
		case 124: goto st32;
		case 126: goto st32;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto st32;
		} else if ( (*p) >= 35 )
			goto st32;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto st32;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto st32;
		} else
			goto st32;
	} else
		goto st32;
	goto st0;
st33:
	if ( ++p == pe )
		goto _test_eof33;
case 33:
	switch( (*p) ) {
		case 10: goto tr40;
		case 13: goto st24;
		case 32: goto st33;
		case 33: goto st34;
		case 59: goto st33;
		case 61: goto st35;
		case 124: goto st34;
		case 126: goto st34;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto st34;
		} else if ( (*p) >= 35 )
			goto st34;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto st34;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto st34;
		} else
			goto st34;
	} else
		goto st34;
	goto st0;
st34:
	if ( ++p == pe )
		goto _test_eof34;
case 34:
	switch( (*p) ) {
		case 10: goto tr40;
		case 13: goto st24;
		case 33: goto st34;
		case 59: goto st33;
		case 61: goto st35;
		case 124: goto st34;
		case 126: goto st34;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto st34;
		} else if ( (*p) >= 35 )
			goto st34;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto st34;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto st34;
		} else
			goto st34;
	} else
		goto st34;
	goto st0;
st35:
	if ( ++p == pe )
		goto _test_eof35;
case 35:
	switch( (*p) ) {
		case 10: goto tr40;
		case 13: goto st24;
		case 33: goto st35;
		case 59: goto st33;
		case 124: goto st35;
		case 126: goto st35;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto st35;
		} else if ( (*p) >= 35 )
			goto st35;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto st35;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto st35;
		} else
			goto st35;
	} else
		goto st35;
	goto st0;
tr59:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
#line 309 "kcar.rl"
	{ write_cont_value(hp, buffer, p); }
	goto st36;
tr62:
#line 309 "kcar.rl"
	{ write_cont_value(hp, buffer, p); }
	goto st36;
tr69:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
#line 308 "kcar.rl"
	{ write_value(hdr, hp, buffer, p); }
	goto st36;
tr72:
#line 308 "kcar.rl"
	{ write_value(hdr, hp, buffer, p); }
	goto st36;
st36:
	if ( ++p == pe )
		goto _test_eof36;
case 36:
#line 1053 "kcar.c"
	switch( (*p) ) {
		case 9: goto st37;
		case 10: goto tr54;
		case 13: goto st40;
		case 32: goto st37;
		case 33: goto tr56;
		case 124: goto tr56;
		case 126: goto tr56;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto tr56;
		} else if ( (*p) >= 35 )
			goto tr56;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto tr56;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto tr56;
		} else
			goto tr56;
	} else
		goto tr56;
	goto st0;
tr58:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
	goto st37;
st37:
	if ( ++p == pe )
		goto _test_eof37;
case 37:
#line 1089 "kcar.c"
	switch( (*p) ) {
		case 9: goto tr58;
		case 10: goto tr59;
		case 13: goto tr60;
		case 32: goto tr58;
	}
	goto tr57;
tr57:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
	goto st38;
st38:
	if ( ++p == pe )
		goto _test_eof38;
case 38:
#line 1105 "kcar.c"
	switch( (*p) ) {
		case 10: goto tr62;
		case 13: goto tr63;
	}
	goto st38;
tr60:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
#line 309 "kcar.rl"
	{ write_cont_value(hp, buffer, p); }
	goto st39;
tr63:
#line 309 "kcar.rl"
	{ write_cont_value(hp, buffer, p); }
	goto st39;
tr70:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
