src/HttpHdrContRange.cc

   1
   2 /*
   3  * $Id: HttpHdrContRange.cc,v 1.1 1998/03/08 21:03:01 rousskov Exp $
   4  *
   5  * DEBUG: section 68    HTTP Content-Range Header
   6  * AUTHOR: Alex Rousskov
   7  *
   8  * SQUID Internet Object Cache  http://squid.nlanr.net/Squid/
   9  * --------------------------------------------------------
  10  *
  11  *  Squid is the result of efforts by numerous individuals from the
  12  *  Internet community.  Development is led by Duane Wessels of the
  13  *  National Laboratory for Applied Network Research and funded by
  14  *  the National Science Foundation.
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License as published by
  18  *  the Free Software Foundation; either version 2 of the License, or
  19  *  (at your option) any later version.
  20  *
  21  *  This program is distributed in the hope that it will be useful,
  22  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *  GNU General Public License for more details.
  25  *
  26  *  You should have received a copy of the GNU General Public License
  27  *  along with this program; if not, write to the Free Software
  28  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  29  *
  30  */
  31
  32 #include "squid.h"
  33
  34 #if 0
  35     Currently only byte ranges are supported
  36
  37     Content-Range = "Content-Range" ":" content-range-spec
  38     content-range-spec      = byte-content-range-spec
  39     byte-content-range-spec = bytes-unit SP
  40                               ( byte-range-resp-spec | "*") "/"
  41                               ( entity-length | "*" )
  42     byte-range-resp-spec = first-byte-pos "-" last-byte-pos
  43     entity-length        = 1*DIGIT
  44 #endif
  45
  46
  47 /* local constants */
  48 #define range_spec_unknown ((size_t)-1)
  49
  50 /* local routines */
  51 #define known_spec(s) ((s) != range_spec_unknown)
  52 #define size_min(a,b) ((a) <= (b) ? (a) : (b))
  53 #define size_diff(a,b) ((a) >= (b) ? ((a)-(b)) : 0)
  54
  55 /* globals */
  56
  57 /* parses range-resp-spec and inits spec, returns true on success */
  58 static int
  59 httpHdrRangeRespSpecParseInit(HttpHdrRangeSpec *spec, const char *field, int flen)
  60 {
  61     const char *p;
  62     assert(spec);
  63     spec->offset = spec->length = range_spec_unknown;
  64     if (flen < 2)
  65         return 0;
  66     /* is spec given ? */
  67     if (*field == '*')
  68         return 0;
  69     /* check format, must be %d-%d */
  70     if (!((p = strchr(field, '-')) && (p-field < flen))) {
  71         debug(68, 2) ("invalid resp-range-spec near: '%s'\n", field);
  72         return 0;
  73     }
  74     /* parse offset */
  75     if (!httpHeaderParseSize(field+1, &spec->offset))
  76             return NULL;
  77     p++;
  78     /* do we have last-pos ? */
  79     if (p - field < flen) {
  80         size_t last_pos;
  81         if (!httpHeaderParseSize(p, &last_pos))
  82             return 0;
  83         spec->length = size_diff(last_pos, spec->offset);
  84     }
  85     /* we managed to parse, check if the result makes sence */
  86     if (known_spec(spec->length) && !spec->length) {
  87         debug(68, 2) ("invalid resp-range-spec near: '%s'\n", field);
  88         return 0;
  89     }
  90     return 1;
  91 }
  92
  93 static void
  94 httpHdrRangeRespSpecPackInto(const HttpHdrRangeSpec *spec, Packer *p)
  95 {
  96     if (!known_spec(spec->offset) || !known_spec(spec->length))
  97         packerPrintf(p, "*");
  98     else
  99         packerPrintf(p, "%d-%d",
 100             spec->offset, spec->offset+spec->length-1);
 101 }
 102
 103 /*
 104  * Content Range
 105  */
 106
 107 HttpHdrContRange *
 108 httpHdrContRangeCreate()
 109 {
 110     HttpHdrContRange *r = memAllocate(MEM_HTTP_HDR_CONTENT_RANGE);
 111     r->spec.offset = r->spec.length = range_spec_unknown;
 112     r->elength = range_spec_unknown;
 113     return r;
 114 }
 115
 116 HttpHdrContRange *
 117 httpHdrContRangeParseCreate(const char *str)
 118 {
 119     HttpHdrContRange *r = httpHdrContRangeCreate();
 120     if (!httpHdrContRangeParseInit(r, str)) {
 121         httpHdrContRangeDestroy(r);
 122         r = NULL;
 123     }
 124     return r;
 125 }
 126
 127 /* returns true if ranges are valid; inits HttpHdrContRange */
 128 int
 129 httpHdrContRangeParseInit(HttpHdrContRange *range, const char *str)
 130 {
 131     const char *p;
 132     assert(range && str);
 133     /* split */
 134     if (!(p = strchr(str, '/')))
 135         return 0;
 136     if (*str == '*')
 137         range->spec.offset = range->spec.length = range_spec_unknown;
 138     else
 139     if (!httpHdrRangeRespSpecParseInit(&range->spec, str, p-str))
 140         return 0;
 141     p++;
 142     if (*p == '*')
 143         range->elength = range_spec_unknown;
 144     else
 145     if (!httpHeaderParseSize(p, &range->elength))
 146         return 0;
 147     return 1;
 148 }
 149
 150 void
 151 httpHdrContRangeDestroy(HttpHdrContRange *range)
 152 {
 153     assert(range);
 154     memFree(MEM_HTTP_HDR_CONTENT_RANGE, range);
 155 }
 156
 157 HttpHdrContRange *
 158 httpHdrContRangeDup(const HttpHdrContRange * range)
 159 {
 160     HttpHdrContRange *dup;
 161     assert(range);
 162     dup = httpHdrContRangeCreate();
 163     *dup = *range;
 164     return dup;
 165 }
 166
 167 void
 168 httpHdrContRangePackInto(const HttpHdrContRange * range, Packer * p)
 169 {
 170     assert(range && p);
 171     httpHdrRangeRespSpecPackInto(&range->spec, p);
 172     if (!known_spec(range->elength))
 173         packerPrintf(p, "/*");
 174     else
 175         packerPrintf(p, "/%d", range->elength);
 176 }