#line 308 "kcar.rl"
	{ write_value(hdr, hp, buffer, p); }
	goto st39;
tr73:
#line 308 "kcar.rl"
	{ write_value(hdr, hp, buffer, p); }
	goto st39;
st39:
	if ( ++p == pe )
		goto _test_eof39;
case 39:
#line 1135 "kcar.c"
	if ( (*p) == 10 )
		goto st36;
	goto st0;
tr54:
#line 332 "kcar.rl"
	{
    cs = http_parser_first_final;
    goto post_exec;
  }
	goto st46;
st46:
	if ( ++p == pe )
		goto _test_eof46;
case 46:
#line 1150 "kcar.c"
	goto st0;
st40:
	if ( ++p == pe )
		goto _test_eof40;
case 40:
	if ( (*p) == 10 )
		goto tr54;
	goto st0;
tr56:
#line 305 "kcar.rl"
	{ MARK(start.field, p); }
	goto st41;
st41:
	if ( ++p == pe )
		goto _test_eof41;
case 41:
#line 1167 "kcar.c"
	switch( (*p) ) {
		case 33: goto st41;
		case 58: goto tr66;
		case 124: goto st41;
		case 126: goto st41;
	}
	if ( (*p) < 45 ) {
		if ( (*p) > 39 ) {
			if ( 42 <= (*p) && (*p) <= 43 )
				goto st41;
		} else if ( (*p) >= 35 )
			goto st41;
	} else if ( (*p) > 46 ) {
		if ( (*p) < 65 ) {
			if ( 48 <= (*p) && (*p) <= 57 )
				goto st41;
		} else if ( (*p) > 90 ) {
			if ( 94 <= (*p) && (*p) <= 122 )
				goto st41;
		} else
			goto st41;
	} else
		goto st41;
	goto st0;
tr68:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
	goto st42;
tr66:
#line 306 "kcar.rl"
	{ hp->s.field_len = LEN(start.field, p); }
	goto st42;
st42:
	if ( ++p == pe )
		goto _test_eof42;
case 42:
#line 1204 "kcar.c"
	switch( (*p) ) {
		case 9: goto tr68;
		case 10: goto tr69;
		case 13: goto tr70;
		case 32: goto tr68;
	}
	goto tr67;
tr67:
#line 307 "kcar.rl"
	{ MARK(mark, p); }
	goto st43;
st43:
	if ( ++p == pe )
		goto _test_eof43;
case 43:
#line 1220 "kcar.c"
	switch( (*p) ) {
		case 10: goto tr72;
		case 13: goto tr73;
	}
	goto st43;
	}
	_test_eof2: cs = 2; goto _test_eof; 
	_test_eof3: cs = 3; goto _test_eof; 
	_test_eof4: cs = 4; goto _test_eof; 
	_test_eof5: cs = 5; goto _test_eof; 
	_test_eof6: cs = 6; goto _test_eof; 
	_test_eof7: cs = 7; goto _test_eof; 
	_test_eof8: cs = 8; goto _test_eof; 
	_test_eof9: cs = 9; goto _test_eof; 
	_test_eof10: cs = 10; goto _test_eof; 
	_test_eof11: cs = 11; goto _test_eof; 
	_test_eof12: cs = 12; goto _test_eof; 
	_test_eof13: cs = 13; goto _test_eof; 
	_test_eof14: cs = 14; goto _test_eof; 
	_test_eof15: cs = 15; goto _test_eof; 
	_test_eof44: cs = 44; goto _test_eof; 
	_test_eof16: cs = 16; goto _test_eof; 
	_test_eof17: cs = 17; goto _test_eof; 
	_test_eof18: cs = 18; goto _test_eof; 
	_test_eof19: cs = 19; goto _test_eof; 
	_test_eof20: cs = 20; goto _test_eof; 
	_test_eof21: cs = 21; goto _test_eof; 
	_test_eof22: cs = 22; goto _test_eof; 
	_test_eof23: cs = 23; goto _test_eof; 
	_test_eof45: cs = 45; goto _test_eof; 
	_test_eof24: cs = 24; goto _test_eof; 
	_test_eof25: cs = 25; goto _test_eof; 
	_test_eof26: cs = 26; goto _test_eof; 
	_test_eof27: cs = 27; goto _test_eof; 
	_test_eof28: cs = 28; goto _test_eof; 
	_test_eof29: cs = 29; goto _test_eof; 
	_test_eof30: cs = 30; goto _test_eof; 
	_test_eof31: cs = 31; goto _test_eof; 
	_test_eof32: cs = 32; goto _test_eof; 
	_test_eof33: cs = 33; goto _test_eof; 
	_test_eof34: cs = 34; goto _test_eof; 
	_test_eof35: cs = 35; goto _test_eof; 
	_test_eof36: cs = 36; goto _test_eof; 
	_test_eof37: cs = 37; goto _test_eof; 
	_test_eof38: cs = 38; goto _test_eof; 
	_test_eof39: cs = 39; goto _test_eof; 
	_test_eof46: cs = 46; goto _test_eof; 
	_test_eof40: cs = 40; goto _test_eof; 
	_test_eof41: cs = 41; goto _test_eof; 
	_test_eof42: cs = 42; goto _test_eof; 
	_test_eof43: cs = 43; goto _test_eof; 

	_test_eof: {}
	_out: {}
	}

#line 403 "kcar.rl"
post_exec: /* "_out:" also goes here */
  if (hp->cs != http_parser_error)
    hp->cs = cs;
  hp->offset = p - buffer;

  assert(p <= pe && "buffer overflow after parsing execute");
  assert(hp->offset <= len && "offset longer than length");
}

static struct http_parser *data_get(VALUE self)
{
  struct http_parser *hp;

  Data_Get_Struct(self, struct http_parser, hp);
  assert(hp && "failed to extract http_parser struct");
  return hp;
}

static void mark(void *ptr)
{
  struct http_parser *hp = ptr;

  rb_gc_mark(hp->cont);
  rb_gc_mark(hp->status);
}

static VALUE alloc(VALUE klass)
{
  struct http_parser *hp;
  return Data_Make_Struct(klass, struct http_parser, mark, -1, hp);
}

/**
 * call-seq:
 *    Kcar::Parser.new => parser
 *
 * Creates a new parser.
 *
 * Document-method: reset
 *
 * call-seq:
 *    parser.reset => parser
 *
 * Resets the parser so it can be reused by another client
 */
static VALUE initialize(VALUE self)
{
  http_parser_init(data_get(self));

  return self;
}

static void advance_str(VALUE str, off_t nr)
{
  long len = RSTRING_LEN(str);

  if (len == 0)
    return;

  rb_str_modify(str);

  assert(nr <= len && "trying to advance past end of buffer");
  len -= nr;
  if (len > 0) /* unlikely, len is usually 0 */
    memmove(RSTRING_PTR(str), RSTRING_PTR(str) + nr, len);
  rb_str_set_len(str, len);
}

/**
 * call-seq:
 *   parser.body_bytes_left => nil or Integer
 *
 * Returns the number of bytes left to run through Parser#filter_body.
 * This will initially be the value of the "Content-Length" HTTP header
 * after header parsing is complete and will decrease in value as
 * Parser#filter_body is called for each chunk.  This should return
 * zero for responses with no body.
 *
 * This will return nil on "Transfer-Encoding: chunked" responses as
 * well as HTTP/1.0 responses where Content-Length is not set
 */
static VALUE body_bytes_left(VALUE self)
{
  struct http_parser *hp = data_get(self);

  if (HP_FL_TEST(hp, CHUNKED))
    return Qnil;
  if (hp->len.content >= 0)
    return OFFT2NUM(hp->len.content);

  return Qnil;
}

/**
 * call-seq:
 *   parser.body_bytes_left = Integer
 *
 * Sets the number of bytes left to download for HTTP responses
 * with "Content-Length".  This raises RuntimeError for chunked
 * responses.
 */
static VALUE body_bytes_left_set(VALUE self, VALUE bytes)
{
  struct http_parser *hp = data_get(self);

  if (HP_FL_TEST(hp, CHUNKED))
    rb_raise(rb_eRuntimeError, "body_bytes_left= is not for chunked bodies");
  hp->len.content = NUM2OFFT(bytes);
  return bytes;
}

/**
 * Document-method: chunked
 * call-seq:
 *    parser.chunked? => true or false
 *
 * This is used to detect if a response uses chunked Transfer-Encoding or not.
 */
static VALUE chunked(VALUE self)
{
  struct http_parser *hp = data_get(self);

  return HP_FL_TEST(hp, CHUNKED) ? Qtrue : Qfalse;
}

/**
 * Document-method: headers
 * call-seq:
 *    parser.headers(hdr, data) => hdr or nil
 *
 * Takes a Hash and a String of data, parses the String of data filling
 * in the Hash returning the Hash if parsing is finished, nil otherwise
 * When returning the hdr Hash, it may modify data to point to where
 * body processing should begin.
 *
 * Raises ParserError if there are parsing errors.
 */
static VALUE headers(VALUE self, VALUE hdr, VALUE data)
{
  struct http_parser *hp = data_get(self);

  http_parser_execute(hp, hdr, RSTRING_PTR(data), RSTRING_LEN(data));
  VALIDATE_MAX_LENGTH(hp->offset, HEADER);

  if (hp->cs == http_parser_first_final ||
      hp->cs == http_parser_en_ChunkedBody) {
    advance_str(data, hp->offset + 1);
    hp->offset = 0;
    if (HP_FL_TEST(hp, INTRAILER))
      return hdr;
    else
      return rb_ary_new3(2, hp->status, hdr);
  }

  if (hp->cs == http_parser_error)
    rb_raise(eParserError, "Invalid HTTP format, parsing fails.");

  return Qnil;
}

static int chunked_eof(struct http_parser *hp)
{
  return ((hp->cs == http_parser_first_final) || HP_FL_TEST(hp, INTRAILER));
}

/**
 * call-seq:
 *    parser.body_eof? => true or false
 *
 * Detects if we're done filtering the body or not.  This can be used
 * to detect when to stop calling Parser#filter_body.
 */
static VALUE body_eof(VALUE self)
{
  struct http_parser *hp = data_get(self);

  if (!HP_FL_TEST(hp, HASHEADER) && HP_FL_ALL(hp, KEEPALIVE))
    return Qtrue;

  if (HP_FL_TEST(hp, CHUNKED))
    return chunked_eof(hp) ? Qtrue : Qfalse;

  if (! HP_FL_TEST(hp, HASBODY))
    return Qtrue;

  return hp->len.content == 0 ? Qtrue : Qfalse;
}

/**
 * call-seq:
 *    parser.keepalive? => true or false
 *
 * This should be used to detect if a request can really handle
 * keepalives and pipelining.  Currently, the rules are:
 *
 * 1. MUST be HTTP/1.1 +or+ HTTP/1.0 with "Connection: keep-alive"
 * 2. MUST NOT have "Connection: close" set
 * 3. If there is a response body, either a) Content-Length is set
 *    or b) chunked encoding is used
 */
static VALUE keepalive(VALUE self)
{
  struct http_parser *hp = data_get(self);

  if (HP_FL_ALL(hp, KEEPALIVE)) {
    if (HP_FL_TEST(hp, HASHEADER) && HP_FL_TEST(hp, HASBODY) ) {
      if (HP_FL_TEST(hp, CHUNKED) || (hp->len.content >= 0))
        return Qtrue;

      /* unknown Content-Length and not chunked, we must assume close */
      return Qfalse;
    } else {
      /* 100 Continue, 304 Not Modified, etc... */
      return Qtrue;
    }
  }
  return Qfalse;
}

/**
 * call-seq:
 *    parser.filter_body(buf, data) => nil/data
 *
 * Takes a String of +data+, will modify data if dechunking is done.
 * Returns +nil+ if there is more data left to process.  Returns
 * +data+ if body processing is complete. When returning +data+,
 * it may modify +data+ so the start of the string points to where
 * the body ended so that trailer processing can begin.
 *
 * Raises ParserError if there are dechunking errors.
 * Basically this is a glorified memcpy(3) that copies +data+
 * into +buf+ while filtering it through the dechunker.
 */
static VALUE filter_body(VALUE self, VALUE buf, VALUE data)
{
  struct http_parser *hp = data_get(self);
  char *dptr;
  long dlen;

  dptr = RSTRING_PTR(data);
  dlen = RSTRING_LEN(data);

  StringValue(buf);
  rb_str_modify(buf);
  rb_str_resize(buf, dlen); /* we can never copy more than dlen bytes */
  OBJ_TAINT(buf); /* keep weirdo $SAFE users happy */

  if (!HP_FL_TEST(hp, CHUNKED))
    rb_raise(rb_eRuntimeError, "filter_body is only for chunked bodies");

  if (!chunked_eof(hp)) {
    hp->s.dest_offset = 0;
    http_parser_execute(hp, buf, dptr, dlen);
    if (hp->cs == http_parser_error)
      rb_raise(eParserError, "Invalid HTTP format, parsing fails.");

    assert(hp->s.dest_offset <= hp->offset &&
           "destination buffer overflow");
    advance_str(data, hp->offset);
    rb_str_set_len(buf, hp->s.dest_offset);

    if (RSTRING_LEN(buf) == 0 && chunked_eof(hp)) {
      assert(hp->len.chunk == 0 && "chunk at EOF but more to parse");
    } else {
      data = Qnil;
    }
  }
  hp->offset = 0; /* for trailer parsing */
  return data;
}

void Init_kcar_ext(void)
{
  VALUE mKcar = rb_define_module("Kcar");
  VALUE cParser = rb_define_class_under(mKcar, "Parser", rb_cObject);

  eParserError = rb_define_class_under(mKcar, "ParserError", rb_eIOError);

  rb_define_alloc_func(cParser, alloc);
  rb_define_method(cParser, "initialize", initialize, 0);
  rb_define_method(cParser, "reset", initialize, 0);
  rb_define_method(cParser, "headers", headers, 2);
  rb_define_method(cParser, "trailers", headers, 2);
  rb_define_method(cParser, "filter_body", filter_body, 2);
  rb_define_method(cParser, "body_bytes_left", body_bytes_left, 0);
  rb_define_method(cParser, "body_bytes_left=", body_bytes_left_set, 1);
  rb_define_method(cParser, "body_eof?", body_eof, 0);
  rb_define_method(cParser, "keepalive?", keepalive, 0);
  rb_define_method(cParser, "chunked?", chunked, 0);

  /*
   * The maximum size a single chunk when using chunked transfer encoding.
   * This is only a theoretical maximum used to detect errors in clients,
   * it is highly unlikely to encounter clients that send more than
   * several kilobytes at once.
   */
  rb_define_const(cParser, "CHUNK_MAX", OFFT2NUM(UH_OFF_T_MAX));

  /*
   * The maximum size of the body as specified by Content-Length.
   * This is only a theoretical maximum, the actual limit is subject
   * to the limits of the file system used for +Dir.tmpdir+.
   */
  rb_define_const(cParser, "LENGTH_MAX", OFFT2NUM(UH_OFF_T_MAX));
  id_sq = rb_intern("[]");
  id_sq_set = rb_intern("[]=");
}